# Question
Title: Does intentionally being aware of an emotion or thought pattern increase the incidence of that thought pattern?
As a means of tracking and exerting control over my life and emotions, I've considered doing a daily log to measure various life metrics, like what time I got up, how much coffee I've drunk, and various emotions etc.

One of the metrics I've considered measuring the prevalence of suicidal thoughts.

But what's put me off this idea is thought that actively considering this question would lead to further ideation, and would be counterproductive over all.

The question - does intentionally taking note of a particular thought, cause you to think that kind of thought more often? Are there any studies or related studies into this?

# Answer
> 6 votes
In general, theories of self-regulation, emotion regulation, psychoeducation, and many forms of therapy posit that, in one way or another, awareness of your emotions or thought patterns is largely adaptive.

This is true because self-awareness facilitates self-regulation (broadly speaking). For example, being able to identify the emotion you're experiencing allows you to plan a course of action to regulate it (e.g., Kashdan, Barrett, & McKnight, 2015). If I become aware that I'm experiencing anger, then I know that I can modify my anger (up or down) by confronting the source of it (e.g., my friend who owes me money). If I become aware of my sadness, then I know that I can down-regulate it by seeking social support. And so on.

Similarly, promoting meta-cognitive awareness of thought patterns can reduce depressive and anxious symptoms (e.g., Papageorgiou & Wells, 2001; Wells, 2009). This is true because it allows you to examine your beliefs about how you think (e.g., "Is the way I think positive or negative? Does it make me feel good or bad?"). And once you've determined how adaptive your thought patterns are, then you'll be able to determine whether you should promote, maintain, or prevent their recurrence.

**However, it's important to note that while self-awareness is *necessary* for better self-regulation, it is not *sufficient*.** Effective self-regulation also relies on your knowledge of, and ability to carry out, adaptive courses of action. For example, you've just identified your thought patterns as maladaptive, and now you want to downregulate those thoughts. Toward this goal, you try to suppress them. However, ironically, this strategy ends up spurring more of those thoughts (as predicted by ironic processes theory; Wegner, 1994). So despite your awareness of your maladaptive thought patterns and your subsequent desire to decrease them, you've actually increased their incidence and made yourself feel worse. Alternatively, you might have used more adaptive strategies like psychologically distancing yourself from your thoughts (e.g., Kross & Ayduk, 2011), engaging in mindfulness (e.g., Deyo, Wilson, Ong, & Koopman, 2009), reappraising the content of your thoughts (Beck, 2011), questioning your meta-cognitive beliefs (Wells, 2009), and other standard therapeutic and emotion-regulatory practices that would have more effectively modified your thought patterns.

So, overall, whether self-awareness increases or decreases the incidence of your thought patterns depends on your subsequent self-regulatory actions.

# Answer
> 3 votes
While not a formal scientific research, I built an app to track just the kinds of things you are talking about. You can see my notes here: http://luciddreamingapp.com/better-mood-tracker/tracking-bad-stuff-part-5/

Here's an example (horizontal scale is 24 hour time, icons have personal significance, for example sleep, games, walk, negative thoughts):

I've kept this kind of log for close to 6 months, before I found the health condition that is responsible for some of my issues.

**Individual events are not that significant.** The important thing about this kind of tracking is that your suicidal thoughts today may be a result of your actions in the 4-5 days before, and the human brain seems to forget this kind of stuff very easily, unless you track it. For example, sleep disturbandes caused by late night "screen time" can push my bedtime later and later. My awakening time fluctuates, sleep quality is poor and as a result, 4-5 days later I can feel really bad.

To address your specific question - from personal experience, such **negative thoughts are highly looping/oscillating/spiraling**. As a folk saying goes: "Misery loves company". Giving in to this kind of thinking creates a negative downward spiral, and this colors your entire perception of past, present and future. Once in the spiral, there's really no motivation to do anything productive, just a desire to escape, typically through some addictive behaviors or substances.

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Tags: thought
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title: Is psychology a science or magic?

text:
# Question
Title: Is psychology a science or magic?
What makes a person to be ever smiling to an extent that they just can't be angry or actually show they are angry even if they are?

# Answer
> 1 votes
From David Myer's Psychology, 10th edition, Page 6,

> Psychology is the **science** of behavior and mental processes.

To answer your actual question, here is what David has said in general that there are 3 levels on which Psychology can be viewed at differently. Following image lists them.

Each level forms an independent yet dependent abstraction with other two. So, to answer your question, the person's current external environment(Socio-Cultural environment which could include his friends, family, lover, stranger, native or foreign society, etc.), internal environment (current biological state which includes hormones,health, other physiological processes, maybe some disease) and Psychological influences(Learned behavior and knowledge shapes the understanding and interpretation of context ) might have created a triad to give the resultant situation.

So, the person might have scored a perfect score in SATs but might have had a emotional breakup the same time which might lead to the situation mentioned by you. Of course, there are infinite possibilities.
I just listed one of the possible Socio-cultural factor. Use your imagination to figure out the rest of the infinite possibilities.

Good Luck.

**P.S:** It is not magic BTW!
From Wikipedia,

> Magic or sorcery is the use of rituals, symbols, actions, gestures and language that are believed to exploit supernatural forces.

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Tags: cognitive-psychology
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# Question
Title: The prisoner dilemma does not violate classical probability laws
### To read before (following some answers or comments)

* My background: As a mathematician, probability theory is my field of research; please do not answer/comment just to refer to a course on probability theory.
* I expose below an erroneous application of probability theory. It is summarized at the end, in the **Summary** section. The two probabilities $\Pr$ and ${\Pr}^\ast$ are explained just before. If you are not a bit specialist in probability theory, please do not downvote if you disagree with this point, unless you show an error in my reasoning at a precise point (after numerous edits, I believe I have enough detailed my explanation so that one can point a precise point).
* The previous comments helped me to write a short summary on my blog (rather oriented in general towards a mathematical audience), about the prisoner dilemma.

---

I have just come across some papers and slides about quantum cognition, including:

Quoting the first one about the *prisoner dilemma*:

> The literature shows: (1) knowing that one’s partner has defected leads to a higher probability of defection; (2) knowing that one’s partner has cooperated also leads to a higher probability of defection; and, most troubling for Classical Probability theory, (3) not knowing one’s partner’s decision leads to a higher probability of cooperation.

The second one provides some empirical data supporting this claim. The data are some relative frequencies: one deals with the frequentist interpretation of probability.

I disagree with the claim that the law of total probability is violated here. **The conditional probabilities are misinterpreted**.

Let $A$ and $B$ be the two prisoners. Consider the experiment consisting in asking them to choose between defecting or cooperating, without knowing the choice of the other prisoner.

Then, the conditional probability $P(A \textrm{ defects} \mid B \textrm{ defects})$ is the long-term *relative frequency of the event "$A$ defects" among all those experiments for which the event "$B$ defects" occurs*.

This has *nothing to do* with the probability that $A$ defects when $A$ ***knows*** that $B$ defects, hereafter denoted by $\Pr^\ast(A \textrm{ defects} \mid B \textrm{ defects})$.

The law of total probability says that $$ \Pr(A \textrm{ defects}) = \Pr(A \textrm{ defects} \mid B \textrm{ defects})\Pr(B \textrm{ defects}) + \Pr(A \textrm{ defects} \mid B \textrm{ cooperates})\Pr(B \textrm{ cooperates}), $$ thereby implying that $\Pr(A \textrm{ defects})$, as a weighted average of the two conditional probabilities $\Pr(A \textrm{ defects} \mid B \textrm{ defects})$ and $\Pr(A \textrm{ defects} \mid B \textrm{ cooperates})$, lies between these two conditional probabilities.

The above mentioned papers claim that the law of total probability is violated because $\Pr(A \textrm{ defects})$ does *not* lie between $\Pr^\ast(A \textrm{ defects} \mid B \textrm{ defects})$ and $\Pr^\ast (A \textrm{ defects} \mid B \textrm{ cooperates})$, where $\Pr^\ast (A \textrm{ defects} \mid B \textrm{ defects})$ is the probability that $A$ defects when $A$ ***knows*** that $B$ defects, and, as said before, $$ {\Pr}^\ast (A \textrm{ defects} \mid B \textrm{ defects}) \neq \Pr(A \textrm{ defects} \mid B \textrm{ defects})$$

So, is it an error, or do I misunderstand the purpose behind the modeling based on quantum probability ?

## EDIT: details on the difference between $\Pr$ and ${\Pr}^\ast$

To explain the difference, I give the way to get an empirical estimate of these probabilites.

### Experiment 1 ($\Pr$)

***Ask $A$ and $B$ to perform the prisoner dilemma, without giving any information.***

Repeat this experiment a large number of times, independently (with others $A$ and $B$). The estimate of $\Pr(A \textrm{ defects})$ is the relative frequency of the experiments for which $A$ defects. The estimate of $\Pr (A \textrm{ defects} \mid B \textrm{ defects})$ is the relative frequency of the experiments for which "$A$ defects" among all those experiments for which the event "$B$ defects" occurs.

### Experiment 2 ($\Pr^\*$)

***Ask $A$ and $B$ to perform the prisoner dilemma with $B$ first, and giving the choice of $B$ to $A$.***

Then ${\Pr}^\ast (A \textrm{ defects})$ and ${\Pr}^\ast (A \textrm{ defects} \mid B \textrm{ defects})$ are estimated in the same way as before.

The *experiment* is not the same, in other words this is another probability (${\Pr}^\*$) on the probability space.

As you can see in Experiment 1, the conditional probability has nothing to do with the probability that $A$ defects ***when $A$ knows that $B$ defects***. In this experiment, $A$ *never* knows whether $B$ defects.

Of course, if you follow the above procedure to estimate the empirical probabilities, the law of total probability cannot be violated. This law is not really a principle, this is rather a definition (up to an elementary calculation, this is just the definition of the conditional probability). That makes no sense to say a definition is violated. If it is violated, that's because it has not been correctly used.

# Summary

The law of total probability implies that $\Pr(A \textrm{ defects})$ is a weighted average of the two conditional probabilities $\Pr(A \textrm{ defects} \mid B \textrm{ defects})$ and $\Pr(A \textrm{ defects} \mid B \textrm{ cooperates})$: $$ \Pr(A \textrm{ defects}) = wavg\Bigl(\Pr(A \textrm{ defects} \mid B \textrm{ defects}), \Pr(A \textrm{ defects} \mid B \textrm{ coop.})\Bigr) $$ and therefore, it lies between these two conditional probabilities.

Similalry, for the other probability ${\Pr}^\ast$, $$ {\Pr}^\ast(A \textrm{ defects}) = wavg\Bigl({\Pr}^\ast(A \textrm{ defects} \mid B \textrm{ defects}), {\Pr}^\ast(A \textrm{ defects} \mid B \textrm{ coop.})\Bigr) $$ The so-called *violation of the law of total probability* is a consequence of the ***erroneous formula***: $$ \Pr(A \textrm{ defects}) = wavg\Bigl({\Pr}^\ast(A \textrm{ defects} \mid B \textrm{ defects}), {\Pr}^\ast(A \textrm{ defects} \mid B \textrm{ coop.})\Bigr), $$ "mixing" the two probabilities. Based on this formula, $\Pr(A \textrm{ defects})$ shoud lie between ${\Pr}^\ast(A \textrm{ defects} \mid B \textrm{ defects})$ and ${\Pr}^\ast(A \textrm{ defects} \mid B \textrm{ coop.})$. This is intuitively wrong, and this has been observed to be wrong on empirical data. But this formula is wrong.

As a side note, I think that the misunderstanding could have been caused by the name *probability of $X$ knowing $Y$* to call the conditional probability of $X$ given $Y$. This has nothing to do with $X$ knowing something about $Y$: $$ \text{Probability of $X$ given $Y$} $$ does not mean $$ \text{Probability of $X$ when $X$ knows $Y$}. $$

# Answer
> 1 votes
After having thought more carefully about my own question, I give my own answer.

I would say that in the quote:

> The literature shows: (1) knowing that one’s partner has defected leads to a higher probability of defection; (2) knowing that one’s partner has cooperated also leads to a higher probability of defection; and, most troubling for Classical Probability theory, (3) not knowing one’s partner’s decision leads to a higher probability of cooperation.

the word *troubling* is not the appropriate one.

As explained, the CP translation of this quote is:

1. ${\Pr}^\ast(A \textrm{ defects} \mid B \textrm{ defects}) \> 0.5$
2. ${\Pr}^\ast(A \textrm{ defects} \mid B \textrm{ coop.}) \> 0.5$
3. $\Pr(A \textrm{ defects}) \< 0.5$

And this is not troubling for CP, because $\Pr \neq {\Pr}^\ast$.

Instead of saying this is *troubling*, I would simply say that *providing a relation between (1)-(2) and (3) is not the purpose of CP*. And roughly speaking, this is the purpose of quantum cognition, using quantum probability.

In the context of QC, a "conditional probability" such as $P(A \textrm{ defects} \mid B \textrm{ defects})$ should be read as *"probability that $A$ defects when $A$ knows that $B$ defects"*. The "event" at right of the conditional bar "$|$" is something about the cognitive state of $A$. In Pothos & Busemeyer's paper, such a notation is used : $$ Prob(happy|employed) = \Vert P\_{happy} \psi\_{employed} \Vert^2 $$ The notation at left is a symbolic one, miming the notation for conditional probability. The notation at right is more rigorous. In quantum probability, $P\_{happy}$ is a projection, and $\psi\_{employed}$ is a quantum state. Here it would be something like $P\_{defects}$ and $\psi\_{B \text{ defects}}$, representing the state of $A$ when he knows that $B$ defects.

I claimed before that *providing a relation between (1)-(2) and (3) is not the purpose of CP*. I should rather say: not in this way. The quantum approach is close to, but not the same as, the idea of a family of probabilities $P\_\psi(A \text{ defects})$ indexed by the state $\psi$ of $A$.

Here is another way to interpret the quote in CP, with only one probability $\Pr$. Assume that one firstly selects at random one of the two experiments (*"true" prisoner dilemma"* or *"faked" prisoner dilemma"*) and then one performs it. Globally, there's only one experiment (a two-stage experiment). The three points in the quote are:

1. $\Pr(A \textrm{ defects} \mid \textrm{$A$ knows that $B$ defects}) \> 0.5$
2. $\Pr(A \textrm{ defects} \mid \textrm{$A$ knows that $B$ coop.}) \> 0.5$
3. $\Pr(A \textrm{ defects}\mid \textrm{$A$ knows nothing about $B$}) \< 0.5$

and they are not inconsistent with any CP law. Because here one does not know anything about the marginal probability $\Pr(A \textrm{ defects})$.

# Answer
> 0 votes
Consider two random variables $E$ and $F$ with the following states:

$E$: $c$ - A cooperates, $\neg c$ - A defects

$F$: $kc$ - A knows that B cooperated, $k\neg c$ - A knows that B defected

PJ Corr claims that:

1. $p(E=\neg c|F=k\neg c)\>0.5$
2. $p(E=\neg c|F=kc)\>0.5$
3. $p(E=\neg c)\<0.5$

Then the application of the law of the total probability results in a contradiction: $p(E=\neg c|F=k\neg c)\cdot p(F=k\neg c)+p(E=\neg c|F=kc)\cdot p(F=kc)\<0.5$

(Note that a weighted average of two variables both greater than $0.5$ must be also greater than $0.5$.)

To defend the probability theory one can extend the state space of $F$ with $\neg k$ - "not knowing one’s partner’s decision".

Or one may add context variables as Corr suggests:

> Everyday equivalents of this situation do not, typically, resemble the decision-making dynamics assumed by CP theory: people have psychological processes that it fails to model, or to even consider to be relevant. For example, in this situation, outcome (1) could simply be (self-serving) retaliation; and in the case of (2) taking the easier route, but, we should wonder, what would happen if the partner was a loved one (e.g., your child)? Scenario (3) is a situation of uncertainty and psychological conflict (at least as perceived by many participants).

It is trivial to model these contexts with CP:

1. $p(E=\neg c|F=k\neg c,\mathrm{A\ wants\ a\ selfserving\ retaliation})$
2. $p(E=\neg c|F=kc,\mathrm{A\ loves\ B},\mathrm{B\ loves\ A})$
3. $p(E=\neg c|\mathrm{the\ situation\ is\ uncertain})$

**Purpose behind the modeling based on quantum probability**: I'm not acquainted with the discussion of quantum probability in cognitive science. However, as with any formalism there is a trade-off between simplicity and explanatory power. One can always devise a cognitive model with high explanatory power by adding contexts and rules for exception handling. Indeed, as evidenced by the recent rise of bayesian cognitive modeling and its critics, probability theory is well suited for such endeavor. As a disadvantage one gets ridiculously complex models and the whole modeling endeavor is difficult to falsify. I can imagine that it is in terms of simplicity that the quantum probability offers a better option than the classical probability.

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Tags: cognitive-psychology, cognitive-modeling, rationality
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title: How to begin neural network Programming

text:
# Question
Title: How to begin neural network Programming
I am a Computer Science Student and recently studied neural networks, but theory only. How can this be implemented in real time programming language. What should I search for or what content should I read so that I can do programs using neural network.

# Answer
A google search for neural network library will return many relevant pages, with neural network libraries written in several programming languages.

You could also look for tutorials on programming perceptrons which are among the most basic neural networks. This would teach you how to actually program the network from scratch, instead of using a pre-made library.

This walkthrough covers the development of a more complex neural network library if you are looking to jump right into building multilayer networks.
> 5 votes

# Answer
Take this course at Udacity. From my experience the course quality there is high and will save you a great deal of research time. You can also try https://www.coursera.org/course/neuralnets. Usually courses are coursera are of a great quality. The bottom line is take a MOOC first.
> 1 votes

# Answer
Here is a free, entry-level e-book.
> 1 votes

# Answer
There are many advanced tutorials which would suit someone with a computer science background, but if you are interested in the connection between neural networks and psychology/cognitive science then these two volumes are very accessible and give enough details to start coding your own networks:

Parallel Distributed Processing, Volume 1 Explorations in the Microstructure of Cognition: Foundations By David E. Rumelhart, James L. McClelland and PDP Research Group (1986) https://mitpress.mit.edu/books/parallel-distributed-processing

Another book with practical details and a good connection to psychology is

An Introduction to Neural Networks by Kevin Gurney (1997) \[no link, I don't have the reputation\]

Both are severely out of date with respect to the cutting edge of modern neural networks, but the fundamentals don't go out of date so I figure they are a good place to start
> 1 votes

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Tags: neural-network, artificial-intelligence
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# Question
Title: Can incubation be facilitated, while, at the same time, being focused on a different problem?
Is it possible to facilitate incubation as well as consciously think about a different problem *at the same time*, in effect **multitasking**, in order to gain insights more quickly, without having to stop and take a break.

For context, see this question on incubation:

How is it that taking a break from a problem sometimes allows you to figure out the answer?

# Answer
This is an interesting question because it relates to different **mechanisms that may be responsible for incubation effects**:

* Does incubation occur because creative insight is helped by **unconscious processes**? (Processes that are best left undisturbed by not consciously thinking about the problem?) In this case, the most important thing would be to focus on something else.
* Or does taking a break simply reduce **mental fatigue** as some have claimed (e.g., Posner, 1973, as cited in Sio & Ormond, 2009)? In this case, just taking a break from thinking might be best.
* Or is it because of **certain patterns of conscious thought** during incubation? In this case, the kind of problem one thinks about consciously during the incubation phase would matter.

Sio and Ormond (2009) have looked at this question as part of their **meta-analysis of incubation studies**:

* They found that performing **low cognitive demand tasks** were associated with stronger incubation effects than just taking a break and doing nothing
* However, **high cognitive demand tasks** were associated with smaller incubation effects

These results are not in line with a simple mental fatigue account of incubation. Instead, they suggest that creative insight profits more from distracting tasks that are low in cognitive demand.

One explanation for these findings is that low demanding tasks allow and promote **mind-wandering** (Baird et al., 2012).

**Conclusion**: So based on this research, when trying to generate some creative insight, it might be good to take a break after an intense preparation period. However, instead of occupying your mind with another hard nut to crack, it might be better to do so with something that is not very demanding. Try cleaning up your desk and water those sad-looking plants in your office!

**References**

Baird, B., Smallwood, J., Mrazek, M. D., Kam, J. W. Y., Franklin, M. S., & Schooler, J. W. (2012). Inspired by distraction: Mind wandering facilitates creative incubation. Psychological Science, 23, 1117–1122. doi:10.1177/0956797612446024

Sio, U. N., & Ormerod, T. C. (2009). Does incubation enhance problem solving? A meta-analytic review. Psychological Bulletin, 135, 94–120. doi:10.1037/a0014212
> 4 votes

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Tags: cognitive-psychology, problem-solving, unconscious, creativity
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# Question
Title: In psychophysics, why are log luminance rather than absolute luminance values reported?
Are there any papers which justify converting into log luminance? For example papers showing humans being sensitive to changes in log luminance rather than luminance *per se*?

# Answer
> 5 votes
In general, subjective sensation increases linearly with the the log of physical intensity, which is described by Fechner's law.

We are sensitive to small variations when light is dim, but we need large differences in intensity under conditions of high luminance (Weber's law). This is a linear relation, but taken together with Fechner these findings are described as the widely-known Weber-Fechner's law, justifying the log scales used.

Another well-known example is the decibel scale in hearing, which is also a log scale.

Any basic textbook on perception or psychophysics will explain this and a reference is added below.

<sub>**Reference**
**-** Masin *et al.*, *J History Behav Sci* (2009); **45**(1): 56–65</sub>

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Tags: perception, vision, psychophysics, sensory-perception
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# Question
Title: The function of pumps in forming the resting potential
I am confused by the following. Apparently the resting potential of -65mV is reached when the two forces, diffusion and electrical gradient are in equilibrium. So why does the book say

"The electrical potential difference across the membrane \[..\] charge is maintained by the work of the ion pumps."

Why should it be "maintained by the pumps" if it is an equilibrium anyway?

One possible answer I can imagine is: the equilibrium is too unstable and so the pumps are stabilizing it. But I have no idea if this is correct. Thanks.

# Answer
> Apparently the resting potential of -65mV is reached when the two forces, diffusion and electrical gradient are in equilibrium.

That is not true. You are confusing a neuron's **resting potential** with what is actually a type of ion's **equilibrium potential**.

An **equilibrium potential** for a particular type of ion--such as Na+ or K+--is the exact voltage across the membrane that exactly opposes the diffusional force for that ion, and thereby prevents a net flow of that ion across the membrane. So, for example, in the case of Na+ (sodium ion), in mammalian neurons, a typical value given in textbooks is something like +55 mV. In other words, the interior of the neuron needs to be 55 mV (relative to the outside of the neuron) in order to prevent all the Na+ ions from rushing into the neuron. There are equilibrium potentials for all the ions that are used in neurons to influence the voltage across the membrane: Na+, K+, Cl-, Ca++. If a fictional neuron were to be at the equilibrium potential for Na+, and there were no other ions at play, *there would be no need for pumps to maintain any concentration gradient of Na+.*, because, by definition, there would be no net flow of charge, and so the situation would be stable.

However, the **resting potential** refers to the voltage of the neuron when it is at rest--not having an action potential--but that voltage is going to be some "weighted average" of the equilibrium potentials of all of the types of ions: Na+, K+, Cl-, and Ca++. Of these, K+ (potassium ion) dominates, and so we find that typical values for the resting potential of neurons is around -65mV, which is closer to the equilibrium potential for K+ (-90mV), than for Na+ (+55mV) or Ca++ (+155mV!).

But since the typical resting potential of the neuron actually *is not equal to any of the equilibrium potentials for any type of ion*, that means by definition all of the ions *are* going to have net movement across the membrane. If ion channels are left open and ions are therefore allowed to flow across the membrane, Na+ is going to flow in, K+ is going to flow out, Ca++ is going to flow in, etc. (I'm leaving Cl- out for simplicity).

Since these ions are flowing with a net direction (either into or out of the neuron), that means concentrations are changing; e.g., K+'s large concentration gradient is getting smaller as it flows out of the neuron. Over time, these ion flows move the concentrations of ions towards equality on both sides of the membrane, and therefore move the neuron's resting membrane potential toward 0 mV. In some sense, the "battery is running down". This would render the neuron incapable of having an action potential, and thus acting as a signaling machine, and therefore must be prevented.

In order to prevent that rundown of concentration gradients, ion pumps **actively maintain** the concentration gradients of the ions. One of the relevant ones here is the **Na+/K+ exchanger**, which uses ATP to power its action of pumping *in* two Na+ ions for every three K+ ions it pumps *out*. Using ATP requires producing ATP, which requires glucose, and so just maintaining "ready to go neurons" is metabolically demanding.
> 3 votes

# Answer
You're on the right track: it is a dynamic equilibrium that must be maintained actively, not a chemically automatic equilibrium that occurs passively (without biological action). Excerpts from Wikipedia:

> Values of resting membrane potential in most animal cells usually vary between the potassium reversal potential (usually around -80 mV) and around -40 mV. The resting potential in excitable cells (capable of producing action potentials) is usually near -60 mV—**more depolarized voltages would lead to spontaneous generation of action potentials**. Immature or undifferentiated cells show highly variable values of resting voltage, usually significantly more positive than in differentiated cells.\[23\] In such cells, the resting potential value correlates with the degree of differentiation: undifferentiated cells in some cases **may not show any transmembrane voltage difference at all**.
>
> Maintenance of the resting potential can be metabolically costly for a cell because of its requirement for **active pumping of ions to counteract losses due to leakage channels**. The cost is highest when the cell function requires an especially depolarized value of membrane voltage. For example, the resting potential in daylight-adapted blowfly (Calliphora vicina) photoreceptors can be as high as -30 mV.\[24\] This elevated membrane potential allows the cells to respond very rapidly to visual inputs; the cost is that maintenance of the resting potential **may consume more than 20% of overall cellular ATP**.\[25\]
>
> On the other hand, the high resting potential in undifferentiated cells can be a metabolic advantage. This apparent paradox is resolved by examination of the origin of that resting potential. Little-differentiated cells are characterized by extremely high input resistance,\[23\] which implies that few leakage channels are present at this stage of cell life. As an apparent result, potassium permeability becomes similar to that for sodium ions, which places resting potential in-between the reversal potentials for sodium and potassium as discussed above. The **reduced leakage currents also mean there is little need for active pumping in order to compensate, therefore low metabolic cost**. \[Emphasis added.\]

Thus it turns out that resting potential is an interesting, functionally variable quality of different cells, and sometimes costs quite a bit of energy to maintain!

**References**

\[23\] Magnuson, D. S., Morassutti, D. J., Staines, W. A., McBurney, M. W., & Marshall, K. C. (1995). In vivo electrophysiological maturation of neurons derived from a multipotent precursor (embryonal carcinoma) cell line. *Developmental Brain Research, 84*(1), 130–141.

\[24\] Juusola, M., Kouvalainen, E., Järvilehto, M., & Weckström, M. (1994). Contrast gain, signal-to-noise ratio, and linearity in light-adapted blowfly photoreceptors. *The Journal of General Physiology, 104*(3), 593–621. Retrieved from http://europepmc.org/articles/PMC2229225/pdf/jg1043593.pdf.

\[25\] Laughlin, S. B., van Steveninck, R. R. D. R., & Anderson, J. C. (1998). The metabolic cost of neural information. *Nature Neuroscience, 1*(1), 36–41. Retrieved from http://www.nature.com/neuro/journal/v1/n1/full/nn0598\_36.html.
> 2 votes

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Tags: neuroscience
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# Question
Title: Are there innate differences between men's and women's behavior?
A stereotypical man is aggressive and competing. A stereotypical woman isn't aggressive and tends to cooperate rather than compete.

A stereotypical boy have toys like cars and plastic soldiers. A stereotypical girl have toys like barbie dolls.

So far I believed this is merely the result of the social conditioning, where boys taught to behave like a men, and girls are taught to behave like a women.

But it seems I need to think it again. I recently read this article about the girls in Salinas. They have a weird genetic disorder that makes boys born like a girl and they won't grow a penis until the age of 12.

The interesting thing is that it seems not only their penis grows but also there is a change in behavior (quote from the article above):

> A little girl named Carla is currently going through the same transformation, aged nine. Despite being brought up as a girl, his mother noticed that from the age of five he was more inclined towards the rough and tumble play of little boys. He has recently had his hair cut shirt after wearing plaits for years.

Also there are examples of transgender people who have gender dysphoria often describing themselves as a "woman who is lost in a man's body" or vice versa.

Is there any serious scientific research that proves / disprove these perceived differences in behavior?

# Answer
This is still a matter of fierce debate between the *essentialist* and *cultural* camps.

There is little argument that gender differences are shaped by culture, but there is now a growing evidence supporting the hypothesis that gender differences are also partly the outcome of biological disposition.

**Much of such biological disposition is the outcome of hormonal influence.** Given that such influence was demonstrated even if prenatal, and that the instructions to the postnatal generation of hormones is coded in our DNA, you can argue that such influence falls into the definition of *innate*.

You may wish to start with these papers:

* Alexander, Gerianne M., and Melissa Hines. "Sex differences in response to children's toys in nonhuman primates (Cercopithecus aethiops sabaeus)." Evolution and Human Behavior 23.6 (2002): 467-479.
* Hassett, Janice M., Erin R. Siebert, and Kim Wallen. "Sex differences in rhesus monkey toy preferences parallel those of children." Hormones and behavior 54.3 (2008): 359-364.
* Maestripieri, Dario, and Suzanne Pelka. "Sex differences in interest in infants across the lifespan." Human Nature 13.3 (2002): 327-344.
> 4 votes

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Tags: sex-differences
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title: Processing Inverted English Script

text:
# Question
Title: Processing Inverted English Script
I was sitting in a restaurant when I realized that it was relatively easy to read this list of a few locations in inverted English script. It made me curious about how it is possible to read this with such ease. It also seems that since these names may be familiar, I might just be engaging in "inverted image" recognition since the normal 'whole image' (e.g. Boston) seems so familiar. Perhaps if these locations were not familiar, it would be slightly harder to process the text.

I was conflicted between posting this in this or in the Linguistics StackExchange but felt that this would be more relevant since there will be multiple perspectives from those interested in neuroscience, psycholinguistics, machine learning and natural-language processing.

A search on the internet seemed to give a lot of instances of the freak-phenomenon of 'mirror writing' and the well-known phenomenon of irrelevance of spelling in comprehension. Furthermore, it is important to notice that this is different from writing of those who are diagnosed with Dyslexia who process language differently (the writing is whole-wise flipped as opposed to individually). However, there seemed to be a dearth of information on this topic in particular. Of course, I am not interested in one-word instances, another example would be like this.

---

My questions are :-

**Are there any good experiments on the phenomenon of processing inverted text ?**

**Although very little is understood about the neuroscience of language, are there any neurolinguistic perspectives on this phenomenon?**

**What are the underlying mechanisms hypothesized by the quoted papers in processing such text?**

**Does there seem to be any evidence of rule-based processing**
(e.g. flipping each letter individually)

# Answer
> 2 votes
> Are there any good experiments on the phenomenon of processing inverted text?

This is probably *the* place to start:

Poldrack, Russell A., et al. "The neural basis of visual skill learning: an fMRI study of mirror reading." Cerebral Cortex 8.1 (1998): 1-10. APA

> What are the underlying mechanisms hypothesized by the quoted papers in processing such text?

"Multiple regions in the occipital lobe, inferior temporal cortex, superior parietal cortex and cerebellum were involved in the reading of mirror-reversed compared to normally oriented text. For novel stimuli, skilled mirror-reading was associated with decreased activation in the right superior parietal cortex and posterior occipital regions and increased activation in the left inferior temporal lobe. These results suggest that learning to read mirror-reversed text involves a progression from visuospatial transformation to direct recognition of transformed letters. Reading practiced, relative to unpracticed, stimuli was associated with decreased activation in occipital visual cortices, inferior temporal cortex and superior parietal cortex and increased activation in occipito-parietal and lateral temporal regions. By examining skill learning and item-specific repetition priming in the same task, this study demonstrates that both of these forms of learning exhibit shifts in the set of neural structures that contribute to performance."

> Does there seem to be any evidence of rule-based processing?

Yes:

"Mirror-reading skill is letter-specific rather than being a general visual transformation skill"

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Tags: cognitive-neuroscience, linguistics, language-processing
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# Question
Title: What brain areas are involved in memorizing sections of a song?
Typically when I listen to a song, the song will have different sections (e.g. chorus, verses, etc). As a composer, I have found that many songs use this structure to create a sense of repetition and help make the song more familiar to the listener. It tends to give the song a cohesiveness that simply introducing new material over and over doesn't yield.

Therefore, when I listen to a song, what brain area helps me remember parts of the song so when I hear them again, they sound familiar?

**Example:**

> We Wish You A Merry Christmas

# Answer
> 5 votes
I would read this paper, its mighty interesting.

**Books**

Snyder, B.(2000) Music and memory: An introduction. The MIT Press. Cambridge 291.

**Hemispheric Coordination and Conflict**

> "...while listening to the melody of the popular carol "Silent Night", the right hemisphere thinks, "Ah, yes, Silent Night", while the left hemisphere thinks, "two sequences: the first a literal repetition, the second a repetition at different pitch levels—ah, yes, Silent Night by Franz Gruber, typical pastorate folk style." The brain for the most part works well when each hemisphere performs its own function while solving a task or problem; the two hemispheres are quite complementary. However, situations arise when the two modes are in conflict, resulting in one hemisphere interfering with the operation of the other hemisphere." (Regalski 1977)

**Melodic Memory**

> "Performance was greatest for the musicians, particularly for the nontonal melody pairs. These differences were not primarily attributable to pitch discrimination or pitch working memory impairments. The findings point to differential contributions of the left and right mesial temporal lobes to melodic memory, with specificity of the right mesial temporal lobe emerging for melodic learning within a tonal musical context." (Wilson, Saling 2008)

**Tonal Memory**

> In general, tonal memory is supported by a wide network including primary and secondary auditory areas more right lateralized, the supramarginal gyrus particularly on the left, and dorsolateral inferior frontal areas, more clearly seen under heavy memory load conditions (Zatorre et al., 1994; Griffith et al., 1999; Gaab et al., 2003). Premotor areas, the cerebellum, basal ganglia and the thalamus are activated when subvocal tonal rehearsal is explicitly required (Hickok et al., 2003; Koelsch et al., 2009). Importantly a direct comparison of memory for verbal syllables and sung pitches under rehearsal and under suppression elicited largely overlapping brain areas consistent with this network (Schulze et al., 2011).

Quoted from this source.

---

**Sources**

Who Knows Where Music Lurks in the Mind of Man? New Brain Research Has The Answer.
*Journal of Music Educators* (May 1977, Vol.63, pages 31-38)

Contribution of the left and right Mesial Temporal Lobes to Musical Memory: Evidence from melodic learning difficulties
Sarah J. Wilson, Michael M. Saling
*Music Perception: An Interdisciplinary Journal*, Vol. 25 No. 4, April 2008; (pp. 303-314)

￼Towards A Neural Basis Of Music Perception.
Stefan Koelsch and Walter A. Siebel
*Trends in Cognitive Sciences* Vol.9 No.12 December 2005

Functional anatomy of pitch memory—an fMRI study with sparse temporal sampling.
Gaab, N., Gaser, C., Zaehle, T., Jancke, L., and Schlaug, G. (2003).
*Neuroimage* 19, 1417–1426.

Neural mechanisms underlying melodic perception and memory for pitch.
Zatorre, R. J., Evans, A. C., and Meyer, E. (1994).
*J. Neurosci.* 14, 1908–1919.

Auditory-motorinteraction revealed by fMRI: speech, music, and working memory in area
Hickok, G., Buchsbaum, B., Humphries, C., and Muftuler, T. (2003).
*Spt. J. Cogn. Neurosci.* 15, 673–682.

Functional architecture of verbal and tonal working memory: an FMRI study.
Koelsch, S., Schulze, K., Sammler, D., Fritz, T., Müller, K., and Gruber, O. (2009).
*Hum. Brain Mapp.* 30, 859–873.

Neuroarchitecture of verbal and tonal working memory in nonmusicians and musicians.
Schulze, K., Zysset, S., Mueller, K., Friederici, A. D., and Koelsch, S. (2011).
*Hum. Brain Mapp.* 32, 771–783.

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Tags: perception, cognitive-neuroscience, memory, music
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# Question
Title: What is the difference between Psychology, and Thymology?
I understand Thymology to not merely be a synonym, but to be a branch or area of Psychology, however I am at a loss of how to properly distinguish the two.

What distinguishes Thymology from Psychology in general?

# Answer
> 4 votes
Thymology is an historical conjecture on why someone thought the way they did. For example, why did Herbert Henry Asquith take his country to war in 1914. What thought processes went into that decision. The decision is often made to seem inevitable given preceding experiences. There is a school of thought that would lump this study alongside other accounts of history and journalism, in that they fall into the trap of searching for causes for things that are just as likely to be caused by randomness (i.e. perhaps he went to war because the decision was made shortly before lunch and he was hungry and irritable, rather than because of a neat causal explanation).

Psychology is the general study of mind and behaviour in general, largely in the present, and tested scientifically with controlled experiments, simulations, statistical inference, and qualitative research.

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Tags: social-psychology
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# Question
Title: Why does even the most rational brain forget logic in a dream?
Scenario 1) Now we all know gravity is real. Yet when we dream that we are flying we forget/or are oblivious to the entire concept of gravity as if you have never experienced gravity.

Scenario 2) When dreaming of a deceased relative long or recent sometimes the dream is in their lifetimes and during the dream the brain has no recollection of the event of their death.

In both these scenarios you can control the dream for example if you are flying you can change directions or set the scenery and are aware you are dreaming but the things you are unaware of are **GRAVITY AND DEATH**. And as soon as you wake up or figure out the reality you become awake. So my question is why does a brain forget reality/logic in a dream?

# Answer
# Neither rational nor logical

> "...there is overwhelming evidence that Humans cannot be \[rational\]" - Daniel Kahneman (Thinking Fast and Slow).

To begin with, the brain is **neither rational nor logical** as you may think (to a large extent it is little rational and its logic is *completely* fuzzy). A perfectly rational and logical organ would not be able to keep us alive (such an organ could take 4 hours to choose between two bottles of wine).

So I assume that your question is more like:

> How comes dreams often involve augmented reality?

# On augmented realities

Try this: shut your eyes and try to imagine your lower body replaced with that of a horse. Can you do this?

You have not done this whilst dreaming, but whilst awake and conscious.

Can you bring memories of a deceased relative whilst awake? Sure you can.

So the ability to experience augmented reality is not reserved for dreams - we can incite such reality by conscious means, certain drugs or brain damage.

# Whilst you were dreaming

There are various theories on why we dream and what happens whilst we dream.

A key to many theories is random brain activity. You actually experience this whilst awake when you leave the **central executive** mode (stay-on-task) and enter **daydreaming** one - where short thoughts are following in what often seems as random.

Such random activity is fully capable of triggering augmented reality, like a half-man half-horse.

There is a higher likelihood for such augmented reality to appear in dreams, since random activity is not tamed by the stay on task mechanism.
> 3 votes

# Answer
I don't think there's a real answer to the question, but I find it fascinating.

Have a look at this really nice paper, too. They asked lucid dreamers to approach other dream characters and ask them to do simple maths. (Not because they were interested in lucid dreaming per se, they just needed somebody to be able to decide what they would dream). The study was done with a low number of participants who were also lucid dreamers, so who knows how valid this is for the general population. But they found that people reported that their dream characters got all mysterious and were seemingly unable to answer the question. In one case, one character covered their face, started crying and ran away. In the other case, they answered cryptically 'gray zone'.

So while maths is not logic, this exploratory study does show that in dreams we can't do the simply things we have no problem in doing in real life.

I know this doesn't answer your original question of *why* this is the case, but I thought you might find it interesting.

**Warning: the paragraph below is pure handwaving and speculation, NOT to be taken as evidence-based**

As pure speculation/brainstorming (so please don't take this seriously, it's just a thought), I like to think that logic might depend on our brain chemistry. While we tend to think that logic is the one thing that we can trust on (Descartes and Bertrand Russell certainly did), it might be the case that logic as we know it depends on our brains. So when we are in a dofferent cognitive state, our logic is different.
> 2 votes

# Answer
**Not everyone forgets gravity in dreams.** I'm speaking out of my experience with lucid dreaming, which allows thousands of people to act consciously in their dreams. This allows them to examine dream concepts in more details, as well as perform experiments.

There's a lucid dreaming **flying technique, which is all about manipulating the gravity** within a dream. Multiple people have independently discovered over the years, which I refer to as "Attraction flying". I saw a mention of the attraction flying in the 1993 book "The art of dreaming" by Carlos Castaneda.

The technique manipulates gravity in the following ways - first, a person levitates over the surface, then uses willpower and intent to "fall" towards a distant object. Once the person is close to that object, another object is selected to fall towards. This creates a zig-zagging flight pattern, somewhat similar to how "Spider man" uses webs to move between skyscrapers.

The existence of this technique, and the fact that **multiple people have independently discovered it** makes me think that the brain is capable of imagining gravity in a dream.
> 2 votes

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Tags: consciousness, dreams
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# Question
Title: Why some people do not perform well with ambiguity and uncertainty?
I've recently read an article about Generation Z, early 20 year olds born after 1995 in the workforce (similar to this one). The article suggests that unlike previous generation, where ambigious goals may inspire 30 somethings to do their best work, the 20 year olds from generation Z prefer to have things broken down into a very clear chunks. An example may be in order:

* Compare the sales figures report
* Versus: We need a sales report for investor meeting by Friday morning, get sales figures from Angela, have Bill help with graphics and verify figures with Jeff. If you are late, we will penalize you.

The article continues to state that if faced with the first scenario, a 20 something would get frustrated and will start seeking another job, while more detailed information would help them rise up to the task.

**Why some people are uncomfortable and unproductive when faced with ambiguous or uncertain goals/challenges?**

# Answer
I'm not 100% sure if this is what you were intending to ask, because your initial opening was about generation Z (which is at the large cultural level) while on the other hand your question written in bold seemed to be geared towards the individual. I have tried incorporating both parts into this answer.

In essence I could not tell between which of the two concepts in psychology you were interested in: **Uncertainty Avoidance** or **Proactive Personality** (the lack of which is what you describe).

There is an intersection between the two concepts. You may start here in case you want to look deeper into the latter.

**Background to Answer**

> Of particular interest in this study is the macro dimension of uncertainty avoidance measured at an individual level. Cultures high on uncertainty avoidance are risk adverse. Individuals in these cultures prefer stability in their lives and careers. They want their environment to be predictable. To foster compliance among their members, cultures high in uncertainty avoidance structure behavior through such mechanisms as laws, religion or customs. Vague situations are avoided in high uncertainty avoidance cultures, and group norms and rules reduce ambiguity. Individuals tend to attach themselves to the dominant cultural group and comply with its expectations (Hofstede, 1980).
>
> However, there has been a suggestion in organizational research that rather than the more passive attachment to the dominant group, some cultures actively try to reduce uncertainty by controlling their future environment. For example, Schneider and DeMeyer (1991) suggested that managers in high uncertainty avoidance cultures are likely to engage in proactive behaviors in an attempt to adapt to a dynamic environment. Geletkanycz (1997) also found that executives who are high on uncertainty avoidance in their cultural background seek strategic solutions that respond to dynamic environments. That is, they engage in adaptation as a way of reduce risk. Because of this alternative way of adapting to uncertainty, Geletkanycz (1997) called for further research to examine the issue that not all individuals react to risk by adhering to the norm but rather adjust to position themselves in a safer position in the future.
>
> Research has also identified that individuals high on uncertainty avoidance make choices for uncertain outcomes that involve gains (Ladbury & Hinz, 2009). For example, individuals can be induced to volunteer for treatment in a randomly assigned process if they are offered monetary compensation for showing up (Harrison, Lau & Rutstrom, 2009). An individual’s income can also have an influence on uncertainty avoidance and outcomes. For example, Yang-Ming (2008) found that as income increases, individuals high on uncertainty avoidance were more willing to take risks.

**Relation between Uncertainty Avoidance and Productivity (Individual Level)**

> In her research with business executives, Geletkanycz (1997) hypothesized that top managers whose background cultures were high on uncertainty avoidance would be uncomfortable with uncertainty. Because of their need for structure, she predicted that they would be resistant to change. They would avoid taking action to alter their situation. However, what she found in her research was that managers whose background cultures were high in uncertainty avoidance reduced their feeling of uncertainty by adapting to the environment. She surmised that in the dramatic changes related to technology and globalization, it was safer and less risky for these executives to adjust to the changing environment rather that inflexibly hanging on to what is known.

**Relation between Uncertainty Avoidance and Productivity (Macro Level)**

> The cultural value of uncertainty avoidance influenced whether Irish firms were successful as compared to German firms (Rauch, Frese, & Sonnentag, 2000). Ireland scores low on uncertainty avoidance in contrast to Germany which is high on the value. It was found that successful small business owners in Ireland did not plan. Rather, customers in that culture valued flexibility and quick solutions to problems. In contrast, German business owners were more successful when they did plan. It was proposed by these researchers that in such high uncertainty avoidance cultures, it was expected that individuals engage in careful planning to reduce risk by attempting to control future events. However, the results were more consistent with the interpretation made by Schneider and DeMeyer (1991) in that they found that planning is culturally appropriate, and this detailed planning resulted in a successful relationship with customers who also valued planning (Rauch, Frese, & Sonnentag, 2000).

---

**Primary Source:**

The Two Faces of Uncertainty Avoidance: Attachment and Adaptation David S. Baker and Kerry D. Carson University of Louisiana at Lafayette

---

**Citations within Source**

Culture’s consequences: International differences in work-related values.
Hofstede, G. (1980). Newbury Park, CA: Sage.

Interpreting and responding to strategic issues: The impact of national culture.
Schneider, S. C., & DeMeyer, A. (1991). *Strategic Management Journal*, 12(4), 307-320.

Uncertainty avoidance influences choices for potential gains but not losses.
Ladbury, J., & Hinsz, V. B. (2009). *Current Psychology*, 28(3), 187-193.

Corporate cash holdings, uncertainty avoidance, and the multinationality of firms.
Ramirez, A., & Tadesse, S. (2009).*International Business Review*, 18(4), 387-403.
> 2 votes

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Tags: cognitive-psychology, social-psychology, behaviorism
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# Question
Title: Why is Wernike's area of the brain called Wernike's area?
My teacher told us that this area of the brain helps with the comprehension of language and it is located in the temporal lobe of the cortex, but she never told us why is was called Wernike's area and she told us it might be on the AP Exam. So why is it called that?

# Answer
> 7 votes
As often the case, named after the person who first described it.

From Encyclopedia Britannica:

> Wernicke area, region of the brain that contains motor neurons involved in the comprehension of speech. This area was first described in 1874 by German neurologist Carl Wernicke.

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Tags: neuroanatomy, psychology
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# Question
Title: What is the underlying genetic basis for ADHD?
According to Psychcentral depression, bipolar disorder, ADHD, schizophrenia and autism are traceable to the same inherited genetic variations

According to AsapSCIENCE, depression could be genetic due to a variation in the serotonin transporter gene. Having at least one short seems to give some kind of genetic predisposition to depression.

So what's the analogue of the serotonin transporter gene in ADHD? Is there a dopamine transporter gene?

I have double posted this question on the Biology StackExchange.

# Answer
> 3 votes
I hope the few sources below answer your question. **I strongly recommend you read actual sources as opposed to the parts I have quoted.** I don't know much about this topic so I did not attempt to translate anything in laymen terms, since I might have distorted or misinterpreted information in the process. However, the three sources below are one of the best-known studies on the genetic basis of ADHD. I have quoted the two sources in direct response to your question about the proposed role of dopamine and serotonin transporter genes.

**Percentage due to variation attributed to heritability**

> Twin, family and adoption studies have suggested that there is a strong genetic contribution to ADHD, with a mean heritability estimate of 76 % However, it has been difficult to implicate any specific gene in ADHD beyond reasonable doubt. The difficulties encountered in identifying genetic variants increasing the risk for ADHD could be at least in part owing to the heterogeneity and complexity of this clinical syndrome.Consequently, it has been proposed that the use of intermediate phenotypes (or endophenotypes) relevant to ADHD are likely to be more informative than the DSM-IV1 diagnoses, allowing for increased detection of genetic effects.

**Genome-wide linkage scans**

> To date, seven genome-wide ADHD linkage scans have been published and some chromosome regions such as 5p13, 14q12, and 17p11 have been indicated in multiple studies \[Fisher et al., 2002; Bakker et al., 2003; Arcos-Burgos et al., 2004; Hebebrand et al., 2006; Ogdie et al., 2006; Faraone et al., 2007; Asherson et al., 2008; Romanos et al., 2008\]. However, no chromosome region has been consistently identified across the scans and the majority of the findings were unique to each study. This is not unexpected because the power of individual scans is likely to be low for a complex trait such as ADHD which may only have genes of small to moderate effects \[Risch and Merikangas, 1996; Waldman and Gizer, 2006\].

**Dopamine transporter (DAT1)**

> The DA transporter (DAT1) gene harbours a 40-bp repeat sequence variable number tandem repeat polymorphism located in the 3′-untranslated region. The most common alleles are the 10- (480-bp, 71.9%) and 9-repeat (440-bp, 23.4%) alleles, although these frequencies are variable from one population to the next. Homozygosity for the 10-repeat allele was reported to be associated with higher DA transporter protein in the striatum, a region where it is heavily expressed56 and where it serves as the primary means of DA reuptake. Several studies have suggested a relation between ADHD and the DAT1 variable number tandem repeat, the 10-repeat allele being the risk allele; however, a roughly equal number of studies have failed to detect such a relation. In a review by Faraone and colleagues, the pooled OR associated with the 10-repeat allele in family-based association studies was estimated to be 1.13 (95% CI 1.03–1.24).
>
> Loo and colleagues40 reported that children carrying 2 copies of the 10-repeat allele exhibit higher commission errors, impulsive responses (β score) and reaction time variability compared with carriers of the 9-repeat allele. Bellgrove and colleagues, who used a CPT–like task (the sustained attention to response task), found higher reaction time variability in children who were homozygous for the 10-repeat allele. However, in this study, the 2 groups did not differ in omission and commission errors.

**Trypotphan hydroxylase 2 (TPH2)**

> The TPH2 gene encodes the rate-limiting enzyme in the synthesis of serotonin in humans and was shown to be associated with completed suicide and major depression. Four studies have shown an association between multiple SNPs in this gene and ADHD. Recently, a significant association was observed between total errors of omission in the test of variables of attention and 2 SNPs (rs1386488, rs6582072). Similarly, a significant association was observed between rs1386488 and another SNP (rs1386497) and total reaction time scores as well as total reaction time variability scores. These intronic SNPs are part of 8 markers found to have strong linkage disequilibrium with each other and that compose a single haplotype block associated with ADHD in the tested sample. A second study tested IQ level and 4 SNPs previously reported to be associated with ADHD, but analyses were negative.

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**Sources:**

Candidate genes and neuropsychological phenotypes in children with ADHD: review of association studies.
Oussama Kebir, Karim Tabbane, Sarojini Sengupta, Ridha Joober
*J Psychiatry Neurosci.* March 2009; 34(2): 88–101.

Molecular Genetics of Attention Deficit Hyperactivity Disorder
Stephen V. Faraone, Eric Mick
*Psychiatr Clin North Am.* 2010 March; 33(1): 159–180.

Meta-Analysis of Genome-Wide Linkage Scans of Attention Deficit Hyperactivity Disorder
Karin Zhou et. al.
*Am J Med Genet B Neuropsychiatr Genet.* 5th December 2008; 147B(8): 1392–1398.

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Tags: abnormal-psychology, adhd, genetics
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# Question
Title: Are there gender differences in color discrimination ability?
There appears to be a prevalent stereotype that girls seem to have "heightened" color perception. By this term, I mean that they can identify the salient features of different shades of color. However, many ideas that are widespread in public consciousness do not seem to be based on empirical evidence.

Is there any research that has investigated gender differences in color perception? In particular, are there any well-performed experiments in the study of perception or cognitive neuroscience that may shed light on this perceived phenomenon?

There are many 'sources' on the internet that seem to have commented on this, but I can't find any compelling evidence personally. There is some literature on cross-cultural variation and cross-language perceptual differences, is there any literature on cross-gender variation?

---

**Sources:**

Jameson, K. A., Highnote, S. M., & Wasserman, L. M. (2001). Richer color experience in observers with multiple opsin genes. Psychonomic bulletin and review, 8, 244-261.

Gilbert, A. L., Regier, T., Kay, P., & Ivry, R. B. (2006). Whorf hypothesis is supported in the right visual field but not the left. Proceedings of the National Academy of Sciences of the United States of America, 103(2), 489–494.

# Answer
> 2 votes
**Short answer:** A recent study suggests that, if you rigorously restrict the sample to normal vision participants, **women do not outperform men in color discrimination**.

**Long answer:**

As @what has pointed out with the link to Google Scholar, there are a number of studies that have investigated sex differences with regard to color vision.

However, if one accounts for the fact that there are **more men who have a deficiency in color vision** (because they have only one X chromosome which is involved in color vision), the differences appear to be small and may even contradict the stereotype.

I found one study (Rodríguez-Carmona, Sharpe, Harlow, & Barbur, 2008) that seems particularly close to your specific question. Citing from the abstract (emphasis mine):

**Background**

> Generally women are believed to be more discriminating than men in the use of color names and this is often taken to imply superior color vision. However, if both X-chromosome linked color deficient males (8%) and females (\<1%) as well as heterozygote female carriers (15%) are excluded from comparisons, then differences between men and women in red-green (RG) color discrimination have been reported as not being significant (e.g., Pickford, 1944; Hood et al., 2006).

**Study Goal, Method, and Sample**

> We re-examined this question by assessing the performance of 150 males and 150 females on the color assessment and diagnosis (CAD) test (Rodriguez-Carmona et al., 2005). This is a sensitive test that yields small color detection thresholds. The test employs direction-specific, moving, chromatic stimuli embedded in a background of random, dynamic, luminance contrast noise. A four-alternative, forced-choice procedure is employed to measure the subject's thresholds for detection of color signals in 16 directions in color space, while ensuring that the subject cannot make use of any residual luminance contrast signals. In addition, we measured the Rayleigh anomaloscope matches in a subgroup of 111 males and 114 females. All the age-matched males (30.8 ± 9.7) and females (26.7 ± 8.8) had normal color vision as diagnosed by a battery of conventional color vision tests. Females with known color deficient relatives were excluded from the study.

**Results**

> Comparisons between the male and female groups revealed no significant differences in anomaloscope midpoints (p = 0.709), but a significant difference in matching ranges (p = 0.040); females on average tended to have a larger mean range (4.11) than males (3.75). Females also had significantly higher CAD thresholds than males along the RG (p = 0.0004), but not along the yellow-blue (YB) discrimination axis. The differences between males and females in RG discrimination may be related to the heterozygosity in X-linked cone photo pigment expression common among females.

**What does this mean?**

Citing from the conclusion of the paper

> Chromatic sensitivity was measured in a large population of normal trichromat males and females (...). On average, females were revealed to have significantly higher RG chromatic thresholds compared with men on the CAD test and larger red-green matching ranges on the Nagel anomaloscope. A correction was applied to exclude the possible effect of female heterozygotes that were undetected by our screening procedures upon our gender comparisons. **On the basis of our results, we can confidently conclude that women do not have superior red-green colour discrimination than men. However, the possibility arises that they may on average have poorer discrimination.** Genetic and physiological explanations related to a sexual dimorphism in X-linked cone photopigment expression are offered as to why this may be the case.

**References**

Rodríguez-Carmona, M., Sharpe, L. t., Harlow, J. a., & Barbur, J. l. (2008). Sex-related differences in chromatic sensitivity. Visual Neuroscience, 25, 433–440. doi:10.1017/S095252380808019X

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Tags: perception, vision, color, sex-differences, gender
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# Question
Title: How do some humans seemingly naturally have positive or mitigated appraisal of stressful events?
Appraisal is how an individual interprets a stressful event or a problem. For recurring problems, I understand that there are neuroanatomical structures that play a role in the appraisal of recurrent problems, problems of a certain type that are encountered frequently. For example, the hippocampus is important in the development of episodic memories, and the amygdala plays a role in fear processing. If we exclude individuals with significant lesions to these areas, we have a population of individuals with these same neuroanatomical structures. However, you can find that some individuals have different appraisals of problems. While these structures are biological intermediaries to cognition, the results are different. How, and why?

For example, this can have implications in sports. Two players of a professional basketball team could both be the most skilled players on their respective teams with a terrible supporting cast of teammates. One player who views this lack of talent as a challenge could take it upon himself to galvanize his teammates and "carry his team on his back", leading to a successful team performance. However, the other player could view his lack of surrounding talent as a detriment, a crutch, and let frustration contribute to his anxiety, leading to a team's downfall.

Moreover, appraisal could lead to nonchalant perspectives of certain problems, which leads to stress reduction in some scenarios. Back to the sports analogies. In sports, it is said that an optimal trait of a quality defender is "short term memory" in the sense that if opponents have scored on them, the defender does not let this event contribute to future encounters defending opponents. That is, the defender does not think to him/herself, "I got scored on last time, oh no", which leads to a compounding lack of confidence and eventually, performance.

A natural psychological explanation could be upbringing or priming, but I can find individuals who grew in stressful environments who can handle stress well, and can't handle stress well. Moreover, I can find individuals who grew in environments where stress was not a significant factor, and again, you can find people who handle stress well and those who don't handle stress well.

# Answer
> 4 votes
The interactions among several factors probably account for variability in reactivity to stressful events, including genetics, epigenetics, early life experience, and culture (e.g., Alexander et al., 2009; Boyce & Ellis, 2005; Francis, Frances, Liu, & Meaney, 2006; Gunthert et al., 2007; Meaney, 2001). And individual differences are observable at multiple levels of analysis, including behavior, physiology, and brain structure and function.

On the one hand, there is a huge literature on the development of emotion regulation in children (e.g., positive appraisal of stressful events). For example, there are models charting the complex influence of the family on emotion regulation development, where parenting practices interact with child characteristics to influence emotion regulation success and strategy use (Morris et al., 2007):

Positive (re)appraisal requires good cognitive control and working memory (McRae et al., 2012), which is associated with functional and structural integrity of cortical areas, most notably prefrontal cortex (Goldsmith, Pollack, & Davidson, 2008; Levesque et al., 2004; Lewis & Stieben, 2004; McRae et al., 2012). And the ability of PFC to dampen negative affect seems to be mediated by functional connectivity with subcortical areas, notably bilateral amygdala (Banks et al., 2007; Buhle et al., 2014; Wager et al., 2008).

Positive reappraisal also benefits from practice, which forms part of the basis of cognitive-behavioral therapy (Beck, 2011; Goldin et al., 2012; Goldin et al., 2013).

Additionally, there is emerging evidence that genes (and gene-environment interactions) are related to emotion regulation strategy use and effectiveness (e.g., *5-HTT*, *OXTR*; Canli & Lesch, 2007; Hariri & Holmes, 2006; Kim et al., 2011). So genetic factors may promote resilience even in stressful environments.

## Conclusion

So as you can see, there is a large host of factors that contribute to one's tendency to appraise (negatively or positively) a stressful situation. And indeed, you may see large within-person variability in the tendency to make positive appraisals, especially as the context changes (Aldao & Nolen-Hoeksema, 2012). Not to mention, positive appraisal may not always be a beneficial way to mitigate stress, and may instead sometimes be harmful or ineffective (Troy, Shallcross, & Mauss, 2013).

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Tags: cognitive-psychology, stress, fear
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# Question
Title: Do characters in a dream have their own separate thoughts or identity?
I am very curious as to if any research has been done in this area, or if such a question even *can* be researched given the current tools and methods available to cognitive scientists. When one dreams, one may experience interactions with other characters, be those characters based on people one knows in their waking life or characters new to the dreamer. I'm interested to understand more about how the interactions between the dreamer *within the dream state* and these characters inside the dream work.

Do the characters in one's dream actually have their own *thoughts*? That is, does the mind "sandbox" each character, keeping track of what each dream character is thinking? When characters in a dream speak or act, what determines what actions they will take? Are their words and actions simply based upon a sense of empathy, or does the mind somehow maintain separate "conscious states" for each dream character? (A better word for that is appreciated, if there is one)

Or, as I suspect, is this concept simply too abstract for us to research given our current level of technology and understanding about how dreams work at a fundamental level?

**Edit:** As an alternative way of asking this question, has any research been done looking for possible relationships between characters within a dream and other better-understood areas of personality, for example multiple personality disorder?

# Answer
> 5 votes
EDIT: To address the changed question:

Similar to how mental visualization stimulates the same neurons/blood flow that actually seeing something does, I suspect that brain scans will show similar processing occuring during the dream interaction as occur during real interactions.

The difference is that the brain is creating the entire subjective experience.

The crazy thought is that there isn't a difference though: subjective experience is ALWAYS completely constructed by the brain, though it's constructed through nerve impulses from external inputs such as electromagnetic waves (sight) or physical waves (sound). During sleep, the body is paralyzed to prevent us from acting out our dreams (which WILL happen if the paralysis is lifted), which implies that sensory data is still coming in (or being generated) and we are simply mis-perceiving it and then trying to catch up.

This was my answer to @alan2here's original question. It mostly still applies, though is also a mixture of philosophy, psychology, and cognitive neurophilosophy (EDIT: i.e. uncited, lol) Take this as you will:

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First off, this is definitely a philosophy question, but I'll try to stay within the bounds of Cog Sci. No promises though...

From my understanding, the mind does not create consciousness. While this is a very thorny issue, and one I'm not super familiar with, I believe a generally accepted view is that consciousness is a (by-)product of the sheer complexity of the human brain coupled with governing systems and feedback loops (and a hell of a lot more of course!).

Furthermore, the perceived barrier between the self and separate beings is just that: perception. Differences in physical properties aside, there are no real barriers between anything. Air is just as much a molecule as plastic, and behaves in a remarkably similar manner. The difference is semantics (not unimportant to subjective beings, but objectively the difference is inconsequential). We just can't see it, and we're conditioned to ignore it, so we see a vast gulf of nothingness where there is actually incredible hidden complexity. Also, the notion of self is a misguided one that we're given through culture. As many Eastern philosophies will tell you, the self is a lie! (just like cake).

To address the actualy question though (kinda), I think you unintentionally answered it yourself with this phrase: sentient seeming entities. The 'people' in your dreams are amalgamations of 'people'-like semantic attributes your brain has constructed from your experiences. These seem like real people and can act like real people, but that's because you've met and experienced real people. If you have never met real people, it's very doubtful that any people-like dream constructs will be created (unless generated from mirror reflections).

Lastly, I have to add this caveat: dreams and dream science is still an incredibly unexplored black box. We still don't have a clear idea about why dreams occur and until then, this question is literally unanswerable. In fact, everything I've said may turn out to be false, but we don't really know. That's why this falls under philosophy.

However, I'll leave you with this: assuming that the human mind is an individual entity (and cannot connect with other people through undiscovered mental (physical, likely subatomic and certain microscopic) means), then the people in your dreams do not exist anywhere else nor to anyone else. Therefore: does it matter? It's a completely subjective experience, so only you can decide how to perceive it.

# Answer
> 1 votes
I've done a few experiments during lucid dreams, and i have found 2 different kinds of dream characters.

1) (The Automata) These guys are basically programs. They are there only to further the plot of the dream. If you make any attempt to break them out of the plot they've been put into, they will stop giving sensical answers. They are not conscious. They only know how to answer a few questions and do a few things.

2) (The "People") These are, as far as i can tell, conscious. They act and behave like people, and can do things completely unrelated to the original plot of the dream. They exhibit creativity, since i have heard genuinely funny jokes from them that i never thought of before and that other people find funny. They exhibit a sense of agency, in the since that i am never able to truly "erase" them. Whatever's left after an attempt to erase them will quickly reestablish itself. They have memories independent to my own, ones that i confirm are real after reading older entries in my dream journal. They also exhibit free will, in the since that they are able to say things that are completely at odds to my expectations. I have only seen very few of them, but the ones that i do see will recur in my dreams.

So, in my opinion, based on the experiments i've done, there are definitely some dream characters that exhibit consciousness. How this happens, i believe that they are incredibly detailed replicas of the same processes that makes our consciousness. But then how are they separate? How do they have independent thoughts and memories? I think that their thoughts and memories form part of the subconscious, in the sense that they escape our conscious awareness. However, cognitive science is still in its infancy, and we are trying to explore the one most complicated piece of software known to man that's running on a piece of hardware that we still don't fully understand. In the end, time will tell what the right answer is.

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Tags: consciousness, dreams
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# Question
Title: Do online mental age tests have any scientific validity?
If you google for 'mental age calculator', you can find several tests that claim being able to assess your **mental age**, as opposed to your chronological age.

1. Is 'mental age' a valid scientific concept?
2. Do online mental age tests have any scientific validity?

# Answer
**No, these tests shouldn't be taken seriously.**

The **scientific term 'mental age'** has a different meaning than the one implied by those tests. In its scientific sense, it's a **historic concept** dating back to the early days of IQ testing. It was defined by Binet, the inventor of the IQ test, **as a means to compare the intelligence of children**. The mental age corresponded to the age group which had, on average, the same test value as the child that was assessed.

Historically, the ratio of mental and chronological age formed the basis of the IQ score. However, today, the IQ scores is determined by assessing the norm of test results within age groups (see this earlier answer) and the concept of 'mental age' has lost its relevance. In addition, the definition makes clear that comparing the 'mental age' of adults does not make much sense, because at some point, the test scores are not so much related to chronological age anymore.

The **online 'mental age tests'** do not try to measure IQ (for the validity of online IQ tests see this earlier question). Instead they ask trivia and attitude questions that are supposed to reflect your age more in a cultural sense.

None of the ones I looked at reported any scientific backing. However several noted they were **for entertainment, only**.
> 1 votes

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Tags: measurement, developmental-psychology, aging
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# Question
Title: Can a brain be modeled as a simplified interaction of different states and their triggers?
I've long been interested in the concept of "states of mind", which influence the perception of the outside world and outlook on past, present and future. They can be thought of as "colored lenses" through which the world is perceived. Each state has a certain trigger. Some example states are:

* Anxiety - world is a terrible place full of danger
* Sexual arousal - brain notices sexual stimuli more and reduces inhibitions
* Creative inspiration - ideas fly and there's a drive to create

Today I've read about an experiment to replicate a part of a rat brain in supercomputer. The following quote jumped at me as rather significant:

> The researchers wrote, that the slow synchronous waves of neuronal activity, which have been found in the brain during sleep, were ‘triggered’ during the simulations, **suggesting that neural circuits may have the unique ability to able to switch into different ‘modes’ that could explain critical behaviours.**
>
> “An analogy would be a computer processer that can reconfigure to focus on certain tasks. The experiments suggest the existence of a **spectrum of states**, so this raises new types of questions, such as ‘what if you’re stuck in the wrong state?” said Markram.

I read that the project is criticized due to it's complexity, seems like they are working from the bottom up, which makes me ask:

**Are there projects out there that attempt to model the brain from the higher levels of abstraction (discrete states and their triggers) down to more detail?**

To use a computer analogy - instead of writing very low level binary code, I can take a high level programming library and work with that. Is there research in this direction?

This image is an example of a state machine - a system is modelled in terms of discrete states and their interactions. The author does not concern themselves with interaction of individual neurons, instead with higher level states:

# Answer
> 9 votes
My answer is probably a weird hodgepodge of sometimes poorly explained stuff, but hopefully it's coherent enough :P

For many decades in psychology, we've had a mechanistic stimulus-organism-response understanding of the brain. That is, a stimulus triggers an internal psychological process, which produces some behavioral response. One of the major limitations of this kind of thinking is that it assumes that the mind is at rest until it's stimulated by something in the environment (even if we add a recursive component to it). However, this is fundamentally untrue.

Instead, the brain is a predictive organ (e.g., Clark, 2013). It's loaded with prior knowledge about past experiences, which is constantly used to predict incoming sensory information. If there is a discrepancy between incoming information and past experience (i.e., prediction error), then our knowledge is updated. This is most clearly seen in the literature on vision, which shows how top-down expectations and prior knowledge robustly bias early visual activity, even in the absence of a visual stimulus (Summerfield & de Lange, 2014). The trigger-state model could not easily account for this.

Moreover, dividing up the brain into mental states may not actually represent how the brain functions. The brain isn't really faithful to the kinds of distinctions we make between cognition and emotion, for example (e.g., Barrett, 2009; Pessoa, 2008). And not only that, those higher order states like anxiety and sexual arousal can be represented in the brain in many different ways. Indeed, there is no dedicated mechanism in the brain or body for producing states like anxiety or creative inspiration (e.g., Wager et al., 2015). They're merely concepts for organizing and communicating our experience. And even then, our brain may not really "have" concepts (see Laurence Barsalou's work; but see also Blouw, Solodkin, Thagard, & Eliasmith, 2015), although it may have a conceptual system that allows us to conceptualize (e.g., Barsalou, 2005).

So I guess what I'm getting at is that brain function is nonlinear, spatiotemporally dynamic, and doesn't adhere to folk psychological categories. Thus, it would probably be difficult to understand the brain by attempting to reduce linear trigger-state relationships to the level of networks, regions, and cells. However, maybe (probably) someone has a better informed, more balanced answer than me! :)

# Answer
> 4 votes
I agree with the previous answer/comments that seeking a simplified abstract model of the brain when it is so complex is probably asking too much. We would need to know a lot more about the "states" you are talking about in order to model them, and in reality the set of "triggers" etc is going to be far too long.

However, given your interest and analogy from computing, you may be interested in reading about cognitive modelling architectures, which try to model some tasks/behaviours/processes at an abstract but tractable level. One of the most well known is ACT-R.

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Tags: cognitive-psychology, cognitive-neuroscience, cognitive-modeling, behavior
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# Question
Title: Is our attention attracted by bright lights?
Bright lights are often used to attract human attention. For example, brightly lit signs, despite often being too bright to look at directly are often used for information and/or advertisement.

Why does this attraction to light occur? I don't see a good reason like how our eyes are attracted to movement, so what's the benefit of it?

# Answer
> 6 votes
In general, evidence suggests that we are attracted to *contrast* rather than *brightness* (luminance). For example, the onset of a bright light on a dark background is often used as an *exogenous* cue for visual attention, but a dark cue on a bright background works just as well. So, signs generally aim to be high contrast against their background. Contrast shows where things change, and hence it is picked up by the visual system for determining edges and objects of importance.

A more specific answer to your question is provided by Vincent et al., 2008. This paper, "Do we look at lights?..." includes discussion of the debate about whether *visual saliency* attracts attention and eye movements. The short answer is that, while saliency does correlate with where we look, on average and in specific circumstances, it depends a lot on our current task demands and the context. You won't look up at the sun if you are looking for your friend in a crowd.

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Tags: perception, vision, attention, eye-movement
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# Question
Title: Are there studies on the effect of nicotine patches on dream vividness and dream recall?
Acetylcholine plays an important role during REM Sleep. I cite an answer to the question "Why do dreams lose clarity quickly over time after we awaken?":

> Activity in the PFC during sleep may be modulated by levels of acetylcholine, dopamine, and other neurotransmitters.

See references and links there. Nicotine also binds to ACh receptors.

Are there studies on the effect of nicotine patches worn while sleeping on dream vividness and dream recall?

# Answer
Here's the only one that's easy to find in google scholar, but there might be more:

Page, F., Coleman, G., & Conduit, R. (2006). The effect of transdermal nicotine patches on sleep and dreams. *Physiology & Behavior*, *88*(4), 425-432.
> 5 votes

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Tags: neuroscience, dreams, neuro-transmitters
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# Question
Title: How is saccadic movement managed in the brain?
I haven't been able to find any decent articles on this specific topic. So I have three (hopefully quick) questions:

1. What part of the brain is actively controlling saccadic movement?
2. If this part were to be removed, does saccadic movement cease to exist and cause the person to go blind from not being able to look around?
3. Additionally, is there a disorder which eliminates saccadic movement in some way?

# Answer
> 6 votes
1. The superior colliculus can be regarded as the center of saccadic eye movement. It contains a topographically organized representation of the visual space in its upper layers, and saccade-related activity in its deeper layers (Van Gisbergen *et al*., 1987).
2. Ablation of the superior colliculus unilaterally eliminates saccades contralateral to the lesion, and hence bilateral ablation will likely eliminate all saccades (Schiller *et al*., 1987). However, the superior colliculi **do not mediate conscious vision**, but mediate **eye movements**. Blindness results after ablation of the primary visual cortex, and obviously after removal of the retinae, or the optic nerves. Also note that "*not being able to look around*" is not dependent only on saccadic eye movement, because head-scanning is still possible.
3. A number of conditions may affect saccades. For example, **stroke** in the brain stem affecting the superior colliculi or cranial nerves may slow saccades and **lesions** in the brain stem may abolish them completely (Ramat *et al*., 2007).

<sub>**References**
**-** Ramat *et al*., *Brain* (2007; **130**: 10–35
**-** Schiller *et al*., *J Neurophysiol* (1987); **57**(4): 1033-49
**-** Van Gisbergen *et al*., *Neurosci* (1987), **21**(2): 541-55</sub>

# Answer
> 5 votes
I agree with much of AliceD's well-cited answer, but here are a few extras.

> 1. What part of the brain is actively controlling saccadic movement?

It is not clear how you would choose just one area of the brain, given that a whole network of cortical and sub-cortical areas are involved, and what you mean by "actively controlling". The superior colliculus is certainly a good candidate, but signals pass through the reticular formation of the brainstem to the eye muscles. In the cortex, the superior colliculus receives projections from the frontal eye fields and the parietal cortex, thought to involve guided attention. Munoz (2002, pdf) is a short review of this network.

> 2. If this part were to be removed, does saccadic movement cease to exist and cause the person to go blind from not being able to look around?
> 3. Additionally, is there a disorder which eliminates saccadic movement in some way?

It follows from the above that there are many lesions which would affect/remove saccades. As noted by AliceD, this does not mean the person will go blind. One interesting case reported a patient with eye paralyis (due to fibrosis of the ocular muscles) who made "head saccades" in order to scan the world in a similar way.

Gilchrist, I. D., Brown, V., & Findlay, J. M. (1997). Saccades without eye movements. Nature, 390(6656), 130-131.

Munoz, D. P. (2002). Commentary: saccadic eye movements: overview of neural circuitry. Progress in brain research, 140, 89-96.

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Tags: neuroscience, vision, eye-movement
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# Question
Title: How much power, in watts, does the brain use?
When IBM's Watson won on Jeopardy a few years ago, it did so using a room full of servers with a cooling system and a fat power feed, competing against a couple of humans powered by the equivalent of a tuna fish sandwich every several hours. How much power does the human brain actually use?

Notes: If other assumptions are necessary, just state what you're answering for (e.g. healthy adults). If you know of differences between groups (e.g. people who are awake vs. asleep), please mention both.

References to scientific papers, especially reviews, are helpful.

This paper, which might be the one discussed here, discusses power usage of individual neurons but not the whole brain.

# Answer
> 13 votes
**20 Watts.**

* Watson mentioned this in 2011: "The human brain only requires 20 watts of power to operate ... Watson? About 20,000 watts." An interview with John Kelly (an IBM senior vice president and director of IBM Research) also puts the brain at "about 20 watts" (but puts the machine at 85 kW; the inconsistency doesn't matter for this question).
* Popular Science also says 20 watts in an article explaining how simulating it in 2009 technology would take tens of megawatts.
* Glenn Elert's high school students cite a collection of resources concluding 20W, as 20% of a 100W full-body power consumption. That's the source cited on Wikipedia.
* The 20W figure is cited like common knowledge from "several different sources" here, but those sources aren't named.

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Tags: neuroscience
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# Question
Title: Predicting the landing site of a saccade while the saccade is still in progress
A brief look through the literature didn't reveal any algorithms that have been directly applied to the online prediction of saccade landing sites while a saccade is in progress.

While there would surely be considerable noise in any such estimate, the direction vector, velocity and acceleration profiles should contain sufficient information to make a reasonable guess. Is anyone aware of any papers which have attempted such an approach?

Also, how good an estimate of landing site could be derived, and how early prior to landing could this estimate be made. What methods would be suggested for making such an estimate?

# Answer
> 2 votes
Interesting question! Trying to interpret your question, I think what you are after is a model that can predict the saccade endpoint based on eye tracking data?

The following answer is more of a basic neuroscientific approach:

The neuronal responses (spike rates) in the **superior colliculus** (SC) can be accurately used to predict the total saccade as a vector. Basically, when you model the response properties of all the SC neurons involved in a saccade, one can calculate the vector sum of all these different neurons. With this vector sum the saccade can be totally described in terms of its direction and amplitude. With the vector sum, hence, the end point can be predicted.

If this subject is of interest to you, the early work of Van Gisbergen and John van Opstal (based in Nijmegen, the Netherlands) are a good source.

Reference: Van Gisbergen et al., 1987

# Answer
> 2 votes
This is an old question, but the following paper might be useful. The authors describe an algorithm of real-time prediction of saccadic landing point.

The algorithm they use is based on a compressed exponential function. Basically, you collect the position samples from an eye-tracker, check if the speed is more than some threshold (e.g., 20 deg/s), then mark this position as a saccade start. Then you continue to collect the samples and as soon as you get enough (at least three) you try to predict the position via non-linear curve fitting. If the fit is good, you use it. If not, you just use the latest available position.

Han, P., Saunders, D. R., Woods, R. L., & Luo, G. (2013). Trajectory prediction of saccadic eye movements using a compressed exponential model. Journal of vision, 13(8), 27.

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Tags: cognitive-psychology, eye-movement
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# Question
Title: Do men have a higher sex drive than women?
It's a common cultural meme that men think about/are driven by sex more than women.

Is there any objective truth to this?

* How do you define and measure 'sex drive'?
* How different are men and women in this respect?

# Answer
> 8 votes
The most straight forward ways to quantify people's sex drive, and hence determine if there's any empirical /objective truth to this disparity, are to measure their self-reported interest in sex (usually by asking "how much do you think about sex?") and also the behavior element (e.g. asking about pursuing sex). Though both of these rely on participants self report, the results are very clear: on average, men think about sex more frequently than women and pursue sex more actively than women.

Here's a WebMD article that summarizes some of these findings and links to various sources:

http://www.m.webmd.com/a-to-z-guides/features/sex-drive-how-do-men-women-compare

**Sex Drive: How Do Men and Women Compare?** Study after study shows that men's sex drives are not only stronger than women's, but much more straightforward. The sources of women's libidos, by contrast, are much harder to pin down.

It's common wisdom that women place more value on emotional connection as a spark of sexual desire. But women also appear to be heavily influenced by social and cultural factors as well.

"Sexual desire in women is extremely sensitive to environment and context," says Edward O. Laumann, PhD. He is a professor of sociology at the University of Chicago and lead author of a major survey of sexual practices, The Social Organization of Sexuality: Sexual Practices in the United States.

\[...\]

**Men think more about sex.** The majority of adult men under 60 think about sex at least once a day, reports Laumann. Only about one-quarter of women say they think about it that frequently. As men and women age, each fantasize less, but men still fantasize about twice as often.

In a survey of studies comparing male and female sex drives, Roy Baumeister, a social psychologist at Florida State University, found that men reported more spontaneous sexual arousal and had more frequent and varied fantasies.

\[...\]

**Men seek sex more avidly.** "Men want sex more often than women at the start of a relationship, in the middle of it, and after many years of it," Baumeister concludes after reviewing several surveys of men and women. This isn't just true of heterosexuals, he says; gay men also have sex more often than lesbians at all stages of the relationship. Men also say they want more sex partners in their lifetime, and are more interested in casual sex.

**Men are more likely to seek sex even when it's frowned upon or even outlawed:**

About two-thirds say they masturbate, even though about half also say they feel guilty about it, Laumann says. By contrast, about 40% of women say they masturbate, and the frequency of masturbation is smaller among women. Prostitution is still mostly a phenomenon of men seeking sex with women, rather than the other way around. Nuns do a better job of fulfilling their vows of chastity than priests. Baumeister cites a survey of several hundred clergy in which 62% of priests admitted to sexual activity, compared to 49% of nuns. The men reported more partners on average than the women.

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Tags: sexuality, sex-differences
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