# Question
Title: Different psychophysiological systems will turn on when dealing with things voluntary instead of involuntary
I heard somewhere that different psychophysiological systems will turn on when dealing with things voluntary instead of involuntary.

> If you compose a stressor on two groups of people.
>
> On one group the stressor is imposed involuntary and on the other group the stressor is picked up voluntary.
>
> The people that picked up the stressor voluntary use a whole different psychophysiological system to deal with it. It uses the system associated with approach and challenge and not the system that is associated with defensive aggression and withdrawal.
>
> The system associated with challenge is much more associated with positive emotions and less associated with negative emotions.
>
> And it is also less hard on you, because the defensive system, the pray animal system, when that thing kicks in it is an all systems go for you. Its peddle to the metal with the brakes on. You are using future resources that you could be storing for future use, using it right now in preparation for emergency.

– Jordan B. Peterson, Biblical Series XI: Sodom and Gomorrah, 2017-08-14

I am struggling to find more data/researches/studies about this. It is a very interesting topic. And it is clearly something we all know in the back of our heads (deal with things now).

Anyone has a good link to data/research/study that supports this?

# Answer
> 2 votes
Peterson is notorious for using imprecise language and failing to provide sources for claims. For example, there aren't multiple "psychophysiological systems" - there's just ... psychophysiology. Similarly, there aren't well-defined psychophysiological response patterns of "challenge" or "withdrawal" (though see fight-or-flight for something vaguely related). However, in lectures like this, Peterson is playing the role of a motivational speaker, rather than a science communicator, so there is no expectation that evidence should support his claims - basically, if his presentation motivates you in a positive direction, then enjoy it. Anyway, let's just ignore Peterson's description then, and ask more broadly:

**What happens when people undertake stressful challenges either voluntarily or involuntarily?**

Well, as is often the case with broad questions like this, the answer is ... it depends. This question is common in the sphere of education, where educators contemplate whether to make programs compulsory to increase participation, or whether doing so will reduce the benefits of those programs.

A well-studied example is service-learning, in which students either volunteer, or are required to volunteer, for community service that ideally supports their learning goals. Service-learning can certainly be challenging and stressful, but research suggests that it has a wide variety of benefits for students and their community. How are those benefits affected by the voluntary nature of participation?

Schmidt, Shumow, & Kackar (2007) for example, found no difference:

> Participation in any service is associated with positive outcomes whether service is voluntary or required.

Similarly, Flanagan et al (2015) report:

> ... we found no differences ... between those youth who were mandated to do community service versus those who engaged in service voluntarily ...

From Henderson, Brown, & Pancer (2012):

> Mandated community service experiences are not significantly different from those entered into willingly.

And similar results from additional studies (eg, Hart et al, 2007; Henderson et al, 2007; Metz & Youniss, 2005). However, other studies did find some notable differences in outcomes (Kackar-Cam & Schmidt, 2014; Horn, 2012; Kim & Morgül, 2017).

There are also studies on voluntary vs involuntary participation in extra-curricular activities that are too numerous to review here, but suffice to say that results do not clearly favour voluntary participation.

**Additional notes:**

* Studies of this nature inevitably suffer from the self-selection bias: Of groups offered the choice, those who have greater competence are more likely to volunteer. Thus, in cases where voluntary participants outperform involuntary participants on some measure, it is not always clear if the reason for this is due to the voluntary nature, or to pre-existing competence. As an example, a study by Rodriguez-Aflecht et al (2017) on voluntary vs involuntary participation in a math tutoring game, found that the volunteer players had higher pre-existing math skills and interest than those who did not volunteer. Nonetheless, involuntary participants outperformed them on many measures.
* Studies of this nature often situate results within self-determination theory (SDT) - a general theory of motivation. SDT predicts that higher levels of autonomy result in greater engagement and improved performance, supporting the assertion that voluntary participation is superior to involuntary. So why does this theoretical prediction not play out in the results exampled above? Well, volunteering is but one small decision in a long series of decisions that participants might make during the course of the program. Indeed, many studies on service-learning find that the program's effectivness depends much more on its content - particularly the level of autonomy afforded to participants within the program, the level of competence that students attain, and the level of social support that they receive - than it does on the initial participation decision.
* Studies of this nature rarely incorporate any physiological measures. For obvious and practical reasons, blood samples are not collected from students participating in service-learning, nor is their brain scanned, etc. In general, psychophysiological studies are typically done in-lab, and use relatively simple, well-controlled manipulations that would not usually be expected to translate well to complex, dynamic, ecological situations. As such, it would be out of context to use such research to support assertions about handling real-life challenges.

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Tags: cognitive-psychology, reference-request, psychophysics
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# Question
Title: Why am I more "musically" creative in the last 30 seconds before falling asleep?
I am a music producer and often my "best" pieces always came to my mind shortly before I fell asleep. Sometimes I actually grab a recorder, hum the melody and finish the idea on the very next day.

My question is now: how can this be possible? In a state where my brain is supposed to shut down (and pretty much does) it is literally exploding out of ideas. I also feel a huge increase in euphoria in these very moments but I can't really tell whether this happens before or after I get the idea for a certain sound/melody.

Might it be that my creativity is "blocked" all day until my brain finally drops all obstacles which then makes way for my creative flow? Or is it that no new input needs to be processed as I lay in total darkness and silence and therefore new "material" to process isn't coming in which leads my brain to "invent" something?

This doesn't happen every time but most often when I am very tired and don't need longer than 15 minutes to fall asleep - usually this is a matter of hours for me, hours in which I am not productive at all.

# Answer
> 7 votes
This is quite a well documented phenomenon - stereotypically these moments of creative insight occur in the shower. A google for 'psychology aha moment' or 'neuroscience creative aha' will give you some articles, in Psychology Today for instance, talking about this.

One characterisation of thought is that links between neurons are created and by travelling down the intricate pathway, you have the thought. A lot of conscious thought is driven by "picking" the "quickest" path and travelling down that, as it is economical in terms of energy use. One understanding of creativity is that it is combining of existing ideas in novel patterns. When you enter a more relaxed state, or even just a more distracted state such as showering or exercising, your brain is free to try novel combinations as you are not consciously driving it down specific well-worn pathways (the "easy" paths).

Mark Beeman has done research on this, which he calls it insight. For more information, see the article he co-wrote "The Aha! Moment: the Neural Basis of Solving Problems with Insight".

For another explanation, Alice Flaherty has done research linking these moments to dopamine release, which is more abundant in our brains when we relax. For more information see the publication "Frontotemporal and dopaminergic control of idea generation and creative drive".

# Answer
> 1 votes
The brain is a complex system, that is to say one made of many (more or less) discrete components, each performing a specific function. These components are connected and work together. During neuroimaging studies, we observe some groups of brain areas that activate in a correlated manner, so-called large-scale brain networks. One such large-scale network and perhaps the most well-known is the default-mode network (DMN). In the past, this network was also called the *task-negative network*, since it appeared to only be active when no task was actively performed. We know today that it can in fact be active at all times, but it remains mostly associated with moments when no task is actively performed. As it turns out, this is also the network mostly responsible for "creativity", as explained here.

What you are describing is textbook DMN behavior: "In a state where my brain is supposed to shut down \[...\] it is literally exploding out of ideas". During the day, your brain is busy, and your focus on other tasks prevents your DMN from running free. While you are trying to fall asleep, it becomes more extensively activated, thus leading to increased creativity.

The points that @ALit makes are correct and in my opinion play some part in the creative process, but if you're looking for the traditionally accepted explanation, this is it.

# Answer
> -2 votes
Creativity is hindered by stress. When you are trying extremely hard to come up with this great musical masterpiece, you're going about it all the wrong way. Think about what artists say about their music so often: "It just came to me". Music (and creativity in general) are linked to inspiration. As you're going to sleep, your body and brain is shutting down. So you start to forget about the logistics of life (the left side of the brain) and your right side is allowed to think more freely.

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Tags: creativity
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title: "Reverse Tolerance" Hypothetical

text:
# Question
Title: "Reverse Tolerance" Hypothetical
Let me use Caffeine as an example for this question, because it's a classically understood case of drug tolerance.

Caffeine is an adenosine antagonist; it works by blocking the adenosine receptors in your brain, preventing adenosine from binding to them. Since adenosine has an inhibitory effect on the central nervous system, the effect is stimulation.

Your brain adapts to Caffeine pretty quickly by making more adenosine receptors, increasing the required dosage of Caffeine to get the same effect. Of course this means if you *stop* Caffeine, you will be absorbing more adenosine than baseline before Caffeine, because of all the new adenosine receptors. Over time off Caffeine, your body removes the excess adenosine receptors until you're back to normal.

**My Question: Can you hack this process in reverse?** Instead of taking an adenosine *antagonist*, say you took adenosine *itself* for some period of time. Following the same logic, would your body adapt by removing adenosine receptors below normal baseline? And then when you stop adenosine, would your "withdrawal" symptoms be a caffeine-like stimulation?

# Answer
Drug tolerance (desensitization) is complicated, featuring many possible mechanisms. There certainly is reverse tolerance (sensitization) as described as well:

> The two notions are not incompatible, and tolerance may sometimes lead to reverse tolerance.

Scott Alexander posted an amusing article on this (note that it's not well referenced, and mentions a lot about anecdotal reports). A couple of excerpts:

> Supposedly if you have ADHD you can just stay on Adderall forever. ... people who *abuse* Adderall develop tolerance all the time, and keep having to up the doses just like heroin abusers do. This is a little weird – my pet theory is that people only develop tolerance to drug effects that aren’t FDA-approved uses – though how your receptors know what the FDA says I haven’t quite figured out.

> Some percent of people who abuse opiates like heroin get what’s called a post-acute withdrawal syndrome (PAWS) ... There is a poorly-studied but anecdotally very helpful treatment for PAWS: low-dose naltrexone. Naively, this sounds like the stupidest possible thing to try. It’s an opiate antagonist, meaning that you’re taking somebody who is undersensitive to opiates and blocking the tiny number of functioning opiate receptors they already have. It should be the only thing capable of making this already bad condition worse. Yet people swear by it. The theory is supposed to be the tolerance reaction again. Your body reacts to this opiate-blocking agent by releasing more opiates. So we’re treating a condition in which drugs that increase opiates cause you to have fewer opiates, by giving you a drug that decreases opiates which will cause you to have more opiates. How annoying is that?!

The article also mentions tachyphylaxis, yet another complication where drug tolerance happens randomly and suddenly.

Basically, if you take adenosine, then it may counteract the effects of tolerance, or your body may increase the number of receptors, or reduce its own production of adenosine, or trigger sudden random acute tolerance, or it might check what the FDA says about it on the label and do that.
> 3 votes

# Answer
While theoretically possible it seems impractical since adenosine has a half life of 0.6 - 10second.

> Adenosine is rapidly cleared from plasma by the cellular elements of the blood and by vascular endothelial cells and subjected to enzymatic metabolism. The drug has a half-life of 0.6 to 10 seconds. Adenosine in the episodic treatment of paroxysmal supraventricular tachycardia

Also, adenosine is usually administered intravenously at dosages in the mg range further complicating practical application as neuroenhancer

> Adenosine is administered intravenously in specific clinical cases. For the management of SVT, adenosine is ideally given through a peripheral intravenous (IV) access initially as a 6 mg dose followed by a 20 mL saline flush for rapid infusion. Subsequent doses start at 12 mg, also followed by 20-mL saline for rapid infusion.

Since you were explicitly asking for theoretical possibility: I couldn't find any literature regarding the usage of adenosine as a neuroenhancer. However drug tolerance is a characteristic of all drug use, although variability exists. (for example alcohol vs. THC) So tolerance to external adenosine application should be expected.

Since you mention "reverse tolerance". This is a term already defined in the medical literature describing increased sensitivity to drug use due to psychological / physiological damage due to drug use. (https://en.wikipedia.org/wiki/Reverse\_tolerance)

A further interesting fact is that certain drugs may potentially "reset" receptor alterations induced by other drugs. This is a field under investigation. For further references consider (https://en.wikipedia.org/wiki/%CE%9A-opioid\_receptor)
> 2 votes

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Tags: neuroscience, psychiatry, psychopharmacology
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title: Why is taboo erotic?

text:
# Question
Title: Why is taboo erotic?
It comes in many forms: exhibitionism, voyeurism, public sex, rape, incest, to name a few. Any johnny with a John Thomas and internet has noticed how prevalent the incest premise has become on porn sites. But why is taboo sex appealing? How does it tickle one's fancy? Is it evolutionary?

# Answer
In a phenomenon known as excitation transfer, physiological arousal from one stimulus is transferred into a temporally proximate secondary stimulus. This transfer occurs because the brain's assessment of arousal relies primarily on reading physiological indicators, which naturally show the combined effect of any stressors present, whether eustressful or distressful. For example, a distressful fear response involves the release of epinephrine, whose physiological effect is then interpreted as eustress (pleasant arousal) as a result of a proximate eustressor.

From the Wikipedia:

> Excitation transfer theory helps to explain the fickleness of emotional arousal (i.e., how it is possible for fear to be transferred into relief, anger into delight, etc.), and how the reaction to one stimulus can intensify the reaction to another.

Excitation transfer can result in a misattribution of arousal, from which a two-factor theory of emotion was developed. In an experiment by Dutton and Aron (1974), participants were made to cross a suspension bridge before meeting a woman:

> They found that the men who walked across the scary bridge were more likely to call the woman to follow up on the study, and that their stories had more sexual content. The two-factor theory would say that this is because they had transferred (misattributed) their arousal from fear or anxiety on the suspension bridge to higher levels of sexual feeling towards the female experimenter.

Hypothetically, these phenomena explain part of the popularity for couples to take date in scary film or amusement park -- so as to maximise erotic appraisal.

As long as physiological arousal occurs, transfer should be possible. Simply thinking about danger should suffice, granted no emotionally disturbing thoughts interfere with the psychological aspect of the transfer.
> 1 votes

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Tags: sexuality
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# Question
Title: Why do we need to know why something is needed or relevant?
I have been doing some research for my thesis and one of the subjects I am researching is motivation. Something that I've generally noticed is that if we do not find something relevant or needed for us, we tend to lose motivation.

For example: In middle school we learn math. Lots of students question the need for math for their own reasons. When they hear an answer that not does not completely answer the question we lose motivation. An answer like: "you need it for your future" or "you just have to".

Other example: Most people learn how to drive a car, because we understand that usually you need a car to get to work. Other people that work from home or live in walking distance from their work, could for that reason, not learn how to drive. If you would make the latter group learn how to drive, most would question the need and therefore lose motivation.

I would like to know if there is a principle or theory about this. A name or a source would be of great help! Or if my presupposition is wrong, please share your thoughts!

Thanks!

# Answer
> 1 votes
The term I think of that is most associated with this concept is salience.

There is a **massively** informative world out there. If you were to spend all your time focusing your attention on arbitrary objects or sensations from the environment you would never get anywhere. You might die of starvation or some other unmet physiological need or get eaten by a tiger while focused on something that isn't dangerous and doesn't help you reproduce - this circumstance is not evolutionarily favorable.

Though salience is often focused on more immediate threats and benefits, more complex organisms including humans are able to plan ahead a bit and put effort into things now that have benefits in the future. Some things seem to be innately salient, others become salient with learning.

# Answer
> -1 votes
Naturally we are driven by instinct. If a proposed activity cannot be mapped to an instinct, or if the resulting assessment (instinct times expectation) is weaker than other proposed activities, we are going to lack motivation. Goals with direct and immediate mapping to an instinct are said to have *intrinsic value*, whereas goals whose end reward requires more steps and abstraction are said to have *extrinsic* or *instrumental value*.

The proposed goal of learning something *you need for your future* is an example of an *instrumental goal*. The skill or knowledge in question may lack immediate gratification, especially if the learner cannot map the learning process itself to an intrinsic drive. A teacher who successfully promotes this mapping may be more effective.

There are three main factors which come to mind in the learner's level of drive:

* The activity must be *framed* in the mind of the learner as having a believable connection with an intrinsic motivator such as *self-preservation* (among others). Painting a clear and visceral image of life with and without the proposed skill or knowledge might help to motivate.
* The activity should produce a benefit within a time-frame the learner can tolerate. Personality and mental factors such as impulsivity and ADHD can play a role here.
* The activity is better learned when intrinsic value is present. Making the activity more social may help to motivate those who value socialising. Making the activity more mentally stimulating or novel may help to activate curiosity. Those higher in need for cognition, and related personality constructs, may require less auxiliary motivation to learn new things.

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Tags: cognitive-psychology, social-psychology, learning, motivation
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# Question
Title: How does the chemical structure of a drug determine potency?
I'm rather new to neuropharmacology, and I am particularly interested in why some psychotropic medications are more potent than others despite being in the same category of one another, (*i.e.*: Oxymorphone, and Etorphine being both opioids) and acting as agonists at the same receptors. I am aware that binding affinities determine the potency and strength of a drug. *E.g.*:

Morphine has an affinity of 1.8 nM (Ki) on the MORs. Whereas Fentanyl has a binding affinity of 0.39 nM (Ki) on the MORs. And so therefore, fentanyl requires a far lower dose than morphine for the patient receiving fentanyl to sustain adequate analgesia.

How are these two, totally structurally different opioids, able to agonise the same receptors, and how do the structures of them make one more potent than the other? A similar question goes for the following Drugs:

Why are most Triazolobenzodiazepines, such as: Clonazolam, Flunitrazolam, and Triazolam far more potent in their dose, and effects, then Benzodiazepines such as: Chlordiazepoxide, Nitrazepam, and Diazepam?

Why do small changes in the skeletal structure of psychoactive drugs have such a large impact on binding affinities?

# Answer
> 6 votes
In fact, the two binding affinities of fentanyl and morphine to the mu opiate receptors are considered to be fairly similar. The reason the former is the more potent one has more to due with its higher **lipophilicity** and therefore its better ability to cross the **blood brain barrier**. In addition, their internal cellular signaling pathways differ. This is caused by the two compounds binding to slightly different amino acid residues in the opiate binding pocket of the mu receptor (Fig. 1) (Lipiński *et al*., 2019).

Another thing to consider, besides **pharmacodynamics**, are the **pharmacokinetics** of different compounds. For instance, methamphetamine is way more potent than amphetamine, which in turn is way more potent that its parent molecule PEA. This is because the methyl groups block MAO from degrading the compounds (Shulgin & Shulgin, 1991). Pharmacokinetics may, or may not play a role in the morphine/fentanyl case as well.

**References**
**-** Lipiński *et al*., *J Molec Mod* (2019); **25**: 144
**-** Shulgin & Shulhin, *Pihkal*, Transform Press, 1991

Fig. 1. Binding of fentanyl (a) and morphine (b) in the mu receptor binding pocket showing different amino acid residues in the receptor protein helices to be bonded causing differences in intracelllular signaling pathways to be activated. source: Lipiński *et al*. (2019)

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Tags: neuroscience, psychopharmacology
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# Question
Title: Why is threshold at 76% correct when d-prime = 1?
In signal detection theory using a 2-alternative forced choice task, when d' = 1, threshold is found at the stimulus intensity which is perceived 76% of the time (https://www.oxfordreference.com/view/10.1093/oi/authority.20110803110358463).

Why 76%?

# Answer
d' is equal to |meanA \- meanB|/SD when you have two gaussian distributions of equal variance and different means.

Imagine SD=1, meanA = 0, meanB = 1, with B\>A as the "correct" answer (perhaps B is the signal, and A is the noise). This will give you a d' of 1 because the difference between the means is 1, divided by a standard deviation of 1.

The % correct would be the fraction of the time that a random draw from the distribution with larger mean is larger than a draw from the distribution with smaller mean. That's what an ideal observer would do given the task to choose the larger distribution: pick the larger number on that trial. This is equivalent to detecting a signal if you think of the other distribution as representing the "noise".

For this example (or any example that satisfies the condition that d' = 1), that rate will be about 76%. I don't believe there is a simple closed form equation to calculate this, and my calculus class days for rearranging integrals are a bit dated, but you can simulate it easily by taking (pseudocode):

```
a = rand(mu=0,sigma=1,n=100000)
b = rand(mu=1,sigma=1,n=100000)
sum(b>a)/100000

```

Note that there isn't any special reason d' = 1 is chosen to make this 76% number be true, it's just a consequence of the assumption of normal distributions and probabilities. If d' = 0, the % "correct" will be 50%.
> 2 votes

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Tags: psychophysics, signal-detection
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# Question
Title: Does something costing \$9.99 really seem cheaper than \$10 to people?
I've always hated seeing prices like this. It makes me immediately distrust the seller. I wish all prices would be "even", such as \\$250 instead of \\$249.98 or whatever. To me, it does *not* look cheaper. Not even subconsciously. It just makes me annoyed every time I see it. I know that people in general are dumb, but I still deeply question this practice.

Do stores sometimes make tests where they change all their prices to round numbers for a while and then compare their sales during that time to their normal sales? And does it then really show that more people buy things because they use these "silly" prices?

# Answer
This is called psychological pricing:

> Research has suggested that pricing products at one cent below a whole number (e.g., 4.99 instead of 5.00) can be an effective method for increasing purchases. Although many reasons for this have been suggested, a commonly proposed explanation is that consumers tend to drop off, or pay less attention to, the rightmost two digits. This drop-off mechanism has garnered much indirect support, but only limited research has been conducted to directly test it. In this study, respondents provided estimates of how many products they could purchase for $73. Analyses indicated that respondents thought they could buy significantly more products priced with 99 endings than products with comparable 00-ending prices. Follow-up analyses showed that (a) errors made by respondents showed a pattern consistent with a dropoff mechanism, and (b) motivation to carefully provide quantity estimates moderated the effect. The study therefore provides rare direct evidence that the drop-off mechanism may contribute to the effectiveness of 9-ending pricing.

Direct evidence of ending-digit drop-off in price information processing
> 3 votes

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Tags: consumer-psychology
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# Question
Title: What psychological indicator activates the parasympathetic nervous system after fight/flight response?
I am new to neuroscience study and read recently about the brain's ability to balance parasympathetic and sympathetic nervous system to achieve homeostasis following stressful stimuli.

From my research, the sympathetic nervous system activates when a threat is identified by the brain and places the body in a fight or flight response. Then once the threat is cleared the brain activates the parasympathetic nervous system to reverse the effects of the sympathetic system and bring the body back into balance.

From my research, I haven't been able to understand the physiological mechanisms (i.e., what the brain does) to trigger to the parasympathetic nervous system that the there is no longer any threat.

More specifically, what is the brains tipping point to switch from sympathetic to parasympathetic following a fight or flight stimuli and response.

# Answer
> 0 votes
The fight/flight response (or what I have referred to as the 5F response) is as follows:

## Examples of single instances of Initial Sensitising Events (ISEs)

Take a soldier in combat who is under constant heavy gunfire and "hell is raining down on everyone around them". Fellow soldiers in their troops are killed in the process, and **maybe** they have come close themselves. **Maybe** they have lost a limb from a mortar bomb explosion. This can be one ISE which on its own causes PTSD.

Take a man/woman who is threatened with their life and raped at knife/gunpoint. Again, this ISE alone can cause PTSD.

### The fight and flight mechanism

A more in depth rundown on this (what I have called the 5F response — fright/flight/fight/freeze/fawn) can be found in my answer to Understanding fear as a response in classical conditioning, but in short, the 5F response is an unconscious reflex to **perceived** threats (loud bang or other stimulus received at an ISE including smells). The process follows the pattern **Perceived Threat → Brain Receiving Signals → Brain Reacts (Fright) → Cortisol and Adrenaline is released → Physical Reactions occur from the release of hormones → Bodily response (Fight, Flight, Freeze or Fawn)**

From experiences provided by those I have helped who have suffered trauma, there is a 6th possible response (flop — fainting or just plain collapse with fear) making the 5F response, the 6F response (fright/flight/fight/freeze/fawn/flop).

(Source: Wikipedia)

### Adrenaline and Cortisol Release

As you can see within the infographic above, the brain initially processes the threat signal in the amygdala and then the hypothalamus and the pituitary gland secretes adrenocortictropic hormone (ACTH) which leads to cortisol and adrenaline release to enable a speedy escape if chosen.

Cortisol is constantly released to maintain the stress response. Once the threat levels lower (either the threat has gone or you have later realised there was no threat after all), the amygdala and hypothalamus are no longer stimulated by the threat and so cortisol release is stopped.

As the cortisol is spent in the body, you start to reach your normal state of calm.

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Tags: neuroscience, nervous-systems
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# Question
Title: math problems which become easy when given to social processing part of brain
I have a young nephew who much prefers history and social science to math and I remembered an article, or maybe it was in a book, which described how some intermediate math problems can be reframed as social relationship or social fairness problems. This allows the social processing part of the brain to kick in and solve the problem almost without effort, when the student would be struggling otherwise. The idea was that abstract combinatorics questions can be reframed as counting the ways you can match different types of people together. Another example was allocation problems where you reframe that as allocating things fairly between people.

My memory of the article is frustratingly incomplete because this approach would be ideal for my nephew. He doesn't do well at math I suspect because he is more interested in how people interact so if he could harness that part of his brain for math as well, he may come to enjoy math a bit more.

I've been googling for 2 days to find an example of this approach and found some interesting related stuff but nothing on this specifically. Can anyone help to explain this approach?

# Answer
AFAIK recent computational neuroscience research shows that there are no specialized brain areas, but rather activity levels coupling certain brain areas, while these couplings have not yet been mapped to general cateogries such as "social processing" or "math processing".

Recent neuroscience research - Quanta Magazine
> 2 votes

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Tags: mathematical-ability, social-cognition
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# Question
Title: Is thermoception part of the sense of touch in the 5 human senses or is it a 6th separate sense?
In an answer provided by DavidCian, it is mentioned that thermoception is separate to the 5 human bodily senses (sight, hearing, touch, smell and taste). Yet, I would have thought it would be part of the sense of touch.

The Wikipedia link mentions that Ciliopathy is a loss of ability to sense heat. Does Ciliopathy prevent you from sensing touch? If not, maybe it is a separate sense after all?

# Answer
**Short answer**
Heat receptors are often grouped under the 'skin receptors', and hence are bundled along with touch (pressure, vibration, stretch), cold and pain receptors.

However, ciliopathy is a disorder affecting some, but not all of the skin receptors, and affecting unrelated sensory modalities like vision and audition. This is because functionally, the receptors responsible for these different modalities include the same molecular cilia (hair)-like components.

**Background**
Great question. The 5 most common 'basic' senses are the ones you listed, namely the visual, auditory, gustatory, olfactory and tactile, corresponding to the systems responsible for sensing and perceiving light, sound, taste, smell and temperature.

However, these are schoolbook examples and the list is more extensive. What about

* The vestibular system that is responsible for perception of acceleration and gait?
* Proprioception, mediated by muscle spindles that feedback muscle activity back to the brain to complete a closed loop system responsible for the perception of bodily position and location?
* The sense of pain (nociception)?
* And within the realm of touch, there is the perception of skin stretch, or the sense associated with the movement of hairs so important for animals like moles and nightly hunters that use them for navigation? Are vibratory receptors to be grouped with those sensing static pressure?

These examples can, however quite easily be categorized under the 'basic senses' by stretching the definitions a bit here and there. The vestibular system is often grouped into the auditory system, because 1) the perception of bodily rotation and acceleration is also sensed by fluid-bound hair cells, akin to the ones in the cochlea sensing acoustic waves and 2) because the end organs of the vestibular system are located in the inner ear and actually coupled to the cochlea. It harbors different receptor cells responsible for sensing acceleration or bodily rotation.

Pain, stretch, hair, vibration and pressure receptors are all grouped into the '**skin receptors**', and often clustered under the group 'touch'. Muscle spindles, though are quite special and very difficult to cluster into anything, because they functionally systemwide into the sense of balance, yet their function is more like a sense of touch.

Thermoception is thus bunched into the group of skin receptors. However, vibration, static pressure, hair movement, pain, heat and stretch are all sensed by different receptor cells with different afferents to the brain and many subtypes exist within these groups, such as fibers mediating pain swiftly ('sharp pains'), or slowly (associated with 'chronic pain' and very responsive to opiates) and vibration receptors that adapt swiftly or more sluggishly etc etc.Thermnoception itself is mediated via receptors sensing 'cold' (sensitive to menthol) and 'heat' (sensitive to capsaicin in peppers).

Concerning cioliopathy, you can see in your linked web page that associated comorbidities include sensorineural hearing loss; hair cells also have cilia that are responsible for detecting movement. Here you can see how difficult classification is; apparently, functionally, pain receptors can be classified into the same group as balance and sound detectors, and even retinal cells seeing the web page you linked. However, their sensory modalities are entirely different. The groupings discussed above are mostly from a sensory modality point of view.
> 2 votes

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Tags: neuroscience, terminology, neurophysiology, sensation, sensory-perception
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# Question
Title: Difference between psychosis and schizophrenia
Can you please illustrate the difference between the psychosis and the schizophrenia?

# Answer
> 3 votes
As loosely indicated by @DanielMera in another answer,

> Psychosis is part of schizophrenia, and it can be part of other psychiatric disorders, too.

## Psychosis (plural = psychoses)

Psychosis is (Hayes & Kyriakopoulos, 2018)

> an umbrella term for a clinical presentation conceptualized, both by the American Psychiatric Association \[APA\] and the World Health Organization \[WHO\], as a combination of hallucinations, delusions, disorganized thinking or behaviour, negative or catatonic symptoms, and functional impairment.

When someone is having a psychotic episode, they are not necessarily suffering all of the symptoms in the combination set in Hayes & Kyriakopoulos above, but could be suffering just one of those symptoms. Basically, psychoses involve a disconnect from reality — It causes you to lose touch with reality (WebMD, 2021; NHS, n.d.). While psychosis is not a mental health disorder on it's own, psychosis is part of mental health issues which can cause very serious problems for those suffering with them.

Another umbrella term for mental health disorders is neurosis.

## Schizophrenia

Schizophrenia is **one of many mental health disorders** which involve psychosis, and the latest edition (5th edition) of the Diagnostic and Statistics Manual (DSM-5) stipulates that because Schizophrenia is a specific disorder separate to other conditions which may involve psychosis — Schizophrenia spectrum and other psychotic disorders include schizophrenia, other psychotic disorders, and schizotypal (personality) disorder (APA, 2013),

> the diagnosis of a schizophrenia spectrum disorder requires the exclusion of another condition that may give rise to psychosis (p.89 - Schizophrenia Spectrum and Other Psychotic Disorders).

You could get a copy of DSM-5 in the library or buy it online directly from the APA or any other good book store.

Insel (2010) also defines Schizophrenia:

> Schizophrenia is a syndrome: a collection of signs and symptoms of unknown aetiology, predominantly defined by observed signs of psychosis. In its most common form, schizophrenia presents with paranoid delusions and auditory hallucinations late in adolescence or in early adulthood. These manifestations of the disorder have changed little over the past century.

Other conditions which involve psychosis include Post Traumatic Stress Disorder (PTSD) as PTSD sufferers can experience hallucinations which can involve one or more of the 5 basic senses. In extremes, the hallucinations can sometimes involve all the senses to totally remove the person from what is going on in the present reality. There can also be paranoid delusions where they can believe, for example, that there is always going to be someone around the corner ready to attack them.

## References

( = open access journal)

APA. (2013). *Diagnostic and statistical manual of mental disorders (DSM-5®)*. American Psychiatric Pub. https://www.psychiatry.org/psychiatrists/practice/dsm

Hayes, D., & Kyriakopoulos, M. (2018). Dilemmas in the treatment of early-onset first-episode psychosis. *Therapeutic advances in psychopharmacology, 8*(8), 231–239. https://doi.org/10.1177/2045125318765725

Insel, T. R. (2010). Rethinking schizophrenia. *Nature, 468*(7321), 187-193. https://doi.org/10.1038/nature09552

NHS (n.d.). *Psychosis - Overview*
https://www.nhs.uk/mental-health/conditions/psychosis/overview/

WebMD (2021). *Psychosis and Psychotic Episodes*
https://www.webmd.com/schizophrenia/guide/what-is-psychosis

# Answer
> -3 votes
Psychosis is part of schizophrenia, and it can be part of other psychiatric disorders, too. Psychosis is a concept that describes specific symptoms. Schizophrenia is a mental illness that has psychotic features. When broken down into symptoms, the notion of schizophrenia vs psychosis makes sense.

Psychosis isn’t a mental disorder by itself. Instead, specific features define the experience psychologists call psychosis. Some of the psychotic symptoms include hallucinations, delusions, confusion, and confused speech.

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Tags: schizophrenia, psychosis
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# Question
Title: Is it allowed for a psychologist to claim to be a friend of the patient
Is there any ethical/therapeutical guidelines preventing a psychologist to claim to be a friend of the patient?

The relevant points are:

* I am aware that there are rules against treating friends, and I have even found references to disciplinary actions when the relationship started after the treatment.
* But here there is no relationship other than the professional one. Patient and psychologist did not knew before treatment, do not meet outside of practice hours, and do not develop any social activity that could be interpreted as friendship. It is just the therapist claiming to be a friend.
* OTOH, there is no ill-intent. No "I am your friend, so tell me your credit card number" schema or anything like that.

Could this kind of action be considered as going against ethical/therapeutical principles?

If a country is needed, it would be in Spain, although I am asking just to inform myself so I would be ok with an "universal" answer if that is possible.

# Answer
When someone says they are your friend, there can be different contexts to the word. For example, Giletta et al (2012) talks of some of these contexts within adolescents.

In the therapy room, Carl Rogers who founded Person-Centred Therapy (PCT) always maintained the importance of Unconditional Positive Regard (UPR) and it is (in its basic form) basic acceptance and support of a person regardless of what the person says or does.

PCT therapists and Integrative Therapists will incorporate UPR into their therapy, whereas Psychodynamic Therapists will be more strict on the client-therapist relationship.

You said,

> there is no relationship other than the professional one

Within therapy, there can be a friendship dynamic in play, and that is fine as it is a therapeutic friendship.

There is the fine line within the therapeutic boundaries of the relationship which needs to be maintained at all times. If that line is crossed, the friendship is more than a client-therapist relationship and therefore ethics state that therapy should be redirected to another therapist to address the potential issues with transference and counter-transference mentioned in my other answer on the subject.

> I have even found references to disciplinary actions when the relationship started after the treatment

It is where the boundaries are not maintained and breaches of these boundaries are not addressed when therapists are disciplined and often removed from Professional Standards Registers in the UK.

## References

( = open access journal)

Giletta, M., Scholte, R. H., Prinstein, M. J., Engels, R. C., Rabaglietti, E., & Burk, W. J. (2012). Friendship context matters: examining the domain specificity of alcohol and depression socialization among adolescents. *Journal of abnormal child psychology, 40*(7), 1027–1043. https://doi.org/10.1007/s10802-012-9625-8
> 1 votes

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Tags: therapy, ethics
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# Question
Title: Belief that I have more holistic understanding and other are just stuck to their details
In meetings and online discussions I've noticed that there are often confident people who don't just believe that they are always right, but specifically assert that (only) they have holistic (gestalt) view while others are stuck to narrow arguments. They end up with fuzzy "systems thinking" science references etc. Is there a name for this cognitive bias?

# Answer
There are 2 possible candidates for your question.

llusion of validity, the tendency to overestimate the accuracy of one's judgments, especially when available information is consistent or inter-correlated (Dierkes et al. 2003).

Overconfidence effect, a tendency to have excessive confidence in one's own answers to questions. For example, for certain types of questions, answers that people rate as "99% certain" turn out to be wrong 40% of the time (Hoffrage, 2004).

## References

Dierkes M, Antal AB, Child J, Ikujiro Nonaka (2003). *Handbook of Organizational Learning and Knowledge*. Oxford University Press. p. 22

Hoffrage U (2004). "Overconfidence". In Rüdiger Pohl (ed.). *Cognitive Illusions: a handbook on fallacies and biases in thinking, judgement and memory.* Psychology Press.
> 1 votes

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Tags: bias, cognitive
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# Question
Title: Is there any evidence that some people who claim to see auras around persons actually see them?
I have found that seeing "auras" is used for diagnosis of some neuropathologies. However, I wasn't able to find evidence that some people truly see what is colloqially known as auras. Is there any evidence that some neurological conditions can trigger seeing lights of different colors around people based on that person's personality as perceived by the observer or something similar?

# Answer
**Simply answer to the question:** Yes, but without real evidence and sole *speculative*.

From neuroscience perspective it may be possible that those people can `self-induce` waves in brain to sole affect visual cortex, so it may be possible and plausible but didn't encountered any research to back those claims.

According to publication Migraine with visual aura associated with thicker visual cortex that aura (symptom) does have an impact on the brain, *increased cortical thickness of visual and somatosensory areas in patients with migraine with aura*, more precise due the increased neural density on those parts on the brain, brain does change and not all time in a good direction, generating more damage.

Most of the people capable of "seeing" aura (paranormal, spiritual or alternative medicine) had an "episode" of excessive brain stimulation and can percept energy completely different compared with others (ones reality is others illusion). At the end of the day were said: **Reality is merely an illusion, albeit a very persistent one**.

**Note:** I won’t deny the fact that by this waves to be enhanced power of `visual cortex` can be associated with seeing other objects `energy` fields as are specialized as Rose aura camera, at the end of the day we are `biological machines` and is still a lot of unknown when does come to neuroscience and brain in general, if those brain neurons/synapse does use electrical to work then we can `anecdotal` say that by this waves, humans can get supernatural `powers` by seeing energy fields around. so far most of aura symptoms does precedes and upcoming damage to human brain or lets say “to biological agents” in general.

**More explanation/details from pure Neuroscience perspective**

**Aura**” referenced in Migraine with aura should be paired with neuroscience/neurology symptoms An aura is a perceptual disturbance experienced by some with epilepsy or migraine with additional info from Mayo Clinic What is AURA and **NOT** with paranormal, spiritual or alternative medicine

**To add some more details to give more “weight” to aura as symptom:** A set of symptoms or sensations, such as flashing lights or zigzag lines, which typically precede migraine headache, seizure, or other neurological events affecting visual cortex of the brain (is complicated and still unsolved phenomenon) also called focal seizures/partial seizures or simple auras and is due the a wave in brain (electrical or chemical). A richer view of aura from nature is a very good read if u do look for more details.
> 1 votes

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Tags: neuroscience, vision, hallucinations, pseudoscience
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# Question
Title: Does human biology compute audio fast enough to benefit from phase accurate audio propagation in 3D space?
In nature when people perceive a point source of audio moving in 3D space say when I am stationary and listening to someone talking who is walking around me does my perception of that audio benefit from resolving out the phase differences in the audio as it is processed and combined knowing I have two ears ? In other words, is human acoustic processing fast enough to be sensitive to phase difference due to separation in 3D space of our ear drums ? Or is localization abilities simply due to amplitude differences due to distance ?

I know some predatory birds earn a living by localizing in 3D space their prey. They process incoming audio data in a certain location on one side of the brain and the neurons from each ear that transport the audio signal to that brain location are of the same length ( so both neural pathways incur the same temporal delay ) however interestingly this brain location is on one side of the brain and the neuron coming from the ear on the same side of the brain winds back and forth burning up its length in a coil before reaching this audio processing center. Its doing this to maintain phase accurate audio information being received from each ear.

***UPDATE*** I will update this to show some back of the napkin maths to zero in on wave length in hearing freq range to reveal the time periods we are dealing with

# Answer
Human perception of location in azimuth of low frequency sounds (or low frequency envelopes of higher-frequency sounds) includes use of interaural time differences \- this is the phase coding you're talking about. There is some rather specialized circuitry in the auditory brainstem to perform those calculations. Your description of how predatory birds accomplish it is the same as is done in humans - this is an evolutionarily conserved trait in land vertebrates.

At higher frequencies, the time between waves is too fast to estimate phase lags, but the head is better at attenuating sound so intensity differences are used. Wikipedia has a fairly informative page on sound localization which would be a good starting point for further reading.
> 2 votes

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Tags: perception, computational-modeling, spatial-cognition, auditory-discrimination
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# Question
Title: Why are synapses that are connected to co-transmitting presynaptic vesicles uniformly distributed on the postsynaptic neuron?
This paper on functional implications of co-release and co-transmission says that "Consistent with a co-transmission phenotype, cholinergic synapses are uniformly distributed on the postsynaptic neuron, whereas GABAergic synapses are non-uniformly distributed."

Why is it the case that synapses across which neurotransmitters/modulators are co-transmitted are uniformly distributed? Also, what is the typical morphology of synapses that are co-released?

# Answer
The paper that you link to cites as reference 32 this paper for the relevant section you quote:

Lee, S., Kim, K., & Zhou, Z. J. (2010). Role of ACh-GABA cotransmission in detecting image motion and motion direction. Neuron, 68(6), 1159-1172.

Importantly, they are contrasting between "co-release", where two different neurotransmitters are released by the same cell by packaging together in the same vesicles, and "co-transmission", where two different neurotransmitters are released by the same cell by packaging them into separate vesicles.

I do not believe or understand the authors to express any substantial importance to the *uniform distribution* of one of the post-synaptic receptors as evidence for co-transmission over co-release; rather, it is that the distribution of post-synaptic receptors is **different** for the different neurotransmitters released, which is evidence that they are not released in the same places which means they must be in different vesicles.

It so happens that what makes it most clear that the distribution is different is that receptors for one transmitter are found all over ("uniform") and for the other they are found only in particular locations ("non-uniform"). Other types of difference in distribution would also be evidence for co-transmission.

For this particular pre/post-synaptic pairing, the significance of this arrangement is that it functionally creates a direction selectivity, where a stimulus appearing from one direction triggers inhibition ahead of excitation, such that the cell does not fire, whereas a stimulus from the other direction triggers excitation first so the cell can be driven to fire before inhibition occurs:

Figure 7 from Lee et al 2010

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I highly recommend reading the whole Lee et al paper, as well as these by Fried et al:

Fried, S. I., Münch, T. A., & Werblin, F. S. (2002). Mechanisms and circuitry underlying directional selectivity in the retina. Nature, 420(6914), 411-414.

Fried, S. I., Munch, T. A., & Werblin, F. S. (2005). Directional selectivity is formed at multiple levels by laterally offset inhibition in the rabbit retina. Neuron, 46(1), 117-127.

Lee, S., Kim, K., & Zhou, Z. J. (2010). Role of ACh-GABA cotransmission in detecting image motion and motion direction. Neuron, 68(6), 1159-1172.
> 1 votes

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Tags: neuroscience, neurophysiology, cell-signaling
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# Question
Title: Is language an abstract concept that is voiced out though a national tongue?
When discussing with my son about a possible future (from the progress of technology point of view), he mentioned that it would be great to have a brain implant that would finally allow everyone to speak every tongue.

He had in mind the ability to have a seamless simultaneous translation but this made me wonder about the current consensus on what a "language" is.

Is this an abstract set of concepts, that get voiced out (literally or in your head) through a national tongue? This would mean that everyone, at their core, shares a common set of concepts that are just voiced the way their surrounding does.

Or is it rather that each concept has the national word attached?

Or something else?

The main point is to see if such a chip would convert abstract concepts into the word of the current language, or if it would be a translation service where a word in one language is translated into another word.

*Note: when mentioning "word" I have also have in mind everything that creates a naguage: the syntax, forms, etc.*

# Answer
> 4 votes
While there appears to be ongoing research and debate on the nature of language in the human mind, some pertinent theories relate to the question here.

At the earliest level of linguistic learning, basic concepts about the nature of objects and relations of objects begin to form as image schemas:

> In contemporary cognitive linguistics, an image schema is considered an embodied prelinguistic structure of experience that motivates conceptual metaphor mappings. Learned in early infancy they are often described as spatiotemporal relationships that enable actions and describe characteristics of the environment.

These schemas go from simple to more complex, often building upon previous schemas by combining them together into ever more composite schemas. An example low-level schema is *path*, or the basic concept of an object continuing in the direction it is moving. Another basic schema is *contact*, or the idea that one object is touching another. We can combine these two into the more complex schema of *hit*, or when path of one object reaches contact with another.

Moving on to language development, one particularly noteworthy set of theories is construction grammar, which basically says that all linguistic understanding stems from *constructions*, or abstract objects (complex schemas) with *form* and *content*. Each construction has an emergent *meaning* stemming from a set of simpler schemas (*content*) combined in a particular *form*. Constructions range in symbolic complexity from simple image schemas, as described above, to schemas with complex inter-scope bindings (that is, having elements of varying complexity and abstraction).

> \[Construction grammar\] posits that there are linguistic patterns at every level of generality and specificity: from individual words, to partially filled constructions (e.g. drive X crazy), to fully abstract rules (e.g. subject–auxiliary inversion). All of these patterns are recognized as constructions. \[...\] The semantic meaning of a grammatical construction is made up of conceptual structures postulated in cognitive semantics: image-schemas, frames, conceptual metaphors, conceptual metonymies, prototypes of various kinds, mental spaces, and bindings across these (called "blends"). \[...\] Embodied construction grammar (ECG) \[...\] \[claims\] that the content of all linguistic signs involves mental simulations and is ultimately dependent on basic image schemas \[...\]

We can probably expect the simplest image schemas to exist in perhaps all fully developed human brains since (a) these relate concretely to basic physical phenomena and (b) most if not all human languages should have terms for common natural relationships and events. However, as the schemas in question become ever more complex, abstract, and specialised, we are bound to find discrepancies between languages. This idea is essentially the basis for linguistic relativity (also called *Sapir-Whorf hypothesis*), which more or less states that a person's native language either determines (*strong* version) or influences (*weak* version) his or her thinking patterns.

> Research on weaker forms has produced positive empirical evidence for a relationship.

Because of these differences in higher schemas, a conversation between persons of different languages would presumably require at least some translation in meaning between comparable higher schemas. For lower schemas (such as pre-linguistic image schemas), perhaps tongue could be skipped altogether. Then again, a sufficiently advanced system may be able to transfer images or spatial models, which could serve as a work-around for certain discrepancies between languages.

A couple of important questions arise here. One, can the mental schemas or meanings behind language be activated directly, such as through a particular pattern of neural excitation? Two, upon activation of a schema or specific meaning, will the associated words or expressions be activated concurrently?

I am not prepared to answer the first question, but I have come across a related phenomenon for the second question called ideaesthesia:

> \[Ideaesthesia\] is a neuropsychological phenomenon in which activations of concepts (inducers) evoke perception-like sensory experiences (concurrents). \[...\] \[E\]mpirical evidence indicated that most phenomena linked to synesthesia are in fact induced by semantic representations. That is, the linguistic meaning of the stimulus is what is important rather than its sensory properties.

Without evidence or good reason to the contrary, we should consider the possibility that activation of linguistic schemas or meanings may be subject to ideaesthetic effects.

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Tags: brain, language, language-processing, brain-computer-interface
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# Question
Title: Electric communication between single neurons
It is believed that neurons communicate through neurotransmitters, released from multiple synapses and flow to the axon of the next neuron. But has it been shown if a single neuron communicate with a single neighbour neuron by its electric field? (not involving the chemical synaptic cleft).

# Answer
Neuronal membranes act as capacitors: there is a charge separation between inside and outside due to the (relatively) impermeable membrane to charged ions. The voltage of a neuron is a charge separated across the membrane. However, the electric field *outside* a capacitor is **negligible**. In many physics problems it's treated as simply zero. See some Q&A on Physics.SE:

https://physics.stackexchange.com/questions/12309/electric-field-outside-a-capacitor

https://physics.stackexchange.com/questions/274155/electric-field-outside-a-infinitely-long-capacitor

https://physics.stackexchange.com/questions/271127/what-is-the-electric-field-and-potential-outside-a-spherical-capacitor

Because of this, there isn't any good reason from the physics of a neuron that you'd expect a neuron to be affected by the electric field of its neighbor. The field itself is tiny, and changes in the field are tinier still.

Some neurons communicate directly to each other through gap junctions, but that's because these connections cause a gap in the membrane that joins the inside space of one cell with the inside of another, allowing ions to flow freely between them. It's also possible for neighboring neurons to be influenced by changes in extracellular ion concentrations, but this really only happens in bulk circumstances such as cortical spreading depression, ischemia, or seizure, rather than normal neuronal communication.
> 2 votes

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Tags: cognitive-neuroscience, memory, eeg, consciousness, electrophysiology
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# Question
Title: What are the differences between bipolar channels and monopolar channels for EEG?
In EEG, each electrode records a biopotential which must be compared to a reference biopotential in order to obtain a channel of measurement. Two types of channels are the so-called bipolar channels and monopolar channels. In the case of bipolar channels, each working electrode uses a different reference electrode, whereas in the case of monopolar channels, each working electrode uses the same electrode as reference.

From an amplifier-technical point of view, reusing a signal can degrade it a bit, so that is indeed bad for the monopolar channels. However, is there any fundamental difference between monopolar and bipolar channels? What if every two channels have a common reference electrode?

At this point I feel the need to mention there is another question mentioning the difference between the two, but it doesn't ask whether there is a conceptual difference between the two, nor does it compare their advantages and disadvantages (in addition to the one accepted answer being rather short in my opinion).

Additionally, this paper mentions that bipolar recordings are generally known to be more robust to noise than monopolar recordings: why would that be the case?

# Answer
In general, closely situated electrodes work well to eliminate environmental noise, at least when a **differential amplifier** is used. Environmental noise is a major problem in case of scalp-recorded signals, think of the electromagnetic distortions caused by electronical devices situated in the vicinity of your recordings. But also muscle artifacts are a nuisance, which can also be eliminated by using closely spaced recording electrodes and differential amplification. This type of electrode placement is called a bipolar recording, as opposed to monopolar recordings where the reference electrode is situated further away (Saab, 2009).

With differential amplification, the potential difference across the electrodes is amplified. Suppose environmental noise is present, or a muscle artifact, then the hopes is that this artifact is similar across closely spaced electrodes. In case of EEG, electrode A, ideally, records a part of the brain situated directly underneath it. An adjacent electrode B records the cortical area next to electrode A. The signal (EEG) is then said to be location specific. Ideal artifacts (though virtually nonexistent) are similar across electrodes. Hence, in a simplified example, when the differential is amplified across electrodes A and B then signal A = A-B, where the signals are different, yet the artifacts are similar (Saab, 2009).

Many other electrophysiological recordings besides EEG are recorded using bipolar recordings, because artifacts are too pronounced to allow a monopolar setup (e.g., Diez *et al*, 2010; Stronks *et al*., 2009; Stronks *et al.*, 2016). Monopolar setups generally result in larger amplitude signals, yet often the artifacts become much more pronounced, and the signal-to-noise ratios are more favorable in a bipolar electrode configuration.

<sub>**References**
**-** Diez *et al*., *Annu Int Conf IEEE Eng Med Biol Soc* (2010): 5803-6
**-** Saab, *Biofeedback* (2009); **36**(4): 128–33
**-** Stronks *et al*.,*IOVS* (2013); **54**:3891–901
**-** Stronks *et al*., *Doc Ophthalmol* (2016); **132**:1–15</sub>
> 3 votes

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Tags: neuroscience, eeg, electrophysiology
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# Question
Title: Is it possible to detect the mental flow state with EEG?
I know that it is possible to detect "focus" with a consumer EEG with a single electrode and a reference point (ear clip), even without conductive gel, but is it possible to detect a flow state with any level of technology (whether it be professional or consumer)? Are flow states and focus synonymous? Is the mechanism of flow by it's nature undetectable by EEG?

# Answer
Bearing in mind the fact that I can't prove a negative, I'm going to say "No, it's not (yet) possible".

*Flow* is rather loosely defined (e.g. "merging of action and awareness"), so coming up with hard measures is a challenge in and of itself -- even without bringing electrophysiology into the equasion. As a *Positive Psychology* concept, it belongs to the realm of "soft science" psychology, and this tends to make fuzzy things stay fuzzy. (Please note that I'm not using "soft science" pejoratively).

I think the best you can do is measure correlates of alertness and attention (e.g. look for desynchronization in the alpha band). If you come up with a very clever design, you might even be able to elicit ERP components related to conscious awareness of a stimulus of interest (e.g. P300b complex), but even that will be very difficult in non-laboratory conditions.

Alternatively, you could turn to machine learning to search for patterns associated with the conscious processing of a stimulus of interest. If you want to go that route, I'd strongly encourage you to read one of my colleagues' Ph.D dissertation \[1\]. This dissertation proposes some novel approaches to pattern classification with EEG (and MEG/iEEG). Note that this problem is a much easier one (classification of non-communicative patients). That, along with the insane amount of noise you're likely to get and the need for a very inventive design, earns you a hearty "good luck" ;)

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1. Characterizing the Electro-magnetic Signatures of Conscious Processing in Healthy and Impaired Human Brains
> 7 votes

# Answer
This is an interesting question. It seems to me that it is impossible to say 100 per cent from the information obtained from an EEG if there is a flow state or not. However, it is possible to identify concepts that are closely related to this state. For example, the identification of brain activity that is linked to positive emotions could be associated with enjoyment, which is a dimension of flow. Likewise, high brain activity could also be identified with task concentration, which is another dimension of flow in line with some authors. Also, an important factor mentioned in the article below is the fact that the consciousness of the flow state is also related to one's own experience of flow. That is, the greater the experience of flow, the greater the consciousness. On this basis, therefore, the increased brain activity identified in the sections of the brain related to the individual's consciousness can be used as indicators of the mental flow state.

Further reading: https://doi.org/10.1108/INTR-08-2020-0482
> -1 votes

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Tags: cognitive-neuroscience, neuroimaging, eeg
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# Question
Title: What are the brain regions related to tinnitus shown in this figure?
I am interested in learning about the neural mechanisms behind tinnitus, and was wondering if someone could help me to name the parts of the brain on the image below from a site of the University Liege that show increased activity in tinnitus sufferers.

From what I understand, the large area showing increased activity is the auditory cortex in the temporal lobe, although my knowledge of brain anatomy is not good enough to identify the others (though I have tried!)

**What are the names of the areas showing increased activity for the tinnitus group in the above image?**

# Answer
> 1 votes
I wasn't able to find the exact figure in the literature or in the webpages you linked, but the pages you link include a web page with references, including a PLOS paper from the University of Liege on tinnitus that is closely related to your current question and from a group affiliated to the same academic institution (Maudoux *et al*., 2012).

This paper includes Fig. 1 below obtained from tinnitus patients and a group of controls where they found the following structures to be involved in altered (either increased or decreased) baseline connectivities (numbers correspond to Fig. 1, the ones indicated with '(-)' showed less activity, the others more):

1. Brainstem/Cerebellum
2. Basal ganglia/NAc
3. Parahippocampal gyri
4. Superior temporal gyrus
5. Orbitofrontal cortex
6. Prefrontal cortex (-)
7. Prefrontal cortex
8. Superior frontal gyrus (-)
9. Inferior frontal gyrus
10. Fusiform gyrus (-)
11. Superior temporal gyrus (-)
12. Postcentral gyrus
13. Precentral gyrus
14. Cuneus/Precuneus (-)

Which of these 12 areas exactly correspond to the ones in your figure, I don't know. Because the ones in your Fig. are colored red, they very likely correspond to increased activities in their connectivity, so areas 1-5, 7, 9, 12 and 13 would be logical candidates.

Fig. 1. fMRI scans showing increased (red) and decreased (blue) connectivity in the auditory resting-state network in tinnitus. source: Maudoux *et al*. (2012)

**Reference**
**-** Maudoux *et al*. PLOS One (2012); **7**(5): e36222

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Tags: neuroscience, neuroimaging, neuroanatomy, hearing
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# Question
Title: Reference for a particular anecdote about the cultural basis of the ethics of homicide
I recently had a conversation with a friend about the psychology of ethics, and it reminded me of an anecdote that I read perhaps 10-15 years ago. The anecdote supposedly originates in the anthropology literature, but I couldn't find an anthropology SE, so I am hoping that someone here will have encountered it. I'm looking for either a reference or perhaps a similar anecdote that does have a reference. If the story can be identified, I'm also interested in how credible the story is (i.e., if there is any known criticism or dispute about it).

I just want to point out in advance that I have no formal training in psychology or anthropology and that I have only read popular literature on these subjects.

I recall picking up a book in a bookstore and reading most of a chapter that was devoted to the idea that most ethical concepts that modern westerners would consider "self-evident" are not universal and are certainly not considered self-evident in many other cultures. One big part of this is the in-group/out-group distinction, where many ethical rules are only considered applicable to the in-group.

As an extreme example, the book related the following story, which comes from an anthropologist who studied the Inuit (or perhaps another Arctic people):

There was a band of Inuit people who were out hunting in a remote area. Some tragedy occurred, and one member of the band died. (I think the tragedy was natural, not human-caused.) Everyone grieved for several hours. Then, in the night, one of the men stood up and shouted, "Shall we suffer, or shall others suffer!?" Four or five of the men got together and went off searching the wilderness for other people. They found a tiny hunting party of strangers, who were all asleep. Then they killed them all. This raised their spirits and they went back to their camp. When questioned, they did not consider this to be ethically problematic at all.

(This retelling is based entirely on my faulty memory.)

I was deeply skeptical of the story when I first read it, but I was also open-minded enough to take it seriously. It is trivial to find examples throughout history of atrocities that are committed against a dehumanized outside group, which lends credence to the argument that humans generally consider ethical prohibitions to only apply within one's own group. It's also conceivable that one's in-group could be small enough that strangers are automatically excluded.

Please let me know if you have read this (or anything similar enough) before and can provide a reference and/or criticism.

# Answer
> 3 votes
I finally had some time to Google this again, and I found the source. The most popular source of this seems to be Ruth Benedict's paper in *J. General Psychology*, **10**, p. 59-80 (1934). Long excepts from it can be viewed without a paywall here.

I think that the original source is from Franz Boas's anthropological work on the Kwakiutl (one group of Kwakwaka'wakw people) from roughly 1895-1920. For example, he published *The Kwakiutl of Vancouver Island* in 1909.

Here is Benedict's retelling of the story:

> Among the Kwakiutl it did not matter whether a relative had died in bed of disease, or by the hand of an enemy; in either case death was an affront to be wiped out by the death of another person. The fact that one had been caused to mourn was proof that one had been put upon. A chief’s sister and her daughter had gone up to Victoria, and either because they drank bad whiskey or because their boat capsized they never came back. The chief called together his warriors. “Now, I ask you, tribes, who shall wail? Shall I do it or shall another?” The spokesman answered, of course, “Not you, Chief. Let some other of the tribes.” Immediately they set up the war pole to announce their intention of wiping out the injury, and gathered a war party. They set out, and found seven men and two children asleep and killed them. “Then they felt good when they arrived at Sebaa in the evening.”

(My memory was pretty good, except for mixing up the Kwakiutl with the Inuit.)

For some context, there is a passage from Benedict's *Patterns of Culture* (available here) describing why this is true in Kwakiutl culture. (As in my question, I don't take this completely at face value, but it does seem to be accepted by the anthropological community.)

> The Kwakiutl recognized only one gamut of emotion, that which swings between victory and shame. ... The Northwest Coast carries out this same pattern of behavior also in relation to the external world and the forces of nature. All accidents were occasions upon which one was shamed. A man whose axe slipped so that his foot was injured had immediately to wipe out the shame which had been put upon him. A man whose canoe had capsized had similarly to ‘wipe his body’ of the insult. People must at all costs be prevented from laughing at the incident. The universal means to which they resorted was, of course, the distribution of property. It removed the shame; that is, it reestablished again the sentiment of superiority which their culture associated with potlatching. All minor accidents were dealt with in this way. The greater ones might involve giving a winter ceremonial, or head-hunting, or suicide. ...

> The great event which was dealt with in these terms was death. Mourning on the Northwest Coast cannot be understood except through the knowledge of the peculiar arc of behavior which this culture institutionalized. Death was the paramount affront they recognized, and it was met as they met any major accident, by distribution and destruction of property, by head-hunting, and by suicide. They took recognized means, that is, to wipe out the shame.

(Here, "head-hunting" refers to what modern westerners would call "murdering random people," as in the story above.)

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Tags: social-psychology, reference-request, cross-cultural-psychology, ethics, anthropology
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# Question
Title: How to calculate Fano Factor for spike train data?
I've heard this used many times but never had to do it myself. How does one calculate Fano Factor (FF) for spike train data?

Let's say that you have for some neuron the spike count in a certain time bin dt and a given trail n to be y(n,t).

I know that FF = var/mean, but should the variance be computed across trials or across time points?

In other words, can I first take the mean across trials y\_mean(t) = mean(y(n,t)) and then FF = var(y\_mean(t))/mean(y\_mean(t))?

OR

do I take the mean across time first y\_mean(n) = mean(y(n,t)) and then FF = var(y\_mean(n))/mean(y\_mean(n))?

OR

you take a FF for each time point across trials?

Thanks!

# Answer
> 2 votes
Frequently, Fano Factor is calculated across time points: it is a measure of the variability in the spiking of a particular neuron. For example, interneurons will frequently have lower Fano Factor than principal neurons.

As Bryan mentions in the comments, you may also be interested in the variance across trials, depending on the question that you are interested in.

*EDIT:* To answer questions from your comment on my answer:
No, you do not want to look at the Fano Factor of the ISI distribution. The ISI distribution of a Poisson process is exponentially distributed, not poisson distributed. The mean and variance of an exponential distribution are not the same (https://en.wikipedia.org/wiki/Exponential\_distribution).

You want to use bin sizes where you expect a small but non-zero number of spikes in each bin.

If a neuron is Poisson with a non-varying spike rate, then it shouldn't matter whether you look over time or over trials. Most neurons have spike rates that vary in response to some value that the neuron is representing (inhomogeneous poisson process). In that case, you want to isolate the time periods for which you expect the poisson process has a constant rate. That may be a certain time period within a trial, or it may be across an entire trial. That is where Brian's suggestion of being specific about what question you are actually asking comes into play.

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Tags: neuroscience, electrophysiology
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# Question
Title: How reliable is this self-administered Mensa IQ test?
I found a Mensa challenge test, which can be taken for free on the Mensa website and involves answering 35 problems within 25 mins. They do mention that it is only for entertainment purposes, but people on Quora seem to suggest that it gives an accurate ballpark score.

Is it really accurate?

How is it different from an IQ test administered by a trained psychologist?

# Answer
You linked website states also that

> But, if you're pleased with your score, you might want to consider taking a properly administered and supervised IQ test.

A formal IQ test is supervised by a trained psychologist who will not only keep track of your performance, but also *how* you reach that goal. There are many aspects of an IQ test, including working memory, analytical skills, logical thinking, but also verbal skills. Verbal skills can for instance be asked with open questions and the way people answer will affect outcomes of the test. For instance a 'describe the following words' test; people that will give examples of the words will automatically score less well than those that can give accurate descriptions not only consisting of examples of the word at hand, but will include unifying, overarching definitions or synonyms. **Computers** cannot really do this and **cannot replace a trained psychologist**.

Also, **people may have questions on a test** and without having that particular question answered prior to starting the test, they may be distracted from the test itself, not knowing what is exactly the purpose of the task at hand. Computers cannot easily replace a human being that can listen and interpret the questions. The questions themselves may also hold implications.

The **psychologist will also assess** whether the **participant is nervous, anxious, tired, easily distracted or otherwise has a handicap that will interfere with performance**. Computers cannot assess this easily, especially not online.

For these reasons formal, guided IQ tests are performed with a psychologist. When the averaged IQ outcome is not a representative reflection of the various sub-IQs (analytical skill set, verbal skill set, processing speed, general knowledge *etc. etc.*) this can be due to various reasons, one of them being widely varying scores on different tests. For instance, when some of the tests are being performed excellent/near perfect, while others are way below average, *i.e.*, there are h**uge discrepancies being the various sub-IQ outcomes, it is a red flag** and can point toward **underlying reasons those underperformed tests failed** to meet up with the others, and are reason for **further/deeper follow-up psychological testing** as too the underlying reasons for the discrepancies. in other words, **overall subscores generally agree to an extent; if they don't, the overall IQ outcome may not be valid**. A simple online test will simply average the sub scores and present the average. **A formal test can easily take the psychologist weeks to assess and interpret**.

The Wikipedia page for instance says:

> Outside influences such as low **motivation** or high **anxiety** can occasionally lower a person's IQ test score. For individuals with very low scores, the 95% confidence interval may be greater than 40 points, potentially complicating the accuracy of diagnoses of intellectual disability.
> 2 votes

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Tags: cognitive-psychology, learning, iq, reliability
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title: Why children dreams aren't distorted?

text:
# Question
Title: Why children dreams aren't distorted?
I'm reading a general introduction to Psychoanalysis and in the eight lecture Freud starts saying that children dreams aren't distorted so they are easier to analyze. Do all children dreams are straightforward? and also why they don't distort the dreams like adults do.

# Answer
> 2 votes
In response to comments by @BryanKrause in my answer in meta, backed up with many citations, I pointed out that Freud did take a scientific approach, and his resulting work was not guesswork. It's just that it was not scientific in the pure sense, just like pretty much any psychology, for good reason, as you can find out in the answer linked.

Freud talks of Distortion in the sense that dream wishes are distorted in dreams by a "censor". That a dream is the *disguised* fulfilment of a *repressed* wish. So, when Freud said that children's dreams aren't distorted, he was saying that children's dreams were not distorted because they don't have any repressed wishes.

One thing I will say is that dream analysis is definitely not accurate and is just a tool to work out possible areas for discussion etc. after careful examination with the client. An example of dream interpretation in a Freudian sense can be seen in my meta answer.

I voted to close this question, because while I am a defender of Freudian and Neo-Freudian psychology, I would have to concede that dream analysis is pseudoscientific because the theories are not accurate and only serve as estimates.

It would be different if the question was along the lines of "How did Freud determine....?" as that can be answered more correctly than the question you posed.

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Tags: dreams
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# Question
Title: Name of cognitive bias that causes experts to overestimate their ability in other areas?
Is there a name for a cognitive bias that causes people who have been successful in one area to be overconfident in their level of knowledge / ability in another unrelated area?

It's related to the Dunning-Kruger effect, but I'm specifically referring to the case where the overconfidence comes as a result of having been successful, and feeling as if that success makes the person qualified to have strong opinions on all matters, even when at odds with experts in that field.

# Answer
> 8 votes
The Dunning-Kruger effect is specific to expertise in a particular domain. The domains tested in the original studies by Kruger & Dunning (1999) are: humor, logical reasoning, and English grammar.

It is fully possible to underestimate your skills in one domain in which you are an expert, and overestimate your skill in another in which you are a novice. As per an interview with Dunning, published at Vox.com:

> But there are a couple things that people get wrong that are major.
>
> The first is they think it’s about them \[i.e., others\]. That is, there are those people out there who are stupid and don’t realize they are stupid.
>
> Now, those people may exist, and the work isn’t about that. It’s about the fact that this is a phenomenon that visits all of us sooner or later. Some of us are a little more flamboyant about it. Some of us aren’t. But not knowing the scope of your own ignorance is part of the human condition. The problem with it is we see it in other people, and we don’t see it in ourselves.
>
> **The first rule of the Dunning-Kruger club is you don’t know you’re a member of the Dunning-Kruger club. People miss that.**

Your description also seems related to a logical fallacy, namely appeal to unqualified authority, or appeal to false authority, typically categorized simply under appeal to authority:

> However, appealing to authority as a reason to believe something is fallacious whenever the authority appealed to is not really an authority in this particular subject, when the authority cannot be trusted to tell the truth, when authorities disagree on this subject (except for the occasional lone wolf), when the reasoner misquotes the authority, and so forth.

<sub> Kruger, J., & Dunning, D. (1999). Unskilled and unaware of it: how difficulties in recognizing one's own incompetence lead to inflated self-assessments. Journal of personality and social psychology, 77(6), 1121. </sub>

# Answer
> 1 votes
Duffx,

The cognitive bias that you are looking for is called the Overconfidence Bias. Your description exactly matches its symptoms. With this bias, *an expert* is more likely to be the victim of overconfidence. This overconfidence, however, is not within the expert's field but within a totally unrelated field in which both the expert and an average layperson have a similar lack of experience. (So, technically, both the expert and a layperson are both laypeople in this field.) For particular reasons, the expert believes that the prowess in their own field will translate over to or aid them with an unrelated field.

A special feature of the Overconfidence Bias is that the expert's overestimation of his abilities *increases* as the difficulty of the task increases. ie. The more difficult/complex the task is, the more confident the expert is that he can complete the task. Reversely, when the task gets easier, the expert still believes that he can accomplish the task better than an average layperson but his advantage is not as great.

Below is a passage from the Wikipedia page about the Overconfidence Bias which restates the above. https://en.wikipedia.org/wiki/Overconfidence\_effect

> The overconfidence effect is a well-established bias in which a person's subjective confidence in his or her judgements is reliably greater than the objective accuracy of those judgements, especially when \[their\] confidence is relatively high. "The Role of Individual Differences in the Accuracy of Confidence Judgments" The Journal of General Psychology. 129 (3): 257–299
>
> "The key finding is that confidence exceeds accuracy so long as the subject is answering hard questions about an unfamiliar topic."
>
> "This phenomenon is most likely to occur on hard tasks, hard items, when failure is likely or when the individual making the estimate is not especially skilled."

The above scenario may initially appear to be the Dunning-Kruger Effect because the expert is indeed a novice in an unrelated field and is overestimating his abilities like in the Dunning-Kruger Effect. However, with the Overconfidence Bias, the expert overestimates his abilities more than the average layperson does. Further, the harder the task, the larger the overestimation by the expert. This particular increase in overestimation will not occur in a normal layperson. As you can see, the Overconfidence Bias differs slightly but significantly from the Dunning-Kruger Effect.

# Answer
> 1 votes
Technically maybe not a "cognitive bias," but... "ultracrepidarianism"?

Wikipedia: "Ultracrepidarianism is the tendency for people to confidently make authoritative pronouncements in matters above or outside one's level of knowledge. Often, those pronouncements fall entirely outside the ultracrepidarian's realm of legitimate expertise."

"Another expression of ultracrepidarianism, as instantiated by those with an actual expertise in something, is the tendency to start treating all other fields as somehow being sub-categories to your own field."

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Tags: cognitive-psychology, perception, bias
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# Question
Title: What term can describe the feeling that a job just does itself?
Is there a term that can describe that a job, however exhausting it might be, just does itself? Meaning, for example, that all doubt concerning *how* you're doing a job, whether or not you *should* do the job instead of something else, or any doubt of the *value* you're creating is just not there?

As an example, I saw an interview where an author was asked how much effort it took to write a particular book. The answer was "No effort at all, the book wrote itself", which is of course not literally true, because it takes reasearch, time, dedication and long hard hours in front of a PC to write a book. Still, I understand what they mean by this, when looking back to certain efforts I've made myself. But I don't know if this can be described in full by a certain term.

I'm surprised how hard it was to find anything about this just googling, so any suggestions would be great!

# Answer
There is a mental state called flow, similar in ways to trance and absorption, in which mental focus is fully taken by one task. In the case of flow, the usual focus on a particular goal is replaced by focus on the task itself, losing both oneself and the future by entering fully into the moment and the action itself. In a way, one's state of being merges with the action, so as to become the action. From Wikipedia:

> In positive psychology, a flow state, also known colloquially as being in the zone, is the mental state in which a person performing some activity is fully immersed in a feeling of energized focus, full involvement, and enjoyment in the process of the activity. In essence, flow is characterized by the complete absorption in what one does, and a resulting transformation in one's sense of time.

Enjoyment of the activity stems from the experience itself, rather than from what one expects to gain as a result of the action. As such the activity is said to be *intrinsically* rewarding. Basically one has transcended worry and self-reflection, fully engrossed without question. From my experience, questioning the task can break the flow. From Wikipedia:

> Some of the challenges to staying in flow include states of apathy, boredom, and anxiety. The state of apathy is characterized by easy challenges and low skill level requirements, resulting in a general lack of interest in the activity. Boredom is a slightly different state that occurs when challenges are few, but one's skill level exceeds those challenges causing one to seek higher challenges. A state of anxiety occurs when challenges are high enough to exceed perceived skill level, causing distress and uneasiness. These states in general prevent achieving the balance necessary for flow.
> 4 votes

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Tags: motivation
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# Question
Title: What is the bandwidth of visual perception?
Approximately how much "bandwidth", in bits per second, can typical human visual perception process?

Consider "The Matrix", where we assume a near-perfect digital encoding that can reproduce any experience nearly perfectly, compressed with a digital intelligence beyond our own. Now they need to create a cable that plugs into our brainstem. How much bandwidth would that cable need to carry, in order to simulate full human visual experiences?

For auditory processing -- given all the effort in digital audio compression, it seems likely the answer is somewhere close to 256 kbps (256,000 bits per second), at least within an order of magnitude, give or take. But vision seems far more complex, and I can't find any study or near-approximation that seems plausible.

Presumably the answer is *somewhere* from 1 mbps (1,000,000 bits per second) to 1,000 times that amount. A naive approach would be what is the theoretical bandwidth to create any arbitrary video, to the fidelity where human perception could not distinguish differences. However, this is so grossly far from accurate that I suspect it is almost meaningless. I am relatively aware that our visual and auditory processing compress and transform the inputs we perceive, leading to optical illusions etc, which would suggest a much lower number than we might otherwise expect.

# Answer
> 2 votes
> From these recordings, the researchers calculated that a guinea pig retina transfers data at about 875 kilobits per second. Human retinas have about ten times as many ganglion cells, giving a “bandwidth” of 8.75 megabits per second.

Read more: https://www.newscientist.com/article/dn9633-calculating-the-speed-of-sight/#ixzz7Ig3MCMrR

Source Paper: (Open access)
Koch, K., McLean, J., Segev, R., Freed, M. A., Berry II, M. J., Balasubramanian, V., & Sterling, P. (2006). How much the eye tells the brain. *Current Biology, 16*(14), 1428-1434. https://doi.org/10.1016/j.cub.2006.05.056

# Answer
> 1 votes
Lets assume you cut the optic nerve and replace it by a computer. There are between 700,000 and 1,700,000 nerve fibers in the optic nerve (lets round it up to 1,000,000 for now). What the temporal resolution of your input should be is less clear. A typical sampling rate in physiology is 1ms so lets choose 1kHz. Then assuming that all you need to know if whether the fiber is carrying a spike or not (1 bit), that gives you a back-of-the-envelope estimate of 1gbps. Surprisingly small, a USB3 port could carry your signal. Furthermore you could theoretically compress that signal by quite a lot without noticeable difference considering the huge redundancies in the signal. So I would say a maximum of 2gbps and probably a lot less than that.

https://en.wikipedia.org/wiki/Optic\_nerve#cite\_note-5

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Tags: perception, encoding
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# Question
Title: Why do we "Freeze" in an Adrenaline Rush?
I heard that Adrenaline stimulates the "Fight-Flight-Freeze" reaction. This is because our brains still think that we are in the wild and there are lions that want to eat us.

But why is there a "Freeze" in the "Fight-Flight-Freeze"? If some of our ancient ancestors were attacked by lions, and they Freezed, they would be eaten by the Lion!

Why wouldn't have Natural Selection filtered out the "Freeze"?

# Answer
The freeze response is still there for a reason. One hypothesis for its adaptive value is that in cases where the probability of either winning the fight or successfully escaping is believed by the subject to be too small, staying still, i.e. freezing, improves the outcome. Indeed, moving may elicit additional attacks from a predator, while immobility may cause the predator to believe the prey is dead and let it loose, providing a better chance of escape. This paper examines the freeze response and links to other relevant research.
> 2 votes

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Tags: behavior
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# Question
Title: What are the ways to measure stress levels regularly at home?
What methods are available for collecting data on a human's **stress levels**?

That is, suppose someone wanted to collect weekly/daily/hourly readings of their stress levels (e.g. in order to use the data to correlate with their activities, reporting, or other reasons) - what methods could someone use?

Such data could be very useful for those overcoming chronic stress.

# Answer
> 1 votes
**TL;DR: measure your 'Heart Rate Variability' with a smartphone app or wearable device**

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The longer answer is more complicated. This meta analysis suggests:

> At present, there is no accepted standard for stress evaluation.

## Biometrics

**Heart Rate Variability**

This study concluded that:

> the current neurobiological evidence suggests that HRV is impacted by stress and supports its use for the objective assessment of psychological health and stress.

So Heart Rate Variability *could* be a useful biometric indicator. However, this study says that *many* things can cause high HRV:

> stress, poor sleep, unhealthy diet, dysfunctional relationships, isolation or solitude, and lack of exercise

so it's possible your HRV could go up independent of your stress levels (so use with caution).

Harvard Health suggests how to measure HRV:

> The gold standard is to analyze a long strip of an electrocardiogram done in the doctor’s office. But in recent years, companies have launched apps and wearable heart rate monitors that do something similar.

**Other biometric indicators**

The University College London measured stress levels in experiment participants by using:

* Pupal dilation
* Perspiration

so these *may* be possibilities too.

## Perceived Stress Scale

There is an old fashioned way... the Perceived Stress Scale was:

> published in 1983, and has become one of the most widely used psychological instruments for measuring nonspecific perceived stress. It has been used in studies assessing the stressfulness of situations, the effectiveness of stress-reducing interventions, and the extent to which there are associations between psychological stress and psychiatric and physical disorders.

Here's a copy of the actual test. The result can be interpreted with detailed scoring:

or, using these rules of thumb:

> ► Scores ranging from 0-13 would be considered low stress.
>
> ► Scores ranging from 14-26 would be considered moderate stress.
>
> ► Scores ranging from 27-40 would be considered high perceived stress.

It looks like a test you would take approximately monthly.

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Tags: measurement, stress
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