# Question
Title: Is there some hierarchy of the human senses?
What I mean by this is to ask if each of the sensory inputs can be quantified by the amount of information the brain is receiving: For example,

Brain says: currently receiving 10 packets of visual information, 3 packets of auditory info, 20 packets of somatosensory input etc...

Or maybe to put it in different terms, to measure the rate at which these sensory inputs are being recorded. For example:

Brain says: currently capturing visual info at 120 frames per second, hearing 20k cycles per second, somatosensory input at ...!?

And thereafter calculate the information content coming from each (per unit of time?) and thereby list them in some order.

Ultimately what I'm trying to understand/see is: if you had such a list (say, 1. visual, 2. touch, 3. hearing,....etc) and you began to remove modes of input from largest to smallest, would/might we begin to see weaker sensory inputs begin to enter the picture (sensory inputs that were being drowned out by the other senses)?

# Answer
> 5 votes
Now I think I have understood your mental model of human perception, I can give you an answer. Correct me if this is not what you meant to ask.

If I understood you, you think that the human brain functions like a robotic brain. A sensor captures an image, sends it to the brain (which is comparable to a central processing unit), then the next one, etc. The brain then processes each incoming image. And analogically for senses other than vision. And you are asking if, if we stopped sending signals form one sense, the brain will have free capacity to process more informaiton from the other senses.

**The theory behind it**

The problem is that you can't define it as neatly as that. On a very high level, this model is almost right, except for the part where the brain takes in one "captured frame" after the other and processes a frame as a whole. Technically, the eye really captures one frame (a fixation), does not see while it moves to a different viewpoint (a saccade), then it captures again. But from then on, the analogy breaks.

The captured light is not sent to a central perception-processing place in the brain as a package. Rather, there are many neurons on the first step of the visual processing (V1 area). And each of them is connected to a few retina cells, a few fellow neurons from the same area, and neurons from the next step of visual processing. No V1 neuron "sees" the whole frame. Each V1 neuron will fire when it is excited enough; but exciting and inhibiting signals come from all directions - retina cells, neighbour V1 neurons, hierarchically "higher" V2 neurons - which means that the input for the object we perceived is not just the light falling on the retina, but also what we have just perceived.

If you pick a single V1 neuron and count how often it fires, you can certainly count some kind of average rate, but it will not be much dependent on the rate at which eye fixations happen (which is actually a constant). It will have something to do with the amount of light falling on the retina, and the rate at which this light changes, but these are only a few of the contributing factors - what the brain has already recognized is another factor, through the signals coming from the "higher" neurons. So, if you try measuring at the first stage of the brain - which is the V1 neurons for vision - you can't operationalise your measures.

Besides, at that stage, no consolidation has happened yet. The information output of the V1 neuron is not a recognized object, they do very low-level recognition of textures, contours and similar. Information coming from other senses - the classical five ones, but also ones not widely known in popular culture, and ones which are known but not categorized as senses (such as pain, body spatial orientation) - gets incorporated into the recognized object along the way.

But one thing to recognize here is that, if you are asking about the effect *where the recognition process starts*, then no, your idea won't work. The V1 neurons can't process information coming from the other senses. They are connected to the retina, not to the cochlea. If we amputate a person's eyes (good thing this is a thought experiment only), the V1 neurons won't start processing sound signals instead.

But you are probably aware that blind people can recognize more of their environment based on other senses like sound, than sighted people wearing eyecovers. This indicates that the brain has learned to use the information coming through the other channels more efficiently.

**A speculation**

I think it is reasonable to assume that in the "sense switched off" situation the brain will also recognize more of the information coming in from other channels. The brain does not recognize everything that comes in from the senses, but only what it is interested in at the current moment. If there is nothing coming in through vision, it might "decide" to recognize more details coming in through sound than it would have otherwise.

This means that the assumption you mentioned in the comments is true, if we start looking at the effect *after recognition has happened* \- a person whose vision was "switched off" will extract more information out of the same amount of audio signals reaching the ear. But it is not really measurable, because we can only speculate how this information is represented within the brain. We don't have any metrics for "information as represented in the brain". Shannon found out how to measure informaiton which is stored somewhere accessible, as in a written word, but the information within the brain is not accessible, and its amount is only weakly correlated with the information available to the sensory organs.

Be aware that not only is the amount of the information in the brain not the one available to the sensory organs, but it is also created from a mix of sensory perceptions and knowledge. At that point, you can't hold apart what came from the senses and what didn't.

> When we look at something, perhaps 95% of what we consciously perceive is not what is "out there" but what is already in our heads in long-term memory. \[Colin Ware\]

Even if we could make measurements there, we wouldn't be just measuring the impact of the senses. We would have big trouble distinguishing it from the impact of memory.

**So, can we have a hierarchy?**

I explained why we can't have a hierarchy at the input-end of the recognition pathways. I speculated that we can have a hierarchy at the output-end - but even if my speculation is true, we can't measure anything at that end. So, the answer to the question as a whole is: **if there is a hierarchy, we can't measure it in the way you propose**.

I think there are experiments which try to make some rude sort of hierarchy, using observation of the kind "a person with covered eyes feels more disoriented than a person with stuffed ears". But this doesn't have the precision you are implying, does not answer to what extent the lower sense can be developed if the first one is missing permanently, and it can only be applied to the more prominent external senses like vision and hearing. (There are authors who argue that being certain of the truth of a statement is a sense - how do you turn that off?) Besides, experimentation with turning senses off can be dangerous, see research on sensory deprivation chambers for details.

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I don't have formatted citations for that post here. The information on the functioning of the visual pathway can be read in the book "Visual thinking for design" by Colin Ware. The info on how well one sense can replace another is certainly available in peer-previewed literature, but the one case I remember vividly is described by a journalist, http://www.mensjournal.com/article/print-view/the-blind-man-who-taught-himself-to-see-20120504. The author who claims certainty is a sense is Robert Burton.

# Answer
> 4 votes
I'm going to leave some commentary on your question—because you actually asked a lot of questions. Disclaimer—my answer is based on my understanding of human cognition, and I am not citing sources because I don't want this to be construed as a scientific answer.

*First question:* does the brain have different "sampling rates" for the various senses?
*Answer:* yes and no. Yes, in the sense that some senses are more sensitive than others (e.g. ears are capable of higher resolution/sensitivity than eyes), but mostly no because the brain does not work that way. It does not "sample" as a computer does. In perceiving senses, the brain is interpreting analog signals, which do not have discrete time-domain sampling. Instead, various parts of the brain work on the analog signals, performing operations to deduct information based on those signals (for example, audio signals are processed for frequency, intensity, spatial balance, etc.), and those computations are then passed along to higher-order cognitive functions. There is evidence that these lower-level processing centers are always operating, and that the resulting information is then processed by higher-order cognitive functions proportionally to the amount of attention you give to it (see information processing theory). If you want to learn more about this, do a search for hearing and/or vision disorders—that's where scientists learn the most about how the lower-level sensory processing works.

*Second question:* is there a rigid hierarchy for how the brain processes information from the senses? *Answer:* Probably not—how the brain processes information is very complex and I doubt anything about it is rigid. But this would be an interesting avenue of research.

*Third question*: are some senses innately less developed than others?
I'm sure the answer to this is yes, but I don't know, and I suspect that nobody else does either. A valid experiment to compare different sensory inputs would be very difficult to design, due to the limited nature of our understanding of how the senses coordinate together. Couple that with needing to control for individual differences, and you have a very difficult study. Furthermore, it has been shown that the brain can adapt to a loss of a sensory input (for example, the vestibular sense can be re-wired in the brain to respond to another stimuli, as in one study where electrical stimuli applied to the tongue of individuals who have lost it).

Finally, your question about `sensory inputs that were being drowned out by the other senses` crosses the divide between sensing and perceiving. Perceiving requires conscious thought and attention, whereas sensing happens automatically with no conscious input required (as far as we know- that was the gist of the multimodality topic in the other answer). So, maybe this can give you some things to think about?

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Tags: perception, measurement, sensation, signal-detection
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# Question
Title: Is there an easy way to tell whether I woke up during REM or non-REM sleep?
I wake up during the night. Is there an easy way to tell whether I've woken up during REM or non-REM sleep?

One way could be to look up the time, calculate how long I've slept and then take into account that, "An adult reaches REM approximately every 90 minutes"...

Are there other ways?

# Answer
> 2 votes
I tagged dreams here too because I think that's a prominent characteristic of REM sleep that might help you judge this. If I'm wrong, please remove the tag...but I don't think people remember dreams as often when they wake during non-REM sleep. That might be one cue, though I'm not certain of this.

Another idea off the top of my head would be recording yourself. Since REM = "rapid eye movement", you could probably tell whether you were in that stage before awakening if you trained a digital video recorder on your face (e.g., over your head, attached to a bedpost or headboard, aimed down at your face), and happen to sleep facing up sometimes. Rapid eye movements are noticeable through eyelids (kinda looks like a cat moving around underneath bedsheets—the raised hemispherical shape shifts around a lot), so given a decently high-resolution video recording of yourself, you could probably check this upon waking, or whenever afterward. If you don't see much eye movement, you might guess that you're not in REM sleep, though I'm not 100% sure you could make this judgment without error by yourself.

A relatively foolproof third option would be to sign up for a sleep study! I believe they routinely monitor brain waves that are more definitional, physiological markers of sleep stages. That might cost you, though.

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Tags: sleep, dreams
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title: Why is Mr. Monk unsure?

text:
# Question
Title: Why is Mr. Monk unsure?
One of the funniest and most psychologically intriguing characters on TV (in my opinion) is Adrian Monk. If you don't know who he is, I highly recommend watching the TV show. It's called "Monk" (naturally).

In the show, Monk is a character with pretty much every phobia imaginable. He has all the quirks and OCD stereotype characteristics. One of the challenges Monk faces often is inhibition when trying to make up his mind. Watch this clip for an example of what I mean:

Monk - Mr. Monk Gets Cabin Fever

I know that Monk is a fictional character, but the symptoms he has are very real and suffered from by many people daily (although seldom all at once, as is Monk's case). What I want to know is:

* What specifically is the trait that Monk exhibits in the clip?
* Does he have a phobia of being wrong, or is he just incapable of being sure of himself?
* Is it as simple as him just being very indecisive?

**Edit:** Thanks Nick Stauner for pointing this out. I will clarify: This question is based on the premise that Monk (or any other person) exhibiting this behavior does this frequently; not just a one time occurrence.

# Answer
> 3 votes
First, a major caveat: a less-than-30-second video clip of Monk in a particularly stressful context is insufficient basis for trait judgments, according to trait theory, which defines traits "as **habitual patterns of behavior, thought, and emotion**. According to this perspective, **traits are relatively stable over time**" (Kassin, 2003). Since this clip doesn't afford the opportunity to observe Monk over time, **it's dangerous to assume his eccentric behaviors are a result of his personality, not of his circumstances**. Most people could find themselves behaving thusly in the right circumstances. BTW, I acknowledge that outside of this clip's context, Monk's (fictional) behavior is often stably similar to this. This point is mostly meant to dissuade application of my points to other cases where context outside a 30-second observation is unavailable. That's not to say personality is entirely unobservable in such a short time though, just that it's difficult. You may want to read about the Realistic Accuracy Model of personality judgment (Funder, 1995, 1997) for a sense of when you can pick up on personality generally.

Second, you might try directing this to the Movies & TV Stack Exchange as well (or instead, if you wish), since Monk is a popular fictional character, and people over there probably love questions like this (can't say for sure, as I haven't spent much time there myself). That's not to say I mind answering here though. I also see you have three upvotes from our community already (make that three plus mine, and one unexplained downvote—shame on them :P ). I appreciate your genuine interest in our perspectives here!

Third, **assuming strictly for the sake of argument** that his behaviors *do* reflect his basic tendencies and characteristic adaptations (for context on these terms, see McCrae & Costa, 1999), *and not* other endogenous causes like physiological conditions (e.g., Parkinson's disease, low blood glucose, drugs)...I can first note that this is a relatively good situation for making trait judgments, in that it's unstructured, hence there's freedom for self-expression (Snyder & Ickes, 1985; Funder & Colvin, 1991), and in that it's an emotionally arousing situation, hence it provokes personality expression.

* The strongest eccentricity I note is the **fidgeting**. (BTW, I focus on strong eccentricities in general because normal behaviors are somewhat less diagnostic of traits, and more ambiguous for their inseparability from behaviors prescribed by social norms.) To me, fidgeting is a signal of high emotional arousal, and probably also slightly negative emotional valence (see the diagram of the circumplex model of emotion I included in this answer). Again, this could just be an emotional state, but assuming it's trait-level **negative emotionality**, this may imply **neuroticism**.
* **Self-doubt** is also characteristic of definitionally neurotic individuals—e.g., Woody Allen, or at least his public persona...though Wikipedia notes self-described phobias, which relate to neuroticism too. I wouldn't call this a phobia in "unsure Mr. Monk's" case though :) nor would I be sure that it's a result of his probable neuroticism. As a detective, it's his job to reason carefully and objectively. I probably should've mentioned before that we need to consider (and control in any statistical model) the stable influence of social roles when making judgments about role-relevant traits like self-doubt too. In this case, I'd read more into his personality from his initial certainty, which he then tempers with reason.
* In contrast to self-doubt, the initial **self-assurance** that he later judges to be inappropriate reminds me of "black-and-white" thinking (a.k.a., *splitting*). To some extent, we all do this initially, as it takes time to elaborate our initial reactions into probabilistic, pluralistic, or otherwise non-absolute judgments. When we act on these thoughts without inhibition, though—even if we later renounce those actions on further reflection—that's another hint of high emotional arousal, and maybe neuroticism. Disinhibition can also indicate low conscientiousness or **extraversion** (which relates to positive affect, including enthusiasm and confidence to the extent that these are emotions).

However, knowing what I do about Monk outside this context, I wouldn't say he's extraverted or unconscientious. If anything, I'd say his quick **switch from enthusiastic confidence** (the eagerness in his "eureka moment") **to self-doubt** expresses a strong ***need for affect*** (see Maio & Esses, 2001). Basically, this is a trait-level motive to seek emotional experience, and relates to emotional intensity in general—both positive and negative. You can probably also infer this need from his initial **decision to become a detective**—it's very emotion-provoking work. Also, his self-checking behavior and thorough reconsideration of the situation—even delayed as it is here—is a marker of high **conscientiousness**. Both detective work and self-checking may also reflect strong **needs for cognition and achievement**.
* Considering that he does the most **talking** and is somewhat **loud** at times, we might have more reason to infer extraversion, because this relates to talkativeness and dominance somewhat. However, again, considering his social role, and the context of the TV series overall (most of which I haven't watched, TBH), I don't really think he's particularly extraverted. This is one of those personality cues we'd probably read too much into if we only had this brief video clip to judge, and nothing more. However, a strong **need for power** might be safe to infer here—again, especially in light of his career choice in law enforcement. He might even tend toward high **authoritarianism**, in as much as this trait entails tendencies toward favoring harsh punishment of rule-breakers and strict enforcement of societal law and order. Authoritarianism is very similar to social dominance orientation and related to conservatism, but I don't think we have much indication here of those traits.
* Another source of information is his appearance. A colleague of mine, Laura Naumann(, Vazire, Rentfrow, & Gosling, 2009), would call the following *static cues* (as opposed to *dynamic cues*): he looks fairly healthy and neat (clean-shaven, clean clothes, buttoned shirt), and *not* what I would call fashionable. Here's what those cues indicated in Naumann and colleagues:

+ Healthy: extraverted, stable, likable, confident, and less lonely
    + Neat: extraverted, less open to experience, and less lonely
    + Unfashionable - introverted, lonely

Mixed signals here overall, especially in the context of the behaviors we've covered so far. The only not-so-mixed signals seems to be "likable" and "not open to experience".
* Your question itself provides some useful context: **obsessive-compulsive personality disorder (OCPD)**. I add the "P" for "personality" here because I happen to know his obsessions and compulsions aren't specific, but generalized, and I've checked this against the show's premise according to Wikipedia. I'm no clinician, so I can't say for sure that he wouldn't get diagnosed differently by a professional (if he were a real person, not just portrayed by one). Then again, professionals often make mistakes, and as far as I know, this is one of the primary ways of distinguishing OCPD from OCD.

OCPD may be useful for trait inferences, because in theory (Widiger, Trull, Clarkin, Sanderson, & Costa, 1994), it is an expression of pathologically extreme traits: i.e., extremely high neuroticism and conscientiousness. This is why I don't think he's unconscientious, and again, another reason why we might be wrong to read low conscientiousness into his initial disinhibition. (Also, a good example of why stability is so important in judging traits!) OCPD may also relate to low **agreeableness** and openness to experience, and to high extraversion, but again, this is according to Widiger and colleagues' (1994) theory, as cited in *The Personality Puzzle* (Funder, 1997).

I express doubt because I tried to find an independent source for these relationships just now, and found Morey, Gunderson, Quigley, and Lyons (2000), which contradicts Widiger and colleagues (1994). Morey and colleagues' data shows a pattern of **high neuroticism, low extraversion (i.e., introversion), and low agreeableness and conscientiousness in OCPD patients** relative to community norms. Low conscientiousness is the main contradiction of Widiger and colleagues. The low extraversion contradicts my previous understanding too, but I expected low agreeableness and high neuroticism.

BTW, the distinction between OCD and OCPD is important for judging trait relationships, as Samuels and colleagues (2000) found some different relationships between OCD and the Big Five. Unfortunately, I don't think they report their data about relationships between OCPD and the Big Five...

In **summary**, that adds up to the following list of probable trait scores:

* High neuroticism and negative emotionality
* High conscientiousness?
    + Monk's character seems based on the theoretical prototype of a conscientious person with OCPD (as in Widiger et al., 1994), but real people with OCPD tend not to be conscientious (Morey et al., 2000).
* Moderate-to-high extraversion?
    + This doesn't sit well with me for Monk. It might be indicated in this clip, but it seems unlikely for a real OCPD case, and doesn't suit my impression of Monk in general.
* Moderate-to-low openness to experience?
    + Indicated by his neat appearance, and maybe Widiger and colleagues' (1994) theory of OCPD
    + Real people with OCPD seem to be relatively average on openness (Morey et al., 2000).
* Somewhat high needs for achievement, power, cognition, and affect.
    + I know this theory a bit less well, but I'm comfortable saying he wouldn't score low on these.
* Maybe moderate-to-high authoritarianism?
    + A loose inference based on his profession and other apparent traits.
    + If I had to guess his political orientation from his traits, I'd say he's conservative. However, the show is set in San Francisco, which is relatively liberal, so this is also iffy.

**References**

Funder, D. C. (1995). On the accuracy of personality judgment: A realistic approach. *Psychological Review, 102*(4), 652–670. Retrieved from http://uwed.yolasite.com/resources/Funder\_On%20the%20Accuracy%20of%20Personality%20Judgment%20A%20Realistic%20Approac\_PR1995.pdf.
Funder, D. C. (1997). *The personality puzzle*. W. W. Norton & Co.
Funder, D. C., & Colvin, C. R. (1991). Explorations in behavioral consistency: properties of persons, situations, and behaviors. *Journal of Personality and Social Psychology, 60*(5), 773–794.
Kassin, S. (2003). *Psychology*. USA: Prentice–Hall, Inc.
Maio, G. R., & Esses, V. M. (2001). The need for affect: Individual differences in the motivation to approach or avoid emotions. *Journal of Personality, 69*(4), 583–614. Retrieved from http://psych.cf.ac.uk/esrcfertilitynetwork/pubs/Greg%20Maio\_%20The%20need%20for%20affect%20Individual%20differences%20in%20the%20motivation%20to%20approach%20or%20avoid%20emotions.pdf.
McCrae, R. R., & Costa Jr., P. T. (1999). A five-factor theory of personality. *Handbook of Personality: Theory and Research, 2*, 139–153.
Morey, L. C., Gunderson, J. G., Quigley, B. D., Shea, M. T., Skodol, A. E., McGlashan, T. H., ... & Zanarini, M. C. (2002). The representation of borderline, avoidant, obsessive-compulsive, and schizotypal personality disorders by the five-factor model. *Journal of Personality Disorders, 16*(3), 215–234.
Samuels, J., Nestadt, G., Bienvenu, O. J., Costa, P. T., Riddle, M. A., Liang, K. Y., ... & Cullen, B. (2000). Personality disorders and normal personality dimensions in obsessive—compulsive disorder. *The British Journal of Psychiatry, 177*(5), 457–462. Retrieved from http://bjp.rcpsych.org/content/177/5/457.long.
Snyder, M., & Ickes, W. (1985). Personality and social behavior. In G. Lindzey & E. Aronson (Eds.), *Handbook of social psychology* (3rd ed., Vol. 2, pp. 883–948). New York: Random House.
Widiger, T. A., Trull, T. J., Clarkin, J. F., Sanderson, C., & Costa, P. T. (1994). A description of the *DSM-III-R* and *DSM-IV* personality disorders with the five-factor model of personality. In P. T. Costa & T. A. Widiger (Eds.), *Personality disorders and the five-factor model of personality* (pp. 41–58). Washington, DC: American Psychological Association.

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Tags: decision-making, phobia, confidence
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# Question
Title: Is it good practice to try to recall things when we are tired?
**Background.** It happens often that, at the end of the day when I return to home, I try to recall past events that took place that day or the day before (memory rehearsal), but surprisingly I find that I have lost almost all details about some of them: while some details are kept "in good state", other are altered (false memory: wrong order of events, memory gaps, inconsistent and incoherent memories), and the rest are forgotten! Boundaries between details are blurred! Such things happen when I'm tired.

On the one hand, if I don't try to recall events, e.g. when I postpone such practice to a later moment (after resting), I will forget some details as I have wasted time.

On the other hand, when I try to rehearse some memories that happened the same day, it seems that the biological state of tiredness affects the ability to recall in such a manner that details become altered and false memories are produced (again a loss of information)! Both cases are bad, but which one is the worse?

The point of this question is to know whether the biological state of tiredness can definitely alter some critical events when we try to recall.

Should we avoid trying to recall events when we are tired?

# Answer
> 2 votes
You might not be looking for an answer about sleep deprivation per se—you might just be interested in normal daily fatigue immediately before normal sleep—but of course sleep deprivation results in tiredness, so the answer seems likely to be equivalent (though I'm not a sleep researcher by specialty). Here's an answer for sleep deprivation and memory (Alhola & Polo-Kantola, 2007):

> Total \[**sleep deprivation\] impairs** attention and **working memory**, but it also affects other functions, such as **long-term memory** and decision-making.

And another equivalent answer (Chee, Chuah, Venkatraman, Chan, Philip, & Dinges, 2006):

> Performance **accuracy declined significantly** during the performance of...**working memory tasks following \[sleep deprivation\]**.

**Reference**

Alhola, P., & Polo-Kantola, P. (2007). Sleep deprivation: Impact on cognitive performance. *Neuropsychiatric Disease and Treatment, 3*(5), 553–567. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/pmc2656292/.

Chee, M. W., Chuah, L. Y., Venkatraman, V., Chan, W. Y., Philip, P., & Dinges, D. F. (2006). Functional imaging of working memory following normal sleep and after 24 and 35 h of sleep deprivation: Correlations of fronto-parietal activation with performance. *Neuroimage, 31*(1), 419–428. Retrieved from http://www.med.upenn.edu/uep/user\_documents/Cheeetal--Functionalimagingofworkingmemory--NeuroImage2006.pdf.

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Tags: memory, arousal
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# Question
Title: When was it recognized that thinking occurs in the brain and not in the heart?
Historically speaking, this misconception used to exist, right? Somewhat like Copernican heliocentrism, no? When (and, if you wish, how) did this folk concept regarding the biological basis of cognition come to be revised?

When was it recognized that thinking occurs in the brain and not in the heart?

# Answer
Alcmaeon of Croton, who lived in the late 6th and early 5th century B.C., is said to have been the first to discover the optical and other sensory nerves. He believed that the nerves were hollow and conducted the sensation to the brain. Alcmaion saw the brain as the organ of perception, memory, thought and the control of action.

The Wikipedia article on the History of Neuroscience gives some more information on the later developments of this view.

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Source:

* Lloyd, G. (1975). Alcmeon and the early history of dissection. *Sudhoffs Archiv, 59*, 113–47.
> 5 votes

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Tags: history-of-psychology
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# Question
Title: How much alcohol is negative for brain function?
How much alcohol can you consume before it starts to kill a single neuron or interfere with proper brain functioning? Does it happen:

* If you take just a few drops of alcohol?
* If you drink a rum and coke cocktail?
* If you get so drunk that you cannot remember what you have done?

I like drinking a bit when I go out to pubs or the like, as I didn't consider that taking a pair of cups approximately once per month could do anything to my brain, but I've reconsidered it, so I'd like to know how much is needed to produce negative effects on the brain. Hope you can guide me with this.

# Answer
There is some debate as to wether alcohol consumption actually destroys brain cells or not. Jensen & Pakkenberg (1993) counted the neurons in the neocortex of deceased acoholics and found that they have the same number of neurons as non-alcoholic men.

Unfortunately the non-alcoholic control group did not consist of teetotallers but only "did not have any history or histological signs of alcohol abuse". It is not unprobable that the brains of people who never drank any alcohol and those of people who drank an amount of alcohol that is merely not considered abusive – a level that is certainly strongly influenced by cultural norms – do differ, so the results of this study have to be interpreted with some caution.

What Jensen and Pakkenberg did find was a reduction of white brain matter to which they attribute the functional deficits that follow alcohol abuse. This brain size reduction is replicated by several other studies, some of which find a reduction in grey matter volume of the frontal lobe as well (Pfefferbaum et al., 1997). For example, Ding et al. (2004) found that the chronic consumption of even smal amounts of alcohol causes brain size reduction. Ding et al. asked 1909 middle-aged adults for their drinking habits, took MRI scans, and found that "each additional alcoholic drink per week was associated with a 0.01 grade greater ventricular size (P=0.03) and a 0.009 grade greater sulcal size (P=0.02) after adjustment for age, sex, race, body mass index, smoking, income, sports index, and diabetes." The ventricles are cavities inside the brain, filled with cerebrospinal fluid, the sulci are the furrows that structure the surface of the brain. What the study found, in other words, was that chronic alcohol consumption enlarged these spaces between brain matter, which means that the brain matter was being reduced in volume.

While Jensen & Pakkenberg (1993) found no difference in the number of neurons of alcoholic and non-alcoholic brains, other studies did find differences, although limited to certain cortical regions. Harper and Kril (1989) found "that alcoholics have reduced neuronal counts in the superior frontal region of the cerebral cortex". That Jensen and Pakkenberg did not find these differences can probably be attributed to a "combined analysis of several cortical regions (Brooks, 2000).

> In summary, a combination of neuroimaging and histopathological data indicates that **heavy alcohol consumption over a long period of time as occurs in chronic alcoholics can result in the death of neurons in specific regions of the human brain, particularly the frontal cortical regions**. Careful selection criterion of subjects, along with unbiased stereological techniques, has provided strong evidence that this neuronal loss in ‘uncomplicated’ alcoholics is due to direct neurotoxic effects of alcohol itself, and not to other factors such as malnutrition or liver disease. (Brooks, 2000; emphasis mine)

The good news is that stopping to drink will have a positive effect (Pfefferbaum et al., 1998):

> However, brain atrophy and related neurological deficits induced by chronic alcohol abuse may be partially reversible through sustained abstinence. (Ding et al., 2004)

"Sustained" in this context means that it will take years for the brain to recover, not just the five workdays between weekend drinking bouts ;-)

Apart from neuronal death and brain atrophy directly caused by alcohol, chronic alcohol consumption has many other negative effects on the human organism. For example it damages the blood-brain barrier (Philips, 1982; Kornhuber et al., 1987; Elmas et al., 2001), which is a main factor in the development of neurodegenerative diseases (Singh et al., 2007). Effects on other organs such as the liver or heart can indirectly cause damage to the brain.

I was unable to find any sources that give exact numbers for how much alcohol (in what period of time) destroys how many neurons, directly or indirectly. The only indication I came upon is the correlation between brain volume reduction and drinks per week given in the study by Ding et al. (2004), that I quoted above. This gives some indication at least to the amount of damage, and that **every glass per week counts**.

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Note:

When you read scientific studies about the effects of alcohol, you must consider the author's affiliation. Many studies are financed by the beverage industry and may be biased. For example, a study that found that alcohol protected against diabetes was financed by the *Alcohol Task Force* of the foundation *International Life Sciences Institute*, in which Moët & Chandon, Allied Domecq, Brasseries Kronenbourg, Heineken und Diageo are members (Exler, 2007). Studies that show that consumption of red wine reduces the threat of cardiovascular diseases, were forged (Jaslow, 2012).

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Sources:

* Brooks, P. J. (2000). Brain atrophy and neuronal loss in alcoholism: a role for DNA damage?. *Neurochemistry international, 37*(5), 403-412.
* Ding, J., Eigenbrodt, M. L., Mosley, T. H., Hutchinson, R. G., Folsom, A. R., Harris, T. B., & Nieto, F. J. (2004). Alcohol Intake and Cerebral Abnormalities on Magnetic Resonance Imaging in a Community-Based Population of Middle-Aged Adults The Atherosclerosis Risk in Communities (ARIC) Study. *Stroke, 35*(1), 16-21. doi:10.1161/01.STR.0000105929.88691.8E
* Elmas, I., Küçük, M., Kalayci, R. B., Çevik, A., & Kaya, M. (2001). Effects of profound hypothermia on the blood–brain barrier permeability in acute and chronically ethanol treated rats. *Forensic Science International, 119*(2), 212-216.
* Exler, A. (2007, March 7). Vom Wein beseelt. *Die Zeit*. http://www.zeit.de/2007/11/Weinlobby
* Harper, C., & Kril, J. (1989). Patterns of neuronal loss in the cerebral cortex in chronic alcoholic patients. *Journal of the Neurological Sciences, 92*(1), 81-89.
* Jaslow, R. (2012, January 12). Red wine researcher Dr. Dipak K. Das published fake data: UConn. *CBS*. http://www.cbsnews.com/news/red-wine-researcher-dr-dipak-k-das-published-fake-data-uconn/
* Jensen, G. B., & Pakkenberg, B. (1993). Do alcoholics drink their neurons away?. *Lancet, 342*(8881), 1201-1204.
* Kornhuber, J., Kaiserauer, C. H., Kornhuber, A. W., & Kornhuber, M. E. (1987). Alcohol consumption and blood-cerebrospinal fluid barrier dysfunction in man. *Neuroscience Letters, 79*(1), 218-222.
* Pfefferbaum, A., Sullivan, E.V., Mathalon, D.H., & Lim, K.O. (1997). Frontal lobe volume loss observed with magnetic resonance imaging in older chronic alcoholics. *Alcoholism: Clinical and Experimental Research, 21*, 521–529.
* Pfefferbaum, A., Sullivan, E. V., Rosenbloom, M. J., Mathalon, D. H., & Lim, K. O. (1998). A controlled study of cortical gray matter and ventricular changes in alcoholic men over a 5-year interval. *Archives of General Psychiatry, 55*(10), 905-912.
* Phillips, S. C., & Cragg, B. G. (1982). Weakening of the blood-brain barrier by alcohol-related stresses in the rat. *Journal of the Neurological Sciences, 54*(2), 271-278.
* Singh, A. K., Jiang, Y., Gupta, S., & Benlhabib, E. (2007). Effects of chronic ethanol drinking on the blood–brain barrier and ensuing neuronal toxicity in alcohol-preferring rats subjected to intraperitoneal LPS injection. *Alcohol and Alcoholism, 42*(5), 385-399.
> 11 votes

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Tags: alcohol, brain-development
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# Question
Title: How to structure affective picture stimuli for an EEG study?
I want to design an EEG paradigm for passive affective picture viewing. Can I use a block design for three different emotions, where each block represent a particular emotion? Or would a better design randomize all the images of all emotions?

# Answer
> 5 votes
*Disclaimer: These are my preferences, biased by my own research experience.*

In general, I am not a fan of block designs. Blocking introduces difficulty in comparing both neural and behavioural activity between blocks due to effects of practice, fatigue, adaptation, learning, boredom, muscle tension and possibly others. It is of course possible to counter-balance block order across participants, but then you have to hope that *within* participants these effects will be roughly of the same magnitude in order to properly cancel out. Since in neuroimaging research we often don't go for large numbers of participants, I tend to prefer event-related designs.

I also sometimes look at signals which are so low in intensity (such as gamma power) that I want to avoid anything that will saturate the signal, and previous trials of the same type do generally saturate it quite a lot, sometimes to the point that I can't see it any more.

However, I also have two reasons for avoiding purely event-related designs. One is that some effects might depend on previous trials. If, for example, people don't react as much to happy stimuli if they're still recovering from the previous angry stimulus, or if they're surprised by the trial change (there's another emotion for you) and you are interested in the happy reaction itself, then you do need blocks... and you also need to discard the first few trials when a block changes. Another reason is that I might be manipulating too many variables in the task and it gets difficult for the study participants. In that case I might decide to manipulate one variable in a block-wise fashion and another in a trial-by-trial fashion. Only you know whether these restrictions apply to your design.

But even if I do go for a block design, I would never\* do all the trials in one trial type at once. Instead, I would create **mini-blocks**, consisting of a small number of trials, for example 10-20. Then I shuffle these mini-blocks randomly per participant, without repetitions. That way you can get all the positive effects from blocking with minimal negative effects.

.\* never again, that is.

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Tags: emotion, experimental-psychology, eeg
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# Question
Title: References for biologically plausible models of knowledge representation?
I'm looking for references that deal with the issue of how various kinds of semantic knowledge are (or might be) represented neurally. Most of the discussion of this topic seems skewed by social psychologists, who talk in very high-level terms of how various semantic constructs (such as goals) might be represented based on behavioral observations (cf. Eitam & Higgins, 2010). But it's been hard to find accounts that are both closer to the metal (that consider neural plausibility) and also high-level (that treat semantics more complex than associative strength between generic nodes.)

Can anyone point me to good material on this topic?

References:

# Answer
> 17 votes
In my experience, the term "semantic knowledge" (or semantic memory or conceptual knowledge) is generally used to refer to knowledge of objects, word meanings, facts and people, without connection to any particular time or place. The neural basis of this kind of knowledge is more or less agreed to depend on a distributed network of cortical brain regions (e.g., Martin, 2007; Patterson, Nestor, & Rogers, 2007). Tim Rogers and Jay McClelland (e.g., Rogers & McClelland, 2004) are among the leaders in developing biologically plausible computational models of semantic memory (and many others are working on it as well).

Goals are usually put in the domain of "executive functions" or "cognitive control" and generally associated with prefrontal (and frontal) cortical regions. I know somewhat less about this area of research, but there are definitely biologically plausible models being developed, including by Botvinick and Plaut (2004) and you might find what you're looking for in the work of Munakata and O'Reilly (e.g., Munakata et al., 2011)

References

# Answer
> 8 votes
I think this recent paper fits your requirements. It considers biological plausibility by showing that the number of neurons required in the proposed method is within a reasonable size for the human brain, and dismisses a series of unreasonable models. Specifically, they create a neural network using the Neural Engineering Framework (NEF) and the Semantic Pointer Architecture (SPA). The network contains 2.5 million neurons to contain a network of 100,000 concepts, which would only require 14.7mm$^2$, in contrast to another model discussed in the paper, which would required 500cm$^2$.

It's also "high-level" enough that it does not just consider relative strengths of nodes, but applies them to analysing vocabulary semantic information. For example, one of the three tests discussed in the paper is to see if the network is "smart" enough to determine that the word "dog" is a synonym for "canine".

The paper itself is kind of hard to swallow if you don't have the background with the NEF and SPA to approach it, so I recommend reading either this tutorial paper to get started or "How to Build a Brain" by Chris Eliasmith.

**Reference**

Eric Crawford, Matthew Gingerich, and Chris Eliasmith. Biologically plausible, human-scale knowledge representation. In *35th Annual Conference of the Cognitive Science Society*, 412–417. 2013.

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Tags: reference-request, cognitive-modeling, computational-modeling, neural-network, theoretical-neuroscience
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# Question
Title: Are there recent theories on physiognomy?
What are recent theories on the relation between personality and facial or body shape, and are there studies to support them?

See Wikipedia on physiognomy and somatotypes & constitutional psychology for background.

*I would be most happy if you could go beyond the well-known facts about intelligence and beauty.*

# Answer
> 14 votes
# Facial shape

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Aggression relates to facial width-to-height ratio (Carré, McCormick, & Mondloch, 2009; Carré & McCormick, 2008). The width-to-height ratio is the distance between the left and right zygion (the outside of the cheek bone) divided by the distance between the top of the upper lip and the mid-brow. Here's a useful image displaying the meaning of this ratio from the 2009 article:

>

Carré et al. found that the lower the width-to-height ratio, i.e. the shorter the distance between lip and brow in relation to the distance from cheekbone to cheekbone, the more aggressive the person is (as measured through a well-validated laboratory task) and is perceived by strangers.

Also, the Big Five differ in **observability** (Penton-Voak, Pound, Little, & Perrett, 2006). Participants were asked to rate the Big 5 aspects of the personality of strangers. There was a strong agreement between these ratings and the results of a personality test the depicted persons had filled in (reliability calculated as Cronbach's $\alpha=.70\text{–}.89$ for all dimensions, only male conscientiousness was $.63)$. Similar results were found with composite images.

Here are some composite facial images from that article:

>

Differences are subtle, but perceptible! BTW, I think I came across this from *The Personality Puzzle* (Funder, 1997) originally, but I'm not 100% certain.

Some of these facial differences may relate to testosterone. Dominance and masculinity relate to perceptible differences in male facial shape due to the prenatal influence of testosterone, but fortunately for the scope of this answer, these differences do not affect attractiveness to females (Neave, Laing, Fink, & Manning, 2003; Swaddle & Reierson, 2002).

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# Body shape

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**Body mass index**

There is some evidence that body mass index (BMI) relates to higher extraversion and psychoticism and lower neuroticism in middle-aged Japanese people (Kakizaki et al., 2008), impulsivity (Murphy, Stojek, & MacKillop, 2014; first citation of the new year!), hypomania (Valenti, Omizo, & Mehl-Madrona, 2011), and worse cognitive executive functioning (Gunstad et al., 2007). However, one study did not find a relationship between BMI and personality psychopathology (Picot & Lilenfeld, 2003). Another study found a positive relationship between neuroticism and BMI in middle-aged American women only (the opposite of the relationship in the Japanese population according to Kakizaki et al., who did not mention prominent sex differences) and extraversion among men only (same direction as in Kakizaki et al., but again, more sex differences), as well as negative relationships with openness, agreeableness, and conscientiousness (Brummett et al., 2006). Low conscientiousness related more strongly to BMI in women, and predicted BMI increases over time.

**Testosterone**

Another set of correlations between personality and body shape are mediated by testosterone, which affects several, readily observable, physical characteristics, including muscle mass, bone length, vocal pitch and tone, hair growth patterns, body odor, dermal oil secretion and acne, subcutaneous facial fat and facial bone contours, and prominence of the Adam's apple. Testosterone relates to many behavioral patterns in romantic relations, the general trend being toward more competitive promiscuity and less long-term fidelity with increasing testosterone (e.g., Burnham et al., 2003). Testosterone increases in men anticipating competition, but may decrease in women (Mazur, Susman, & Edelbrock, 1997). This effect may be moderated by implicit power motivation (Schultheiss, Campbell, & McClelland, 1999); if so, it's conceivable that personality could affect appearance over time by altering testosterone levels. Power motivation interacts in complex ways with sex and the outcome of social contexts in affecting testosterone (Schultheiss et al., 2005; Schultheiss, Wirth, & Stanton, 2004).

One of the underlying personality differences associated with testosterone appears to be in sexual motivation, which manifests in non-human animals as well. Testosterone also relates to sensation-seeking (Roberti, 2004; Gerra et al., 1999; Daitzman & Zuckerman, 1980; Zuckerman, Buchsbaum, & Murphy, 1980) and risk tolerance (Sapienza, Zingales, & Maestripieri, 2009; Stanton et al., 2011; Stanton, Liening, & Schultheiss, 2011), though the relationship exhibits some complexities across domains of risk (Stenstrom, Saad, Nepomuceno, & Mendenhall, 2011). The relationship between testosterone and risk aversion may be mediated by abstract reasoning ability (Brañas-Garza & Rustichini, 2011).

Testosterone also relates to dominance (Mazur & Booth, 1998), aggression (Archer, 2006; Birger et al., 2003; Ehrenkranz, Bliss, & Sheard, 1974; Archer, Birring, & Wu, 1998), and lack of empathy, the last of which appears to be an empirically established effect of testosterone (Chapman et al., 2006; Knickmeyer, Baron-Cohen, Raggatt, Taylor, & Hackett, 2006; van Honk et al., 2011; Ronay & Carney, 2013; see also Auyeung & Baron-Cohen, 2013). Testosterone may even explain deficits in social development (Knickmeyer & Baron-Cohen, 2006) and autistic traits in general (Auyeung et al., 2009; Ingudomnukul, Baron-Cohen, Wheelwright, & Knickmeyer, 2007), according to a theory that conceptualizes autism as extreme cognitive maleness (Baron-Cohen, 2002; Baron-Cohen, Knickmeyer, & Belmonte, 2005; Chakrabarti et al., 2009).

Testosterone relates positively to emotional arousal and anger, but also relates positively to attentiveness to angry facial expressions in others (van Honk et al., 1999). This latter result demonstrates that testosterone doesn't unilaterally decrease awareness of others' emotional states, especially to whatever extent they pose immediate threat. The relationship between testosterone and antisocial behavior is also moderated by socioeconomic status (Dabbs & Morris, 1990). These complexities may limit the otherwise impressive relationships between personality and testosterone.

In women, estradiol may instead play a similar role to testosterone in men, modifying dominance motivation (Stanton & Schultheiss, 2009). Wikipedia lists some observable physiological effects of estradiol, but these claims currently lack supporting citations.

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**References** (there's a ton; I recommend zooming in with `Ctrl`+`+` or copy-pasting into a word processor)
 **·** Archer, J. (2006). Testosterone and human aggression: An evaluation of the challenge hypothesis. *Neuroscience & Biobehavioral Reviews, 30*(3), 319–345. Retrieved from http://aggroreview.googlecode.com/svn-history/r31/sources/downloaded/testosterone/Archer\_2004.pdf.
**·** Archer, J., Birring, S. S., & Wu, F. C. (1998). The association between testosterone and aggression among young men: Empirical findings and a meta‐analysis. *Aggressive Behavior, 24*(6), 411–420.
**·** Auyeung, B., Baron‐Cohen, S., Ashwin, E., Knickmeyer, R., Taylor, K., & Hackett, G. (2009). Fetal testosterone and autistic traits. *British Journal of Psychology, 100*(1), 1–22. Retrieved from http://www.personal.rdg.ac.uk/~sxs02dtf/auyeung2009.pdf.
**·** Auyeung, B., & Baron‐Cohen, S. (2013). Prenatal and postnatal testosterone effects on human social and emotional behavior. In S. Baron-Cohen, M. Lombardo, H. Tager-Flusberg, & D. Cohen (Eds.), *Understanding Other Minds: Perspectives from developmental social neuroscience*. Oxford University Press.
**·** Baron-Cohen, S. (2002). The extreme male brain theory of autism. *Trends in Cognitive Sciences, 6*(6), 248–254. Retrieved from http://cogsci.bme.hu/~ivady/bscs/read/bc.pdf.
**·** Baron-Cohen, S., Knickmeyer, R. C., & Belmonte, M. K. (2005). Sex differences in the brain: implications for explaining autism. *Science, 310*(5749), 819–823. Retrieved from http://docentes.cs.urjc.es/~odeluis/Docencia/ABP/Articulos/baroncohen.pdf.
**·** Birger, M., Swartz, M., Cohen, D., Alesh, Y. A., Grishpan, C., & Kotelr, M. (2003). Aggression: The testosterone-serotonin link. *IMAJ-RAMAT GAN-, 5*(9), 653–658. Retrieved from http://www.ima.org.il/FilesUpload/IMAJ/0/54/27288.pdf.
**·** Brañas-Garza, P., & Rustichini, A. (2011). Organizing effects of testosterone and economic behavior: Not just risk taking. *PLoS ONE, 6*(12), e29842. Retrieved from http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0029842#pone-0029842-g001.
**·** Brummett, B. H., Babyak, M. A., Williams, R. B., Barefoot, J. C., Costa, P. T., & Siegler, I. C. (2006). NEO personality domains and gender predict levels and trends in body mass index over 14 years during midlife. *Journal of Research in Personality, 40*(3), 222–236. Retrieved from ResearchGate.
**·** Burnham, T. C., Chapman, J. F., Gray, P. B., McIntyre, M. H., Lipson, S. F., & Ellison, P. T. (2003). Men in committed, romantic relationships have lower testosterone. *Hormones and Behavior, 44*(2), 119–122. Retrieved from http://www.bec.ucla.edu/papers/Gray\_10-20-03.pdf.
**·** Carré, J. M., & McCormick, C. M. (2008). In your face: Facial metrics predict aggressive behaviour in the laboratory and in varsity and professional hockey players. *Proceedings of the Royal Society B: Biological Sciences, 275*(1651), 2651–2656. Retrieved from http://rspb.royalsocietypublishing.org/content/275/1651/2651.full.pdf%20html.
**·** Carré, J. M., McCormick, C. M., & Mondloch, C. J. (2009). Facial structure is a reliable cue of aggressive behavior. *Psychological Science, 20*(10), 1194–1198. Retrieved from http://carrelab.com/Carre\_et\_al\_2009\_Psyc\_Sci.pdf.
**·** Chakrabarti, B., Dudbridge, F., Kent, L., Wheelwright, S., Hill‐Cawthorne, G., Allison, C., ... & Baron‐Cohen, S. (2009). Genes related to sex steroids, neural growth, and social–emotional behavior are associated with autistic traits, empathy, and Asperger syndrome. Autism Research, 2(3), 157–177. Retrieved from http://onlinelibrary.wiley.com/doi/10.1002/aur.80/full.
**·** Chapman, E., Baron-Cohen, S., Auyeung, B., Knickmeyer, R., Taylor, K., & Hackett, G. (2006). Fetal testosterone and empathy: Evidence from the empathy quotient (EQ) and the “reading the mind in the eyes” test. *Social Neuroscience, 1*(2), 135–148. Retrieved from http://docs.autismresearchcentre.com/papers/2006\_Chapman\_etal.pdf.
**·** Daitzman, R. J., & Zuckerman, M. (1980). Disinhibitory sensation seeking and gonadal hormones. *Personality and Individual Differences, 1*, 103–110.
**·** Dabbs, J. M., & Morris, R. (1990). Testosterone, social class, and antisocial behavior in a sample of 4,462 men. *Psychological Science, 1*(3), 209–211. Retrieved from http://connect.issaquah.wednet.edu/cfs-file.ashx/\__key/telligent-evolution-components-attachments/13-8431-00-00-00-04-77-28/Testosterone-and-Antisocial-behavior.pdf
**·** Ehrenkranz, J., Bliss, E., & Sheard, M. H. (1974). Plasma testosterone: Correlation with aggressive behavior and social dominance in man. *Psychosomatic Medicine, 36*(6), 469–475.
**·** Funder, D. C. (1997). *The personality puzzle*. W. W. Norton & Co.
**·** Gerra, G., Avanzini, P., Zaimovic, A., Sartori, R., Bocchi, C., Timpano, M., Zambelli, U., Delsignore, R., Gardini, F., Talarico, E., & Brambilla, F. (1999). Neurotransmitters, neuroendocrine correlates of sensation-seeking temperament in normal humans. *Neuropsychobiology, 39*, 207–213.
**·** Gunstad, J., Paul, R. H., Cohen, R. A., Tate, D. F., Spitznagel, M. B., & Gordon, E. (2007). Elevated body mass index is associated with executive dysfunction in otherwise healthy adults. *Comprehensive Psychiatry, 48*(1), 57–61. Retrieved from http://postcog.ucd.ie/files/Gunsted.pdf.
**·** Ingudomnukul, E., Baron-Cohen, S., Wheelwright, S., & Knickmeyer, R. (2007). Elevated rates of testosterone-related disorders in women with autism spectrum conditions. *Hormones and Behavior, 51*(5), 597–604. Retrieved from http://beyond-belief.org.uk/sites/beyond-belief.org.uk/files/Baron-Cohen%20hormonesandbehavior.pdf.
**·** Kakizaki, M., Kuriyama, S., Sato, Y., Shimazu, T., Matsuda-Ohmori, K., Nakaya, N., ... & Tsuji, I. (2008). Personality and body mass index: A cross-sectional analysis from the Miyagi Cohort Study. *Journal of Psychosomatic Research, 64*(1), 71–80.
**·** Knickmeyer, R. C., & Baron-Cohen, S. (2006). Fetal testosterone and sex differences. *Early Human Development, 82*(12), 755–760.
**·** Knickmeyer, R., Baron-Cohen, S., Raggatt, P., Taylor, K., & Hackett, G. (2006). Fetal testosterone and empathy. *Hormones and Behavior, 49*(3), 282–292. Retrieved from http://www.researchgate.net/publication/7540638\_Fetal\_testosterone\_and\_empathy/file/50463515da285cea18.pdf.
**·** Mazur, A., & Booth, A. (1998). Testosterone and dominance in men. *Behavioral and Brain Sciences, 21*(3), 353–363. Retrieved from http://cogprints.org/663/1/bbs\_mazur.html.
**·** Mazur, A., Susman, E. J., & Edelbrock, S. (1997). Sex difference in testosterone response to a video game contest. *Evolution and Human Behavior, 18*(5), 317–326. Retrieved from http://cogprints.org/630/1/Pong.html.
**·** Murphy, C. M., Stojek, M. K., & MacKillop, J. (2014). Interrelationships among impulsive personality traits, food addiction, and Body Mass Index. *Appetite, 73*, 45–50.
**·** Neave, N., Laing, S., Fink, B., & Manning, J. T. (2003). Second to fourth digit ratio, testosterone and perceived male dominance. *Proceedings of the Royal Society of London. Series B: Biological Sciences, 270*(1529), 2167–2172. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1691489/pdf/14561281.pdf.
**·** Penton-Voak, I. S., Pound, N., Little, A. C., & Perrett, D. I. (2006). Personality judgments from natural and composite facial images: More evidence for a “kernel of truth” in social perception. *Social Cognition, 24*(5), 607–640. Retrieved from http://www.alittlelab.stir.ac.uk/pubs/Penton-Voak\_06\_kernaloftruth\_SocCog.pdf.
**·** Picot, A. K., & Lilenfeld, L. R. (2003). The relationship among binge severity, personality psychopathology, and body mass index. *International Journal of Eating Disorders, 34*(1), 98–107.
**·** Roberti, J. W. (2004). A review of behavioral and biological correlates of sensation seeking. *Journal of Research in Personality, 38*(3), 256–279. Retrieved from ftp://psyftp.psychology.mcmaster.ca/dalywilson/Papers/DawnPatrol/Roberti2004.pdf.
**·** Ronay, R., & Carney, D. R. (2013). Testosterone’s negative relationship with empathic accuracy and perceived leadership ability. *Social Psychological and Personality Science, 4*(1), 92–99. Retrieved from http://faculty.haas.berkeley.edu/dana\_carney/published.Ronay%26Carney.2012.SPPS.pdf.
**·** Sapienza, P., Zingales, L., & Maestripieri, D. (2009). Gender differences in financial risk aversion and career choices are affected by testosterone. *Proceedings of the National Academy of Sciences, 106*(36), 15268–15273. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2741240/.
**·** Schultheiss, O. C., Campbell, K. L., & McClelland, D. C. (1999). Implicit power motivation moderates men's testosterone responses to imagined and real dominance success. *Hormones and Behavior, 36*(3), 234–241. Retrieved from http://www.psych2.phil.fau.de/~oschult/humanlab/publications/scm1999.pdf.
**·** Schultheiss, O. C., Wirth, M. M., & Stanton, S. J. (2004). Effects of affiliation and power motivation arousal on salivary progesterone and testosterone. *Hormones and Behavior, 46*(5), 592–599. Retrieved from http://www.psych2.phil.uni-erlangen.de/~oschult/humanlab/publications/sws2004hb.pdf.
**·** Schultheiss, O. C., Wirth, M. M., Torges, C. M., Pang, J. S., Villacorta, M. A., & Welsh, K. M. (2005). Effects of implicit power motivation on men's and women's implicit learning and testosterone changes after social victory or defeat. *Journal of Personality and Social Psychology, 88*(1), 174–188. Retrieved from http://www.psych2.phil.uni-erlangen.de/~oschult/humanlab/publications/s2005jpsp.pdf.
**·** Stanton, S. J., Liening, S. H., & Schultheiss, O. C. (2011). Testosterone is positively associated with risk taking in the Iowa Gambling Task. *Hormones and Behavior, 59*(2), 252–256. Retrieved from http://www.scottliening.com/research/publications/StantonLieningSchultheiss\_HB.pdf.
**·** Stanton, S. J., O’Dhaniel, A., McLaurin, R. E., Kuhn, C. M., LaBar, K. S., Platt, M. L., & Huettel, S. A. (2011). Low-and high-testosterone individuals exhibit decreased aversion to economic risk. *Psychological Science, 22*(4), 447–453. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3653580/.
**·** Stanton, S. J., & Schultheiss, O. C. (2009). The hormonal correlates of implicit power motivation. *Journal of Research in Personality, 43*(5), 942–949. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2818294/.
**·** Stenstrom, E., Saad, G., Nepomuceno, M. V., & Mendenhall, Z. (2011). Testosterone and domain-specific risk: Digit ratios (2D: 4D and *rel*2) as predictors of recreational, financial, and social risk-taking behaviors. *Personality and Individual Differences, 51*(4), 412–416.
**·** Swaddle, J. P., & Reierson, G. W. (2002). Testosterone increases perceived dominance but not attractiveness in human males. *Proceedings of the Royal Society of London. Series B: Biological Sciences, 269*(1507), 2285–2289. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1691166/pdf/12495494.pdf.
**·** Valenti, M. P., Omizo, M. M., & Mehl-Madrona, L. (2011). Personality and obese Body Mass Index. *The New School Psychology Bulletin, 9*(1), 34–38. Retrieved from http://www.nspb.net/index.php/nspb/article/viewFile/204/294.
**·** van Honk, J., Schutter, D. J., Bos, P. A., Kruijt, A. W., Lentjes, E. G., & Baron-Cohen, S. (2011). Testosterone administration impairs cognitive empathy in women depending on second-to-fourth digit ratio. *Proceedings of the National Academy of Sciences, 108*(8), 3448–3452. Retrieved from http://www.researchgate.net/publication/49817064\_Testosterone\_administration\_impairs\_cognitive\_empathy\_in\_women\_depending\_on\_second-to-fourth\_digit\_ratio/file/d912f50b5d773ca9e0.pdf.
**·** van Honk, J., Tuiten, A., Verbaten, R., van den Hout, M., Koppeschaar, H., Thijssen, J., & de Haan, E. (1999). Correlations among salivary testosterone, mood, and selective attention to threat in humans. *Hormones and Behavior, 36*(1), 17–24.
**·** Zuckerman, M., Buchsbaum, M. S., & Murphy, D. L. (1980). Sensation seeking and its biological correlates. *Psychological Bulletin, 88*(1), 187–214.

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Tags: personality, physiology
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# Question
Title: Cosyne vs CNS conferences for Computational Neuroscience?
While Googling, I noticed there are 2 conferences for computational neuroscience: Cosyne and CNS.

My questions are:
1) What are these conferences' differences in terms of material & impact/size?
2) Are there any other major computational neuroscience conferences I missed?

Thanks!

# Answer
I have participated in NIPS, CNS, and COSYNE at least a couple times each. In fact, I have participated in all 3 last year.

COSYNE is the smallest conference, but it's growing fast. It's a great conference because it has a good balance between experimentalists and theorists. It takes an extended abstract (2 pages). It emphasizes the systems aspect of the brain.

CNS has more physicist/mathematicians (COSYNE and NIPS also have a high number of them, but CNS has the most), and has a feeling of "European" science. The themes are more theory oriented. I heard that it is usually bigger when it's held in Europe (it alternates).

NIPS started half machine learning, half neuroscience a long time ago, but it has been overrun by ML people. But, in recent years, I see more and more computational neuroscience coming back to NIPS. It has a strict double blind reviewing with high rejection rate around 25% for an 8 page full paper (+1 page reference).

Each conference has its own niche, so the impact would depend on your area within computational neuroscience. NIPS is the only one with a full paper, so it tends to be cited more. However, a lot of networking happens in COSYNE and CNS among neuroscientists, so it would definitely have more impact to experimentalists.

Feel free to ask me more questions.
> 7 votes

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Tags: computational-modeling, theoretical-neuroscience
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title: Neuroscience student

text:
# Question
Title: Neuroscience student
I'm thinking about studying neuroscience, but the only **interests I have in the general area** are:

* Where thought or consciousness come from and how it all works
* How memory works and why it can't be accessed at all times
    + Can it be increased, and does it have a limit?
    + How a smell can bring back a memory?
    + Why, if I remember a scene or a moment, can I not relive an entire day or month? Will this be possible in the future?

Also, I love biology and am doing a course in chemistry and lab work at the moment, but I'm afraid I'll be disappointed if I study neuroscience for these reasons. **Are these questions more theoretical and philosophical than what a neuroscience student would actually study?**

# Answer
Cognitive sciences are an interdisciplinary field between:

* psychology
* sociology
* philosophy
* medical sciences
* biology
* physics
* chemistry
* palaeontology / anthropology
* ethnology
* information sciences
* linguistics
* I believe I forgot something

The core is probably somewhere around psychology, neurobiology (including endocrinology) and artificial intelligence, though others would lay the focus elsewhere.

It does not matter much which of these fields you study, if you aim at an academic career studying cognition, because you will have to make yourself familiar with, or even an expert, in most of the other fields, if you want to go beyond a master's degree. Where you put *your* focus, is a matter of personal preference, and no matter where that is, you will be working in a team of experts from different fields. I'm studying psychology, and at our institute (of psychology) we have researchers who studied medicine, physics, information science, and pedagogy. In the neuroscience institute next door, there are psychologists, biologists, medical scientists (including psychiatrists) and probably more that I don't know. Despite their different backgrounds, they now all work on the same research topics.

So while it does not matter (much) which first topic you choose, you need to be open and curious of mind, to be successful in science. If, as you say, you are interested only in a very narrow field, interdisciplinary work will be impossible for you. You won't be able to follow your topic to where it leads you. Sometimes, when you research something, you realize that the answer to a relevant question, that you need to answer before you can go on, lies in another field. Then you must study that field. If you don't, that will hamper your understanding and research.

The best scientists, in my opinion, are those that are basically curious and want to understand and learn. They all have their individual talents, and certainly no one can know and understand everything, but the most successful researchers today are experts in several fields and interested in several others.

On the other hand, there are those hard working lab rats that get things done, and they are invaluable, too. The question is, can you see yourself as doing the grunt work, or do you want to really understand it all?

But then maybe that is all something you cannot know in advance. You need to experience things to know if they are for you or not. When I was fresh from school, I had very limited interests and a wide array of clearly defined dislikes (everything I had to learn in school). But in the years that followed, I understood that I am basically interested in everything, even the subjects that I hated in school. And what I found the most interesting at first, I lost interest in after studying it for a few years. Now I study something else.

What I would recommend is:

* read the internet sites of the university institutes and some introductory textbooks in the three or four fields that you are most interested in
* choose the one whose *methodology* you like best: do you want to dissect brains, do statistical data analysis, program software, work on people or animals, theorize or spend nights in the lab, ... ?
* study that
* if after a year or two you realize you want something else, switch (but understand that every field includes stuff you find boring)
* finish your master's
* reflect on what you learned and understand what interests you for the next few years
* find a research group and do your Ph.D.
* again reflect and decide on the next steps
* don't worry, there are many successful non-linear careers in science
> 3 votes

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Tags: theoretical-neuroscience, neurology
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# Question
Title: Can placebo effect be increased by modifying the perception about prescription/intake setting?
I've noticed the following pattern within my own thinking - multiple unrelated events "combine" to produce a certain action, particularly creativity and innovation. I'm trying to understand if this phenomenon is true or common among people. As a way to learn more about this, I thought that placebo effect would be a good place to start.

To clarify my question: imagine you are going to get a drug prescription. It will be a placebo, but you don't know that. **Would combining factors like below increase the effectiveness of placebo?**

* clean doctors office
* a traditional white coat doctor like on stock photos treating you
* positive demeanor of staff
* perception of privacy
* thinking you are being prescribed a drug you have researched well and feel safe about
* seeing a presentation about the advances of modern medicine within a week before

Contrast this with the following:

* a dark, cramped waiting room
* long wait and short consultation
* a physician assistant or a nurse practitioner seeing you instead of MD
* unknown drug you have never heard of
* perceiving some negative news within last week

I'm trying to understand **if a combination of unrelated events indeed does combine to affect the effectiveness of placebo?** If so, is there the primary cause of change (like PA-C prescribing vs MD)?

I found the following on Wikipedia which makes me even more curious:

> The expectancy effect\[of placebo\] **can be enhanced** through factors such as the enthusiasm of the doctor, differences in size and color of placebo pills, or the use of other interventions such as injections. In one study, the response to a placebo increased from 44% to 62% **when the doctor treated them with "warmth, attention, and confidence."\[47\]**

Here is what I think the traditional expectation of a doctor is:

# Answer
> 6 votes
I think the field of **persuasive communication** is relevant for your answer, as well as research into the **efficacy of psychotherapy**.

Customers trust advertising if it is communicated by:

* attractive persons
* credible experts

Psychotherapy is more effective if:

* the therapist believes that his methods are effective (!)
* patient and therapist share the same world view and values
* patient and therapist like each other

What constitutes attractiveness, expertise, common values, and sympathy, will differ among individuals. For some, expensive architecture makes a bank more trustworthy; for others it is a sign of waste and mismanagement. So you will have to identify the exact parameter value for each target group or, for perfect fit, even each individual person. But basically what you have here are *moderators* that affect the efficacy of a placebo.

What is noteworthy is that the belief of the person administering the placebo has an effect. So it's better they don't know it is a placebo, but have been given it by a person they in turn trust.

---

There is *a lot* of research into both areas; I give only one introductory source each (both of which respectively include what I quoted above):

* Goldstein, N. J., Martin, S. J., & Cialdini, R. B. (2008). *Yes!: 50 Scientifically Proven Ways to Be Persuasive*. New York: Simon and Schuster.
* Wampold, Bruce E. (2001). *The Great Psychotherapy Debate: Models, Methods and Findings*. New York: Routledge.

Don't be fooled by the popular nature of the first book; Robert Cialdini is an eminent expert on persuasion. If you want, there are more scientific publications by this author.

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Tags: cognitive-psychology, conditioning, placebo
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# Question
Title: How does the brain learn what something is for the first time?
**I'm trying to understand how the idea of what a thing is originates in humans.**

For example, in computer science, it is possible to know what an object is and what it does, by examining its "parent/ancestor" objects with concepts of inheritance:

> In object-oriented programming (OOP), inheritance is a way to reuse code of existing objects, or to **establish a subtype from an existing object**

and polymorphism, where objects may share similar function:

> Subtype polymorphism, often referred to as simply polymorphism in the context of object-oriented programming, is the ability to create a variable, a function, or **an object that has more than one form**. In principle, polymorphism can arise in other computing contexts and shares important similarities with the concept of degeneracy in biology

What makes me interested in this is that human children do not learn all words at once - there's a slow, but steady exposure to new stimuli, which are quantified, remembered and become available as concepts and words. The exact order of exposure is unknown, but if I remember correctly, most people know about 20000 words, and use about 6000 in daily interactions.

For example, a child has never seen a potato. A child sees a potato for the first time. A child has neither an idea nor a word for a potato. Now the child's brain has to create an idea of what a potato is.

**The question**: When a child is exposed to a new stimuli, as in the example above, does the child's brain:

1. create a brand new representation of an object
2. or does a person's brain modify and re-purpose the "closest matching" idea and add extra attributes to it? (a potato looks like a brown rock)

In other words, has there been any research that found evidence for case 2: a **"common ancestor" for ideas and objects within a person's mind?** (if a person forgets "rock", then the person also forgets "potato").

I don't know where to begin a search for the answer. Are there some keywords that I can use? Maybe scholarly articles on cases of unusually high working memory capacity for related objects?

# Answer
> 13 votes
According to current models of human concept learning, the answer to your question is **both**.

Think of a simplified domain in which every object consists of only several features, and therefore can be visualized as a point in some multidimensional feature space. For example, the features that define objects might be its size, shape, color, and weight. Furthermore imagine that objects tend to be clustered throughout this space according to what category they belong to, because members of the same category are generated by the same natural process.

So based on current models, a novel stimulus is compared to existing concepts and is either placed into the concept (cluster) that it's closest to, or if it's insufficiently close to any existing concept, then a new concept will be created. This is the basic idea of current Bayesian theories such as the Rational Model, which treats human category learning as a problem of probability density estimation, and its contenders such as SUSTAIN.

Here's a video lecture by Josh Tenenbaum, a leading researcher in both machine learning and cognitive science, in which he gives an excellent introduction to a number of these issues and many more.

# Answer
> 4 votes
You are looking at learning from the wrong direction.

A child does not learn a word. A child learns about a detail of the world *and* the word that is used to denote it. The word comes with the experience and is only attached to that experience as a label. What the child learns is the world.

Adult learning is mostly similar. You either observe or experience that applying a certain action to a certain object leads to a certain result. You label these objects, actions and results with words for easy communication.

E.g. you won't understand what an accelerator pedal is, unless you observe, experience or have explained what it does and how it is used. That is, learning about complex objects, like the accelerator pedal, you will have to put them in relation to other aspects of the world that you have already learned (what is a car? what is the purpose of transportation? etc.). The first and very simple details about the world that we learn as children will have no previous knowledge that they can be related to, so you learn them *as is*: red creates this reaction in your brain, sour makes your face scrunch up.

Children learn the fundamental aspects of the world before they even know their first word, and they will continue learning, even if they are not or only rarely exposed to language (e.g. with mute parents). Words are not necessary for learning, although they can facilitate it greatly.

# Answer
> 2 votes
I've found an additional concept that may be related to the original question: prototype theory. Here's a summary from Wikipedia:

> Prototype theory is a mode of graded categorization in cognitive science, where some members of a category are more central than others. For example, when asked to give an example of the concept furniture, chair is more frequently cited than, say, stool. Prototype theory has also been applied in linguistics, as part of the mapping from phonological structure to semantics.

According to this theory, **rather than a common ancestor for words, there's a common shared category**, which can be thought as a parent object. A potato and a fist sized rock would share the rounded object category, but the rock would also have a "rocky texture" category

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Tags: neuroscience, learning, memory, language, perceptual-learning
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# Question
Title: What is the purpose of hemispheric specialisation in the brain?
What is the benefit or purpose of having different hemispheres of the brain contribute more to different cognitive processes?

# Answer
> 5 votes
First, biological features do not always arise from some intrinsic benefit. They can also be byproducts of other adaptations, or *spandrels*.

That being said, one example of a possible benefit is specialization. For instance, birds will develop asymmetries in their visual system based on light inputs to their outward-facing eye (one eye faces the eggshell, the other is obscured within the egg). Distinct asymmetries in the brain allow birds to use one eye or brain region for finding and tracking prey (a very robust detail-oriented object identifier), and the other will be turned towards the sky, looking out for predators (and isn't as detail-oriented).

From **Encoding asymmetry within neural circuits**:

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Tags: cognitive-psychology, cognitive-neuroscience, neuroanatomy, lateralization
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# Question
Title: What is the psychological function of nostalgically reenacting activities from before we were born?
I'm asking specifically about nostalgia for a time before you were born, e.g. the Blitz parties / 40s tea dances that have big in the UK for the past decade, or the popularity of Speakeasy-themed bars in the US. I'm thinking of nights that require you to dress in theme specifically and celebrate that time.

I was discussing it with a friend today, and I said it seems like it's a way to participate in something your grandparents did that strengthens your bonds to your own family, but she (rightly) replied that her own grandma had never been to a dance – she'd been too poor. It seems to me like when we're at the tea dance or in the speakeasy or whatever, we're doing something more than faithfully reenacting the things our forebears did, but I'm not sure what that is or why. Are we celebrating the best bits and leaving the rest behind? Are we thoughtlessly celebrating a time of awful gender and racial inequality? Does anyone have any insight into this kind of nostalgia, the nostalgia for things you've never experienced yourself, and the act of participating in themed events, and what functions that has socially/psychologically?

# Answer
> 3 votes
Historic reenactment and historically themed social events may serve a variety of functions for the different people that participate in different events:

* Some people in virtually all societies value traditionalism (Schwartz, 1992).
    + Traditionalism relates to religiosity (among Judeo-Christian faiths; Schwartz & Huismans, 1995).
* Some hold romantic ideals of the past (e.g., the notion of "simpler times"). Personality traits related to these attitudes *may* (I'm speculating here) include the past-positive type of time perspective (Zimbardo & Boyd, 1999) and low openness to experience, which also relates to traditionalism.
* Some may desire an escape from the ordinary environments they're used to in daily life.
* Some enjoy dated fashions that don't seem quite right to wear in ordinary, modern contexts.
* Some events involve celebration of history, which is valuable in its own right.
* Some attendees probably enjoy any opportunity to dress up, act a part, or socialize in general.
    + Extraversion and self-monitoring may be relevant traits for understanding these motives.
    + The motive itself may be the need for affiliation, which is stronger in some individuals.
    + Social contact serves many psychological functions, including the enhancement of well-being.

Surely some celebrants are ignorant of the social issues of those times, but some aren't. Either way, many choose to celebrate the times for their good aspects, and at least a few probably feel the good aspects include the less modern social views of those times. It's conceivable that some people would even feel more comfortable in situations where attitudes such as misogyny or racism could be expressed more freely by excusing them as part of an act. However, my mere intuition and very limited personal experience suggest that most celebrations of the past aren't celebrations of the more controversial aspects such as these.

**References**

Schwartz, S. H. (1992). Universals in the content and structure of values: Theoretical advances and empirical tests in 20 countries. *Advances in Experimental Social Psychology, 25*(1), 1–65. Retrieved from http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.220.3674&rep=rep1&type=pdf.

Schwartz, S. H., & Huismans, S. (1995). Value priorities and religiosity in four Western religions. *Social Psychology Quarterly, 58*(2), 88–107.

Zimbardo, P., & Boyd, J. (1999). Putting time in perspective: A valid, reliable individual-difference metric. *The Journal of Personality and Social Psychology, 77*, 1271–1288.

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Tags: social-psychology, memory, motivation, experimental-psychology
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# Question
Title: What is the difference between spike-triggered averaging and reverse correlation?
I'm interested in the difference between spike-triggered averaging and reverse correlation.

In some papers (i.e., Schwartz, Odelia, et al) I see the term 'Spike Triggered Averaging'. In others, (ie Ringach et al 2004) I see the term 'Reverse Correlation'. According to wikipedia, they are the same:

> Spike-triggered averaging is also commonly referred to as “reverse correlation″ or “white-noise analysis”

I was wondering though: **Is there a subtle difference between spike-triggered averaging and reverse correlation?**

### References

* Schwartz, Odelia, et al (2006). "Spike-triggered neural characterization." Journal of Vision 6.4
* Ringach, Dario, and Robert Shapley. "Reverse correlation in neurophysiology." Cognitive Science 28.2 (2004): 147-166

# Answer
There's the naïve version of spike triggered averaging, and the sophisticated version. Both of them are consistent estimators for a linear-nonlinear system under certain conditions (Paninski, 2003). If your stimulus is $x\_i$ and your spike count in a small bin is $y\_i$, naïve version is $$\mathrm{STA} = \frac{1}{N} \sum\_i x\_i y\_i$$ The sophisticated version is equivalent to linear regression where a (pseudo-)inverse of the stimulus covariance is premultiplied to the naïve version. The naïve version converges slower in general.

In short, both of them are trying to estimate the same thing and will converge to the same thing, and sometimes called the same thing. However, it could refer to different things too, so read the methods section of papers before figuring out which one is which.

* Paninski, L. (2003). Convergence properties of three spike-triggered analysis techniques. *Network: Computation in Neural Systems, 14*, 437–464.
* Dayan, P. and Abbott, L. F. (2001). *Theoretical neuroscience: Computational and mathematical modeling of neural systems*. Massachusetts Institute of Technology Press. http://amzn.to/1nGUdII
> 5 votes

# Answer
Spike trigger is a specific type or you could say a sub-set of reverse correlations, covariance and probabilities. Other various examples include differential reverse correlation, Poisson spike trains, nonlinear reverse correlation and motion reverse correlation.
> 2 votes

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Tags: vision, computational-modeling, theoretical-neuroscience
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# Question
Title: Research on properties of effective feedback
I've been searching everywhere I know of for research concerning the topics listed below, but have been unable to find anything. The best I can come up with is general literature on feedback. Specifically I am looking for research on the following subjects:

1. The effects of feedback on an artifact given *in-context* of artifact versus *out-of-context*. A concrete example is feedback on a report; is it preferable to provide written feedback in the report margins (in-context) or in a separate document (out-of-context), and why/why not?
2. Context switches in workflows and why they are bad/good in general.
3. Related to 2: theory supporting integration of related workflows into a single computer, supported workflow. A concrete example is Microsoft Word which has a feature to edit images inside the application itself even though it is a word processor. Why is this preferable compared to e.g. editing the image in an external application and inserting it afterward? And is it (always)? Are there special cases where it may be counter-productive?
4. Properties of effective feedback. Preferably supporting the theses that:

4.1 feedback on a produced artifact is more effective if given early than late. This could be supported by arguments about memory and learning in general, e.g. that it's easier to remember what you did just now than a few hours ago, and thus also easier to comprehend feedback about what you did and the artifacts you produced in that time.

4.2 feedback on an artifact is more effective when the receiver is in the same "environment" he was in when the artifact was produced. A counterexample would be to give feedback on a report written in Microsoft Word by copying the report onto a web page and writing the feedback there. In that case the environment where the feedback is read by the receiver (the webpage) is completely different from the one where the artifact was produced (Microsoft Word). This has negative effects on effectiveness (which and why?).

I imagine the literature would be within cognitive load theory, learning theory, user interface design, usability design etc, but any suggestions are very much appreciated.

# Answer
Here are a few theories and sources I happen to know that relate to your questions:

1. Contextual cues aid recall of context-dependent memories. Plenty of research exists on these topics. An easily digestible example may be found through PsychCentral (Nauert, 2009).
2. We have another great question about context-switching here already that you might want to check out: https://cogsci.stackexchange.com/q/4993/4086
3. Haven't got much to offer in response to this question beyond the suggestion that you see what they have to say about it over at the User Experience Stack Exchange.
4. Theories to support your theses 4.1 and 4.2:
    1. This idea seems to relate to the *primacy and recency effects* in memory, which promote recall of first and last items in a list, respectively. Here's a graph from Wikipedia that combines these ideas into the *serial position effect:*
    <sub>(source: wikimedia.org)</sub>
    2. Haven't got more to add here beyond the link to the other question I mentioned in response `2.` I hope you get some other, helpful responses here!

**Reference**

Nauert, R. (2009, December 14). How cues and context help memory. *PsychCentral: Psychotherapy News.* Retrieved from http://psychcentral.com/news/2009/12/14/how-cues-and-context-help-memory/10159.html.
> 3 votes

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Tags: cognitive-psychology, learning
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# Question
Title: Button box for a reaction time study on OS X
I am running a language production study, and I want to collect reaction times. I am considering getting a button box, because I understand that my laptop (macbook pro) keyboard is not precise enough for many reaction time studies. I am looking for recommendations for a relatively inexpensive button box.

# Answer
First off, what button-box you use is going to be influenced by what software you're using to run the experiment, so ideally you should specify that.

* The PST serial response box is probably the industry standard, and is what we have in my lab, although a lot of that is probably down to it coming from the makers of EPrime. EPrime doesn't work on OSX though, and the PST box isn't cheap, so you might want to consider...
* Neil Stewart has done some work on building your own accurate button boxes. I haven't tried this myself, but if you are, or know someone who is, up to the technical challenge, this could be helpful.

+ Caveat: The paper describes how to do it on Linux. It almost definitely wouldn't work on Windows, but OSX and Linux are pretty similar deep down.
    + Caveat #2: Do Macbooks have serial ports?

When I started writing this, I thought I knew of other, cheaper makers or SR boxes. Apparently I imagined that.

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Edit:

Whatever you end up doing, make sure you also take a look at `How can I create computer based psychology experiments using OS X?`.
> 7 votes

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Tags: methodology, reaction-time
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# Question
Title: How do hallucinations appear through reversing goggles?
If one is experiencing elaborated visual hallucinations, what will happen when one puts on reversing goggles? Will hallucinations change their orientations as well? Links to relevant papers will be most welcome.

# Answer
> 5 votes
Karl Jaspers describes clinical reports in which patients hallucinatory perception was changed in accordance with the optical distortion. For example, a prism would double the images of devils, binoculars enlarge or decrease the image, colored glasses make it colored, etc. He refers "Seppilli, Contributo allo studio delie allucinazioni unilaterali. Riv. sper. di fren. 16, 82. 1890" and "Pick. Beitrage zur Lehre von den Halluzinationen. N. C. 11. 329. 1892" Now, the question is, has anyone done a study on that in the 20th century.

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Tags: vision, hallucinations
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# Question
Title: Neuroplasticity and Treatment of Depression
After reading 'The Brain That Changes Itself' by Norman Doidge, 'The Mind and The Brain' by Jeffrey Schwartz and a few other books, I've become curious about the science of neuroplasticity, which, as I understand, is a new paradigm in neurophysiology that replaced the older doctrine of brain immutability.

There's a wealth of empirical evidence in studies conducted by Bach-y-Rita, Taub, and Merzenich that confirms that brain remains plastic for pretty much the whole life, after a period of hyperplasticity in childhood.

This seems to be a powerful tool that can contribute to treatment of various disorders, such as depression and anxiety, especially in cases when the condition is resistant to medication. I'd like to know if this idea has been applied with some success, and if anyone developed a specific neuroplasticity-based approach.

# Answer
> 5 votes
It may interest you to know that depression and anxiety relate to emotional stability (essentially the opposite of neuroticism), a personality trait which tends to decrease over the lifespan, especially in young adulthood (Roberts & Mroczek, 2008). Here's a figure depicting this trend (bottom left):
This article points out that most of the personality changes depicted above occur during young adulthood. This supports the hypothesis that plasticity is an important enabling factor in these changes. Roberts and Mroczek also describe these changes as mostly positive, which supports the hypothesis that these changes are a partly intentional process of social adjustment. I'm not aware of any evidence that supports these hypotheses more directly, but any such evidence would also support the plausibility of interventions that target neuroticism during earlier life stages when plasticity is generally greater.

The language of plasticity appears sparsely in a similar article that describes change in adult personality (Srivastava, John, Gosling, & Potter, 2003), though no explicit references to *neural* plasticity appear. However, this article also presents a complication and a challenge through its own evidence of change in neuroticism over the lifespan, depicted in this figure (top left; neuroticism $\approx (-1)\cdot$ emotional stability):
The complication is the sex difference in change over time: only women's neuroticism seems to decrease in this study's evidence. The challenge is the apparent linearity of both trends; neither supports the importance of plasticity. Therefore it's not clear that any intervention focused on altering neuroticism would function equally well for both sexes, nor take advantage of neuroplasticity. Nonetheless, a very recent article recognized the malleability of neuroticism and recommended exploration of options that would intervene at this basic trait level of disorder development (Barlow, Sauer-Zavala, Carl, Bullis, & Ellard, 2013, in press). Thus it seems further evidence to support your idea may be forthcoming!

**Neuroticism aside**, other recent articles have promoted biofeedback, neural decoding, and neural interface technology as ways of "targeting", "promoting", and "exploiting" neuroplasticity in treating neurological dysfunction (Wang et al., 2010; Seitz, 2013; incidentally, Seitz works at my alma mater and published this shortly after I graduated...it's a small world). Biofeedback and neurofeedback have established applications in the treatment of depression and anxiety (see for review Yucha & Montgomery, 2008). Biofeedback methods seem to have been around just about as long as theories of neuroplasticity (discounting one particularly early study at the end of the 18th century), so I wouldn't say biofeedback was intended as a neuroplasticity-based approach, but evidently it has turned out to be a somewhat inadvertent application of neuroplasticity. Clearly, theorists and clinicians are actively capitalizing on this convenient convergence of neurology and clinical methodology – this trend seems likely to continue.

**References**

<sup>\- Barlow, D. H., Sauer-Zavala, S., Carl, J. R., Bullis, J. R., & Ellard, K. K. (2013, October 14; in press). The nature, diagnosis, and treatment of neuroticism: Back to the future. *Clinical Psychological Science*, DOI: 10.1177/2167702613505532.
\- Roberts, B. W., & Mroczek, D. (2008). Personality trait change in adulthood. *Current Directions in Psychological Science, 17*(1), 31–35. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2743415/.
\- Seitz, A. R. (2013). Cognitive neuroscience: targeting neuroplasticity with neural decoding and biofeedback. *Current Biology, 23*(5), R210-R212.
\- Srivastava, S., John, O. P., Gosling, S. D., & Potter, J. (2003). Development of personality in early and middle adulthood: set like plaster or persistent change? *Journal of Personality and Social Psychology, 84*(5), 1041–1053. Retrieved from http://j.b5z.net/i/u/2043019/i/PersonalityDevelopmentInAdults.pdf.
\- Wang, W., Collinger, J. L., Perez, M. A., Tyler-Kabara, E. C., Cohen, L. G., Birbaumer, N., ... & Weber, D. J. (2010). Neural interface technology for rehabilitation: exploiting and promoting neuroplasticity. *Physical Medicine and Rehabilitation Clinics of North America, 21*(1), 157–178. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2788507/.
\- Yucha, C., & Montgomery, D. (2008). *Evidence-based practice in biofeedback and neurofeedback*. Wheat Ridge, CO: AAPB. Retrieved from http://web.archive.org/web/20101009135554/http://isnr.org/uploads/EvidenceBasedYuchaMontgomeryW.pdf.</sup>

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Tags: neuroscience, cognitive-neuroscience, depression
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# Question
Title: Are there any agent based cognitive models that are inspired by complex systems studies of ant colonies and economies?
I think that certain aspects of ant colony behavior seem almost like economic decision-making in behavior. There are also links between ant colony optimization and features of the brain like selective attention. I was just wondering if any research group has taken up the problems of cognition from the perspectives of economics and/or ant colonies.

It may seem to be mostly analogy on the surface, but the interface of the three seems like a fruitful area to look for new ideas.

# Answer
> 4 votes
## Partial answer:

Douglas Hofstadter has written quite a lot about this from a more philosophical approach. His style isn't for everyone, I think it's introduced well in this chapter ('Ant Fugue').

For more applied work from the same, you might look at Mitchell and Hofstadter's CopyCat model of analogies (described briefly here, as well as on wikipedia).

All this aside, I don't know of any empirical work along the same lines, but I wouldn't rule it out.

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Tags: cognitive-modeling, computational-modeling, economics
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