# Question
Title: How does the mind build a model of reality?
I'm interested if there has been any research or experiments that deal with **how the human mind creates and perpetuates the idea of knowing something**.

I'm struggling to concisely express the question, so a roundabout explanation is in order. I'm thinking of the succession of frameworks that explained how the world works to a layman:

* ancient pagan religions, which explained the reality in terms of the complicated interaction of spirits and forces of nature.
* Then came monotheistic religions which once again have attempted to explain the world.
* Somewhere in between there have been many forms of philosophy
* Then came a myriad of scientific models which are erected in all domains of science:from biology to psychology, etc.

Each one of these frameworks attempts to explain the world. Each one has been at the cutting edge of thought at the time. Yet it seems to me that even the most accomplished physicist(the pinnacle of modern knowledge?) may still live with a patchwork of a world model, because said physicist may not be as well versed in neurobiology or some other "arcane" domain of science.

It seems to me that in this chain of succession, because knowledge is preserved, most of the successive models incorporate at least bits and pieces of the previous models. **Do individuals build their own models of reality from whatever knowledge is available to their minds?**

In the example above (from Nous on wikipedia), the model is neatly created from the understanding that was available to the medieval mind. I'm interested if this kind of tendency to "fill in the holes" and **present a finite understanding of a infinitely(?) complex reality as complete** is a natural part of how the human mind works.

For example, would the contemporary physicist's model of reality be primarily shaped by the knowledge of physics, with other knowledge "filling in the holes"? I know that there are such things as cognitive biases and follies of thought, are these the mechanisms by which the model of the world is shaped?

Thank you for your feedback! This question is rather broad, and I would appreciate if you suggest keywords or names of articles that I can investigate further.

# Answer
Taking @BenCole's suggestion on the bolded parts...

> how the human mind creates and perpetuates the idea of knowing something

I think the philosophic response to this is "What does it mean to *know* something?". I'd recommend Searle's Chinese Room argument \[1\] and the many rebuttals to it (which include some computational explanations of understanding) to get a better idea.

> Do individuals build their own models of reality from whatever knowledge is available to their minds?

The simple answer is yes. But the interesting question is how much of our reality is shared vs how much of it is specific to each individual. In Computational Cognitive Science, the one area that tries to address this separation is Cognitive Architectures. CAs divide rational thought into two parts - the architecture that represents the common functionality across all humans and the knowledge which is different for each of us. For further reading, see Newell's *Unified Theories of Cognition* \[2\] for the groundwork, Anderson's *How can the human mind occur in the physical universe?* \[3\] for an emphasis on ACT-R (an example CA), and Laird's *The Soar cognitive architecture* \[4\] for an emphasis on Soar (another CA). Soar and ACT-R are the big two of the CA field but there are many others.

> present a finite understanding of a infinitely(?) complex reality as complete.

I'd argue that the opposite is true. That is, instead of presenting reality as complete, the mind lives off of the differences between its understanding and the reality. Expectation-based cognition suggests that people are always generating expectations of what they expect to sense (see/hear/smell/feel etc) in the near future. These expectations are matched against observations. If expectations and observations match, then all is good. When they don't match, cognition is alerted. In this view, predictions flow top-down and errors (discrepancies between the prediction and the observation) flow bottom-up. Some good references on this idea are \[5\] and \[6\]

\[1\] J. Searle. (1980). Minds, brains and programs. Behavioral and Brain Sciences 3 (3): 417–457.

\[2\] A. Newell. (1994). Unified theories of cognition. Harvard University Press.

\[3\] J. Anderson (2007). How can the human mind occur in the physical universe? Oxford University Press.

\[4\] J. Laird. (2012). The Soar cognitive architecture. MIT Press.

\[5\] Lee, T.S., Mumford, D. (2003) Hierarchical Bayesian inference in the visual cortex. Journal of Optical Society of America, A. . 20(7): 1434-1448.

\[6\] Hohwy, J., Roepstorff, A., & Friston, K. (2008). Predictive coding explains binocular rivalry: an epistemological review. Cognition, 108(3), 687-701. ELSEVIER SCIENCE BV. Retrieved from http://discovery.ucl.ac.uk/136548/
> 6 votes

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Tags: cognitive-psychology, intelligence, theory-of-mind
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# Question
Title: Do persons with autism have a bigger genetic predisposition to psychosis/schizophrenia?
Do people with autism or Asperger's syndrome have a higher genetic predisposition to psychosis or schizophrenia than that of healthy people?

# Answer
> 8 votes
Generally speaking, yes; it's relatively more common for psychosis to be comorbid with or present after diagnosed Autism.

For a good overview of this topic read Autism and Schizophrenia (Yael Dvir, MD and Jean A. Frazier, MD).

> COS (Child Onset Schizophrenia)—the onset of psychosis before age 13 years—is considered a rare and severe form of schizophrenia. Systematic studies of COS show high rates of the disorder being either preceded by or comorbid with autistic spectrum disorders (ASD).7

Note however that the similar (but not identical) features between COS and Autism:

> Although the disorders are distinct, they have shared clinical features. Social withdrawal, communication impairment, and poor eye contact seen in ASD are similar to the negative symptoms seen in youths with schizophrenia.11 When higher-functioning individuals with autism are stressed, they become highly anxious and at times may appear thought-disordered and paranoid, particularly when they are asked to shift set (such as being asked to change a topic of conversation or to stop an activity that they are engaged in and begin a new activity).12 A subset of children (28%) in the ongoing NIMH study of COS have been reported to have comorbid COS and ASD.7

There's also likely a bit of sample bias going on; children presenting *severe* symptoms of either Autism or COS are logically much more likely to be seen by medical professionals than neurotypical children or those who may have Autism but present less significant external symptoms. So take the specific percentages with a grain of salt, but the two certainly seem to be related.

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Tags: autism, psychosis, schizophrenia
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# Question
Title: Do action video games have an effect on spatial skills?
I've just watched a TED talk by Daphne Bavelier, who seems to be a major researcher on plasticity and video games. In it she presents results from a controlled lab study in which participants needed to perform mental rotations (around 14 minutes into the video), before and after having played 10 hours of action video games over a period of 2 weeks. She demonstrates results which show an improvement up to 5 months after having gotten the 'training'.

I'm interested in finding out more about this research and the methodologies it followed. So my first question is whether somebody could link me to the original research.

* Did they take into account learning effects?
* Did they use a control group?

My skepticism comes from a previous question on video games in which D. Bavelier is mentioned often. It has gotten some concerned responses involving methodological flaws.

# Answer
> 3 votes
The concept of mental rotation was introduced by Shepard & Metzler (1971). The 3D assemblages of cubes were part of their original experiment. Vandenburg and Kuse (1978) later developed a paper-and-pencil test based on this prior experiment, named the Vandenberg and Kuse’s Mental Rotation Test (VMRT).

The study which Bavelier most likely refers to is one done by Feng et al. (2007). \[PDF\]

> In Experiment 2, we compared spatial attention and cognition in men and women before and after 10 hr of action-video-game training. **A control group trained for 10 hr with a non-action game**. \[...\] In addition, we assessed higher-level spatial abilities using a mental rotation test (MRT; see Fig. 1b). We expected to ﬁnd enhanced MRT performance as a by-product of improvements in spatial attentional capacity after training.

The games played were Medal of Honor: Pacific Assault by the experimental group, and Ballance, a 3-D puzzle game by the control group.

> We had not originally planned a follow-up testing session; however, we were able to contact and retest all 20 subjects after an average interval of about 5 months (16–24 weeks).

Results

> **Both males and females in the experimental group improved, but there was no signiﬁcant change from pretest to posttest in the control group** \[...\] furthermore, the improvement in the experimental group was larger for females (2.0 to 2.7) than for males (2.9 to 3.2), F(1, 8) 5 5.193, prep 5 .87, Z 2 5 .39, and the performance of the females on the posttest was indistinguishable from that of the males in the control group. Although the gender difference on the MRT was not eliminated, its size was much reduced (see Fig. 3, lower left panel).

---

Although not the exact study which Bavelier demonstrated, a study done by Isabelle D. Cherney (2008) demonstrates similar results using the VMRT test. A huge section of the paper reviews existing relevant research which might be interesting to look into. The focus of this particular study is to ...

> ... examine whether the type (3-D vs. 2-D) and delivery (massed vs. distributed practice) affect the degree of improvement of males’ and females’ mental rotation performance and how individual differences such as anxiety, prior spatial experiences such as computer game play, and mathematical performance might affect performance. Two existing visuospatial tests, Vandenberg and Kuse’s (1978) mental rotation test and the card rotation test (CRT; Educational Testing Services Sanders et al. 1982) that have shown gender differences and that are of different levels of difficulty, were used.

Tested games were The 3-D Antz© racing computer game, the 2-D Tetrus© computer game, or several paper-and-pencil logic games.

> An equal number of men and women were then randomly assigned to \[the games\] for a half hour. Participants returned to the laboratory for another three times for 1 h of practice each. About half of the participants in each practice condition were randomly exposed to either: (a) distributed practice sessions (they completed the three 1-h practice sessions over more than 2 weeks) or (b) massed practice sessions (they completed the three 1-h practice sessions within 3 days). During the final session, after a half hour of practice, participants completed the two mental rotation tests as a posttest. Participants were exposed to a total of four training hours. They were asked to abstain to play any computer games between the practice sessions.

Practice effect analyses

> Bonferroni adjusted paired sample t-tests on both mental rotation pre-and posttest scores showed that, **for the VMRT there were significant improvements for women, t(30)=−3.6, p=.001, but not for men**

<sub> Shepard, R. N., & Metzler, J. (1971). Mental rotation of three-dimensional objects. Science 171, 701-703.
Steven, G. V., & ALLAN, R. (1978). Mental rotations, a group test of three-dimensional spatial visualization. Perceptual and motor skills, 47(2), 599-604.
Cherney, I. D. (2008). Mom, let me play more computer games: They improve my mental rotation skills. Sex Roles, 59(11), 776-786.
Feng, J., Spence, I., & Pratt, J. (2007). Playing an action video game reduces gender differences in spatial cognition. Psychological Science, 18(10), 850-855. \[PDF\] </sub>

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Tags: reference-request, plasticity, video-games, spatial-cognition
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# Question
Title: Have the abilities of John Lorber's patients with limited cortical mass been further evaluated in adulthood?
Short of minor lesions or infarcts, most high-functioning adults have an intact cerebral cortex. Yet, a surprising result published anecdotally in Science in 1980 caused a lot of scientists to take note of Dr. John Lorber's hydrocephalus patients in England.

Most famously, Lorber reported:

> There's a young student at this university...who has an IQ of 126, has gained a first-class honors degree in mathematics, and is socially completely normal. And yet the boy has virtually no brain...instead of the normal 4.5 centimeter thickness of brain tissue between the ventricles and the cortical surface, there was just a thin layer of mantle measuring a millimeter or so.

Now, arguing that the subject had "virtually no brain" is perhaps a bit of hyperbole, but the fact remains, he had accomplished an academic feat which many "normal" humans have not. What's even more astonishing about this particular case is that this subject was purportedly not even aware of his condition until the initial brain scans were performed.

Aside from 1-2 other publications in peripheral journals around the same time period, I have never heard anything further about these patients that Dr. Lorber was following.

In the intervening 30+ years, have there been any follow-up scans/studies of these patients particularly those featuring the mathematics scholar mentioned above?

What mechanisms does the cortex use in these unusual circumstances to counter the effects of decreased cortical thickness? Are the cortical columns shorter, and in what sense does their connectivity compensate for lower neuron counts/lower cell densities?

> Lewin, R. (1980). Is your brain really necessary? *Science 210*(4475):1232-1234.

# Answer
> 18 votes
It's unclear whether follow-up tests were ever performed on Lorber's patients, and in particular the student referenced by Lewin. Patient confidentiality precludes a systematic search of the literature, particularly because the Lewin (1980) article does not provide a pseudonym with which we can use to track the patient (e.g. "HM"). It is possible that this patient has been the subject of other scientific studies, but there does not appear to be any information that would uniquely identify him as the patient referred to in this article. John Lorber has since passed away (1996), making it unlikely that we'll know for sure.

However, the condition itself has not been ignored. Lorber himself has later studies which look at the brains structure of hydrocephalus patients (Jackson & Lorber, 1984). A more recent study by Feuillet et al. (2007) seems to show similar results with regard to brain tissue, but the IQ of Feuillet's patient was measured at 75. He appeared to function normally in society, but his intelligence is regarded as significantly below average. A news article about this study, including CT images, can be found here.

In 2011, a review article by De Oliveira et al. discussed the above two cases and others. However, no mention of a follow-up to Lorber's original patient is discussed. It seems likely that if a follow-up were performed, it would be mentioned in this review.

There does not appear to be a concrete answer with respect to how these patients can function despite a deficit in cortical tissue. However, De Oliveira and colleagues discuss one hypothesis, as quoted below:

> Computational models such as the “small-world” and “scale-free” network might explain clinical resilience in various situations (Friston and Price, 2003; Noppeney et al., 2004; Achard and Bullmore, 2007; Van den Heuvel et al., 2008). Small-world networks predicts that neuronal cells are engaged in clustered connectivity with fewer long-range connections (Friston and Price, 2003; Achard et al., 2006). Thus, there would be a shorter path length between any pair of neurons or Brain regions, resulting in higher dynamical complexity, lower wiring costs, and resilience to tissue insults. A scale-free network is characterized by the existence of a small number of nodes having more connections than the other nodes. The nodes that have such a high connectivity degree are referred to as hub-nodes and are suggested to play an important role in the overall network organization (Friston and Price, 2003).
>
> Brain resilience may be also the final result of processes such as redundancy, degeneracy, and pluripotentiality of neural systems (Friston and Price, 2003; Noppeney et al., 2004). Another possible mechanism would be the local neurogenesis already reported in structures such as the basal ganglia, with preferential distribution in sub-regions of the ventral striatum (Stopczynski et al., 2008).

**References**

> De Oliveira, M. F., Pinto, F. C. G., Nishikuni, K., Botelho, R. V., Lima, A. M., & Rotta, J. M. (2011). Revisiting hydrocephalus as a model to study brain resilience. Frontiers in human neuroscience, 5. PDF
>
> Feuillet, L., Dufour, H., & Pelletier, J. (2007). Brain of a white-collar worker. The Lancet, 370(9583), 262.
>
> Jackson, P. H., & Lorber, J. (1984). Brain and ventricular volume in hydrocephalus. Z Kinderchir, 39(Suppl 2), 91-93.

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Tags: neuroscience, neuroimaging
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# Question
Title: Ignoring minority while generalizing about a group, any theoretical reference?
In conversation, we might define a particular group by the characteristics that the majority of that group holds even if a minority in that group doesn’t possess those characteristics.

Some possible examples:

* Human being eats meats *(even though ~3-5% of human are total vegetarians)*
* Russians like vodka *(many don’t drink there)*
* Asians are brown *(though there are many who are white)* (Ignore the figures or classification it’s just for explaining purpose)

The point is, why are we programmed to make generalizations this way, i.e., disregard the small or even significant but minority of a group while taking it as a whole, this is understood by common sense, but, I was wondering is there a scientific basis for this, perhaps some kind of theory presented by someone or a research that established this rule?

# Answer
I think the exceptions are implied. If someone says, "**All** Russians like vodka" then we understand that there are no exceptions to the rule. People get frustrated when you're overly specific about the percent of Russians who like vodka. Instead it's safer to just say Russians like vodka. And bears.

*Influence: The Psychology of Persuasion* talks about why we operate based on generalizations. We would freeze if we analysed all the details of every situation before we act, so we make generalizations.

*Thinking, Fast and Slow* is an excellent book talking about the latest research in human biases from one of the foremost experts in the field.
> 5 votes

# Answer
As @Jeff mentions you are essentially asking why people stereotype. Steretyping is a huge topic particularly in social psychology. The wikipedia article on stereotypes provides a basic introduction to the functions of stereotypes where it talks about cognitive and social functions. It seems like most of the examples you provide are referring more to the cognitive functions (e.g., simplifying thinking and decision making).

An article by Macrae et al (1994) typifies this perspective. You might want to have a read of the article. Here is an extract from the opening paragraphs that talks about stereotypes as tools for minimising the use of cognitive resources.

> Social psychologists have frequently characterized stereotypes as energy-saving devices that serve the important cognitive function of simplifying information processing and response generation (e.g., Allport, 1954; Andersen, Klatzky, & Murray, 1990; Bodenhausen & Lichtenstein, 1987; Brewer, 1988; Fiske & Neuberg, 1990; Tajfel, 1969). Building on this tradition, Gilbert and Hixon (1991) aptly characterized stereotypes as "tools that jump out" of a metaphorical cognitive toolbox "when there is a job to be done" (p. 510). Anyone who has ever succumbed to the temptation to evaluate others in terms of their social group membership would doubtlessly recognize the power of this contention. Individuation, in its many guises, is a rather time consuming and effortful affair (Brewer, 1988; Fiske & Neuberg, 1990; Fiske & Pavelchak, 1986). Stereotyping, in contrast, relies only on the execution of some rather rudimentary skills: most notably, the ability to assign people to meaningful social categories (see Hamilton, 1979; Hamilton & Sherman, in press; Hamilton, Sherman, & Ruvolo, 1990; Hamilton & Trolier, 1986). Once achieved, this categorization provides perceivers with a veritable wealth of stereotypic information.
>
> The metaphorical view of humans as cognitive misers has attained a zenith of popularity among contemporary social cognition researchers (see Fiske & Taylor, 1991; Higgins & Bargh, 1987; Sherman, Judd, & Park, 1989), but the notion of stereotypes as simplifying mental devices has its origins in much earlier times. Lippman (1922), for example, argued that reality is too complex for any person to represent accurately. Stereotypes, accordingly, serve to simplify perception, judgment, and action. As energy-saving devices, they spare perceivers the ordeal of responding to an almost incomprehensibly complex social world. Seventy years later, these sentiments are characteristic features of cognitive writings on the topic. As Fiske and Neuberg (1990, p. 14) remarked, "we are exposed to so much information that we must in some manner simplify our social environment. . . for reasons of cognitive economy, we categorize others as members of particular groups—groups about which we often have a great deal of generalized, or stereotypic, knowledge.

I also think Tyler and Ana make good points about what is meant by statements such as "Russians like vodka". One interpretation is that the exceptions are implied. Another is that when we say "Russians" or any other group we are referring to the group as an entity. Thus, to say that a group has a certain property is to speak about the tendency of the individuals in the group rather than each individual.

### References

* Macrae, C. N., Milne, A. B., & Bodenhausen, G. V. (1994). Stereotypes as energy-saving devices: A peek inside the cognitive toolbox. Journal of Personality and Social Psychology, 66(1), 37. PDF
> 4 votes

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Tags: social-psychology, political-psychology
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# Question
Title: What's the name of the quantifying preference for visual stimulus by varying size or distance as compared to a reference task?
Say that you enjoy looking at two beautiful paintings (A and B). But you really can't tell which one you like more, and you want to (quantitatively).

So, you compare them both to your favorite painting (C), which you know you really like to look at (adjusting for novelty).

In order to do this, you vary the size of your favorite painting C on a computer screen (or its distance from you in real life), and find the point at which C is so much smaller that you'd rather look at A. You do the same for painting B.

You then attempt to quantify how much you prefer A to B by asking: for which painting (A or B) was C larger when you first preferred to look at that painting rather than C? This is the one that you prefer more, and the distance between the C "breakpoints" gives some measure of your relative preference.

Of course this difference will be at best an interval measurement, not a ratio one, but that's usually better than no measurement.

Here is my question: **what is this procedure (or some variant of it) called**? This seems like a basic enough test that it must already be in use, and I am curious to hear more about it.

Related question: How is the size of a video related to its perceived quality?

# Answer
> 2 votes
Dude. This is an awesome experiment.

Emotional Design is written by my favorite cognitive psychologist, Donald Norman. It's full of research on taste. In it, he says **taste** is highly subjective and **based on culture**.

C is probably equally distant in both cases, at the point where it becomes unreadable. Unless at that point you'd rather look at C and say, "Hey, what's that?!" Like ship sails far away in the ocean.

One last point. We have no idea why we behave. We just rationalize it afterward. What we say we like and the way we behave are totally different. Girls just want to be with a nice guy.

There was a Harvard study for a painting class. Each class painted 5 paintings (or something). At the end of the semester, the teacher gave a class one of their paintings back. For the other class, the students took home their **favorite** painting. They waited 6 months (or something) and interviewed the students. The students who were given their painting **LOVED** it. They had their painting proudly displayed somewhere. The students who were given a choice were unhappy. **They kept wondering what-if?** They never felt right about their painting and most of them hid it away, maybe under a bed.

There's good evidence that if you want to stay happily in a relationship with someone, DON'T THINK ABOUT WHY YOU LIKE THEM. It will end badly. There's a whole study on this as well. It got ugly.

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Tags: terminology, vision, aesthetics
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# Question
Title: How do you know if it's psychosomatic or not?
"It's in your head" is often true and often offensive. But as your head can invent any number of psychological and physiological symptoms how can you distinguish whether something is or isn't psychosomatic?

My naive stance (which I'm looking to correct) so far is that if the symptoms are too vague or too arbitrary it's psychosomatic. This probably has some indirect legitimacy but is entirely anecdotal. For example something too arbitrary would be: experiencing pain in your feet after standing in water in a shower, but standing in a bathtub, pool, lake, or ocean doesn't cause it.

# Answer
> 8 votes
I believe 'psychosomatic' describes a way the mind has effects on the your body which might result in somatic symptoms. Often psychosomatic disorders are diagnosed as such when:

* no somatic correlate to the experienced symptoms can be found
* somatic correlates do not sufficiently explain the experienced symptoms

This often results in patients who visit different doctors over a longer period of time, desperately looking for a reason for their symptoms.

Also psychosomatic can refer to diseases which have a clear somatic correlate (e.g. Hashimoto-Thyreoiditis) but the cause of the disease is unknown and the symptoms are influenced by your state of mind (e.g. symptoms worsen under stress).

However as medical diagnostic tools are limited, it cannot be excluded that there is really no somatic cause for psychosomatic disorders.

ICD-10 diagnostic criteria for psychosomatic disorders are available online, e.g. for somatization disorder: http://apps.who.int/classifications/icd10/browse/2010/en#/F45.0

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Tags: perception, abnormal-psychology, psychiatry, well-being
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# Question
Title: Are there any standard psychometric scales that are only applicable to within-subject designs?
A while ago, I asked the question whether Presence questionnaires are valid in between-subject designs (see the question for the background to this assumption).

While the question garnered some encouraging feedback, no one seems to know the answer as of yet.

**Example**: By way of a contrived example, I was suggesting that the situation would be similar were we to perform an experiment in which half the participants are told that they are to receive 1 litre of free beer, whereas the other half are told that they are given 10 litres of free beer.

If you asked all participants to rate their level of happiness at receiving the news that they are given said quantity of free beer, I think you would not see a difference (because free beer is free beer!).

However, if you were to repeat the experiment a second time with the same participants and now swapped the amount of beer between the two groups, I would expect people to lower their happiness ratings if their amount of beer got lowered, and up their ratings if their free beer levels went up. (NB: Participants do not actually receive free beer but are simply asked how happy the news of receiving free beer would make them, so they don't actually receive 1 litre instead of 10 or get 11 litres)

**Question:** So I'm wondering: **Are there any standard tests or phenomena that are, in a sense, meaningless when applied to between-subjects but work as a relative scale when applied to within-subjects experiments?**

# Answer
I think your intuitions are correct, and the reason is that Likert scales often suffer from poor construct validity.

One example that comes to mind is Alter et al. (2010), who use a mixed design, and note that participants in both conditions gravitate toward the middle of the scale on their first rating. They suggest that participants do not know how to use the scale at first; however, their second rating is informative because it can be compared to the first.

Several other studies (e.g. Dittrich et al., 2007; Olson et al. 2007) suggest that Likert scales are best used for *relative* rather than *absolute* judgments. Within-subject designs may abide by this rule because participants will implicitly use their previous ratings as anchors.

Although within-subject designs are often preferred, many times they are not feasible. (For instance, an experimental manipulation may make it impossible for a subject to be in both conditions without jeopardizing the effect of the manipulation). However, a properly designed scale may be usable in a between-subjects design. The key here is wording the question such that subjects will make judgements *relative to some other criterion*. So you may say something like:

```
"Compared to the last time you received one free beer, how happy were you upon receiving
 ten free beers?"

-5       -4       -3       -2       -1       0       1       2       3       4       5
less happy than last time      neither more or less happy     much happier than last time

```

This example is a little contrived--in fact it's not that great since the question is leading--but hopefully you get the idea.

Since you mention happiness, I will note that this issue has arisen in the happiness literature. Happiness is often assessed by a Likert scale, but the wording of the question can evoke different comparative standards. For instance, Steffel & Oppenehimer (2009) report that people respond differently whether they think about intra- vs inter- personal happiness (i.e. "How happy are you compared to others?" vs "How happy are you compared to how happy you would like to be?") When left to their own accord, they typically adopt an inter-personal comparison. However it is best to make this comparison explicit whenever possible to avoid these issues.

> Alter, A. L., Oppenheimer, D. M., & Zemla, J. C. (2010). Missing the trees for the forest: A construal level account of the illusion of explanatory depth. Journal of personality and social psychology, 99(3), 436. PDF
>
> Dittrich, R., Francis, B., Hatzinger, R., & Katzenbeisser, W. (2007). A paired comparison approach for the analysis of sets of Likert-scale responses. Statistical Modelling, 7(1), 3-28. PDF
>
> Olson, J. M., Goffin, R. D., & Haynes, G. A. (2007). Relative versus absolute measures of explicit attitudes: Implications for predicting diverse attitude-relevant criteria. Journal of Personality and Social Psychology; Journal of Personality and Social Psychology, 93(6), 907.
>
> Steffel, M., & Oppenheimer, D. M. (2009). Happy by what standard? The role of interpersonal and intrapersonal comparisons in ratings of happiness. Social indicators research, 92(1), 69-79.
> 5 votes

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Tags: measurement, statistics
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# Question
Title: Are dice and domino dot arrangement conventions related to readability?
I noticed dice and dominos both use the same convention for dot placement. Is there a reason for this? Is there any research on how to layout dots so that they are most readable?

# Answer
> 3 votes
These dots are known as pips. Pip placement tends to follow a convention, but this placement may vary by region, as you can see by this comparison between Western and Asian dice (from wikipedia):

I suspect this arrangement has nothing to do with cognitive science or usability, but is simply a convention. However, you may note that on the Western-style dice, pips are arranged so as to maximize the distance between any two pips while maintaining symmetry-- this should aid in quick recognition regardless of how the dice are rotated when they land.

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Tags: reading
---


# Question
Title: Source for standardized audio files for an experiment in German
I need some audio files for an experiment. In this experiment, numbers will be played to the subjects via headphones, so I need sound files with spoken numbers. Actually, a single file with a sequence of numbers is fine.

The goal is to produce a similar experiment as the one by Neil W. Mulligan (The Role of Attention During Encoding in Implicit and Explicit Memory). In this experiment, the material from the test set developed by Blaxton (1989) were used.

Is there any standardized database for this kind of things? I know there are standardized face databases, but I am not sure about sound files and googling did not help.

The problem is that the subjects will be from Germany, so I need the numbers in German.

# Answer
Try this:

```
http://translate.google.com/translate_tts?tl=de&q="1"

```

or this:

```
http://translate.google.com/translate_tts?tl=de&q="11;27;39;81;32;53"

```

At the moment, I can't test if it pronounces the full numbers right, but I hope it will work.

I think the pronunciation of higher numbers are better if you write them like this: *NineHundredSixtySix*
> 1 votes

---
Tags: experimental-psychology, auditory-discrimination
---


# Question
Title: Why have historically most inventors been men?
I noticed something strange when I looked at about.com's list of famous historical inventors. You can see that most of the inventors are men, and only a few are women.

* Can this be explained by *cognitive science* in terms of men's brains having better abilities for inventing something?
* Or is this due to social factors or something else?

# Answer
> 22 votes
A large part is cultural, because, until recently, the people with the best education and most of the money have been men.

Sexism kept women out of schools for a long time. It also kept pushing women into what were perceived to be more appropriate studies (nothing technical) when they were allowed into schools.

Have a look at the sexism page at Wikipedia.

There is some evidence, as discussed in this Wikipedia article, there are differences between male and female human brains. Especially in spacial temporal reasoning regions and the language areas. As well as Wikipedia, in the book Cognitive Neuroscience: The Biology of The Mind<sup>\[1\]</sup>, the authors state that human females are less good at the maths people are taught at school, which is linked to spacial reasoning.

However, this disparity is across the species as a whole. It is an average. Inventors, by their very nature, are not average. Thus the neurological differences are not the main contributing factor to why you see more men in your list than women.

Also, have a look at confirmation bias.

\[1\] Cognitive Neuroscience: The Biology of The Mind, 2nd ed. M. S. Gazzaniga, R. B. Ivry, G. R. Mangun. Page 602

# Answer
> 14 votes
*This is a big topic, which I don't feel I can do justice to, but here are a few thoughts nonetheless. It's also important to see how resort to biological arguments could help to perpetuate such gender differences.*

### Brain is not behaviour

Brain differences are irrelevant if they do not manifest in behaviour. Thus, to show that size of structure of the brain varies between genders may be suggestive. However, to use this to explain gender differences in the historical differences in inventors is a big leap.

### Empirical evidence for gender differences

The best data I've seen examining the size of gender differences on a wide range of psychological variables was the summary of meta analyses by Hyde (2005). Hyde puts forward

> the *gender similarities hypothesis*, which holds that males and females are similar on most, but not all, psychological variables. Results from a review of 46 meta-analyses support the gender similarities hypothesis. Gender differences can vary substantially in magnitude at different ages and depend on the context in which measurement occurs. Overinflated claims of gender differences carry substantial costs in areas such as the workplace and relationships.

In particular, check out the first section of Table 1 of Hyde (2005) where you can get a summary of meta-analyses of gender differences in cognitive ability. In general the differences between males and females tend to be fairly small, and there are several meta-analyses that found females to have slightly superior ability to males. Furthermore, such studies don't prove whether the generally small differences observed will change in the future should society change in its treatment of males and females.

### What makes a great inventor?

I imagine that all sorts of factors related to social context, individual traits, and learning experiences would be related to the emergence of great inventions. Furthermore, the emergence of great inventors is often seen within a broader historical context, which encompasses periods of time where women's access to education, access to career opportunities, and role expectations provided minimal opportunity to become a great inventor.

I think the expertise literature would provide a reasonable lens for thinking about what it takes to become an expert. E.g., check out some of the articles by K. Anders Ericsson. It emphasises the importance of spending thousands of hours of practice and effort in acquiring the skills required to become an expert.

Thus, we might switch the question around to say, what causes someone to spend thousands of hours devoted to learning and developing skills relevant to making a great invention?

### References

* Hyde, J. S. (2005). The Gender Similarity Hypothesis. American Psychologist, 60, 6, 581, 592. PDF

# Answer
> 3 votes
*First of all, I agree that socialization and culture are most certainly the main reasons why today most famous inventors are male.*

If you are looking for sex differences that may explain further variance, studies have found that the variance in IQ (*g*) among males is greater than among females:

> Some studies have identified the degree of IQ variance as a difference between males and females. Males tend to show higher variance on scores, though this may differ between countries. A 2005 study by Ian Deary, Paul Irwing, Geoff Der, and Timothy Bates, focusing on the ASVAB showed a significantly higher variance in male scores. The study also found a very small (d' ≈ 0.07, less than 7%, of a standard deviation) average male advantage in g. A 2006 study by Rosalind Arden and Robert Plomin focused on children aged 2, 3, 4, 7, 9 and 10 and stated that there was greater variance "among boys at every age except age two despite the girls’ mean advantage from ages two to seven. Girls are significantly over-represented, as measured by chi-square tests, at the high tail and boys at the low tail at ages 2, 3 and 4. By age 10 the boys have a higher mean, greater variance and are over-represented in the high tail."

(see Wikipedia for references)

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Tags: intelligence, problem-solving, sex-differences
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# Question
Title: Why does it seems in similar cases sometimes classic conditioning happens and in others habituation?
I'm slightly confused and was hoping you guys could correct me.

In classic conditioning as with Pavlov's dogs if we ring a bell just before a dog is given food, the bell will give the same response for the dog as the food alone would have, such as an excess of saliva. On a cellular level when two cells fire at a similar time one can cause the other cell to fire.

What I don't understand is why this doesn't happen in cases of habituation. So we already have the connection fattening foods taste good and when we eat a burger it should strengthen the connection between this is a fattening food, you like fattening foods you like this burger, but this doesn't happen if we had burgers everyday we get bored of it.

So guys where am I going wrong here? One a cellular level whats going on?

# Answer
The Wikipedia article on Habituation explains it fairly well:

> The habituation process is a form of adaptive behavior (or neuroplasticity) that is classified as nonassociative learning. Nonassociative learning is a change in a response to a stimulus that does not involve associating the presented stimulus with another stimulus or event such as reward or punishment.\[4\] (Examples of associative learning include classical conditioning and operant conditioning). Habituation is the decrease of a response to a repeated eliciting stimulus that is not due to sensory adaption or motor fatigue.

Classical Conditioning strengthens associations and elicits a response because the stimulus is associated with something. The bell means food, pay attention to it. Habituation happens when there's no association; why keep getting worked up by the church bells ringing when you know it doesn't mean anything important (as opposed to a tornado siren).

To generalize "classical conditioning" further into just "associative learning", they're two sides of the same coin; if something is important, connections in your mind strengthen; you remember and a response is illicited. If something isn't important, you stop caring about it and might fail to notice the stimulus at all. This is why excessive fire drills (and worse, false alarms) can be a bad thing; many college students end up being habituated against fire alarms rather than being classically conditioned to know "loud noise" -\> "get the heck out".
> 4 votes

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Tags: motivation, habituation
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# Question
Title: Can neural spiking in an organism temporarily cease?
I'm interested in modeling human brain spiking activity.

Are there cases in which neural spiking completely ceases in an organism and yet later resumes?

I've considered:

* hypothermic drowning, but medical reports (e.g., here) on the topic suggest that recording a patients' EEG or other indicators of spiking activity is not a priority when trying to revive a patient.
* cryptobiosis, but haven't found any relevant studies.

# Answer
Your link to Wikipedia's cryptobiosis article mentions that Tardigrades are capable of reducing their metabolic activity to 0.01% of normal levels, and their water content to 1%, a state which they can maintain for up to 10 years. Possessing a considerable nervous system, it is almost certain that Tardigrade neurons are not active at all during that period, especially since neurons are some of the most energy-demanding cells. Some nematodes, which apparently are also cryptobiotic, would be a similar case.

Another relevant context would be hypoxic insults to brain tissue. Hypoxia-induced neurological damage results partly from a cascade of glutamate-release that is caused by diminished ATP production in neurons. According to a study by Bickler and Donohoe (2002), some animal's neurons, in order to preserve ATP levels, are equipped to block action potentials at the onset hypoxic incidents. See the section "Why does the lack of O2 kill typical neurons rapidly?"--they even cite a study that performed EEGs (as you suggested) on anoxic turtles.

Whether it is anything-but-rare for spike trains to be completely inhibited during the course of regular nervous system function is another question, and I wish I knew the answer.

<sub> Bickler, P. E., & Donohoe, P. H. (2002). Adaptive responses of vertebrate neurons to hypoxia. Journal of experimental biology, 205(23), 3579-3586. \[PDF\] </sub>
> 6 votes

# Answer
When hamsters are cooled sufficiently, their brain electrical activity ceases. When the hamsters are later revived, brain electrical activity resumes.

### References

> * Gerard, R.W. (1953) What is Memory? Scientific American. Sept. 1953:118-126.
> 3 votes

# Answer
Yes, according to MIT scientist Sebastian Seung:

> Some victims of drowning in icy water have been resuscitated after being effectively dead for tens of minutes. Even though their hearts had stopped pumping blood, the icy cold prevented permanent brain damage. The lucky ones recovered with little or no memory loss, despite the complete inactivity of their neurons while their brains were chilled.

### References

* Seung, S. (2012) Connectome: How the Brain's Wiring Makes Us Who We Are. Boston: Houghton Mifflin Harcourt.
> 1 votes

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Tags: neuroscience
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# Question
Title: Is there any chromatic analogue of the Shepard tone?
Is there any chromatic analogue of the Shepard tone? I am imagining that each pure tone would correspond to a pure wavelength of light, transformed in such a way that the middle of three consecutive octaves would correspond to the peak sensitivity of the R, G, and B cones respectively. Would the light have the corresponding description of "always getting bluer (redder)"? If, say, one had been spending a long time immersed in a game like this, would it create the illusion of accelerating toward (away) without actually moving? Any references to similar ideas?

# Answer
> 5 votes
One similar idea is the Blue Diamonds Optical Illusion, is a series of identical things that appear to be a series of darker and darker and darker things, indefinitely. It shows that the Cornsweet illusion can be repeated over and over again. This reminds me of the way the Shepard tone plays the same thing over and over again, but the pitch seems to get higher and higher.

I suspect a similar approach might be able to construct an illusion that appears to be "always getting bluer".

# Answer
> 2 votes
Peter Tse's Infinite Regress Illusion creates the illusion of a stimuli that is continually moving away from a target.

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Tags: perception, color, auditory-discrimination
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# Question
Title: How does the brain process concurrent visual or sensory data?
I tried thinking about an apple and simultaneously an orange. (I was thinking about its appearance and taste). Despite my best efforts I was not able to do parallel processing to think about the apple and orange at the same time. What I was doing was concurrent processing, thinking about Apple and orange in time division multiplexing.

I noticed that my brain (which is also responsible for thinking) was indeed able to manage my two hands simultaneously, and was able to help me understand sounds comings from multiple sources, so it was helping me to see many things at the same time, in parallel, not concurrently.

I have asked a similar question here which compares processing by the brain with parallel processing by computers.

How exactly we explain these differences of operation by brain in dealing with sensory data (for example touch which can be felt in parallel), and thinking or visualization?

# Answer
> 4 votes
The tongue is made up of a surface area of about five different types of taste receptor. They are:

* salt
* sour
* bitter
* sweet
* unami

These inputs are handled by your gustatory system which can certainly parallel process them. You may know or have heard of combinations of them. Sweet n Sour, Sweet and Salty.

> The facial nerve (VII) carries taste sensations from the anterior two thirds of the tongue, the glossopharyngeal nerve (IX) carries taste sensations from the posterior one third of the tongue while a branch of the vagus nerve (X) carries some taste sensations from the back of the oral cavity.

From the wiki on the gustatory system

It's more likely that you've just never taste apple and orange at the same time, so you don't have the experience to remember.

But we do have a semantic memory that's specifically focused towards object identification. This means we put things in little boxes. You have a box for oranges and a box for apples. There are neurons in your temporal lobe that Kristoph Koch could find that fire only when you see an apple or even the word apple\[1\]. There is no such thing as an orpple, so you've never required a box for it. I don't think imagining it simultaneously is really beyond your imagination though if you worked at it.

(this article is actually somewhat similar idea, competition between two objects in the temporal lobe: here it's pictures of two people) http://www.klab.caltech.edu/news/Cerf-et-al-10.pdf

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Tags: cognitive-psychology, cognitive-modeling
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# Question
Title: Does medication to treat Obsessive-Compulsive Disorder reduce associated cognitive deficits?
Some studies point to existence of cognitive deficits in OCD (it seems that these deficits are not comorbid but have the same neurological roots as OCD). Unfortunately I found no studies with positive effects of medication (SSRI etc.) on cognitive deficits/impairment in OCD patients. I found only one study about cognitive-behavioral therapy and improvement of cognitive deficits symptoms in OCD.

Is there any research that indicates medication used to treat OCD (such as SSRIs) can mitigate these cognitive deficits?

**Related articles:**

> * http://www.steveseay.com/ocd-cognitive-deficits-obsessive-compulsive-disorder
> * Fenger, M. M., Gade, A., Adams, K. H., Hansen, E. S., Bolwig, T. G., & Knudsen, G. M. (2005). Cognitive deficits in obsessive-compulsive disorder on tests of frontal lobe functions. Nordic journal of psychiatry, 59(1), 39-44. PDF
> * Purcell, R., Maruff, P., Kyrios, M., & Pantelis, C. (1998). Neuropsychological deficits in obsessive-compulsive disorder: a comparison with unipolar depression, panic disorder, and normal controls. Archives of General Psychiatry, 55(5), 415. LINK

# Answer
> 2 votes
Look up Jeffery Schwartz. He has done decades worth of scientific studies with hundreds of OCD patients. In his book "You Are Not Your Brain" (worth a read) he mentions this bad brain wiring or cognitive deficits are the culprit behind the "Deceptive Brain Messages (OCD).

His studies show that self directed neuro-plasticity make the most corrections in brain wiring - and that the medicine can be an aid in the self directed steps. These self directed steps rely on the mind to alter the physical brain.

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Tags: cognitive-psychology, abnormal-psychology, depression
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# Question
Title: Scientific findings of strobe lights and the brain
While there is a lot of general discussion and articles on the web that strobe lights cause epileptic seizures - I am looking for more specific data. Perhaps scientific references, papers or articles that list what exactly changes in the brain, when exposed to strobe lights.

For example, how does it alter consciousness, what happens to the frequency of the brain after exposure, what part of the brain does most of the change happen in and if there are ways to revers the effects on the brain, etc.?

Any point in the right direction is greatly appreciated,

**EDIT**
This article just came out, looks like this issue will be getting more attention in the near future:
http://www.pcmag.com/slideshow/story/306026/the-hobbit-and-other-movies-that-will-make-you-sick-and-may#disqus\_thread

# Answer
The presentation of flickering lights usually leads to so-called steady-state visual evoked potentials, that is, oscillatory responses in the visual cortex with the frequency of the stimulus as well as its harmonics. See for example:

Herrmann CS. (2001) Human EEG responses to 1-100 Hz flicker: resonance phenomena in visual cortex and their potential correlation to cognitive phenomena.Exp Brain Res 137(3-4):346-53. Pubmed

There is a lot of research concerning this phenomenon. For a list of papers, please see http://www.ncbi.nlm.nih.gov/pubmed?term=steady%20state%20visual%20evoked%20potential
> 5 votes

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Tags: consciousness, brain-injury
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# Question
Title: Can Sensory Processing Disorder (SPD) present symptoms from very particular stimuli?
Sensory processing disorder can cause over or under reactions to sensory input, like loud sound. Can those afflicted with this disorder be okay from a particular sound played at a particular volume but react to a different sound played at the same volume? How can this disorder be differentiated from a phobia or various other disorders?

# Answer
> 4 votes
To answer your first question, I am fairly certain that those afflicted with this disorder, or more directly, a person who cannot tolerate a particular sound at a particular volume but react differently (find tolerable) to another sound even at the same volume, is definitely possible. For example, to provide a concrete example, let's assume an individual with SPD throws a tantrum when he hears a note out-of-tune, but can tolerate in-tune notes, regardless of volume. Some associate SPD with Autism Spectrum Disorders \[\] (even one of the symptoms in the DSM-IV-TR for Asperger Disorder \[\] make note of sensory hypersensitivity and hyposensitivity). In the example I mentioned, I don't think one would use the term "phobia" to characterize the reactive behavior to the stimuli. And someone with auditory SPD might not be able to simplify tolerable versus intolerable noises based solely on volume. SPD is a matter of difficulty in processing information received through the senses \[\] - though difficulties may arouse anxiety, "phobia" is a pretty specific *irrational* fear, not to be attributed to a difficulty in processing.

Specific phobia(s) and SPD aren't necessarily mutually exclusive, but one way in which they can be differentiated is by one of the symptoms for Specific Phobia.

> C. The person recognizes that the fear is excessive or unreasonable. Note: In children, this feature may be absent. \[\]

In SPD, what seems to be critical in response to stimuli is the idea of the "just-right" perception. In SPD, the reactive response to stimuli may not necessarily be indicative of a phobic response. For example, someone with SPD may absolutely hate being poked by others. But this person would not go out of his way to avoid being poked - dislike for tactile response purposes is different from a fear of pokes.

### References

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Tags: cognitive-psychology, developmental-psychology
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# Question
Title: What are the internal and external variables for varying levels of self-awareness?
I'm looking for references to studies that show which variables increase or decrease self-awareness and to what degree.

For example, **internal variables** could be level of a certain vitamin, brain chemical, oxygen level, form of spine, etc. and/or **external variables** like emotional trauma, meditation, altitude, contact with water, etc.

# Answer
> 4 votes
*This is just a sketch of an answer*. It is important to clarify how we define "self-awareness".

**The self**: There is a huge social psychological literature on the self. For a scientific review, see for example Ellemers et al (2002). Even the concept of self-awareness is contentious in that it posits that there is a self to be discovered whereas I assume most researchers would acknowledge that the self is at least partially a social construction.

**Psychological well-being:** A sense of self-awareness also relates to many other constructs such as having a sense of life purpose or meaning. For more information on that you could look at the psychological well-being literature. At the risk of self-promotion, I can point you to Grant et al (2009) where we reported some of Big 5 correlates of psychological well-being where for example we showed that self-reported purpose in life (i.e., a little bit like self-awareness) correlated well with high extraversion (r=.33), high conscientiousness (r=.45) and low neuroticism (r = -.44).

**Self-efficacy:** An alternative perspective would be to look at self-efficacy research. Such research often looks at the relationship between a person's predicted and actual performance. Such research often shows that specific performance feedback with practice is important in generating accurate self-beliefs about one's own competence.

**Self-other correlations**: I imagine also that there is literature that looks at self-other correlations for various characteristics. It would be interesting to see what predicts the size of self-other discrepancies in such domains as personality, and performance. Unfortunately, I don't have any particular references on hand.

### References

* Ellemers, N., Spears, R., & Doosje, B. (2002). Self and Social Identity\*. Annual review of psychology, 53(1), 161-186. PDF
* Grant, S., Langan-Fox, J., & Anglim, J. (2009). Big Five Traits as predictors of subjective and psychological well-being. Psychological Reports, 105, 201-231. PDF

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Tags: consciousness
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# Question
Title: How long does it take to read a sentence with X number of characters?
How does the time needed to read a sentence scale with the number of characters? Or does this time scaling depend on something more than just character count?

For example, let $X$ be the number of characters and $F(X)$ the seconds to read an entire sentence of $X$ characters long. There are 3 options:

1. **Linear** $F(X) \in \Theta(X)$: Is the relationship linear? That is, if it takes 0.5 seconds to read "*hello*", it would take 1.0 second to read "*hello world*": $F(X) = 0.1 X$
2. **Sublinear** $F(X) \in o(X)$: Or does it decay? That is, as people read a long sentence, their reading speed increases (crazy example $F(X) = 1 / X$)
3. **Super-linear** $F(X) \in \omega(X)$: Or is it like quadratic? That is, each additional character ads more time than the previous word? (example: $F(X) = X ^ 2$)

**Which of the above 3 options best describes reading speed based on length of text? Is the specific functional form of this relationship known?**

---

### Motivation

I am creating an iPhone app where I need to show transient confirmation messages. For example, when a user submits a comment, I pop up a message saying "*thanks for submitting your comment*". Shortly after, the message will fade away. There exist many such transient messages all over my iPhone app.

What I would like to do is to calculate the optimal time to show each message based off of the number of characters in that message. I want users to have enough time to comfortably read the message, but not so long that the message annoys them. The purely UX version of this question is here:

How long does it take to read X number of characters?

# Answer
I've studied this a little bit within the context of timing responses to personality test items. General models of reading speed look at both the time to read the words as well as to comprehend. From memory, eye tracking studies have shown how the eyes will often back track to confusing parts of a sentence (apologies for lack of reference).

Some general findings that I've found in my own data on time to answer personality test items of different lengths:

* Expect an initiation period. I.e., the time between displaying a message and the commencement of reading. In mathematical terms, this will translate to a non-zero constant in your model of reading time as a function of properties of the text.
* The more familiar the content and the words are to the reader, the quicker they will be. This translates both in absolute terms that simple words are quicker to read, and also to interactions between individuals and the content.
* In general, character count, word count, and syllable count tend to be highly correlated in normal prose. From my own data, these indices tend to have a relatively **linear effect on reading speed**.
* More complex sentences (e.g., ones with negation, multiple clauses, etc.) take longer to read. For example, I found that sentences with "not" took systematically longer to process.
* Individuals differ substantially in reading speed. Expect to see a distribution of individual differences that is a little bit positive skewed from normal. Thus, if you are designing a system where you determine the length of time text is displayed, you may need to pitch the speed of your system to capture a certain percentage of that distribution (e.g., 95, 99% etc.). Various factors explain variation in reading speed including whether English is a second language and education.
* There are also outliers. People get distracted. Thus, there is reading time when people are focussed and there is reading times that incorporate distraction and other processes.

More generally, if you have the resources, you can do some pilot testing on a sample of individuals where you time how long people take to read the text, ideally within the context of the application. This could allow you to develop a domain specific model of reading speed.

Although a little tangential, some articles that discuss speed of item responding in a personality testing context include Casey and Tyron (2001) and Wagner-Menghim (2002).

### References

* Casey, M.M. & Tryon, W.W. (2001). Validating a double-press method for computer administration of personality inventory items.. Psychological assessment, 13, 521.
* Wagner-Menghin, M. (2002). Towards the identification of non-scalable personality questionnaire respondents: Taking response time into account. Psychologische Beiträge, 44(1), 62-77.
> 11 votes

# Answer
If you really wanted to know you could use models of reading behaviour - e.g. EZ-Reader or Swift. The Rayner reviews are the classic go-to to outlne this kind of thing:

Rayner, K. (2009). Eye movements and attention in reading, scene perception, and visual search. The Quarterly Journal of Experimental Psychology (2006) (Vol. 62, pp. 1457-506).

It will depend on: \- Size of text \- Language \- Word frequency \- Word length \- Predictability \- and a whole host of other factors.

Of all the words put together, plus any occasions where regressions to previous words are made because the observer has failed to understand the text.

In practice, it's probably not worth worrying about to this level of complexity so just beta test it with some people and make sure they don't complain that they don't get enough time to read the messages.
> 7 votes

# Answer
A few thoughts spring to mind:

1. Part of the answer might depend on the maximum value of X (if all the messages are relatively short, that's a key piece of information).
2. It doesn't decay, I don't think. The more information presented to the user, the more it all has to put into context with each other. But I don't think it's quadratic, either; that seems too steep.
3. If X is the number of characters, and W is the number of words, the time might be more dependent on W than X.

> Do you remmeber tihs erxesice? It's fnuny how wlel you can raed wrods as lnog as the fisrt and lsat ltteers saty cnonstat. Wehn redanig, our birans seem iclinned to prcoses by the wrod, mroe tahn by the ltteer.

**EDIT**: Those were my initial thoughts, when this question was first posed on English Language & Usage. I won't pretend I'm an expert (I'm not), but there does seem to be quite a bit of research that would support my third hypothesis – that readers often parse by word, more so than by letter, so the number of words in a text string might be more significant than the number of letters. I'll cite one paper I managed to track down and peruse:

Inhoff, Albrecht Werner, *Integrating information across eye fixations in reading: The role of letter and word units*. Acta Psychologica (73:3), April 1990, Pp. 281–297
> 4 votes

# Answer
I just had a project where I had to figure this out. I found that a good rule of thumb was the following:

$$timeToRead = 1300 + (chars * 65);$$

So that's an initial time of 1300ms to adjust to what you need to be reading and about 65ms per character including spaces.
> 3 votes

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Tags: experimental-psychology, reading, linguistics, human-factors
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# Question
Title: Stiffing the tip as groups get larger ... like the prisoner's dilemma but ...?
Is there a game theory analysis or other research or modeling describing the commonly perceived phenomenon whereby the amount by which people underpay a gratuity seems to be proportional to the number of people at the table?

In other words is there term of art for this behavioral pattern just as we use the phrase "Prisoner's Dilemma" to describe the game theoretical mechanics of two parties who can collude (to their mutual benefit) with risk, or betray their colleague in an effort reduce or eliminate their own risk?

(I would suggest that the mechanisms by which people exploit common resources and by which people fail to invest and maintain such resources (for example ecologically) are similar to this other group dynamic but I'm curious what research has been done on this).

# Answer
> 3 votes
## Bystander Effect

The Bystander Effect could be your answer. The **more people**, the **less** personal **responsibility**.

* Person gets assaulted and mugged on a **crowded street** in **broad daylight**, **nobody calls** the cops.
* Software bugs slow company productivity almost to a halt, **many employees**, **nobody reports** the problem.

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## Tragedy of the Commons

The tragedy of the commons has been studied from many perspectives. You can use that commons dilemma link as a jumping off point to hopefully happen across something relevant. But **I would start by looking at** the psychology behind the **bystander effect**.

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Tags: social-psychology, economics, game-theory
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# Question
Title: How do graphic objects in data visualisation facilitate ease of interpretation?
**Background**: I vaguely remember reading in a book (I think it may have been Nudge - Thaler and Sunstein) about the advantages of using graphics for visualising data, such as a smiley face, or traffic lights, to communicate a message in an easily interpreted, visual language.

* **To what extent do graphics such as smiley faces and traffic lights in visualisations facilitate ease of interpretation?**
* **What is the cause of this ease of interpretation?**
* **What research has studied this phenomena?**

**Initial thoughts:** I imagine that the ease of interpretation is due to these items being purely visual that we quickly recognise them, and they can make complicated, unfamiliar information (for instance health results) that much easier to comprehend. Is that an accurate summary?

If it's any further help I'm looking into this specifically for use in the communication of health results. So for example if you have a 20% risk of developing a disease, a good way to illustrate this could be 100 smiley faces - of which 20 are :( and 80 are :)

# Answer
> 1 votes
As you mentioned, data visualization and visual stimulation in general, trigger a primitive brain response, which results in an easier comprehension and engagement/rejection process - a process more trivial than sensing and comprehending symbols. Thus, numerical information such as percentages, distributions, and relativistic data in general, immediately get infused into the cognitive realm, provided the visual field is not excessively cluttered. Too much visual stimulus in a presentation results in a more laborious attempt at comprehension, and hence may lose favor.

When it comes to non-numerical / non-quantitative data, visualizations serve as a promoter of cognitive engagement. Traffic lights to draw attention, smiley faces may be used to encourage the receiver, boxes and other demarcations to engrave specific items of information in memory, the list goes on.

I think the effectiveness of the visual presentation largely depends on the creativity and imagination of the presenter to resonate with the target audience, in terms of the mood, awareness, humor (mood?), social values and other variables which maybe of interest, of the target audience.

Again, if the visual field is excessively populated, the labor involved in the comprehension process may impede the effectiveness of the presentation.

Also, the ease at which visual information is processed also depends on how distinct the objects that are communicating information in the visual are. In your example, smiley faces to depict percentages maybe less effective compared to, say a colored pie chart, or something to that effect, because smiley faces are not easy to distinguish by themselves - even if they are ordered into separate regions. And in the possible event of conveying grim news , grim graphics may not received in the highest of spirits :P.

Cheers!

# Answer
> 0 votes
This is a great question. I'm not a cognitive psychologist by training, but I can offer a usability perspective on this from a person who is a trained cognitive psychologist. Jakob Nielsen recommends using icons when users don't have to **guess** what they *represent*. If the icon is vague, there's no additional benefit to including an icon with your label. It might actually confuse people. People aren't going to understand the meaning of your icon as well as you probably assume. This is because you have an expert bias in choosing your icon.

It doesn't sound like you're creating an interface. You say you'd like to visualize data using graphics like smiley faces. Emoticons (**smiley faces**) are the one **exception** to this icon rule. People immediately recognize emotions and faces. Our brains are hardwired to turn anything into a face. Every car has a face and an emotion, for example. The first thing you recognize when you look at a picture subconsciously will be the expression on everybody's face. In eyetracking studies, the first thing people notice in pictures is faces.

This is getting really deep, but on the subject of smiley faces, the more simplified the face, the more we project ourselves into the character. The character can be drawn very realistically, and it looks like a photographic picture. In this case, you are an observer looking at the character. Or the character can be less detailed. In this case, you become the cartoon character. This is why cartoons are so universal and permeate our culture.

Your representation of a face in your mind is like a cartoon. You don't see yourself wearing a photographic picture of your face. When you're smiling to someone, you see yourself with an upturned mouth. You see yourself wearing a very simplified smiley face. That's the abstract idea of your appearance in your mind. It's like looking at a bike. You don't see two wheels, a frame, and so on. In your mind, you see the abstract concept of "bike."

The more simplified the cartoon, the more we identify with it. This is demonstrated well in japanese comics. When the artist wants a character to seem otherly or distant from the reader, he draws them very detailed.

So if you want people to feel a certain way about your data, they will automatically empathize with the emotion of the cartoon characters you draw. Hope all this explanation answered your question and was relevant. ;)

## Edward Tufte

If you want to dive deep into data visualization, buy any book by **Edward Tufte**. Envisioning Information was awakening for me. The Quantitative Display of Information might be a better place for you to start. The graphics aren't as colorful and pretty, but it really gets into data visualization. Tufte's books are seminal.

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Tags: cognitive-psychology, software, health-psychology, visualization
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title: Possibility of perfect virtual reality

text:
# Question
Title: Possibility of perfect virtual reality
Is it biologically possible to build a "perfect" virtual reality, in which the person in that world cannot distinguish it from the real world? (e.g. as in the movie The Matrix)

From my knowledge (which is very limited), we perceive everything as a result of electrical activity within nerves. If we were able to encode/decode the patterns of the electrical activity and understand how the brain communicates with and intercepts all the nerves between the brain and the other parts of the body, would this mean that a perfect virtual reality is possible?

# Answer
> 3 votes
If you look at the phenomenon of lucid dreaming, where people consciously explore their dreams, you will recognize that **perfect virtual reality is possible** with the biology that is already in place.

The lucid dreaming related phenomenon called "false awakening" is another piece of evidence for perfect virtual reality. When a lucid dreamer experiences a false awakening, it is indistinguishable from reality. A person wakes up in the same bed. walks through replica rooms. Such person may use restroom, brush teeth, start making breakfast, then wake up in reality. The only two consistent differences between a false awakening and reality would be inability to see consistent time on a digital display and inability to adjust light levels with light switches. **The defining characteristic of false awakenings is that they trick the dreamer into thinking the dreamer is interacting with reality.**

I should probably mention that expert dreamers, those who keep a dream journal and train to remember dreams, experience their dreams more intensely. As such, it is not uncommon to hear of "hyper-real" dreams, which are more visually and cognitively clear than baseline reality.

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Tags: neuroscience
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title: How does the brain know what to crave?

text:
# Question
Title: How does the brain know what to crave?
I remember that at some point on House, M.D., one of the characters mentioned that her patient craved milk because it contained some chemical he/she needed. How does the brain figure out what chemicals it can get from what foods, and by extension what to crave? I know one craves very specific foods, but I eat a lot of foods per meal so I don't see how the body can connect something to its composition.

# Answer
Check out this question on biology.stackexchange: Do omnivore mammals vary food preferences based on dietary needs?

The answers in that question mention that experiments on Rats and Birds determined that there's an internal **chemosensor, the anterior piriform cortex (APC)** within bird and rat brains that senses lack of Indispensible Amino Acids (IAA). Animals show aversion to foods that lack IAA in as short as 20-30 minutes.

There's another example listed that mentions that being sodium deficient makes animals like salt more. Their preference for salty taste increases.

I don't know if these findings apply to humans though.
> 8 votes

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Tags: decision-making
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# Question
Title: Does the relationship between positive mood and motivation for sex differ between males and females?
**Background:**
I recently heard the saying from a doctor: "men are motivated to have sex when they ***want to*** feel good and women are motivated to have sex when they ***already*** feel good".

(In a side note, such a difference would help to explain why males might not understand female sexual motivation.)

**Questions:**

* Do any scientific studies support the claim that males have greater sexual motivation when they want to feel good (or are experiencing temporary lower subjective well-being) whereas females have greater sexual motivation when they already feel good ?
* If so, what is the reason for this difference?

# Answer
> 12 votes
In men, Mitchell et al. (1998) found that positive mood induced by music affected greater sexual arousal, and that musically induced negative mood affected reduced sexual arousal. In women, Ter Kuile et al (2010) found similar results for women.

However, your question is not quite addressed by these studies. Whereas these studies address the effect of mood on arousal in the presence of erotic stimuli, it is possible that negative affect may still induce pleasure-seeking (even if it reduces the pleasurable effect of stimuli in general).

Indeed, Lykins et al. (2006) found that a subgroup of both men and women reported increased sexual interest during depressed and anxious moods. Men were more likely than women to report increases of sexual interest during negative mood states. One's inclination toward sexual excitation was the strongest predictor of this relationship between negative mood and sexual interest. To speculate a little, this may be because it moderates the effect of negative mood on arousal that is mentioned above. That is, people inclined toward sexual excitation may not show the arousal damping effect of negative mood.

> Mitchell, W. B., DiBartolo, P. M., Brown, T. A., & Barlow, D. H. (1998). Effects of positive and negative mood on sexual arousal in sexually functional males. Archives of Sexual Behavior, 27(2), 197-207.
>
> Ter Kuile, M. M., Both, S., & Van Uden, J. (2010). The Effects of Experimentally‐Induced Sad and Happy Mood on Sexual Arousal in Sexually Healthy Women. The journal of sexual medicine, 7(3), 1177-1184.
>
> Lykins, A. D., Janssen, E., & Graham, C. A. (2006). The relationship between negative mood and sexuality in heterosexual college women and men. Journal of Sex Research, 43(2), 136-143.

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Tags: well-being, sex-differences, sexuality
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# Question
Title: Does the transcription method used (e.g., printing, handwriting, typing, voice recording, etc.) affect memory retention?
When I was in high school, one of my teachers used to make us hand print copies of materials from transparencies on an overhead projector (I may be showing my age), with the reasoning that re-writing notes by hand was better for memory retention.

I later was told, via sources I can no longer recall, that typing out notes wasn't as good for memory retention because it was too easily done without thinking. Hand printed/written notes, I was told, were superior because they forced you to think about the words and letters being written, whereas typing uses more or less the same actions for each character and can be done faster with less conscious thought. Anecdotally, I know I certainly type faster than I write, and am better able to multitask as I do.

* Is there any evidence to support the idea that writing is better for retention than typing?
* Does it matter if you print or handwrite the transcription?
* Do other transcription methods, such as dictating into an audio recording device, have better or worse retention rates?

# Answer
A recent senior thesis by Schoen (2012) addressed this exact question. Students watched a filmed lecture and were randomly assigned to take notes with either by typing or handwriting. After the lecture, students were given a few distractor tasks, and then given a retention test. Other students were assigned to take notes from a textbook, instead of a lecture.

In contrast to your theory, there was a *main effect* of transcription method, such that **typing notes led to better retention.** However, there was an *interaction* with context, and it appears that there is no *simple main effect* for textbook notes. (see figure below)

One could posit that this interaction occurs because of the demands of the task. Taking notes by typing is easier and faster, i.e. more fluent. Hand-writing notes leads to higher cognitive load, which may lead to the student paying more attention to note-taking and less attention to the lecture itself. This would explain why textbook notes showed no effect. I only skimmed through the paper, but it seems very interesting and right to the point of your question, so I would suggest reading it for more info.

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**Additional information:**

Before looking this up, I expected the opposite pattern. Bjork & Bjork (2009) have found that creating **desirable difficulties** in learning can promote retention. For instance, it is well known that generating information, such as fill-in-the-blanks, promote better retention compared to, e.g., multiple choice tests. Diemand-Yauman, Oppenheimer, & Vaughan (2010) have found that presenting study material in hard-to-read fonts leads to better encoding and retention of the material.

Similarly, a study by Yang, Gallo, & Beilock (2009) looked at the effect of motor fluency on retention. Subjects typed a two-letter dyad (such as `ae` or `aq`). *Fluent* dyads were letter pairs which were typed with two fingers; these pairs are typed faster and more easily than dyads that used the same finger because there is no motor bottleneck. Subjects were later given a recognition test to determine which dyads were presented to them. They found that subjects produced more false alarms for fluent dyads than disfluent dyads. This is particularly strange because false alarms, by their nature, *were not actually typed by subject*. This effect only held for expert typists, corroborating previous literature which suggests that fluency leads to false recognition. (Presumably for novice typists, none of the dyads were fluent enough to produce a higher level of false alarms).

So it seems there is a confluence of effects here. Disfluency--that is, making things more difficult--can promote deep processing and lead to better encoding and retention. However when this process causes one to neglect other information, such as paying attention to the lecture itself, retention suffers.

For additional reading on the effects of fluency on problem solving, I suggest Alter, Oppenheimer, Epley, & Eyre (2007) and Oppenheimer (2008).

From Schoen (2012):

> Alter, A. L., Oppenheimer, D. M., Epley, N., & Eyre, R. N. (2007). Overcoming intuition: metacognitive difficulty activates analytic reasoning. Journal of Experimental Psychology: General, 136(4), 569. PDF
>
> Bjork, E. L., & Bjork, R. (2009). Making things hard on yourself, but in a good way: Creating desirable difficulties to enhance learning. New York: Worth Publishers. PDF
>
> Diemand-Yauman, C., Oppenheimer, D. M., & Vaughan, E. B. (2011). Fortune favors the **Bold** (*and the Italicized*): Effects of disfluency on educational outcomes. Cognition, 118(1), 111-115. PDF
>
> Oppenheimer, D. M. (2008). The secret life of fluency. Trends in Cognitive Sciences, 12(6), 237-241. PDF
>
> Schoen, I. (2012). Effects of Method and Context of Note-taking on Memory: Handwriting versus Typing in Lecture and Textbook-Reading Contexts. Pitzer Senior Theses. Paper 20. PDF
>
> Yang, S. J., Gallo, D. A., & Beilock, S. L. (2009). Embodied memory judgments: a case of motor fluency. Journal of Experimental Psychology: Learning, Memory, and Cognition; Journal of Experimental Psychology: Learning, Memory, and Cognition, 35(5), 1359. PDF
> 10 votes

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Tags: memory, learning, educational-psychology, writing
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# Question
Title: Is it possible to measure the differences in processing and interpretation of reality between individuals?
What variables can be measured to compare, for example, two different individual's conscious processing and interpretation of the same objective reality ? For example, when terms like "distorted view of reality" are thrown around, how does one measure that or can conclude that?

How can we measure the differences in the processing and interpretation of reality between individuals and if it's impossible, please explain why it can not be done or what can not be measured.

# Answer
> 6 votes
The answer to this question is rather philosophical will mainly depend on who you ask.

If you ask someone who is close to physicalism, he would probably respond that there exists nothing that cannot be measured, hence, differences in the processing and interpretation are measurable in principle too, although we might lack the necessary apparatus and methods right now.

However, if you ask some who is closer to dualism, he would probably respond that there are (at least) two kinds of consciousness: access-consciousness (or a-consciousness) which can be measured with scientific methods, and phenomenal-consciousness (or p-consciousness) which is only accessible to ones own mind and cannot be measured by scientific methods in principle (cf. the hard problem of consciousness).

Please note that this answer is a simplification that gives only a glance into a debate that filled volumes (cf. http://en.wikipedia.org/wiki/Philosophy\_of\_mind)

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Tags: cognitive-psychology
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# Question
Title: Can we stop the brain from processing a particular task?
Imagine a task of high involvement and great complexity, but one that is not very important, e.g., a strategic computer game. Because of high involvement, the brain continues to process the problem to find solutions after playing the game. Because of the task complexity, I believe there is no right way to solve the problem, and the task is processed by the brain for a very long time but with no solution. The problem is absolutely non-important in 'real life' terms.

Is there a way to "tell" the brain not to process tasks anymore in order to prevent the uncomfortable feeling of having an "unsolved" task?

**UPDATE**: One of the commentators posted a good additional example of what may happen when your brain continues to process a task:

"A while back I played a game called diplomacy, which is very complex strategically. When I went to sleep that night, thinking about the upcoming turn, my brain was going through all possible combinations of turns and outcomes. One by one. For about 3 hours as I could not fall asleep because of this. While I did find the correct solution, it was quite unpleasant , non normal sleep."

I believe this one is the one of the most unpleasant results of an unwanted task processing. To some extent, a similar thing may happen during the day or even days after the task was "implanted" in the brain. It's just like in a middle of a day, you spontaneously start thinking about that task. So brain was processing that task all the time, it's just you were more busy with other things to not feel it and not start aware thinking of it.

Regarding night time task obsession, I was trying to focus on different things, lying with open eyes, aware thinking of something else, trying to stop the brain, but this doesn't help at all, only makes things worse (because you can't do anything). The solution I found is to not to go to sleep immediately, but to do something different or just rest (do nothing) for approximately an hour, you'll feel after that your brain is calmed a lot. This somehow diminishes that brain task activity and despite, you still may receive task thinking attacks, they won't be so severe, long and pressures.

# Answer
> 5 votes
One answer is through turning off these messages or "tasks" via mindful awareness and focused attention on another task requiring much less cognitive load - like breathing.

Look up Dr. Jeffery Schwartz's book "You Are Not Your Brain" for scientific data on this.

Basically, latest scientific research shows that we can use our mind to stop the brain (or really work around the task, observing it, until it slowly diminishes activity in the bran).

It's the old saying; "mind over matter" - where the brain is also matter.

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Tags: problem-solving
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# Question
Title: Is a Hopfield network with a continuous activation variable and a discrete time variable possible?
I've found plenty of resources on Hopfield networks that use either discrete variables for both activation level and time or continuous variables for both activation level and time. **Is it possible to construct a Hopfield neural network that uses a continuous variable for activation level and a discrete variable for time?** If it is possible, can anyone offer resources and/or tips on how to construct one in software?

# Answer
> 5 votes
After doing some additional research, I think the answer is yes. It just means using a fixed timestep for the continuous-time activation equation (as described here). Since this is a differential equation, implementing it in software requires implementing a numerical integration method. I recommend the Exponential Euler Method as a starting point, because it's relatively simple and it's designed for differential equations of the sort that's used for the continuous Hopfield network.

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Tags: neural-network
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# Question
Title: What's the difference between projecting and mirroring?
In Psychology 101, I learned about **Projecting** and **Mirroring**... I know one is where an individual sees his own problems in other people... I always forget the other concept and/or confuse the two. What's the difference between projecting and mirroring?

# Answer
**Mirroring** is when one acts like others one is in the presence of. For example, an individual may pick up inflections, wording, or mannerisms of others they spend time with. From Wikipedia:

> Mirroring is common in conversation. The listeners will typically smile or frown along with the speaker. If one person throws in sports metaphors, the other will likely parry along similar ideas. Since people usually accept their mirror image with ease, mirroring the person with whom one is speaking generally makes them feel more relaxed and encourages them to open up.

**Projection** is a defense mechanism whereby an individual "projects" their own views, issues, or thoughts over someone else, preventing the individual from getting an accurate view of the other person and believing the thoughts come from the other individual rather than oneself. Again, from Wikipedia:

> Psychological projection or projection bias is a psychological defense mechanism where a person subconsciously denies his or her own attributes, thoughts, and emotions, which are then ascribed to the outside world, usually to other people. Thus, projection involves imagining or projecting the belief that others originate those feelings \[...\]
>
> An example of this behavior might be blaming another for self failure. The mind may avoid the discomfort of consciously admitting personal faults by keeping those feelings unconscious, and by redirecting libidinal satisfaction by attaching, or "projecting," those same faults onto another person or object

**Projection** may be easily confused with **Mirroring** because with Projection, an individual sees their own traits in another, but the proper term can be remembered because the individual who is projecting "blanks out" others like a blank movie screen, and "projects" their own image, seeing what they are projecting instead of what is really there. WIth Mirroring, an individual is like a mirror themselves, as opposed to Projecting, when the individual is like a movie projector.
> 9 votes

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Tags: cognitive-psychology, terminology
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# Question
Title: What causes people to remember events which did not take place?
How do we "remember" events which did not take place, or future events? I'm using remember as a way of describing the experience of recalling a future scenario. For instance, when you were little say your mom promised you a soda at the grocery store, but then didn't give you one. You might have created, imagined, a scenario where this did happen, memorized it as such, and then later when you didn't get the soda you remembered the other, expected, imagined. It's not the expectation I'm focusing on, but the act of creating, and remembering something that never happened, and is expected in the future.

I've read a few articles, mostly philosophical, about this sort of thing, and what I've gotten from that is we know about the future because we have a memory of the past. So in a way this is a question about memory itself.

I don't understand why we are able to remember events which did not happen, like events in the future. What causes the brain to be able to do this? Do we know yet, or is there research on-going?

# Answer
There is some misinformation out there put forth by Brooks Agnew about "remembering the future". This is the same guy who advocates a "hollow earth" theory. It's not grounded in science, I'm afraid.

We predict and imagine the future. Often our predictions aren't even conscious (reflexes, for instance, can be programmed in the lower brain; we're often not conscious of our reflexes until right after they've done their job). But reflexes are a product of the past, either genetically, or through experience (depending on the reflex).

In fact, we generally consider it one of the arrows of time that humans remember the past and not the future; with Newtonian physics, deterministic physics implied events were completely invertible (reversible in time) while remaining valid. This is one of the interesting features of classical physics. There are now, many physically observable arrows of time, though: entropy, expansion of universe, quantum arrow (wave function collapse).

just a wiki article to get you started, http://en.wikipedia.org/wiki/Arrow\_of\_time
> 5 votes

# Answer
I believe what you're talking about is an **internal-external reality source-monitoring error**. Quoting from A Specific Brain Structural Basis for Individual Differences in Reality Monitoring:

> Remembering a previous experience often involves distinguishing information that was generated by internal cognitive functions (e.g., thought and imagination) from information that was derived from the outside world, an ability termed “reality monitoring” (Johnson and Raye, 1981). \[...\] Although we may feel that our reality monitoring abilities are reliable, there is evidence of substantial variability in accuracy across individuals. This is most apparent in the reality monitoring impairments often observed in patients with clinical disorders such as schizophrenia (Keefe et al., 2002), but variability in performance is also seen in apparently healthy volunteers (Hyman and Billings, 1998)

To describe basically what is happening in the scenario you described with a childhood memory, **the individual isn't "remembering the future**, they are confusing their imaged scenario for reality\**. It's a memory error: Rather than remembering what actually happened, the individual remembers the *imaged scenario* but gets the source of that memory (their imagination) wrong, believing the scenario to be real.

I suspect that Reality monitoring By Johnson, Marcia K.; Raye, Carol L. Psychological Review, Vol 88(1), Jan 1981, 67-85. would be of great interest to you on this.

**References**

Marie Buda, Alex Fornito, Zara M. Bergström, and Jon S. Simons (2011) A Specific Brain Structural Basis for Individual Differences in Reality Monitoring
> 3 votes

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Tags: memory
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# Question
Title: How does one study the effect of a dietary supplement on cognition?
I've really enjoyed this talk by Molly Crockett: Beware neuro-bunk. The speaker outlines the limitations of modern neuroscience when **accessing the effectiveness of dietary supplements** intended to enhance cognition. I believe the speaker mentioned that 68% of (americans?) take dietary supplements for a variety of reasons.

I've done some research, and these compounds typically go into "neuro enhancing" products:

* DMAE
* GABA
* N-Acetyl-L-Tyrosine
* Vinpoceitine
* 5-HTP
* Vitamin B complex

This got me thinking: **How does one assess the effectiveness of dietary supplements on cognition?** These are low- dose compounds that may be taken at random times of a day, combined with assorted other supplements. How does one study the effects of something like that? **Is there a "gold standard" study** that I can take a look at to understand how this is done?

What I'm interested in is how do they account for the time of day, and other supplements/drugs/activity that happened and followed the study.

When thinking about "real psychoactive drugs", their effect is much more profound, and thus easier to study, with a fairly well defined onset times, intensity curves. For example, I can go to erowid.org and see curves like the one below for

With a graph like that, one can with a reasonable certainty estimate the duration and intensity of effects. But what about dietary supplements? Is it just big placebo?

# Answer
> 7 votes
To the general question of **how to test the claims** , there's a couple things you want to show:

* 1) that the body absorbs the supplement (measure the absorption rate)
* 2) that the supplement crosses the blood brain barrier
* 3) that the supplement actually plays the role of agonist, antagonist, or allosteric modulator (or possibly even has a toxic effect). These are biochemical roles that depend on molecular properties like shape and charge distribution, as well as kinetic interactions (chemistry).
* 4) that the interaction of the ligand or effector (or toxin) with the receptor (or system) that's being affected by the supplement produces a cognitive benefit.

The first three are feats of biochemistry, the fourth of behavioral/psychological biology. So this is a complicated interdisciplinary task in the first place. Now if we want to consider all the control situations (especially 4) it becomes even more complicated.

**Known cognitive benefits** are come from substances like caffeine, nicotine, chocolate (it has theobromine), amphetamines, and other stimulant-like drugs.

GABA, on the other hand, exists naturally in the brain. It's part of an integrated molecular system and is tightly controlled by the citrus cycle (aka Krebs Cycle) and the GABA shunt. If you have more of it, but you don't need it, your body will just break it down or convert it (it's part of a very dexterous set of metabolic molecules).

The best cognitive benefit you can get is simply from eating right, not having nutrient deficiencies, omega 3's are good for long-term brain health. Circulatory health is good for long-term brain health (so exercise and less cholesterol). Pretty much all your typical healthy habits. Most of the evidence for the nutrititional/exercise claims I provided in this thread

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Tags: neuroscience, methodology
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