# Question
Title: Cognitive Models of learning Working Memory usage
Recently in deep learning, there's been a surge in learning how to use memories as part of the optimisation process (i.e. LSTM's and Stacks). However, these aren't really analogous to how a cognitive systems learns how to use it's working memory.

Are there models of how working memory modules (where a saved value decays over time) can be learned to be optimally leveraged? Either via reinforcement learning or supervised learning?

# Answer
ACT-R is a complete cognitive model that incorporates Working Memory, Declarative Memory and Procedural Memory, but also incorporates input (visual and auditory) and output (manual) buffers. It is a really interesting model about the human in its entirety but, it is at a high level of abstraction.

The paper about memory you want is "REFLECTIONS OF THE ENVIRONMENT IN MEMORY" by Schooler and Anderson. It describes how and why memory is like Reïnforcement learning. In this paper you can read how memory is used for studying. About learning to leverage the working memory, I don't exactly know what you mean, but I think these papers give you a nice headstart.

If you want to learn more about ACT-R, I would recommend this book, or just read the many papers they have published over the years. They have great examples that explain multitasking and time perception among others.
> 2 votes

# Answer
I could only find a single instance of learning to leverage a memory. "The Origin of Epistemic Structures and Proto-Representations" by Chandrasekharan and Stewart shows how to include the option to save the current state (by training a neural network to output '1' given the current state input) and input this memory into the state representation of a reinforcement learning task. In the paper, this method allows an agent to switch between foraging and returning home.

Frustratingly, checking the citations of this paper leads to a dead end, so further references would be greatly appreciated.
> 1 votes

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Tags: memory, reference-request, cognitive-modeling, reinforcement-learning, short-term-memory
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# Question
Title: In SPSS, should you change the significance level for One way ANOVA post-hocs?
When running a one-way ANOVA, selecting "Post-hoc" and ticking "Bonferroni":

There is a box at the bottom which says "significance level" and the default is 0.05.

My question is: should I leave the default value (assuming SPSS adjusts accordingly) or change the value to 0.05/k (k groups)?

# Answer
> 3 votes
Leave it at 0.05 . SPSS corrects it properly. Only when you want to test with different alpha's (.10 or 0.01 e.g.) you should change it.

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Tags: statistics
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# Question
Title: Is there a technical term for someone being burnt out on something they enjoy?
What I mean is like how one might tire of a typical everyday activity they enjoy if they indulge in it too much, like how if you listen to your favorite album too many times you eventually won't be able to enjoy it anymore. I guess this would also be analogous to how addicts develop a tolerance to their drug of choice.

I figure it is an interesting phenomenon that must have a very large affect on our behavior patterns so there must be a technical term for it. I wanted to know so I can look into any research there has been on it.

# Answer
> 4 votes
There is no specific term for this *entire* phenomenon because there is more than one psychological theory playing a role in your overindulgence or "binge". Fatigue from repetitiveness, durability bias, and habituation all play a huge role in determining how long you can listen to a certain song before its gets repetitive and boring. On the other hand, tolerance from substance abuse has its own special term: Drug Habituation. You would be best off searching scholarly journals using the keywords fatigue and habituation.

Further Reading:

https://en.wikipedia.org/wiki/Habituation http://changingminds.org/explanations/theories/durability\_bias.htm

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Tags: cognitive-psychology, terminology, addiction
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# Question
Title: Group differences reflecting different use of a rating scale vs actual difference in perception
I was reading a paper that reports average ratings of chords by two different groups of subjects (trained musicians, and non-musicians).

The paper makes the argument that "These group differences may reflect either the manner in which the two groups of subjects used the rating scale or in their perceptions of the chords."

Obviously, one would hope that the latter is the case rather than the former, although from this graph one can't be sure since error bars, which would be very informative in this case, are not shown. My question is: is it correct to say that the answer to this question can be given if one compares the variances across groups, e.g.with Levine's test? And that, if found to be unequal, one can argue that the group difference reflects an artefact, i.e. a difference in the way the two groups of subjects used the rating scale?

# Answer
> 2 votes
I indeed think that it is not possible to conclude that the scales are used differently, based on variance alone. Normally one would assume the scale is used properly and the effect you see is indeed the result of (not) having a trained ear.

There do exist ways to investigate how one uses a subjective scale. In a paper I presented, we looked at how people interpreted a subjective workload scale. This scale contained verbal descriptors that conveyed a particular amount of workload, and this amount was estimated by the participants. This scale was designed to be linear and cover workload from "no workload" to "work too demanding". Therefore, we would expect a linear line that starts at 0 (no workload) to 150 (complete overload; we used 150 instead of 100). The results indeed confirmed this and the groups perceived the items on the scale similarly.

So far, the method is kind of similar to your paper. The difference is that we gave the participants anchor-points to help them rate the items: The zero-point (no workload) and the 150-point (complete overload). This way the participants had the same reference points, which should enable them to use the entire range, regardless of their experience or something.

You could also use these anchor points to see how consonance ratings differ. Let them listen to a perfect dissonant and a perfect consonant tone and say they are rated zero and ten respectively (or something like that). If the two groupsc rate the sounds similarly now, they have probably interpreted the scale differently before. However, if you still find the same difference as before, it may suggests that untrained musicians can indeed not distinguish the sound very well (and the scale was interpreted properly before).

# Answer
> 1 votes
No, I don't think so . Greater variance could reflect variance in perception just as much as variance in the way the rating scale is used.

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Tags: experimental-psychology, statistics
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# Question
Title: Can reading a non-fiction book with great curiosity account to taking a break?
In our day to day life, especially at work(in Office say a software company), due to the nature of work, it requires a lot of attention and deep involvement in the system/code. It is popular belief that taking breaks increases one's productivity.

Considering that in order to take a break, a person spends 30 minutes reading a non-fiction book, on his/her favorite topic, totally unrelated to office work, will it account to taking a break. Or due to the huge context switch, will it actually lead to more curiosity and distraction from office work and affect productivity inversely?

# Answer
> 1 votes
A lot depends on your definition of what constitutes 'a break'. Many are likely to argue a break involves relaxing, a 'fun' pastime, which in another question on this site has been discussed to be beneficial for the work environment **in the case of social activities**:

> ..., having fun at work was perceived to positively influence workplace relationships to a moderate-high degree, contribute to managing stress to a moderate degree, improved job satisfaction to moderate degree **and was reported to have a little more than neutral, direct impact on workplace effectiveness**. These outcomes must however be examined in the context of results, suggesting not only are different types of fun activities enjoyed more, but different types of activities are highly salient in relation to the particular organisational variable measured.

However, these results do not seem to generalize to your scenario, as you seem to be more interested in taking a break from ongoing work and potentially switching to other **mentally demanding individual** work.

Therefore I believe the following study on **multitasking**—the interleaving of several primary tasks—which are executed one at a time) by Adler and Benbunan-Fich (2012) measures results more in line with what you are after.

> Our results show an inverted-U pattern for performance efficiency (productivity) and a decreasing line for performance effectiveness (accuracy).

There is thus an optimal amount of task switching which leads to the highest productivity. However, increased levels of multitasking lead to a significant loss in accuracy, indicating a trade-off between productivity and accuracy.

These results thus seem to confirm that in at least the context of the study **switching to a different task can improve productivity**, in line with increased effectiveness when taking 'a break'. To which degree (and if at all), however, will depend highly on the specific tasks and work environment. For example, a follow-up study by the same authors (Adler and Benbunan-Fich, 2015) shows that **subjective task difficulty is a determining factor**: easy tasks benefit from multitasking by increasing stimulation, whereas hard tasks decrease performance as the result of an overload in mental workload.

<sub> Adler, R. F., & Benbunan-Fich, R. (2012). Juggling on a high wire: Multitasking effects on performance. International Journal of Human-Computer Studies, 70(2), 156-168.
Adler, R. F., & Benbunan-Fich, R. (2015). The effects of task difficulty and multitasking on performance. Interacting with Computers, 27(4), 430-439. </sub>

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Tags: io-psychology, reading
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# Question
Title: Would Artificial Super-Intelligence From Science Fiction "Speed Up" The Brain and Wear it Out Faster Leading to Earlier Death?
In stories such as Flowers for Algernon by Daniel Keyes, the main character, Charlie Gordon, receives an operation on his brain that triples his intelligence.

Could something like this be achieved if the brain is somehow sped up and forced to do more in less time? And wouldn't something like this cause the brain to deteriorate rapidly from being "worn out" by so much use?

I found in this article that as the brain ages, it will shrink and will have larger fissures in it. In the story, after what seems to have been a short life, the mouse dies and is dissected. The mouse's brain is found to have much larger fissures and have shrinked.

Is this wearing out or aging of the brain due to increased activity by surgical means accurate in any way?

# Answer
> 1 votes
Our brain runs on a series of chemical and electrical reactions running at a stable pace. Unlike computers, you cannot "overclock" the brain into running these reactions any faster than normal. However, if we were to assume the psuedoscience to be true, it would be logical for the brain to undergo premature death. With the rates of these reactions increased you would see the rate of DNA mutations increase along with the amount of oxidative stress. All of which are causes of cancer and cell death.

How to actually improve cognitive function: http://m.wikihow.com/Increase-Your-Brain's-Processing-Speed

# Answer
> -1 votes
I've seen this TED talk that suggests that cooking allowed humans to ingest more calories in a given day by "pre-digesting" food using fire. This caused "rapid" evolutionary increases in brain size. The talk suggests that gorilla brains are small because they spend almost entire day eating low calorie food and don't have spare energy to devote to brain development.

In the modern age, 50000 calories from sugar costs less than 10$. The definition of "binge eating disorder" is eating 5000-15000 calories in one sitting. From this point of view, the modern man has plenty of energy to dedicate to "overclocking" the brain.

Frequently used neuronal networks develop Myelin sheath, which increases nerve impulse propagation speed. Apparently training a specific move in sports causes myelin sheath to develop around the responsible neural network, causing increased performance. I'm not aware of negative side effects of myelination process.

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Tags: intelligence, aging
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# Question
Title: Is the Resting Potential and Action Potential Thresholds the same across all neurons in a network?
Does the action potential and resting potential of a given neuron differ from another neuron within the same network or is it constant? If not what determines and affects these potentials and can they change overtime? If so what factor contribute to this change and how?

# Answer
> 4 votes
In short no. The speed at which and Action Potential (AP) occurs, resting membrane potential, and threshold to AP all vary across types of neutron. See the graph below (Bean, 2007)

The reasons for these differences are various, as you will see if you read the referenced article, which I highly recommend as everything I write from here is based upon it. The main factors influencing AP differences are firstly that the classical AP diagram is based on an isolate squid giant axon (not neuron) in a superficial environment.

When we investigate neurons in mammals we investigate them relative to surrounding neurons, which influences chemoelectric potentials and subsequently APs. Furthermore neurons aren't uniform in shape which also has an influence. Secondly voltage gating varies within and between ions gates in the neural membranes for instance "the kinetics of sodium currents differ in detail between different types of neurons62 and, remarkably, even between different regions of the same neuron, with sodium channels in hippocampal mossy fibre boutons (formed by the axons of granule cells of the dentate gyrus) inactivating twice as fast as the sodium channels in the granule cell sonata" Bean (2007). Potassium channels appear to lack uniformity as well. See below for difference in voltages across ion channels between neurons.

And there are other factors as well of course, such as frequency of activation influencing voltage required to depolarise. Depolarisation rates, and differences between fast spiking neurons, such as purkinji, and others.

Overall the brain is not uniform, despite what you may learn or have learnt in text books in classes. This is done to ease learning, can you imagine trying to learnt this without the basics? However this fundamental research has important implications for neural imaging, psychopharmatuics, and of course cognitive processes such as speed of processing etc.

In case you can't access the reference... The referenced journal article is a brilliant review in nature about this exact topic, its called "The action potential in mammalian central neurons" By Bruce P Bean

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Tags: neural-network
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# Question
Title: Paul Ekman suggests that in near-accidents, fear motivates people to hit their car brakes. Is the fear response fast enough to do this?
> Recall a time when you were driving your car and suddenly another car appeared, going very fast, seeming as if it were about to hit you. Your conscious mind was focused on an interesting conversation with a friend in the passenger's seat or the program on the radio. In an instant, before you had time to think, before the conscious, self-aware part of your mind could consider the matter, danger was sensed and fear began. As an emotion begins, it takes us over in those first milliseconds, directing what we do and say and think. Without consciously choosing to do it, you automatically turned the steering wheel to avoid the other motorist, hitting the brake with your foot.

Paul Ekman writes in "Emotions Revealed: Recognizing Faces and Feelings to Improve Communication and Emotional Life" that in near-accidents people hit the brakes because they feel fear.

Is the fear response fast enough to do that or do people first hit the brakes and then switch to an emotional state of fear?

# Answer
*This was much longer than I expected! There's quite a bit of ground to cover, but I try to go over it quickly.*

So, there are two implicit theoretical assumptions in your question:

1. We have an "affect program" for fear in our brain (e.g., Ekman & Cordaro, 2011). When the fear program is activated, a specific pattern of changes in experience, behavior, physiology, and cognition occur (i.e., the fear response).
2. Present emotions are the primary causes of future behavior.

I'll briefly examine these assumptions, and then I'll draw a conclusion.

## Assumption #1: Affect programs

By "affect program" I mean a discrete module or circuit in the brain that, when activated, automatically produces a fear response. So if I see a car about to hit me, it might activate my fear program, which will produce my fear response.

**Your question uses this assumption by asking about the speed of the fear response.** How fast can my fear program activate my fear response (which would motivate me to hit the brakes)? Does my fear program trigger a response too slowly, such that my fear response will occur after I hit the brakes?

In recent years, the "affect program" idea has been called into question (e.g., Barrett, 2006; Lindquist et al., 2012). As it stands, it's a fairly controversial assumption that I would argue has iffy empirical support and explanatory power.

If there isn't a "fear program," then what is there? Well…that's tricky. I could get into a whole lot of theory, but that would take up a lot of space (although if you're interested, see Satpute, Wilson-Mendenhall, & Barrett, 2015). **I think the point that I want to make is that it's difficult to talk about the speed of the fear response.** Without having a consensual definition of "emotion," we can't talk very easily about the nature of fear (i.e., what it is, what it looks like, when it begins, when it ends, its function, its neural basis, its evolution, etc.).

## Assumption #2: Present emotions cause future behavior

The idea that fear causes me to run away, that anger causes me to approach, or that sadness causes me to withdraw seems very intuitive. In fact, despite its mixed empirical support, many researchers seem to accept this idea without reservation.

On the other hand, Roy Baumeister and colleagues have argued that present emotions affect future behaviors indirectly (Baumeister, Vohs, DeWall, & Zhang, 2007). In fact, they argue that behavior tends to follow emotions, not the other way around.

To make a long story short, **Baumeister argues that *anticipated emotions* are the more direct causes of present behavior.** So If I anticipate feeling relieved as a consequence of hitting the brakes, then I will hit the brakes. That is, I will hit the brakes because this will lead to future relief. My fear is not motivating this behavior; instead, my expectation of relief is. Indeed, a recent small-scope meta-analysis supports this theory (DeWall, Baumeister, Chester, & Bushman, 2015)

## Conclusion

So I made things pretty complicated! I posed two questions:

1. Can we meaningfully talk about the speed of the fear response without a consensual definition of emotion?
2. Do present emotions cause future behavior (e.g., fear causing me to hit the brakes)?

My answers to both questions were ***no***. However, I think if we ignore the yuckiness of the first question, we can say that **fear probably doesn't cause us to hit the brakes**, but rather the expectation of relief does (or some other anticipated feeling).

When and how quickly the fear response occurs during this situation is hard to answer (but can be resolved somewhat depending on your theoretical perspective). If we assume that emotions are multi-componential, then we might imagine that the *experience* component need not occur at the same moment as the *behavioral* component (mirroring studies of emotion coherence, e.g., Mauss et al., 2005). **Thus, the experience of fear could (hypothetically) occur before or after the braking behavior.**
> 11 votes

# Answer
I think we can respond to something reflexively long before fear has a chance to happen. If you almost stumble, your body responded, perhaps even by spinal reflex, before the "news" had even reached your brain. Walking is conditioned by years of practice, including practice almost falling. We get better and better at not falling, otherwise things like skating or riding a unicycle would be impossible. Driving builds on the same sensory and motor mechanisms as walking: We see threats and feel conditions which trigger the appropriate correct responses by reflex.

Have you ever wondered why when you are poked by something sharp you *always* move away from it, never drive it into your body? Almost magic. Reflex. Anything involving locomotion works the same way. People with experience in momentum-altering activities like skiing respond better to loss of traction when driving a car. (So it is fortunate that most of the skiers live in areas where the roads get snowy! What a useful coincidence!)

So, fear doesn't even enter the picture until you are already starting to respond, unless you have no reflexes in place to get triggered, like being on a roller coaster or while someone else is driving. I was driving a boat once when I started to notice an object ahead in the dim glow of the red-green forelight. It was about 20 feet away (a small part of a second) and as I was peering at it in perplexity my hands had *already* turned the wheel hard over and the boat went up on its side. Meantime, I had four separate verbal thoughts at once, one of them about the huge meteor streaking across the horizon ahead at that very moment. By the time I felt any fear, I had stopped the boat and was looking over the side for a hole (which was not there, fortunately).
> 0 votes

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Tags: emotion, motivation, fear
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title: Is there a way to make a DIY EEG?

text:
# Question
Title: Is there a way to make a DIY EEG?
I have MATLAB. I would like to try out a small EEG project because my field of interest is in neuroscience, however I'm still doing my undergrad.

# Answer
> 12 votes
The OpenEEG project has some information for building your own EEG system. Instructables has a "simple" EEG circuit you can build. Note that this is going to be somewhat costly and time consuming because you are dealing with tiny voltages and high impedances.

OpenBCI has some hardware for sale (still expensive but not as bad as research-grade equipment) and their forum can be helpful for the DIY EEG enthusiast.

You also might want to look into utilizing some existing publicly available EEG datasets instead of collecting the data yourself:

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Tags: eeg, electrophysiology
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# Question
Title: Is it possible that people perceive time differently than others do?
All of my life I have been told to be more patient, to stop "racing through life", etc. Happily, I am finally mature enough to accept that as solid advice, but I am curious as to whether it is possible that I perceive time differently than others do.

Today, for example, I was stuck at a red light in traffic on a road that was three lanes wide. I was in the second row of cars that were stopped at the intersection. When the light turned green, it seemed to me like 10-20 seconds elapsed before any of the three cars in the first row began to move forward. Obviously, it is unlikely that all three cars in the front row reacted this slowly--hence my question.

# Answer
## Short Answer

Yes. People estimate time differently, by focusing their attention on time in more or lesser degree. Also within a person, time estimation may vary due to stochastic variations.

## Long answer

This is a really nice paper that tries to explain time-perception in a cognitive architecture called ACT-R. It is a model of human cognition that tries to explain human behavior with only basic functions (declarative and procedural memory, vision, working memory a.o.).

Very shortly, the model is as follows: There is a pacemaker. This pacemaker creates pulses that are counted and saved in memory, and this memory is coupled to a particular time-frame. Each time you start counting, you reset the pacemaker to zero. So, for instance, after some practice, you learn that five seconds consists of 23 pulses, and eight seconds is equivalent to 30 pulses.

The pacemaker has two properties however. First, the pacemaker is not perfect. There are minor variations in the duration of each interval between the pulses. Five seconds may thus sometimes be perceived as 22 pulses and sometimes as 24 pulses. This is the reason variability exists in time estimations.

Secondly, the duration of intervals between pulses increases over time. Where the time between a pulse may be 200 ms (+- random value) when you start to count, it may be 400 ms (+- random value) after ten seconds. On top of that, the effects of random noise also becomes larger. If you count the pulses, the precision of the counting will thus decrease. Therefore it is increasingly difficult to estimate longer periods of time as compared to shorter periods of time. In figure 2 in the paper, this is depicted with the increasing width of the normal distributions.

**Attention** So far I have only explained how one person may perceive time differently due to stochastic differences in pulse productions. What I left out so far is the attentional component of the model. When you focus your attention on the pulses your estimates will be rather good, because you perceive these pulses more consciously. However, as anyone may know, "time may fly" (when you're having fun). This is believed to be caused by the lack of attention to the pulses, therefore being unaware of how time passes. It is however not entirely clear how this attentional component works, and the debate is still ongoing.

## Neuro-biology:

The model was based on a paper written by Mattel and Meck (2004), which provide a neuro-biological explanation for the pacemaker. The model they propose is the "striatal beat frequency model", which states that there is neuronal activity oscillating at different rates in different networks of neurons. The oscillations are then detected by Striatal Spiny Neurons, which result in a sort of "barcode"(i.e. an array neurons being active and inactive; see Figure 1A). It is these barcodes that are memorized and associated with a particular duration (See Figure 1B).

*Figure 1: Striatal beat frequency model. Picture taken from Researchgate*

As mentioned earlier, the pacemaker needs to be reset when you start counting from zero. It is theorized that this is done by a burst of dopamine.

Here is a review about the neural pathways for time-estimation by Buhusi and Meck (2005). My neuro-biology is a little rusty though, so if there is anyone that could comment/elaborate on this, that would be highly appreciated.

## References

Buhusi, C. V., & Meck, W. H. (2005). What makes us tick? Functional and neural mechanisms of interval timing. Nature reviews. Neuroscience, 6(10), 755.

Matell, M. S., & Meck, W. H. (2004). Cortico-striatal circuits and interval timing: coincidence detection of oscillatory processes. Cognitive brain research, 21(2), 139-170.

Taatgen, N. A., Van Rijn, H., & Anderson, J. (2007). An integrated theory of prospective time interval estimation: The role of cognition, attention, and learning. Psychological Review, 114(3), 577.
> 9 votes

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Tags: psychology, sensation, time, cognition
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# Question
Title: Do all types of synapses in the brain change based on spike-timing-dependent plasticity?
Synapses likely change their strengths based on a form of spike-timing-dependent plasticity. Is this true for all types of synapses in all parts of the human brain? I wonder if there are also synapses with hard-wired connectivity, i.e. that do not depend on the activations of nearby neurons or do not change at all.

# Answer
> Synapses likely change their strengths based on a form of spike-timing-dependent plasticity. Is this true for all types of synapses in all parts of the human brain?

No, not all. For example, there is **frequency-dependent-plasticity**, where the firing frequency of the pre-synaptic cell will change the synaptic strength. In Nikolaev, et. al. (2013), frequencies below ~5Hz will depress the synapse, while those above 5Hz will facilitate.

> I wonder if there are also synapses with hard-wired connectivity, i.e. that does not does not depend on the activations of nearby neurons or does not change at all.

It's possible that there might be, after all, you're talking about a complex object like the human brain. Though, this may be very rare. For example, even electrical synapses, or gap junctions, appear to exhibit plasticity. In Fig 6 of Pereda et. al. (2012), you can see how the conductance of the gap junctions is altered by the activity of nearby cells.
> 2 votes

# Answer
Probably not. STDP has mostly been demonstrated in excitatory glutamatergic neurons in the hippocampus. Considering all the other types of cells in the brain (dopaminergic, serotonergic, inhibitory, those located in cortical areas with closed plasticity windows those in the brain stem), it's erroneous to assume they all implement STDP like rules. That said, I can't think of any examples off the top of my head...
> 3 votes

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Tags: neuroscience, learning, plasticity
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# Question
Title: How can a persons good or bad be accurately measured?
The majority of people who think certain people are bad people are usually because they have been exposed to the bad things they do or also because they measure how bad they are based on only the bad things they do, and vice versa with good. There's several very ethically and morally good people that would never be able to harm anyone regardless of circumstance but there's also good people (on the same scale as the previous example) that (like me) would not think twice about killing someone if it came to a life or death situation or something similar. How could a persons real good or bad be evaluated in an approach that would be decorrelated of errors, unbiased, and as accurate as possible? Would it be best to weigh their wrongdoings?the good things they do? Both? How would they be weighed to provide the most accurate result?

# Answer
In a way, I agree with the answer given by AivanF.

But more can be said. One of the greatest biologist of our times, the scientist **Edward O. Wilson** has something to say about what humanity has been calling good and evil, regardless of any particular world view.

> "What have been thought of as moral sentiments are now taken to mean moral instincts (as defined by the modern behavioral sciences), subject to judgment according to their consequences. Such sentiments are thus derived from epigenetic rules -- hereditary biases in mental development, usually conditioned by emotion, that influence concepts and decisions made from them. The primary origin of moral instincts is the dynamic relation between **cooperation and defection**. The essential ingredient for the molding of the instincts during genetic evolution in any species is intelligence high enough to judge and manipulate the tension generated by the dynamism. That level of intelligence allows the building of complex mental scenarios well into the future. It occurs, so far as is known, only in human beings and perhaps their closest relatives among the higher apes."

That dynamism is, in a way, the old issue of good vs. evil:

> "We are determined by the interplay between individual and group selection where **individual selection is responsible for much of what we call sin, while group selection is responsible for the greater part of virtue. We're all in constant conflict between self-sacrifice for the group on the one hand and egoism and selfishness on the other**. I go so far as to say that all the subjects of humanities, from law to the creative arts are based upon this play of individual versus group selection."

So, all the science that studies these issues agreees that a moral development means a greater ability to take into account the wellbeing of something else than me (something like "I care about: me -\> my family -\> closest people -\> my nation -\> all human beings -\> live on the planet..."). So, we are also talking about empathy.

That been said, there are people unable to take empathy into account: **psychopaths**. Differences in their brain have been found related to prosocial behaviour: they just don't care about other people's feelings or wellbeing (they can't, just like blinds can't see). So, we could state they are pure evil, from this point of view. But that doesn't mean that they can't do good, just that their motivation to do so is selfish. What differentiates people in terms of moral is not what they do (their wrongdoings or the good things they do), is *why they do what they do*. Is my main motivation selfish while I don't care if it damages you or not? That's the question.

So, can we state that a "good person" is empathic and a "bad person" is selfish? If we set aside psychopaths (and people with strong **narcissistic** traits, but explaining this would make this answer too long), **we all behave in both ways**, given the situation. And that doesn't mean we are bad people, **that means we are human!**

As the famous old sentence states: "Homo sum, humani nihil a me alienum puto" "I am a man: I deem nothing pertaining to man foreign to me."

So, in scientific terms and from this point of view, the only way to measure "good or bad" is measuring moral development. And we must take into account age, otherwise a two year old kid would be a demon!! ;) :D

As an example to do so: The **Moral Development Scale for Professionals (MDSP)**, based on **Lawrence Kohlberg**’s theory of moral development.
> 3 votes

# Answer
I think answers to your questions are fully based on your moral principles and your world view. Because there is no obvious common principles. Christians believe in objective rightness of God's rules. For atheists that is good doing, what is good for person and society. Some wild men can think that eating each other is a good thing for many generations.

In addition, have a look on stages of moral development, you might be interested in that. It is about how person's understanding of moral principles changes through time, how a person learns more general concepts.
> 2 votes

# Answer
Before we can even begin to discuss how to *measure* a person's relative good and bad degrees, we must define *good* and *bad*. These terms are far too vague on the surface. Even if we agreed on more specific terms such as *moral* and *immoral*, there would still be a fair amount of disagreement on their meanings. For example, *moral* could be grounded in religion; emotion; group survival; species survival; planetary biological continuity; perpetuity of culture, information, and consciousness; or something else entirely. Similarly, when we speak of *good*, we should ask ourselves, "Good for what"? Is it good for Me? You? This or that nation? Advancing technology? Destroying your enemy? Equality? Non-human animals and nature? Having fun?

Often times we hear of *good* being that which "chooses the group over the individual", but even in that definition I doubt we can find agreement. For example, any individual who fails to be productive would do better for the group by taking his or her own life. Would everyone agree on this type of action being the *good* of which we speak? Taking it further, some individuals work harder than others while consuming less resources. Would it thus be *good* for all but the most productive individuals to cease to exist? That would be, after all, good for the group as a whole since it would provide selective pressure toward maximum productivity and efficiency.

Another type of *good* is happiness. If we agreed that happiness is that which makes us feel good, then we find ourselves in a hedonistic pursuit. Virtual reality and carefully-crafted drugs could probably bring about a very large amount of this "happiness" while consuming the least natural resources per-capita. In this situation, those individuals who develop VR and drugs would be the most *good* individuals since they bring us further toward happiness.

Once we have defined very carefully what we mean by *good* and *bad*, we could then measure an individual against those criteria. Without formal, solid definitions we can expect the debate to be inefficient and inconclusive. It would be unrealistic to make a measuring tool for an undefined property. In that case, we might as well assign individuals random values.

To answer your main question directly: First define *good* and *bad* in a concrete way. Then develop ways to measure for each person his or her relative contributions to these definitions of good and bad. Finally, subtract the measurement of bad from that of good for a given person to obtain a general level of *net goodness*.
> 1 votes

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Tags: cognitive-psychology, cognitive-neuroscience, philosophy-of-mind, cognitive-development, ethics
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title: How to deal with a friend who cuts

text:
# Question
Title: How to deal with a friend who cuts
I am asking here since I have no idea where else I could of asked. I have a friend who is having difficulties with depression. I don't how long this has been ongoing, but he is often down. I presume it might of have been because he got rejected by the girl he liked. My friend often jokes about being in depression or suicide.

Today, we were walking outside and talking and my friend suddenly pulls up his sleeve and we (we were 3 other friends with him at that time) saw lots of cuts, around 15 of them, and one huge one in the middle (a very deep wound). He seemed *proud of showing off his cuts*, and bragged about the scar his big one would leave. We were quite shocked and did not know how to react. My other friend then confessed that he had seen the scars on a picture my friend sent him, but he thought it was a joke.

My friend has been seeing the school therapist for a while, but these scars were (presumably) from yesterday. I wonder if he is telling everything to this professional. I am a bit worried about my friend; that was a very deep wound.

I would like to have some tips on how to deal with a situation like this. He is seeing professional help, but I don't know if it is helping.

# Answer
Although popular culture and public opinion may lead people to believe that self injury is either a phase or people seeking attention. The truth is that this behavior becomes an unhealthy coping mechanism for any number of unpleasant scenarios.

The idea of distractionary coping mechanisms by themselves are not harmful, but self injury is specifically more dangerous because causing injury in the first place opens ones self up to infection, permanent physical damage, even accidental suicide.

Self injury often co-occurs with another mental illness, both disorders need to be diagnosed and treated by a decent psychiatric team which may include medications, but most definitely therapy. This is much more than a school therapist can provide. There is more information here: Mayo Clinic on Self Injury

If your friend is not receiving the level of help that he needs or he cannot commit to safety, it would be best to take some type of action.

Possibly:

* Call a help line
* Inform the school therapist
* If your friend has any supportive family members, maybe informing them would help
* In any immediate emergency call 911
> 1 votes

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Tags: abnormal-psychology, developmental-psychology, therapy
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title: Official Color-Emotion relations

text:
# Question
Title: Official Color-Emotion relations
I'm trying to find colors that trigger different sort of emotions for people. I keep finding different answers for different colors.

Ex. Some say blue means friendly and calm. Others say that green means calm but not blue?

Is there an official chart for this that is backed up by research?

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**Edit:**

I am a blogger so I am trying to analyze what colors I need to use in order for my audience to understand what I'm saying.

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**Another edit**

I feel bad for not adding this. lol My blog is about learning how to blog and increasing traffic. I'm trying to learn more about color theory so that I know what colors to use to catch people's eye. Here are specific examples:

1. Landing page color button
2. Background colors to induce trust
3. colors that try to show creativity

Does that help?

# Answer
> 4 votes
Not really, that would be too easy!

Because there are several factors which can influence the emotion from the color. I have several in mind:

* One of them is cultural background, as norms and habits, and thus cultural value, meaning, may change between people for a same color (interindividual differences).
* Another one is context, as color preference may be affected by the field where it's used. For a bold example, black color would look "nice" on a luxury ad, but not so much for an health communication (intrapersonal differences). See also Bonnardel, N., Piolat, A., & Le Bigot, L. (2011). The impact of colour websites on appealing and users’ cognitive processes. Displays, 32, 2, 69-80.
* And you also have physiological issues. Color perception is affected by surrounding other colors (see Johannes Itten). Therefore the emotion would change as well. As a result, it may be more relevant to elicit the emotional impact of a set of colors instead of one only. Also there are several strategies to make colors fit together.
* Also in a physiological view, some people have color deficiency, and it may therefore affect their "emotional perception" (I don't have any reference on that, just a personal hypothesis).

So, what I would suggest is to test the emotions elicited by a specific set of colors, for a specific field/context, for a specific audience. You would therefore get some clues for those conditions.

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Tags: social-psychology, emotion
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# Question
Title: Why people assign blame to deliberate act?
Say we buy stocks. Then stocks either go up or down. Neither is deliberate. No body deliberately buy the wrong stocks.

But free market assign full responsibility.

However, if someone accidentally committed manslaughter against a kid, he'll get lower sentence than if someone deliberately murdered a child.

Why do we feel that way (and yes most of us do feel that way).

Do we take into account that deliberate mistake are often repeated? Those who deliberately rob us must have rob so many people so many times? Do we recognize that giving huge incentive do not reduce "undeliberate" mistake?

What happened?

Is there a math model or evolutionary model for that?

# Answer
> 3 votes
First, we need to distinguish between those punishments brought about by nature and those brought about by society and law. Many actions in nature have an **implicit consequence**, such as harm, that may come back on the performer. Regardless of whether a particular person or group agrees that the consequence is "right" or "just", jumping off a high cliff and landing on rocks will probably kill you. The stock market example is like this -- the consequence of a bad prediction can be disastrous on one's finances, and the result is basically independent of what society thinks about the situation. Many actions in society, on the other hand, have **explicit consequences** set by humans. Because these consequences are not determined by *natural phenomena* so much as *thoughts of man*, questions of intent, prior occurrence, and extraneous circumstance may be brought into the picture.

*Free market* is a system that while created by humans behaves like a natural system. Consequences in a free market generally do not consider intent, prior occurrence, of extraneous circumstance. Larger entities, as an exception, may have special treatment by governments since these entities may have strong effects on society as a whole.

Now to the question of *why* people (and other thinking animals) tend to consider intent when evaluating an action or inaction of another being. On the surface, one may argue that deliberate and unintentional results should be treated equally since they have the same potential for harm. If we look at the **goal of preventing further harm** in the future (to society as a whole), however, we see a very important difference between deliberate and unintentional results:

When the harmful result of a person's actions was **unintentional**, the result alone should prompt the person to control himself or herself. After all, we tend to disagree with results that do not meet our intentions. These results make us **feel stupid**, and they make us **look stupid**, the combination of which is in many cases **sufficient deterrence from relapse**. Those having empathy are even less likely to make the same mistake again when they see the unintended harm they have caused.

When the harmful result of a person's actions was **deliberate**, on the other hand, the balance of natural forces of deterrence is considerably different. Since the result was intended, the person will *not* feel stupid. In fact, he or she will probably **feel proud** of having succeeded. In some cases, we will still have empathy playing a role. In practice, however, those individuals lacking empathy are far more likely to commit crimes and other wrongdoing while simultaneously **lacking any remorse**. In the extreme case we call these people **psychopaths**. While the psychopath proper may be relatively uncommon, lesser forms such as many **narcissists** may still exist in sufficient number that we cannot expect empathy alone from acting as deterrence from relapse.

Hence, **we must consider intent** when an action leads to harm. Other important factors to consider are prior occurrence, extraneous circumstance, and the psychological profile of the individual. When a person has a history that suggests a lack of empathy, we can expect that person to be more likely to relapse and hence more dangerous to society.

A side case is that of the **idiot**. These individuals often **lack prudence** when acting or making decisions. While an idiot may not intend to do harm, he or she may be naturally unsafe as a result of being unable to make proper judgements. **Punishment may be unsuitable** for complete idiots since they may not be able to change their ways due to lack of awareness and understanding. In these cases, one option is to keep these individuals **away from means to causing harm**. For example, it is best if idiots do not operate motor vehicles or firearms.

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Tags: cognitive-psychology
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# Question
Title: People's subjective tendency: Is there a mathematical model?
In our everyday life, people always intentionally or unintentionally value some objects. However, some tend to overvalue the value of objects, while others tend to undervalue them. For some the deviation is big, while for others it is small.

So I wonder, are there existing research findings related to this? Or is there a mathematical model to model different people's subjective tendencies on how they value objects in daily life?

# Answer
> 1 votes
I think there is a mathematical model for this. Have a look at **Bayes' Theorem**. It is also very interesting from a philosophical and psychological point of view.

Here is a link from Stanford Encyclopedia of Philosophy: http://plato.stanford.edu/entries/bayes-theorem/

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Tags: cognitive-psychology
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title: Anger and problem solving

text:
# Question
Title: Anger and problem solving
Is there any evidence that a little bit of inner anger is healthy when engaging in problem solving? I personally feel this way, but feel that people around me misinterpret my anger as being directed at them and the world around me instead of at the problem I'm trying to solve. Thanks.

# Answer
> 3 votes
According the the Yerkes–Dodson law, a moderate level of arousal gives energy to the task, improving performance.

> The Yerkes–Dodson law is an empirical relationship between arousal and performance, originally developed by psychologists Robert M. Yerkes and John Dillingham Dodson in 1908. The law dictates that performance increases with physiological or mental arousal, but only up to a point. When levels of arousal become too high, performance decreases.

Anger is an emotion that creates arousal, but it is also a negative emotion that makes other people more hostile and negative. Other emotions that create positive arousal are excitement, interest, curiosity etc.

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Tags: problem-solving, mood
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# Question
Title: Is neuroplasticity limited to the cerebral cortex in the brain?
In this question, I am defining neuroplasticity as being the creation of new connections between neurons. I'm aware that there is a high degree of neuroplasticity in the cortex and that new connections are created frequently in that brain area. However, in what areas of the brain are the connections constant or change rarely? I'm assuming that any brain area that controls muscles (such as the superior colliculus in the midbrain) are statically connected.

# Answer
> 3 votes
**Short answer**
Subcortical structures can definitely show neuroplasticity in adults. Most likely, all brain structures can show plastic changes to some degree.

**Background**
The question is rather broad, as there are many subcortical structures and neuroplasticity is age-dependent. I will therefore restrict my answer to three examples I dug up from the literature.

For example, in primates it has been shown that **thalamic** and **brainstem** areas projecting to the somatosensory cortex are plastic and change their projections to the cortex to aid in the rearrangement of the somatotopical map (Jones, 2000).

Changes in the connectivity between hemispheres has been associated with plastic changes in the **callosal pathway** (***corpus callosum***) after somatosensory lesions in the cortex (Duffau, 2009).

As a last example, subcortical plasticity has been shown after lesioning the spinal cord in monkeys and rats. By interrupting the ascending projections of mechanoreceptor afferents of the forelimb and the rest of the lower body the corresponding part of the somatotopic representation of primary somatosensory cortex becomes completely deafferented and unresponsive to tactile stimuli. If some of the afferents from the hand remain intact after such dorsal column lesions, the remaining afferents will extensively reactivate portions of somatosensory cortex formerly representing the hand over the course of a month. This functional reorganization has been linked to the sprouting of preserved afferents within the **cuneate nucleus** of the **dorsal column–trigeminal complex** in the **medulla**, also subcortical brain structure (Kaas *et al*., 2009).

In terms of structures that are resilient to plasticity, Aguire from USC argues that every brain structure has the potential for neural plasticity to occur. Basically, because the term plasticity is pretty much all-encompassing, and I quote:

> \[N\]europlasticity is the ability of elements in the brain to show structural and functional changes in response to internal and external events. Neuroplasticity occurs at different levels: structural\[ly\], functional\[ly\] and \[through\] all the molecular and cellular mechanisms that accompany these changes. \[...\] At all times, these players are constantly changing \[...\].

Admittedly it is a popular-scientific and broad answer to this question, but I do agree with it.

<sub>**References**
**-** Duffau, *Neurosci Res*(2009); **65**: 131–5
**-** Jones, *Annu Rev Neurosci* (2000); **23**:1-37
**-** Kaas *et al*., *Exp Neurol* (2000); **209**(2): 407–16</sub>

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Tags: neuroanatomy, plasticity
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# Question
Title: What is the proper term: optical Illusions or visual illusions?
I answered the question "Why aren't optical illusions called visual illusions?" and would like to get more information to improve my answer.

In doing a search on Ngram for occurrences of the expressions "optical illusion" and "visual illusion" I saw that "visual illusion" appeared in 1900. It might have existed earlier.

My questions:

1. When did "optical illusions" start being seen as "visual illusions?" By visual illusions, I mean phenomena of the brain and visual system.
2. In your field (cognitive/neuro sciences) is the expression "visual illusion" now preferred over "optical illusion?"
3. Also, sources say that interest in optical illusions goes back to Aristotle and the ancients. What were these optical illusions they were interested in?

# Answer
* ad 1. Difficult to answer, but I found an article from as early as 1825 that links the rotating spokes illusion to the retina (Roget, 1825).
* ad 2. Interesting question, but more a question of semantics I think. Personally, I think optical illusion is fine, as used by a master of illusions Michael Bach. Admittedly, he is German, so if this is linguistically the best term may be better off at English.SE. Visual illusion may be better targeted for (pathological) phenomena associated with the use of hallucinogens and psychotic states such as those seen in episodes of positive symptomatology. Although here, visual delusions and hallucinations are more appropriate terminology, in my opinion. One way or the other, for the use of referring to benign brain trickery, I would stick to optical illusion, but visual illusions is fine too.
* ad 3. Reportedly, one of the most well-known contributions in optical illusions are his writings on the motion-after effect. He believed, erroneously, that the motion aftereffect was a form of visual inertia, a tendency to continue seeing things move in the same direction because of the inertia of some physical movement stimulated in the brain (Ramachandran & Ramachandran, 2012).

<sub>**References**
**-** Ramachandran & Ramachandran, *Sci Am* (March 2012)
**-** Roget, *Phil Trans Royal Soc B* (1825); **115**: 131-40</sub>
> 2 votes

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Tags: terminology, history-of-psychology
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# Question
Title: Are the language and sound centres of the brain in the same area?
I am an English major currently taking a Psycholinguistics module. One of the things we learned is that speech perception is handled differently from non-speech sound perception. Our brain is trained to break down speech signals more intricately than non-speech information, which is why we are able to distinguish syllable and word boundaries.

Since speech sounds are perceived differently than general sounds, my question is this: **do different areas of the brain light up when speech is perceived as opposed to a general sound?**

I've spent a few hours Googling this, but I found no answers. The only thing I found is that a particular section of the temporal lobe is responsible for auditory perception.

I would expect that a general sound activates mainly the temporal lobe while hearing speech would activate the temporal lobe and areas of the brain associated with the words currently in the content of the speech.

# Answer
**Short answer**
The primary auditory cortex is mainly involved in relatively simple processing of sound. The language areas involved in producing and understanding speech are associative auditory cortices and are considered to be areas higher up in the hierarchy. They are connected to the primary auditory cortex, but are situated at anatomically different locations in the brain.

**Background**
The primary auditory cortex is engaged in the **low-level processing** of sound. For example, it contains a tonotopic map that is used to separately process the various frequencies in the incoming sound (Purves *et al*., 2001) (Fig. 1).

The language area involved in **production of speech** of the brain is called Broca's area (Fig. 1) and is anatomically distinct from the primary auditory cortex.

The part of the brain dealing with **understanding speech** is Wernicke's area (Fig. 1), and is also a distinct anatomical structure in the brain.

The angular gyrus has also been associated with specific speech production pathologies (Fig. 1).

Fig. 1. Central auditory system. source: McGill University

**Reference**
**-** Purves *et al*. (eds). *Neuroscience*, 2nd ed. (2001). Sunderland (MA): Sinauer Associates
> 3 votes

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Tags: cognitive-psychology, neuroscience, neuroanatomy
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# Question
Title: Does the retina contribute in distinguishing lines and borders?
I think there is a phenomenon behind the way which our eyes judge between lines of contrast, like black lines on a white page, by just recognizing the contrast areas at the level of the rods and cones. I don't understand how this phenomenon works in the retina.

# Answer
> 2 votes
**Short answer**
Yes, retinal circuitry enhances the perception of contrast.

**Background**
In the retina, the neurons that guide the visual signal to the brain, the retinal ganglion cells (RGCs), process contrast. The receptive fields (RFs) of these cells exhibit a so-called **center-surround** organization (Fig. 1). They integrate the signal from multiple cones in the retina. ON RGCs fire when their RF is illuminated in the center (the central cone in the retina in the RF is illuminated) and they are inhibited when their surround is illuminated. OFF-center RGCs do the reverse. Together this organization results in sharpening of contrasts and aids in the coding of edges and contours. Midget cells also have RFs like this.

Remember that the retina is considered a part of the central nervous system by some. Thi because of its embryological origins, but also because of its complexity.

Note that further processing of contrast and edges occurs in the primary visual cortex (V1) (Schmolesky, 2002) and that awareness of that contrast information, i.e., the **perception** of edges, patterns and objects within the visual field occurs at high-tier associative cortices (Lorreys, 2005).

Center-surround RFs in RGCs. ON cells (left) fire when illuminated in the center, and are inhibited when illuminated in the surround. OFF cells have a reversed pattern (right). source: Stanford University

**References**
**-** Lorreys, *Trends Cogn Sci* (2005); **9**(12):556-9
**-** Schmolesky, *Webvision, The Organization of the Retina and Visual System*, Kolb *et al*. (eds). Utah University

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Tags: neuroscience, vision, neurophysiology, sensation, sensory-perception
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# Question
Title: What is the location of the center-surround receptive fields of retinal ganglion cells?
I have read wikipedia article about receptive fields of visual system and it states the following:

> The receptive field is often identified as the region of the retina where the action of light alters the firing of the neuron. In retinal ganglion cells (see below), this area of the retina would encompass all the photoreceptors, all the rods and cones from one eye.

I understand the part where it says that the neurons firing increases as we put light on the center of the receptive (for the ON center type) and *etc.*

What I'm not sure about is the location of this circle, in other words, **where is this circle that we put light on**?

What I think is that the circle is the area of retina where we have the rod and cone shaped photoreceptors. Does this means that for every ganglion cell the photoreceptors connected to it are always shaped like a circle ?

# Answer
A nice illustrative image of how the photoreceptors connect to the retinal ganglion cell (RGC), and thereby facilitate the center-surround structure is provided in figure 1 below. It shows a cross section through the retina.

Fig. 1. Photoreceptor organization and connections to the retinal ganglion cell. source: McGill University

The receptive fields (RFs) are determined by the number of photoreceptors connected to the RFs. RFs are smaller in the central high acuity area of the retina (the **fovea**) and increase in size more eccentrically. As a result, visual acuity is highest in the center visual field, and degrades more eccentrically in the field of view.
> 2 votes

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Tags: neuroscience, vision, neurophysiology
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# Question
Title: What is the definition of a receptive field?
I have read the wikipedia article on receptive fields (RFs). There, a receptive field is defined as:

> The receptive field of an individual sensory neuron is the particular region of the sensory space (e.g., the body surface, or the visual field) in which a stimulus will trigger the firing of that neuron

Now in the online course that I am taking, the slides of prof. Rao defines the receptive field as:

> specific properties of a sensory stimulus that generate a strong response from the cell.

The first definition states that the RF is a sensory area, while the second one is saying that it is the stimulus and its properties.

Which one of these options is correct, or are they both correct?

# Answer
**Short answer**
A receptive field is an area in which stimulation leads to response of a particular sensory neuron.

**Background**
A receptive field is often functionally characterized by electrophysiological experiments. During these experiments, a certain area of the body is stimulated: *e.g.*, a certain part of the visual field is illuminated, or a certain area of the skin is haptically stimulated (Fig. 1), *etc.*. Then it is determined if a neuron shows a response, either a stimulation (increased firing rate), or inhibition (decreased firing rate). By probing multiple, overlapping areas, the RF can be characterized.

Levine and Shefner (1991) define a receptive field as an "**area in which stimulation leads to response of a particular sensory neuron**".

The **RF** is hence **a property of the neuron** and not of the stimulus.

However, that property of the neuron depends heavily on the stimulus. For example, an ON retinal ganglion cell will not respond when the, say, red-cones in the center of its receptive field in the retina are illuminated with UV light, while it will vigorously respond when the light is red. It is here where your professor may have been hinting at, i.e., at the close interplay between stimulus and response.

Fig. 1. Schematic of the receptive field (RF) of a pain in the skin. The RF is determined by the arborations of the free nerve endings in the dendritic zone of the pain receptor cell. source: Lumen Learning
> 2 votes

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Tags: neuroscience, terminology, neurophysiology
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title: Find the panda among snowmen!

text:
# Question
Title: Find the panda among snowmen!
I just saw this picture puzzle, and found it easily by doing a row-by-row scan, but it seems harder to find it just by looking around. I was thinking that the puzzle was intentionally designed to draw attention away from the correct location, by the following features:

1. Every snowman is different and its nose points in an apparently arbitrary direction, so as to prevent any uniformity that would give the panda away.
2. A sizeable fraction of the snowmen have extra things like scarves, hats, bow-ties and and even candy sticks, most of which are also brightly coloured. These distract the viewer as they automatically spend more time looking at these oddities, especially those with patterns. (Saccades tend to concentrate about them.)
3. The panda ears are almost the same size as the buttons on the chest of each snowman, and the snowmen themselves are positioned such that many of them have their buttons appearing just above the snowmen in front of them at about where the ears should be.

So I was wondering what are the psychological processes that facilitate such visual misdirection. Is it just the saccade mechanism? My second question is whether there are more convincing examples. For other kinds of visual illusions there are plenty of unambiguous examples, but this one does not feel like an illusion as the task is just to find something.

# Answer
> 2 votes
At least three things play a role here:

1. **Camouflage**: the panda looks like the snowman in shape and coloring. Further, the ears of the panda are the buttons of the snowmen behind, *i.e*. the panda partly merges with the 'background' snowmen;
2. **Clutter**: there are simply many, many snowmen;
3. **Distracters**: The colored hats and other attributes are more salient and draw the attention away from the colorless panda.

Saccades are indeed often made to salient features in the visual scene, so that may indeed be one of the factors (cf. point 3).

I am unsure what you mean with more convincing examples and illusions, but this is not really an illusion. Below examples of camouflage (Fig. 1) and cluttered images (Fig. 2).

Fig. 1. Find the leaf-tailed gecko. source: Bored Panda (apt!)

Fig. 2. Find the coffee maker. source: EtchingFitness

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Tags: perception, vision
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# Question
Title: Where would a cognitively separated person get their brain signals excited from?
I suppose there's nothing wrong about the idea that a cognitively separated person could cognitively function as anybody else. But brain as I understand it always needs a potential from some sense. If I suddenly lost all my senses and my brain would stop working for a second would I be able to recover my brain activity?

Otherwise, the brain keeps the same electrical impulses running in the brain so you can't really think of anything new, right? I am really interested just in the way the brain creates new electrical potentials, "just on his own."

# Answer
Seems that you are asking:

> I am really interested just in the way the brain creates new electrical potentials, "just on his own."

and

> whether \[sic\] the brain would 'stop working', implying that there no longer is any neural activity due to the lack of external impulses.

If you were to theoretically disconnect the brain from all sensory input, there could be several sources of activity. For example:

* **Random noise.** Neurons are messy objects, there are many small and large molecules floating inside and outside the cells. Furthermore, the membranes themselves are relatively dynamic, and are studded with receptors, ion channels, and other proteins, some of which migrate regularly (see Lipid rafts). The ion channels (e.g. sodium and potassium) that contribute to the electric currents that generate action potentials, can be affected by thermal fluctuations, and thus change their open-closed states in a stochastic manner. Notice the fluxuations in Figure 1 of Horn and Vandenberg (1984) obtained from a single sodium channel.
* **Some cells fire without any external stimulation**. Central pattern generator circuits is one example, and pacemaker neurons is another. Take a look at Figure 1 of Alving (1968) where an isolated neuron exhibits regular spiking without any external input. One can imagine that one such spiking cell could be connected to other neurons and could cause them to spike as well.
* **Gain control mechanisms might amplify noise.** In your scenario, if the brain is not receiving sensory input, the natural gain control mechanisms, attempting to maintain a certain activity range, might increase amplification to such an extent that the thermal noise fluctuations become consciously perceived. For example, sensory deprivation can result in hallucinations, which might be explained by noise amplification by gain control mechanisms. Similar mechanism can also be seen in the Ganzfeld effect

Overall, any one or a combination of the mechanisms described above could cause spontaneous brain activity without external stimulation.
> 6 votes

# Answer
## Physics

Perhaps you are asking, "Where would the energy, or the electrical potential, come from?" Short answer: Sugar. Or, at the cellular level, ATP. Point is -- nerve impulses from the senses are \[probably\] not the brain's main source of energy.

## Internal Stimulation

The five senses provide external stimulation to the brain. But that stimulation takes time to spread through the brain. Not only that, the brain's operation is not a one-way street. Signals can (and do) backpropagate. So, cutting off input for a second will not instantly reduce signal transduction to zero. Over time, yes, overall activity would likely decrease significantly. You could test this by putting someone in an isolation tank and doing an MRI. (Sensory input isn't totally muted in this scenario, but it's clearly reduced.)

The human brain certainly has internal mechanisms that allow the mind to recall previously experienced stimuli. Ever heard the phrase "the mind's eye"? That's one name for the thing that allows us to remember things we've seen, heard, touched, or tasted before -- and imagine experiences we've never actually had. Art, creativity, and even hallucination come to mind. (More on that last one in a second. But first...)

...Let's talk about dreams! The separated person's state is a lot like sleep. During sleep, sensory input is chemically muted, or at least turned wayyyyy down. The mind doesn't pay as much attention to its surroundings. If you sleep especially long, the mind 'gets bored' and finds ways to entertain itself, like dreaming. Think about a prisoner that's been locked up for years, whose main source of entertainment is, in fact, the self. This is another example of the idea: When no novelty exists in the stimulation from the outside world, the self works to manufacture the novelty it craves.

Also, drugs. Hallucinogenic chemicals like psilocybin (found in "magic" mushrooms), LSD, and DMT can cause people to ignore their senses in favor of more novel stimulation generated internally. DMT users often use "dreamlike" to describe their experiences, and the parallels between a hallucinogenic "trip" and an ordinary "dream" are pretty obvious.

So, suppose your senses are cut off suddenly. Unless you have never dreamed, visualized something, heard a song in your head, had a sexual fantasy, or otherwise imagined something, I don't think your mind would "stop working"!

## Artificial Neural Networks vs. Human Brains

A brain is one kind of mind.

Another kind of mind is an artificial neural network, or ANN. To my knowledge, all ANNs have inputs.

A brain without senses would be like a neural network without inputs. For the reason I just stated, this doesn't really compute (ha.) But, a biological brain has a little more to it than the simple little computer brains that run our search engines and social networks. ANNs only simulate SOME features of human brains -- specifically, neurons and the signals they pass to each other. In addition to the neurons and signals, human brains have lots of chemicals, like sugar and neurotransmitters, that affect their operation.

Most ANNs are designed to take one set of inputs and turn it into one set of outputs. For a human, "one set of inputs" is not clearly defined, because our existence does not appear to be framewise (until MAYBE you get REALLY into physics). We receive input continuously, and produce output continuously. Lots and lots of of operations per second!

The point is: For a simple feed-forward neural network, cutting off input would cause it to stop functioning, yes. But there are versions of neural networks (convolutional, I think?) that feature neurons that feed back into previous layers, and those, like the human mind, will continue producing output long after input is reduced to zero. In fact, it would take a very specific (and you could say improbable) neural network to produce zero output when given zero input. Most of the ones I've seen are initialized with some random weights. I guess a human brain isn't exactly random when it grows. But a baby kicks (output) in the womb, before it's received much "input"!
> 4 votes

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Tags: cognitive-psychology, perception
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title: Do we have a sub- or super-unconscious?

text:
# Question
Title: Do we have a sub- or super-unconscious?
Being conscious (awake) and unconscious (asleep) are two mutually exclusive states.

The boundary between them ("falling asleep") is very pleasant. Why?

Conscious =\> Unconscious

Some people say sleeping is their favorite thing (or one of); but it's not really sleeping that they love, because they are unconscious and thus unaware of the state they're in; it has to be the boundary between the two that they love so much.

Going the other direction (waking up) is not usually so pleasant. Why not?

Conscious and subconscience are two coexisting areas:

```
Conscious
------------
Subconscious

```

e.g., our conscious may realize that the light turned red before we got to the intersection, while our subconscious is noting that the tree on the corner was trimmed yesterday. It may be that we have a "superconscious," too - known as "intuition" or such.

But what about in our unconscious state - is there a sub and/or super unconscious, like so:

```
Superunconscious
----------------
Unconscious
----------------
Subunconscious

```

?

If so, which or both? Is that where our dreams live? And why is it that in that part of our unconscious (the dream state) we sometimes seem to have no conscience?

Do we have a subunconscious and/or a superunconscious?

When we cross over from consciousness to unconsciousness, do we ever go straight into the dream state, or is a dreamless unconsciousness always achieved first (we have to get to the dream state from the unconscious state)?

BTW, I realize that dreaming is referred to as a state, but it is not mutually exclusive to unconsciousness (you are dreaming *while* you are unconscious/sleeping, not dreaming *instead* of sleeping).

# Answer
Sleep and dreaming is somewhat of a specialty of mind, so I can comment on the wake-sleep-wake transition.

People typically love the feeling of relaxation and warmth associated with sleep. Waking up naturally can feel just as good - imagine lounging in bed on a Sunday morning without having to get out of bed. Waking due to alarm is an abrupt event which is indeed unpleasant.

In terms of conscious - unconscious transition at wake/sleep. There are a number of techniques, sharing the acronym WILD - Wake Induced Lucid Dreaming, where a person, through practice, enters dreaming state directly from waking state, while remaining conscious. There are different variant of this technique, some accompanied by vivid hallucinations and sleep paralysis, while other are more subtle.

I believe the existence of wake induced lucid dreaming demonstrates that the wake-sleep transition is not a binary event, but instead is a sequence of predictable events. Typically the ability to record short term memories is gone first, followed by intensification of mental imagery, followed by seamless transition into a dream featuring that imagery. **You can think of dreaming as "dimming" of consciousness, rather than turning it off.**

There are a number of drugs/supplements that are known to boost vividness of dreaming or increase subjective experience of consciousness (such as use of logic, decision making and control). After a certain threshold the person becomes self aware of the fact that he is dreaming.

In this way, consciousness can be described as a hologram. Adding pixels to hologram makes it more vivid, removing pixels makes it more fuzzy. At a certain number of pixels, the ability to recognize the image is gone. Add these pixels back and the image returns.
> 1 votes

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Tags: consciousness, dreams, unconscious
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# Question
Title: What does "Convolutional" signify in "Convolutional Neural Network"?
The "Types of Neural Networks" wiki page doesn't even have the word "convolution" in it, and yet there's an entire Javascript library based on Convolutional Neural Networks (CNN).

So, what makes CNNs "convolutional"? When I hear "convolution", I think of either smearing/blurring together (as in the "convolve" tool in programs like Photoshop), or complexity/tangling (e.g., "a long and unnecessarily convoluted explanation").

When I think of neural networks, I think of networks with distinct layers, where neurons from one layer only connect to neurons of the next layer. To me, "convolutional" suggests that the neurons are more intricately connected somehow—or "tangled up". But I see nothing in the javascript library's documentation to suggest that this is the case.

The background section in the "On Complex Valued Convolutional Neural Networks" master thesis suggests that CNNs are what has made neural networks actually useful for tasks like computer vision and face recognition. Why remains unclear, however, the term "convolution operation" was mentioned.

<sub> Guberman, N. (2016). On Complex Valued Convolutional Neural Networks. arXiv preprint arXiv:1602.09046. </sub>

# Answer
> 4 votes
Convolution is a technical term, and comes from the signal processing field. Unfortunately, it is easily confused with "convoluting". Effectively, "to convolve" means to pick a small "window", slide it across your signal, and compute the same function for each step.

In CNNs, when applied to classifying, for example images, it means taking a small window, of say 3x3 pixels, sliding it across the whole image, and feeding the small sections of the larger image under the window into a neural network. The outputs of the network are then combined into a new layer and can then be fed into another NN layer for classification.

In the example above, the window is 3x3 pixels wide, and the step size is 1. Depending on the application, it's possible to have larger/smaller windows and step sizes.

The resulting layer can be said to be the *result of convolving the original image with a neural network*.

When using convolution filters in, say Photoshop, it's using a similar method where it takes sliding windows of pixels and computes a function (for example to achieve blur, the average RGB values of the window pixels) and creates a new image out of those. You can then say that *convolving an image with a pixel average function results in a blurred image*.

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Tags: neural-network
---


# Question
Title: Why does the brain skip over repeated "the" words in sentences?
For example, in this sentence by the the time you are done reading you will have already skipped over the double "the".

I have searched this on the internet a little, but I have found nothing that focuses on why this happens and shows actual proof and not just a hunch someone has on why it happens. Would someone explain this and post a link to a trustworthy website that explains it in more detail.

# Answer
A study by Rainer *et al*. (2011) has shown that words are skipped and apparently filled in mentally quite often (in the order of 8 to 30% of times).

Two important factors that increased skipping rates were the *length* of the word and the *predictability* of the word due to contextual constraints. Both cases apply on the word '*the*', because it is **short** and **highly predictable**, being a common adjective and in fact one of the most used words in the English language. In other words, besides being short and predictable, it is also a very common word that has relatively little impact on the meaning of a sentence.

<sub>**Reference**
**-** Rainer *et al*., *J Exp Psychol Hum Percept Perform* (2011); **37**(2): 514–28</sub>
> 14 votes

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Tags: perception, language, reading, language-processing
---


# Question
Title: Does work exist on relative valuations versus numeric valuations?
I've been trying to use Google Scholar to find something on this issue, but I fear I may not have found anything due to using incorrect terms. I am looking for any work which looks at rating systems and people's use of them (I hope this is the right forum). We are all familiar with the idea of rating things numerically, like out of a scale of 5.

But it is also possible for people to rate things relatively ie A \> B and B \> C. Other preferences can then be inferred, ie A \> C.

In certain instances, where people may be reluctant to provide low ratings, these relative valuations may therefore be useful. I am wondering if this is something which has been looked at in any work that anyone knows of? Is 'relative valuation' the correct term for this?

# Answer
> 2 votes
**Short answer**
Sensory systems in general operate on a relative basis. Hence, seemingly objective rating scales are often still relative, because subjects implicitly, or explicitly compare previous trials to the current one. Perception is per definition always relative. So numeric ratings are similar to ''larger than'', or ''smaller than'' ratings. The advatnage of numeric ratings is that it is a (semi-)continuous scale, allowing for quantitative analyses.

**Background**
You are asking about **rating scales** and specifically to the difference between numbering opposed to larger-than / smaller-than ratings.

You have to realize that when subjects rate on a scale from, *e.g.*, 0 to 10, the S is already quite explicitly indicating whether a trial's stimulus is larger or smaller than a previous trial. Even if you force an absolute number scale, the result is a comparison nonetheless.

Moreover, even if you as an experimenter force an absolute rating, Ss will always start comparing later conditions to previous ones (this is larger/bigger/brighter/more intense than the last trial, *etc*.), either consciously or subconsciously. The only really absolute one, in absence of a baseline measure, will be the very first trial. It is a known phenomenon that previous trials affect subsequent ratings because of that. Hence, true absolute ratings are a rarity.

Also - perception *is physiologically and per definition*always relative. Sensory systems operate at relative measures at the neural level.

And to conclude, as a comment - What often happens in rating experiments is that the experimenter assigns a certain baseline. For example, consider the rating of speech-understanding. First, the listener can be instructed to rate speech in silence from 0 (unintelligible) to 10 (highly intelligible). You might urge the S to rate it 10, as speech in silence is per definition highly recognizable and understandable. After that, you present various distorted speech forms, or speech in variable amounts of noise. Under these conditions, Ss will (likely) rate these trials lower, because of lower signal-to-noise ratios. This way, the absolute ratings are relative less than/larger than comparisons nonetheless, because Ss are rating the subsequent trials relative to baseline. i.e., they are comparing the noisy conditions to 10 - per definition a relative measure, whether you are asking them to give numbers, or larger than, or smaller than answers. The big advantage of numbers is that it allows for (semi-)quantitative analyses, while '\<', '=' or '\>' will make your life a lot harder to do stats.

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Tags: measurement, terminology, methodology, psychophysics, experiment-design
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# Question
Title: Have there been any studies into language development in the blind?
The title pretty much says it all. I'm looking for any studies or experiments into language development in those **born** blind.

I'm interested as part of my investigations into AI on how language is developed without visual cues and if language is impaired in anyway because of this and I've yet to come across any. Has anyone heard of such an endeavor?

# Answer
Yes, there have been a number of studies on language development in children with congenital profound visual impairment (PVI) over the years. Selma Fraiberg first described differences in early development, specifically later emergence of personal pronouns compared to typically sighted children \[1\]. More recent studies found that the vocabulary development of children with PVI follows a different trajectory. Vocabulary sizes is initially smaller compared to typically-sighted children, then develops rapidly and may surpass the vocabulary size of typically-sighted children of the same age \[2\]. Differences in the way that language is acquired in the early years, e.g. through shared gaze interaction with the caregiver, may part of the reason for the different developmental trajectories.

This is only a very superficial treatment of this question. There are entire books on this topic that offer a detailed discussion of the research:

Perez-Pereira, M., & Conti-Ramsden, G. (1999): Language development and social interaction in blind children. Hove, UK: Psychology Press/Taylor and Francis.

Pring (2004): Autism and blindness. Research and reflections. London: John Wiley & Sons.

\[1\] Fraiberg (1968): "Parallel and divergent patterns in blind and sighted infants" The Psychoanalytic Study of the Child, Vol 23, 1968, 264-300.
\[2\] McConachie & Moore (1994). "Early expressive language of severely visually impaired children" Developmental Medicine and Child Neurology, 36(3), 230–240.
> 4 votes

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Tags: learning, language, artificial-intelligence, cognitive-development
---


# Question
Title: Are ADHD and OCD under some type of mental illness?
Related to question.

Mania, hypomania, depression and bipolar are mood disorders, from what I understand.

Are ADHD and OCD under some category as well? From what I understand, the are opposite ends of some impulsive-compulsive spectrum?

OCD is an anxiety disorder (same link as earlier), from what I understand, but what about ADHD? Is there another description of OCD that also applies to ADHD?

# Answer
ADHD is considered a neurodevelopmental disorder.

> Neurodevelopmental disorders are impairments of the growth and development of the brain or central nervous system. A narrower use of the term refers to a disorder of brain function that affects emotion, learning ability, self-control and memory and that unfolds as the individual grows.

You are correct in that OCD is generally considered an anxiety disorder. They are not the same because ADHD is characterized by cognitive impairment, and OCD is characterized by anxiety (in the form of obsessions and compulsions). However, you can find both disorders in one person.
> 5 votes

# Answer
Different diagnostic systems may assign these syndromes to different categories based on theory or clinical opinion. In the DSM-IV era, OCD was listed under the "Anxiety disorders" category; however, in the DSM-5, it is now listed under a different "Obsessive-Compulsive and related disorders" category. ADHD is currently under the "Neurodevelopmental disorders" category.

However, many would argue that categorization should be based on empirical evaluation of the co-occurrence of syndromes and lower-level symptoms rather than on psychiatric theory or clinical opinion. When approached from this viewpoint, you find that OCD loads highly on the *Internalizing* spectrum (along with MDD, GAD, PTSD, and eating disorders) and ADHD loads highly on the *Externalizing* spectrum (along with substance abuse and conduct-related disorders) and moderately on the *Antagonism* spectrum (along with narcissism, antisocial, and histrionic disorders). There are many articles on such empirical evaluations and various dimensional and hierarchical approaches to understanding psychopathology that I could share if you are interested. One place to start is would be the Hierarchical Taxonomy of Psychopathology (HiTOP) system.
> 5 votes

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Tags: depression, adhd, mood, anxiety, bipolar-disorder
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# Question
Title: What is the function of the connection between the two halves of the thalamus?
What kind of direct exchange do we have between the two halves of the thalamus, whether going through the thalamic adhesion or not? Do we know what parts of left and right thalamus are connected and what kind of information they exchange?

# Answer
**Short answer**
The function of the thalamic adhesion in humans is unknown.

**Background**
The two halves of the thalamus are separated by the third ventricle. In about 80% of people, the thalami are connected via the thalamic adhesion (*massa intermedia*, Fig. 1), which mainly contains cell bodies, but also commissural fiber systems that connect some thalamic nuclei (Satheesha & Soumya, 2010; Sen *et al*., 2005). Because the structure is absent in about 20% of the people, it is not a critical structure. The significance and consequences of its presence or absence is not known in humans (Sen *et al*., 2005).

It is known that there are sex-differences between the presence of the structure. It is present in 78% of females and 68% males (Allen & Gorski, 1991) and it is about 50% bigger in females, when present. In schizophrenics, female patients were shown to have a significantly higher incidence of absent *massa intermedia* (33%) than their healthy controls (14%), whereas male patients showed no such difference (Nopoulus *et al*., 2001).

In rhesus monkeys, ablation of the structure has been shown to lead to ipsilateral motor deficits (Lumley, 1972), but that has likely no relation to the commmissural tracts in question.

Fig. 1. Dissection showing the *massa Intermedia* connecting the two thalami through the third ventricle. source: Wikipedia

**References**
**-** Allen & Gorski, *J Comp Neurol* (1991); **312**(1):97-104
**-** Lumley, *Brain* (1972); **95**(2): 347-56
**-** Nopoulus *et al*., *Schizophr Res* (2001); **48**(2-3): 177-85
**-** Satheesha & Soumya, *Int J Anatomic Va*r (2010); **3**: 174–5
**-** Sen *et al*., *Neuroanatomy* (2005); eISSN 1303-1775 • pISSN 1303-1783
> 2 votes

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Tags: neuroscience, neuroanatomy, neurophysiology
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title: How to measure stress quantitatively?

text:
# Question
Title: How to measure stress quantitatively?
I am wondering what the most straightforward way is to measure stress levels objectively and quantitatively \*, and specifically, **cognitive load**. I am open to suggestions, but my understanding is that **pupil dilation** and increased **skin conductivity** are good objective and quantifiable measures of stress.

My question now is - **is there an established opinion which of the two is the preferred method?**

The thing is that skin conductance is relatively straightforward. An electrode or two suffices - too easy. Pupillometry, on the other hand, requires either cumbersome glasses or a head-mounted device, or, alternatively, a table-top device necessitating the subject to focus on a restricted field of view (otherwise the camera looses the pupil).

Given we are considering measuring children, an electrode would intuitively be better, as it can be secured firmly to a finger, it allows for easy instructions - 'don't touch it', and it is relatively robust to artifacts, given that puil recordings suffer from eye blinks.

**Should we consider practical considerations only and choose skin conductance, or are there compelling reasons to use an eye tracker instead** \**?

<sub>\*: we wish to avoid questionnaires due to time constraints
\**: we don't have money for both :-)</sub>

# Answer
**When your goals is to measure one option over the other**

As part of a Human-Computer Interaction (HCI) study I also needed to measure cognitive load in order to assess whether a particular user interface could reduce perceived cognitive load (as compared to a control group). Because of practical reasons (and not to intrude too much in 'ordinary' computer usage) I decided to stick to the commonly used NASA TLX scale (Hart, 2006). However, for small-scale studies (mine involved just 16 participants) I have the impression you are just as well off merely asking for qualitative feedback. Of course you can't run statistics on these, but interpreting effect size on such small sample sizes is arguably meaningless either way. You could thus simply ask participants which option is preferred in regards to perceived cognitive load and report on this as a 'significant' result. Of course I can not guarantee whether reviewers would agree. :) In the case you have suitable existing NASA TLX measures to compare against this still remains a worthwhile option.

However, as you state a big downside to such a scale-based test is that it can only be administered at a few points throughout the study, since filling out scales is time intensive.

**For large scale or continuous quantitative studies**

Skin conductance, blood volume, and pulse rate seem quite promising and are being used in HCI (Janssen et al., 2015; Mark et al., 2012), which are indicative of *arousal*. These nowadays can more easily be measured in an easy form factor (e.g., a watch). However, it is important to mention that arousal is not indicative of *valence*—the pleasantness or unpleasantness of stimuli. Neither is using such equipment straightforward. Establishing a baseline for participants takes a considerable amount of work and care needs to be taken to do it properly (if one wants to compare results with other participants). Measurements on the wrist (as in measured by a watch) are weaker than on palms. For some people, no suitable signal is measured at all. Environmental factors like temperature changes and movement (in regards to skin conductance) and changes in lighting (pupil dilation) need to be controlled for.

To answer one of your containing questions, I do not believe there is an *established* opinion or a preferred method and it still relies heavily on what can be measured in the given context and what is to be expected (e.g., can it be presumed there is no positive valence?). Depending on the study one could still be preferred over the other (does the task involve movement?), and I definitely would not rule out qualitative measures.

**Studies comparing different measures**

When I was looking for information I did run into some sources which compare different measures. However, I can not summarize them by heart, but I hope the current mentioned issues and sources can already guide you in the right direction.

<sub> Hart, S. G. (2006, October). NASA-task load index (NASA-TLX); 20 years later. In Proceedings of the human factors and ergonomics society annual meeting (Vol. 50, No. 9, pp. 904-908). Sage Publications.
Janssen, C. P., Gould, S. J., Li, S. Y., Brumby, D. P., & Cox, A. L. (2015). Integrating knowledge of multitasking and Interruptions across different Perspectives and research methods. International Journal of Human-Computer Studies, 79, 1-5.
Mark, G., Voida, S., & Cardello, A. (2012, May). A pace not dictated by electrons: an empirical study of work without email. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (pp. 555-564). ACM.
Forne, M. (2012). Physiology as a Tool for UX and Usability Testing. School of Computer Science and Communication, Master. Royal Institute of Technology, Stockholm.
Haapalainen, E., Kim, S., Forlizzi, J. F., & Dey, A. K. (2010, September). Psycho-physiological measures for assessing cognitive load. In Proceedings of the 12th ACM international conference on Ubiquitous computing (pp. 301-310). ACM. </sub>
> 5 votes

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Tags: measurement, stress, experiment-design
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# Question
Title: Difference between thoughts and sensations
I am interested to know how to distinguish sensations from thoughts, according to the techniques and concepts of neuroscience and psychology. Is there an explicit distinction between them, or are there cases where the instrumental techniques and theoretical concepts fail?

# Answer
> 5 votes
**Short answer**
Sensations are different from thoughts and are separated in the spatial and temporal domain. The distinction between thoughts and perceptions, however, is less well defined, but can still be dealt with experimentally.

**Background**
A description of **sensation** is as follows:

> The physical process during which our sensory organs \[...\] respond to external stimuli. \[...\] During sensation, our sense organs are engaging in transduction, the conversion of one form of energy into another. Physical energy such as light or a sound wave is converted into a form of energy the brain can understand: electrical \[impulses generated in neurons\].

Sensation precedes **perception**, which includes the process of processing stages higher up in the brain, during which we become *aware* of the sensations and make sense of it all (*integration*).

More concisely, sensation is the **detection of physical stimuli by low-level, peripheral neural processes**. Perception is the **processing of sensations that lead to becoming aware of the sensation**, the latter mediated by higher cortical processes.

**Thoughts** are generated centrally in the brain, without the need for external input. So to answer your question - thoughts are generated in the central nervous system in the brain, while sensation occurs peripherally, e.g., in the eye (detection of light by the retina), skin (detection of touch by mechanoreceptors), the ear (setection of vibrations by the mechanoreceptors in the cochlea), *etc*. Electrophysiologically, a sensation hence will occur at an anatomically different place and will precede the activity in the brain in time. These two processes are separated both in the spatial and temporal domain. Note that thoughts can not activate peripheral sensory systems.

Perhaps you were more after the *distinction between **perception** and thoughts*? Here, the distinction becomes less well-defined, as **imagery** of sensory input may activate sensory brain areas in much the same way as the factual perception of a physical stimulus (*e.g*., Aleman *et al*., (2001)). For example, brain imaging studies in late-blind folks (people that lost their eye sight later in life) and even in the congenitally blind, can be complicated because of this. When brain activation is tested in a blind person using a vision aid (e.g. BrainPort) when looking at visual stimuli, the activation pattern can be dictated or compromised, because they can **imagine** the stimulus to be there based on early memories when they still had functional vision. Hence, the distinction between thoughts and perceptual phenomena is less distinct. Nonetheless, perceptual phenomena are preceded by sensation, while imagery is not. Hence, this causality of the former can distinguish it from the latter.

<sub>**Reference**
**-** Aleman *et al*., *Neuroreport* (2001); **12**(11): 2601-4)</sub>

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Tags: neuroscience, perception, sensation, sensory-perception, thought
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