# Question
Title: How to convince subjects that the computer is playing fairly
We are planning an experiment using the odds-and-evens game. The rules of the game are simple: player A selects either "1" or "2"; player B selects simultaneously either "1" or "2"; if both select the same number, player A wins \\$1 and B wins nothing; if they select different numbers, player B wins \\$1 and A wins nothing.

In our experiment, player A is a human subject and player B is a computer program (the computer is programmed to play randomly - select "1" or "2" with equal probability each time). Our concern is: how to convince the human that this is really what's going on? The problem is that, the human reveals his choice by clicking a button, before the computer reveals its choice. So in theory, we could have programmed the computer to always choose a number different than the choice of the human. Indeed, we have an incentive to do so because it will reduce the amount of money that we will have to pay to the subjects!

How can we convince the human subjects that the computer makes its choice simultaneously and does not "cheat"?

As computer scientists, the first option that came to our mind is to use a cryptographic commitment scheme. But, this might be too complicated for the subjects to understand. Are there simpler solutions?

# Answer
> 1 votes
I'm imagining a system that chooses the computer's response not in a stochastic manner, but chaotically. Suppose you have some chaotic mapping function from the \[0,1\] interval to the {heads, tails} set. Choosing any real number in the set will get you some deterministic mapping to heads or tails. This mapping equation should be quite complex, but made visible to the user. Have them choose a number in \[0, 1\], and you'll get an output that appears random, but could be computed if the user chose to take the time. You just need to make the mapping function complex enough that it's not easily computable to rig the game, and also such that it maps 50% to heads and 50% to tails.

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Tags: experimental-psychology, game-theory, experiment-design
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title: Why so few subjects in psychophysics?

text:
# Question
Title: Why so few subjects in psychophysics?
Why is it that most psychophysics experiments only use a handful of subjects (typically around five, but sometimes even four, three or two), whereas the "norm" for experimental psychology (assuming a medium effect size) is around N=25? Is the motivation to reduce sampling error and increase external validity not the same for psychophysics as it is for e.g. decision-making experiments? Or is it the case that individual differences are smaller in perception than they are in cognition?

# Answer
> 4 votes
It is partly as you already guessed, because the phenomena that are studied don't vary as much between individuals. This doesn't necessarily mean that individual differences in perception are smaller, it means that individual differences *in those aspects of perception that are studied in psychophysics* are smaller.

Another reason is that it is customary in psychophysics to instead use large numbers of stimuli - sometimes thousands - thus making sure that the estimate per individual is *very* precise. In that sense the more cognitive topics are much more underpowered, often employing groups of several tens of stimuli to generalize about entire classes of objects.

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Tags: statistics, psychophysics, sampling
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# Question
Title: Do animals that sleep during the day have a different sleep architecture than those who sleep at night?
A typical hypnogram, delineating the sleep architecture for a (human) mammal looks like

A distinct distribution of non-REM and REM sleep can be observed.

Is this pattern of sleep cycles particular to that of diurnal mammals, and if so, how would the sleep architecture of a mammal that sleeps during the daytime be different?

# Answer
One study (Zhao et. al., 2010), investigating the sleep architecture of two bat species (one nocturnal, and one mixed), notes the following:

> *C. sphinx* was found to sleep predominantly throughout the day (60% of total sleep quota) during which time it spent significantly longer time in NREM and REM sleep. Compared to *E. spelaea*, *C. sphinx* had significantly less REM and NREM sleep episodes but their duration was significantly longer. *E. spelaea* appears to distribute its time at wake and in REM and NREM sleep equally throughout the light and dark phases.

Top three rows are for the predominantly nocturnal bat *C. sphinx*. Note the "Wake" rows for the two species.

Source:

Zhao, X., Sun, H., Tang, Z., Flanders, J., Zhang, S., & Ma, Y. (2010). *Characterization of the sleep architecture in two species of fruit bat.* Behavioural brain research, 208(2), 497-501.
> 4 votes

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Tags: sleep, physiology
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# Question
Title: What is the relationship between Working Memory and Attention, and how can one assess his WM?
If someone who had low working memory scores as a child suddenly sees in improvement in attention as he grows older, does his ability to hold and manipulate information also increase? Or does attention serve as bottleneck score for such working memory exams?

Also, is there a way for someone to assess his WM at home?

# Answer
> 3 votes
Engle has published extensive papers about this topic and if you are interested I suggest looking him up.

In 2001 Kane, Bleckley, Conway, & Engle (In Engle, 2002) attempted to directly measure the relationship between WM and executive attention, and conclude that that the underlying factor responsible for the relationship between measures of WM capacity and performance on higher-order cognitive tasks is a domain-free executive-attention system.

> Although individuals possessing different WM capacities will show differences in number of items stored in a variety of memory tasks, this is a result of differing ability to maintain and inhibit information, particularly in the face of distraction and interference. Only when the context makes it difficult to maintain the appropriate task goal do people with high WM spans perform better than people with low WM spans.

In 2003 he found that:

> Individual differences in working-memory (WM) capacity predicted performance on the Stroop task in 5 experiments, indicating the importance of executive control and goal maintenance to selective attention

In my opinion the two are obviously linked however it would be difficult to infer causality or direction in the relationship. It would make sense that if your attention improves your working memory would also improve, however it's hard to say if one causes the other or if they are intrinsically linked and would just both increase at the same time.

In terms of measuring WM at home here is a link to an n-back test which I think will be fairly easy to do at home:

http://cognitivefun.net/test/4

The n-back task requires participants to decide whether each stimulus in a sequence matches the one that appeared n items ago. N-back has become a standard measure for WMC, however treat results with a pinch of salt as Kane et al (2007) have called it's validity into question.

References:

Engle, R. W. (2002). Working memory capacity as executive attention. Current directions in psychological science, 11(1), 19-23.

Kane, M. J., & Engle, R. W. (2003). Working-memory capacity and the control of attention: the contributions of goal neglect, response competition, and task set to Stroop interference. Journal of experimental psychology: General, 132(1), 47.

Kane, M. J., Conway, A. R., Miura, T. K., & Colflesh, G. J. (2007). Working memory, attention control, and the N-back task: a question of construct validity. Journal of Experimental Psychology: Learning, Memory, and Cognition, 33(3), 615.

# Answer
> 2 votes
Working memory (WM) and attention are interrelated, as a precondition for WM to operate is attention. In addition to attention we need awareness. The general view is that WM is explicit - conscious - and never implicit. The key difference between the term "working memory" and the older term "short-term memory", is precisely highlighting the role of attention and updating in memory.

To answer your question, we should consider that there are different types of attention. We can distinguish between momentary "spot-light" attention (or we could speak of "selective attention") and sustained attention (vigilance). In addition to WM training, there are training tasks for improving sustained attention. These are distinct put overlapping domains.

Unfortunately, the n-back task that was recommend in another answer varies due to different designs of the task and a score is therefore not easily comparable to other n-back scores, but for the same task only. One important distinction can be made between tasks that are designed for testing and tasks that are designed for training. In training tasks you are supposed to change your score and these tasks are therefor not ideal for measurement, whereas test tasks should ideally be more robust to change.

There are some clinical tools that have been established for assessing short-term memory. These tasks include Raven's progressive matrices and the Corsi block task. The advantage of these tests is their comparability between individuals. A disadvantage is that they are rarely computerized and less accesible outside the neuropsychological community.

WM is a very broad and colorful concept. Maintaining and updating information are two separate aspects of WM. The first requires sustained attention, the second requires flexibility of thought. Traditionally, the upper limit of the capacity for a number of items is measured. This is equivalent to storage in short-term memory.

However, one further requirement for defining WM is the online manipulation of maintained items. The size of the short-term store - number of items - is just another index of WM performance, although it is still considered the gold standard. However, the score is heavily dependent on what task you choose.

As a student I am currently working on a classical working memory task for testing that runs in your browser. I hope to release it this year as open source. There is still much work to be done to give people at home the ability to test working memory.

Finally, motivation and working memory are strongly linked. Comparing yourself to your peers can reduce performance. It is therefore better to take a "master-oriented" approach and to compare your score with your previous scores.

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Tags: memory, attention, working-memory
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# Question
Title: What are the techniques to get over the learning plateau?
I often end up having loads of things which I am learning. One of the pattern which I have observed over time is that I often end up leaving things half way - for months and then, I have to restart doing the basics again. I feel that if only I ended up taking a few steps more, I could have gained much more from my revisions.

I have a couple of questions -

1. Is this good practice?
2. Is there any cognitive reason behind this?
3. How does one overcome/control this tendency to start off something new before finishing the older ones?

# Answer
> 1 votes
Increased spacing between learning sessions has been found to improve long-term learning when studying for tests. The key is to study less per session, but more often. To develop a habit, you could start by connecting your time of study to a habit that you have already established. For example, if you always brush your teeth, you could associate putting the toot-brush back with walking over to your study area and opening a book.

Repeated learning further enables learning. This is one of the reasons spaced learning works. Once you have studied a chapter the previous session, you go back to the same chapter, skim it, and think about the concepts that you have learned. Repetition is key to rote learning.

Facing the hard parts requires a very thorough understanding of the basics. Know the basics. Don't be afraid of your brain working harder on some problems. The more advanced stuff will take more time to learn. That is the natural course.

TLDR:

1. No.
2. A lack of repetition, spacing, and knowledge of the fundamentals.
3. See above.

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Tags: psychology, self-discipline
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# Question
Title: What is the effect called whereby people don't offer help when in a crowd because they assume someone else will help?
If you are in a crowd and you hear someone call for help you assume that someone else will deal with it. If you are alone and you hear someone call for help you go and help them. What is that effect called?

# Answer
It's called the bystander effect:

> The bystander effect, or bystander apathy, is a social psychological phenomenon that refers to cases in which individuals do not offer any means of help to a victim when other people are present. The probability of help is inversely related to the number of bystanders. In other words, the greater the number of bystanders, the less likely it is that any one of them will help.

It was highlighted by the Murder of Kitty Genovese, which is part of the negative image of New Yorkers as apathetic, and is therefore sometimes also called "Genovese syndrome".

The bystander effect is a sub-type of Diffusion of responsibility.
> 6 votes

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Tags: social-psychology
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# Question
Title: What do chimpanzees do with fire in the wild, and can they be trained to manipulate burning objects?
It seems that most animals run away or avoid fire at all costs. This is especially apparent during wild fires. Humans, obviously, have figured out how to use fire as a tool.

Are we the only known species that is capable of manipulating fire? Do chimpanzees, or other primates, learn to approach fire? Are there any known examples of successfully training primates to use fire as a tool?

# Answer
Primatologist Jill Pruetz at Iowa State University in Ames was observing savanna chimpanzees in Senegal and found that chimps there have mastered the first step in controlling fire.

However there is this article from worldnewsdailyreport.com, which talks about a group of chimps in the Congo mastering the use of fire through experimentation and observation.

The BBC also had a documentary called Monkey Planet which showed a bonobo chimpanzee in a zoo in Illinois building a fire, lighting it using matches, and toasting marshmallows on it.
> 4 votes

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Tags: behaviorism, evolution, animal-cognition, evolutionary-psychology
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# Question
Title: What is "Attention" in terms of brain activity?
A rather basic question, but I don't know the answer to that - **What is human "attention" that can be focused on different parts of the body or outside objects?**

For example, I can focus my attention on my hand. What happens in the brain when I do so? Is attention localized to some specific brain area or neurotransmitter system (ex: reward seeking is mediated by the limbic system)?

# Answer
Firstly its important to note that attention basically the outcome of automatic processes, although attention may easily be directed by conscious choices.

As a previous poster mentioned the reticular formation does have a mediating role in attention. However its doesn't really control attention, so much as it does direct it based on processing in other brain areas, Sturm and Willmes (2001) aptly encapsulate this as...

> For an interpretation of the findings, we have proposed a network in which the anterior cingulate gyrus and the dorsolateral frontal cortex intrinsically control the brain-stem NA activation system via the reticular nucleus of the thalamus.

The vast majority of attentional processing at the most basic level is scanning the environment, in order to create a simulation in our minds. This simulation is not perfect by any means, in fact it appears that we only pay attention to a few key features and it is only when we focus or are guided to use a narrow area of the perceptual field that we attended to things we might not have seen, such as demonstrated by the phenomenon known as 'change blindness'.

From a perception perceptive, early attentional processing is influence by a number of factors relating to stimuli variability, which may guide the deployment of attention, such as motion, size and colour.

Fig 1. Unguided environment scanning is non selective, feature scanning which requires more processing is selective and aids quick recognition. Searching for an object requires use of both of these systems.

This early feature recognition is strongly associated with activity in the ventral visual system, see fig 2.

Fig 2. Diagram of the dorsal visual stream (non selective) and ventral visual stream (selective).

The excellent work of Prof. Jeramy Wolfe, over views much of this perceptual research. When looking for particular information an individual easily guide there attention to the relevant information, such information may even be primed rather than instructed. The pathways and areas of the brain associated with selective attention are relatively simple: the frontal eye (motor control), super parietal lobe (suppress normal attentional flow to specify new target), intraparietal sulcus (spatial orientation, salience mapping, and short-term visual memory).

Fig 3. Areas associated with attentional control, and orientation (Blue).

Luckily after years of research we understand attentional processing from a perceptual viewpoint rather well, however simple questions are far more complex than they at first seem. The current focus on research are narrowing down these areas, personally I think the more interesting questions regard saliency and hedonics. These questions look at reward processing in the brain, and how attention is implicitly guided, if your interested in this then you should check out Kent Berridge's research, which guides this area of research. Finally I'll just mention that acting on implicit processes seems to depend on executive functioning, and working memory capacity.
> 7 votes

# Answer
I'm unsure if there are necessarily specific areas for focusing on body parts, but I would assume that what you are talking about would function as part of the attentional system, which is a form of executive control; and is found in specialized cortical areas of the frontal and parietal lobes (Posner & Peterson, 1989). Attention is carried out by a network of anatomical areas. It is neither the property of a single center, nor is it a general function of the brain operating as a whole (Mesulam, 1981; Rizzolatti, Gentilucci & Matelli, 1985).

Posner & Dehaene (1994) emphasise this further:

> Recent brain-imaging and neurophysiological data indicate that attention is neither a property of a single brain area, nor of the entire brain. While attentional effects seem mediated by a relative amplification of blood flow and electrical activity in the cortical areas processing the attended computation, the details of how this is done through enhancement of attended or suppression of unattended items, or both, appear to depend on the task and brain-area studied. The origins of these amplification effects are to be found in specialized cortical areas of the frontal and parietal lobes that have been described as the anterior and posterior attention systems.

References:

Mesulam, M. (1981). A cortical network for directed attention and unilateral neglect. Annals of neurology, 10(4), 309-325.

Posner, M. I., & Dehaene, S. (1994). Attentional networks. Trends in neurosciences, 17(2), 75-79.

Posner, M. I., & Petersen, S. E. (1989). The attention system of the human brain (No. TR-89-1). WASHINGTON UNIV ST LOUIS MO DEPT OF NEUROLOGY.

Rizzolatti, G., Gentilucci, M., & Matelli, M. (1985). Selective spatial attention: One center, one circuit, or many circuits. Attention and performance XI, 25, 1-265.
> 2 votes

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Tags: cognitive-psychology, cognitive-neuroscience, attention
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title: What causes CSF to flow?

text:
# Question
Title: What causes CSF to flow?
Since matter at rest tends to stay at rest until acted upon, there must be some mechanism in the brain causing cerebrospinal fluid to move from the choroid plexus to other areas of the central nervous system. Is there some kind of hydraulic pump that causes it to flow from one area to the next?

Also, the ventricular system seems to be more of a continuous cavity, rather than a unidirectional closed circuit. How does the fluid make it's way into the far corners of the lateral ventricles, and other nooks and crannies of the ventricular system without the risk of fluid in some areas staying stagnant?

# Answer
The following is taken from the bio answer https://biology.stackexchange.com/questions/94/how-does-cerebrospinal-fluid-circulate-in-the-central-nervous-system

> Venous system has generally low pressure, thus sucking the CSF up to drainage points. Speaking about drainage we also should consider the fact that the venous system has a pressure lower than the atmospheric pressure and much lower than pressure in any middle-sized arterial vessels. This is reached by having elastic walls and by transmitting the negative pressure from the mediastinum during the inhale, when the diaphragm and the thorax expand. This negative pressure propagates mostly to the connected vessels, including sinus system. Due to the elastic wall other parts of venous system can accommodate this negative pressure constrict their lumen, but not the sinus system which has a hard external framework formed by dura mater and bones. That is here we can measure the lowest pressure and this is the pressure that sucks CSF in into the venous system
> 0 votes

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Tags: neuroscience
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# Question
Title: Open-source software for analyzing Electrodermal activity
Electrodermal activity (EDA) is a measure of the sympathetic activity, typically caused by stress or an emotional state. Analysis not a straightforward process like analysing reaction times. It requires some sophisticated algorithms to distinguish tonic activity (Galvanic Skin Level; GSL) and phasic activity (Galvanic Skin Responses; GSRs; see Figure 5). For a more elaborate explanation of EDA and how to analyze it, please see Bouscein (2012).

BioPac (Braithwaite, 2013) and Movisens provide software toolboxes for analyzing this data, but these are costly packages. Ledalab and PsPM are open-source Matlab toolboxes that are also able to pre-process and quantify GSL and GSRs. Unfortunately, Matlab itself is not open-source and quite expensive. **Are there other free solutions that allow you to analyse EDA data, such as Python or R packages?**

---

Bouscein, W., Roth, W. T., Dawson, M. E., & Filion, D. L. (2012). Publication recommendations for electrodermal measurements. Psychophysiology, 49, 1017-1034.

# Answer
> 8 votes
I have found a list of Python and Matlab packages. I'll summarize them over here. As soon as I have gone through the packages, I'll provide some additional details.

## Online

* edaExplorer: Also in Python.\*
EdaExplorer is a tool that is able to detect noisy data from clean data. Five second epochs are made which will be categorized by a model that is the result of a supervised machine learning algorithm (a support vector machine). The data can be marked binary (clean vs noisy) or multiclass (clean, doubtfull or noisy). The noisy data can subsequently be removed. Moreover, edaExplorer is able to find peaks (GSRs) and you can label epochs by walking through the data.

## Python

* *edaExplorer:
* cvxEDA: Also in Matlab.\**
cvxEDA uses a convex optimization procedure to separate the data into three components: (1) a tonic component, (2) a phasic component and (3) a noise term. The noise term is simply a sequence of zero-averaged Gaussian random variables with variance $\sigma^{2}$. The phasic component is determined by the convolution of sudomotor nerve pulses. The tonic component is all that is left, slow varying changes in conductivity. The function is physiologically plausibly and has shown to outperform the continuous deconvolution analysis (CDA), as implemented in Ledalab.
* PyPsy 0.1.1 or PyPsy 0.1.5:
* ...

## R

* ...

## Java

* ...

## Matlab

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Most packages came from http://affect.media.mit.edu/software.php. The website provides tools for analyzing several other stuff, such as facial recognition. Definitely worth taking a look.

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## References

edaExplorer: Taylor, S., Jaques, N., Chen, W., Fedor, S., Sano, A., & Picard, R. Automatic identification of artifacts in electrodermal activity data. In Engineering in Medicine and Biology Conference. 2015.

cvxEDA: A Greco, G Valenza, A Lanata, EP Scilingo, and L Citi. cvxEDA: a Convex Optimization Approach to Electrodermal Activity Processing, IEEE Transactions on Biomedical Engineering, 2015. DOI: 10.1109/TBME.2015.2474131

edaSleep: Akane Sano, Rosalind W. Picard, Toward a Taxonomy of Autonomic Sleep Patterns with Electrodermal Activity, IEEE EMBC 2011, Boston, USA, August 2011

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Tags: emotion, methodology, software, data, workload
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# Question
Title: Does anyone know how to explain Quinian bootstrapping process by Carey to a layperson (like me)?
I've been trying my best to understand what *Quinian bootstrapping* is, by reading scientific articles on this topic, but I come across more and more philosophical concepts like "sortals" or similar.

I would like to just grasp the idea behind Quinian bootstrapping - what does a child *do* when understanding some abstract concepts, like "weight". Does anyone know how to explain how it works in a less complicated, but maybe more simplistic way?

I can add that I know what is bootstrapping.

References

* Carey, S. The Origin of Concepts (Oxford: Oxford University Press, 2009).
* Carey, S. “Precis of The Origin of Concepts”, in Behavioral and Brain Sciences 34 (2011), 113-167

# Answer
The basic idea of *Quinian Boostrapping* is that you start off not understanding a concept, but use a symbolic placeholder for it, and then fill in the details over time. For example, right now you don't understand *Quinian Bootstrapping* but you do have the placeholder term "Quinian Bootstrapping" that you can hold in your mind and relate to other things you know and learn. Over time, your placeholder is replaced with the actual concept.

Note that this is how nearly all of our concepts work. What is "water" or "planet" or "electricity"? You start off with "I learned some arbitrary word that picks out some category of thing in the universe" and then approach the real concept over time. But note that an "expert" on the concept may surprise you: "ice is a form of water even though you think it is not" and "Pluto is not a planet even though you think it is" and "the bright flashes during a storm and the stuff that makes the TV work are the same."

You asked specifically about weight. Imagine a child newly learning "weight" as opposed to "mass" (and as opposed to "density" and "volume" and other nearby terms). The child will start off just knowing that there are various terms that are picking out nearby concepts, but not understanding what makes them different. But as the child is led through examples (e.g., "the same object will weigh more on Earth than on Mars") the placeholders become elaborated into concepts.

This bootstrapping ability relies on being able to relate information from a variety of sources to an arbitrary placeholder symbol, which means it is likely unique to humans.
> 2 votes

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Tags: philosophy-of-mind, thought
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# Question
Title: Binaural Beats Meditation EEG versus Non-aided mediation EEG
Can anybody point me to a recent scientific publication(s) that show the changes in a person's EEG using binaural beat meditation is similar to the EEG changes observed using traditional non-aided meditation.

# Answer
> 3 votes
Theta and Alpha are the waves associated with meditation (KaKasamatsu & Hirai, 1966; Khare & Nigam, 2000).

Owen and Atwater found that:

> binaural auditory beats in the EEG alpha frequency range may increase alpha EEG production and subjective relaxation

Furthermore On et al (2013) found that binaural beats could increase Theta activity:

> Binaural beat is the rhythmic stimulus which is generated to produce the desired audio frequency with the intention to make brainwave to follow that frequency. In the end of our research, the result shows that Theta brainwave increases after listening to binaural beat. Although the Delta brainwave is not really affected in this experiment, there is still an increment of delta brainwave after listening to binaural beat. The result shows that binaural beat affected on delta and theta brainwaves.

I also found one from Lavallee (2011) that found the experienced meditators couldn't be hindered by binaural beats:

> Based on the results of this study, novice meditators were not able to maintain certain levels of θ power in the occipital regions when hindering binaural beats were presented, whereas when the facilitative binaural beats were presented, the experienced meditators displayed increased θ power in the left temporal lobe

Suggesting that the effect of binaural beats may not be as strong as long term meditative practise.

Lavallee, C. F., Koren, S. A., & Persinger, M. A. (2011). A quantitative electroencephalographic study of meditation and binaural beat entrainment. The Journal of Alternative and Complementary Medicine, 17(4), 351-355.

On, F. R., Jailani, R., Norhazman, H., & Zaini, N. M. (2013, March). Binaural beat effect on brainwaves based on EEG. In Signal Processing and its Applications (CSPA), 2013 IEEE 9th International Colloquium on (pp. 339-343). IEEE.

Kasamatsu, A., & Hirai, T. (1966). An electroencephalographic study on the Zen meditation (Zazen). Psychiatry and Clinical Neurosciences, 20(4), 315-336.

Khare, K. C., & Nigam, S. K. (2000). A Study of Electroencephalogram in Mediators. Indian Journal of Physiology and Pharmacology, 44(2), 173-178.

Owens, J. E., & Atwater, F. H. (1995). EEG correleates of an induced altered state of consciousness: mind awake/body asleep. Submitted for publication.

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Tags: meditation, brain-waves, binaural-beats
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# Question
Title: Does the Structured Clinical Interview for the DSM contain a Global Assessment of Functioning measure?
I suspect that only licensed psychiatrists get to see the contents of the Structured Clinical Interview for the DSM (SCID). I am drafting a proposal currently and need to know if the data I am applying for access to use has the data structures I need for my experiment. I need to know that the SCID generates evaluation measures of symptom clusters from disorder types in the DSM AND a measure of *Global Functioning*. Is this the case? What does phenotypic SCID data look like?

# Answer
> 3 votes
I couldn't find the SCID anywhere on the web. So i did some digging I found one literature search that used the DSM SCID as an example of a semi-structured interview from which GF data could be found (H Monrad, 2014). I also found that DSM- 5 had removed the GF scale (Gold, 2014), but presumably the alternative measures the same properties.

> the Global Assessment of Functioning Scale (GAF), the previously endorsed numerical rating scale used for assessment of functioning and reported on Axis V, has been eliminated. In its place, DSM-5 offers psychiatrists a new tool for assessment of global functioning and impairment, the World Health Organization Disability Assessment Schedule 2 (WHODAS 2.0).

And finallly I found a study by Aas which looks at rating the GF assesment, in which they reference a study by Williams which looks at the test retest reliability of the SCID.

> Rating GAF may mean choosing the lowest score for other specified time periods, for example the lowest level in the past month or for the worst week during the month prior to interview (Williams et al, 1992).

Based on the above it is reasonable to conclude that the SCID contains a measure for GF, even if it now called WHODAS.

Aas, I. M. (2011). Guidelines for rating global assessment of functioning (GAF). Annals of general psychiatry, 10(1), 1.

Williams, J. B., Gibbon, M., First, M. B., Spitzer, R. L., Davies, M., Borus, J., ... & Wittchen, H. U. (1992). The structured clinical interview for DSM-III-R (SCID): II. Multisite test-retest reliability. Archives of general psychiatry, 49(8), 630-636.

Gold, L. H. (2014). DSM-5 and the assessment of functioning: the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0). Journal of the American Academy of Psychiatry and the Law Online, 42(2), 173-181.

H Monrad Aas, I. (2014). Collecting Information for Rating Global Assessment of Functioning (GAF): Sources of Information and Methods for Information Collection. Current psychiatry reviews, 10(4), 330-347.

# Answer
> 0 votes
I know for a fact that it generates evaluation measures of symptom clusters.

I assume that it would also show global functioning patterns because it rates the severity of client symptoms, from which it would be easy to calculate a metric for Global Functioning.

Source: I am in my last year of study to become a psychologist.

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Tags: psychology, data
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title: Why don't people read instructions?

text:
# Question
Title: Why don't people read instructions?
Some people are very careless when reading instruction on a work task they've been given or in reading any other kind of text. They would skip some of the sentences, not get deep into other and generally care very little if they understood the text right.

What is the common reason behind such behaviour - too little "cognitive capacity" or general disrespect towards other people/ egocentrism or too much dependence on emotional stimuli vs reasoning challenges or attention deficit disorder or simply low intelligence, etc?

# Answer
> 9 votes
### Multiple causes of not reading instructions

As @crash notes, there are likely many explanations for not reading instructions. It may be motivated by not caring about task performance. And such dispositions may be specific to the particular task or setting, or they might be partially related to some general disposition of the individual in terms of conscientiousness or skill.

### The skill of not reading instructions

However, more generally, the concept of information reduction is related to skill acquisition. Haider and Frensch (1996) discuss the idea of how gradually over time participants start to ignore elements of a task that appear to be unrelated to task performance. So on one level, learning to ignore irrelevant information is a skill.

With regards to instructions, it is not always the case that reading an instruction manual is the most efficient means of achieving your goals. Trial and error, exploration, and so on are other strategies which often work quite well. In particular, many devices and software these days are designed to encourage people to explore. Likewise, it can often be a waste in learning information that may or may not be relevant, and so in some cases it makes sense to access instructions on an as needed basis.

It is also one thing to sit in the position of all knowing observer where you can know that in a particular case it would make sense to read the instructions over using an alternative strategy. However, from the actors perspective, they are in a sense operating without that knowledge. So they are in a sense averaging over their experience to form a decision about whether or not and in what detail to read the instructions. In some cases this will work out for the best, in others it wont.

### General problem of task design

If you know that reading the instructions is particularly important in a given domain then you may want to alter the system or the task to encourage reading the instructions. Many organisations have compulsory training with a test in order to force users to learn certain information. Alternatively, you could make clear why reading the instructions is particularly important for this task. Similarly providing strong negative feedback when task instructions are not followed may help the individual to learn that in this domain reading instructions carefully is important. That said, it's often even better if you can incorporate human factors principles to design a system which is user friendly.

### References

* Haider, H., & Frensch, P. A. (1996). The role of information reduction in skill acquisition. Cognitive Psychology, 30(3), 304-337.

# Answer
> -1 votes
In my experience, there are people who like to follow instructions and those who don't. It's in their nature, they were born like this.
Some want to do the thing right, the way it was intended, not make mistake, and take most profit from it.
Some like to figure things on their own, push all buttons to see what does what.

Now regarding why people read badly when they read. I'll attribute this to the continuous and general decay of the modernized civilization. Compared to their parents and grand parents, people know less vocabulary, less grammar, have less concentration, less analysis skills, less dedication, and worst of all they don't care !

# Answer
> -2 votes
If you have ADHD you will probably not follow instructions properly, which could be either, not at all, or just partially, partly due to being impulsive, not being able to remember what they've just read or heard (I'm talking seconds here), being distracted, not learning from past mistakes (because they've been forgotten or did not bubble up into memory in time).

I know this because (a) I have ADHD and (b) I do this all the time and (c) its documented all over the internet.

Hope this helps (belatedly) :D

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Tags: cognitive-psychology, motivation, intelligence, reading, human-factors
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# Question
Title: What stands behind the desire to want things now?
We've all heard the sayings that we would rather have half of a chocolate right now, than a whole chocolate in a month, because we, as wild animals, are constantly seeking for sources. But what's really the evolutionary principle behind this? Is it just that we are better at imagining a near pleasure?

# Answer
> 1 votes
The evolutionary significance of **self-regulation** is that humans are more capable of this feat than apes. We can solve problems without visual feedback, by visualization. Apes are good problem solvers, but have difficulties when the task does not offer visual cues, but requires prospective and causal reasoning. This is one of the reasons monkeys fail on delay discounting tasks.

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Tags: decision-making, evolution, health-psychology
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# Question
Title: How to measure visual salience quantitatively
Salience makes objects pop-up from their surrounding and immediately attract our attention. A salient object in the visual domain would, *e.g.*, be a red dot among white ones. We can sometimes intuitively say an object is more salient than the other, *e.g.*, a moving red dot might be more salient than a static one.

**Is there a way to quantify how salient an object is?**

---

UPDATE

To narrow down the question a little, suppose you have a set of different output devices that can provide either visual or auditory cues (LEDs, loudspeakers, lamps, screens...) and they are near a target object you which to attract attention to. Ideally one would choose the output device that is closest to the target object to attract attention, but depending on the distance, the output device may not be as conspicuous. So at a given distance, I would like to know, which device will attract attention the most. The environment would be mostly static and well lit.

# Answer
> 1 votes
The duration of eye fixation has been used in both infants and adults to measure locus of attention. This can be achieved using an eye-tracker. A more primitive and less exact way is to manually count the frames of a video recording of subjects. The frames per second (FPS) would be a limiting factor. In addition, the item that was first observed is the more salient one, provided that there is no secondary bias in the task (i.e. the objects should be an equal distance apart or the distance could be randomized).

For **visual search** and serial search tasks, responses are gathered and individual response curves (reciever operator characteristics, ROC) for participants and conditions can be computed using **signal detection theory (SDT)**. The discrimination index d prime (d') can then be calculated only if *two* explicit responses are required exist.

Another option is to vary the presentation time systematically in order to quantify processing speed, but this requires a more computational approach.

# Answer
> 0 votes
As with many such questions, this depends on your definition of (visual) salience. Your question suggests that you want to compare this across sensory modalities (auditory and visual) which comes with considerable difficulties.

One possible definition of "salience" is the property of a stimulus which makes it stand out from its background and grab our attention (see http://www.scholarpedia.org/article/Visual\_salience). You could measure this empirically by asking observers to find/respond to the item in various different locations. They should be quicker to do so if this item is more salient (all other things being equal). This is essentially the logic behind most experiments into visual attention and visual search. As mentioned in another answer you could also monitor where the observer is looking, because salient things should be looked at earlier and more often.

There is now a huge amount of research into modelling image-based, visual salience. In theory, such models aim to take a picture of a scene and predict which parts of the image are going to attract attention. Another way to quantify the salience of different items would therefore be to measure the contrast or activity in the saliency map for particular locations. There is much more about this, and many references, in the scholarpedia reference above.

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Tags: cognitive-psychology, measurement, methodology, attention
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# Question
Title: Where can I obtain a button box for reaction-time measurements under a Windows OS?
I need a button box / response box to hook up with a laptop computer and Windows Operating System for a reaction time study. A simple box will suffice and I do not need more than two buttons. I need a reaction time accuracy of at least +/- 10 ms. Ideally, the box will work with the Praat MFC environment on a Windows machine.

I am searching for a proven, commercial solution, instead of building something myself.

The answer to a previous question recommends a product that is not available anymore, and the producer doesn't seem to have a new product in this line. Additionally, the recommendations in that question are targeted at a OS X and Linux solution.

# Answer
**Short answer**
You can try a Cedrus response pad. They are reasonably priced and my personal experiences with these boxes are good.

**Background**
Response latency (RT) measurements using standard USB input devices like a mouse or keyboard are possible, but USB devices limit accuracy. For example, the standard polling latency of any USB device is 8 msec. On top of that, the keys on a standard USB keyboard are serially polled, introducing additional latencies of up to 20 msec (Li *et al*., 2010). If you are measuring standard reaction times in the order of 150 - 200 ms, such a hardware delay may well be too much.

Response pads dedicated for RT measurements have internal hardware that take into account any such latencies and determine RTs typically with accuracies in the submillisecond range.

I have used the **Cedrus RB-530 response box**, which is one of the simpler models in the response box series the Cedrus Company offers. Admittedly, although I have used the Cedrus to register RTs, I have never actually analyzed these results in detail. However, as far as I can see, the RTs obtained made sense and the device seems reliable.

The good thing is that the Cedrus RB-530 response box is supported by a set of functions in the the **Psychophysics Toolbox (PTB-3)**. The PTB documentation, as well as the PTB discussion forum (*e.g.*, this thread) thrust forward by Mario Kleiner contain a wealth of tips, tricks and pitfalls in RT measurements. The PTB-3 Matlab extensions are specifically designed to cope with the hopelessly senseless and sluggish Windows-way of internal-process timing. Linux is by far the best OS for well-controlled timing operations, and also Mac outruns Windows substantially.

Note, however, that not all the reviews on the Cedrus RB-530 are unequivocally positive.

<sub>**Reference**
**-** Li *et al*., *Behav Res Methods* (2010); **42**(1): 212-25</sub>
> 3 votes

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Tags: measurement, methodology, experimental-psychology, reaction-time, psychophysics
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# Question
Title: How does parental expectation lead a child from adaptive perfectionism to rebelliousness?
I find many sources saying that parents with perfectionist ideals can ultimately push a child to shed his or her attitude of wanting to please their parents and become rebellious. What I cannot find is an explanation of the mechanism behind this change. Are there any theories or studies that attempt to explain this **reversal of character**?

Sources:

Rimm (essay)

Parents.com (article - anecdotal)

# Answer
Childhood/adolescent rebelliousness could be explained by psychological reactance theory (Brehm, 1966) and self-determination theory (Ryan & Deci, 2000).

Psychological reactance theory, Brehm states:

> The idea fundamental to reactance theory, namely, that people become motivationally aroused by a threat to or elimination of a behavioral freedom. This motivational state is what is called psychological reactance. It impels the individual to restore the particular freedom that was threatened or taken away. It does not impel the individual to acquire just any freedom--only the one threatened or taken away will do.

Psychological reactance would be elicited when freedom is taken away, thereby motivating individuals to engage in oppositional behavior. It follows that it parents are perfectionist they would be more likely to take away freedom from their child.

Self-determination theory:

Central to SDT are the basic psychological needs for autonomy, relatedness, and competence. When satisfied, these needs foster growth and psychosocial adjustment. When frustrated, people would display maladjustment and psychopathology (Ryan & Deci, 2000; Vansteenkiste & Ryan, 2013).

Essentially "Don't tell me what to do"

Another idea is that parental pressure can create a lot of stress, and that rebelling or dropping out is simply a reaction to this stress. Stoeber & Rambow (2007) found that:

> Parental pressure to be perfect and negative reactions to imperfection, are associated with the motivation to avoid failure and low well-being and thus may undermine healthy adolescent development.

However they do also go on to say:

> Not all aspects of perfectionism are neurotic, unhealthy, or maladaptive. On the contrary, strivingfor perfection can form part of a healthy pursuit of excellence (Shafran, Cooper, & Fairburn, 2002) and may be adaptive in achievement situations where perfectionistic strivings could provide students with additional motivation to do their best and thus achieve better grades.

It appears to me that children/ adolescents reaction to perfectionist parenting is not a change in character, but just a reaction to the environment that has been created for them.

References:

Brehm, J. W. (1966). A theory of psychological reactance.

Deci, E. L., & Ryan, R. M. (2000). The" what" and" why" of goal pursuits: Human needs and the self-determination of behavior. Psychological inquiry, 11(4), 227-268.

Stoeber, J., & Rambow, A. (2007). Perfectionism in adolescent school students: Relations with motivation, achievement, and well-being. Personality and individual differences, 42(7), 1379-1389.

Vansteenkiste, M., & Ryan, R. M. (2013). On psychological growth and vulnerability: Basic psychological need satisfaction and need frustration as a unifying principle. Journal of Psychotherapy Integration, 23(3), 263.
> 4 votes

# Answer
Balswick & Macrides (1975) found adolescent rebellion to be the product of the specific home environment. Among other factors, they found that a patriarchal and restrictive home often led to rebellious adolescents. A very restrictive home leads to frustration and then to aggression. The authors explain their findings with the frustration-aggression theory (Berkowitz, 1989). This theory suggests that

> ...frustration, or failure to reach a certain desired goal due to circumstance, often leads to aggression or behavior that intends harm.

Although the authors did not look specifically at parental expectations, I think the theory can be applied to your question nonetheless. High expectations of a child may not necessarily lead to frustration and reactive aggression. What may well trigger frustration and aggression is when the parental expectations are *too* high such that they cannot be possibly met by the child. Frustration and aggression of the child may then be fueled by the incapability to meet those expectations.

<sub>**References**
**-** Balswick & Macrides, *Adolescence* (1975); **X**(38): 253-66
**-** Berkowitz, *Psychol Bull* (1989); **106**(1): 59-73</sub>
> 3 votes

# Answer
well,Freud explains in Sigmund Freud – Psychological Projection as `“Projecting our problems onto other people”`

> According to the theories of Sigmund Freud, psychological projection is a psychological defense mechanism whereby one “projects” one’s own undesirable thoughts, motivations, desires, feelings, and so on onto someone else (usually another person, but psychological projection onto animals and inanimate objects also occurs). The principle of projection is well-established in psychology.

As an example,

> If a parent has repressed feelings that they have a lazy nature, they will see a hint of laziness in their child and begin to rage against this. A child will do anything it is told not to do, because it is a way of getting the parents attention, even though it may be negative behavior. Over time this negative attention feels like love to the child. They get reversed wired and begin to do passive aggressive behavior to get the attention of the parent, even though it is painful for both. To the child this negative behavior begins to feel like love.

**That scales up and hence the rebelliousness.**

Also, have a look at this Research which has shown that parental expectations for children’s academic achievement predict educational outcomes more than do other measures of parental involvement, such as attending school events.

Hope this helps.
> 2 votes

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Tags: personality, developmental-psychology
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# Question
Title: Term for using hyperbole to make a softer argument seem more palatable?
Say that I wanted to convince a person that oranges tasted nice. One particular method I could use would be to go on an hour long spiel, where I take on two voices - a hyperbolic voice (which says that we should ONLY eat oranges every single day because they are LITERALLY the best tasting thing ever) and a rational voice (which is more subtle, gives reasonable arguments as to why oranges taste nice like 'they have high sugar content', and is generally less explosive)

After hearing the hyperbolic "WE SHOULD ONLY EAT ORANGES" message, which the person will probably immediately reject, it seems likely that the person will accept the more rational message that 'oranges taste pretty nice' as a *compromise*.

This might sound very vague, but I feel like I've read about this theory (in some form) a few years ago, I just can't remember what it's called? Is there a specific term in psychology for this effect, or does this make no sense?

# Answer
> 5 votes
There are several cognitive biases which describe why people are often more likely to accept a position after being presented with an unreasonable position.

## Focalism

Focalism or anchoring is the cognitive bias in which humans rely heavily on the first piece of presented information (the *anchor*) to make subsequent judgments. From the wiki definition:

> For example, the initial price offered for a used car sets the standard for the rest of the negotiations, so that prices lower than the initial price seem more reasonable even if they are still higher than what the car is really worth.

## Door-in-the-face technique

The DITF method is a compliance manipulation technique in which a persuader attempts to convince a respondent to agree or comply with an argument by initially making a substantial and unreasonable request, and then when it is turned down, making a second more reasonable request. See Cialdini (1975) for the founding investigation.

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Tags: social-psychology, terminology, persuasion
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# Question
Title: How do you form a rationale to justify choice of time windows in ERP analysis?
Event-related potentials (ERPs) can reflect the electrophysiological phenomena behind perception & attention. Often, certain time windows are applied for the analysis of ERP peaks (components). I cannot find any explicit justification in the literature why or how those time windows are chosen? E.g., P1 being the largest amplitude between 90 - 120ms. What factors should one consider when choosing time windows, and how ought this to be reported?

# Answer
**Short answer**
Electrophysiological responses in general often come in waveforms. These are characterized by a number of peaks and troughs. Dependent on the specific response, arbitrary naming conventions are used. Generally something along the lines of P1 (positive peak #1), N1 (negative peak #1), P2 etc. Sometimes latencies are used as a subscript too to indicate which peak it is.

**Background**
The timing of ERP peaks is more of a convention than anything else. In fact, electrophysiological responses often have specific latencies, but only specified in a certain range. Age, medical conditions, random recording variability, equipment and analysis method may all affect the specific peak latencies.

Generally spoken, there are three main methods to characterize positive (P) and negative (N) deflections in electrophysiological responses.

The 1st method simply denotes the first positive peak as P1, the first negative peak as N1, the second positive peak as P2 and so forth (Fig. 1). Auditory CAP recordings are designated this way, for example.

Fig. 1. Peaks in an auditory oddball ERP. source: Chernyshev *et al*. (2013)

Alternatively, deflections may be designated a number that indicates their approximate latency. For example the P300 is an often encountered wave in oddball-paradigm ERPs. The P300 relates to the subject's attention to the task at hand. Given the higher-order processing involved, it appears relatively late in ERP recordings namely around 300 ms or so (Fig. 2), hence the name P300.

Text book ERP example showing N200 and P300 peaks. source: Pattel & Azzam (2005)

Another commonly applied notation are Roman numerals; PI, NI, PII *etc*. ABR peaks are often designated this way (Fig. 3).

Fig. 3. Auditory brain stem response. source: UNSW

In the end, the *rationale* you are talking about is all about conventions, approximations and generalizations. In fact, when people investigate specific responses that are not yet characterized by generally accepted conventions, the authors often just make something up along the lines pointed out above. As long as you define it specifically in your report whether it is a longstanding accepted scientific convention, or a simple customized numbering devised by your lab, it's all OK, really.

**References**
**-** Chernyshev *et al*., *Psychol Neurosci* (2013); **6**(3)
**-** Pattel & Azzam, *Int J Med Sci* (2005); **2**(4): 147-54
> 3 votes

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Tags: terminology, eeg, electrophysiology
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# Question
Title: Are there neural loops within a column or an area of the cortex?
Neuronal networks can make loops because a neuron has a direction (from dendrite to axon).

What's the smallest area in the cortex where we can find a loop and what are these loops?

I understand there are loops between different cortical areas through the white matter.

Experiments, like this one, show there are interactions between cortical layers. But it doesn't necessary mean there are loops.

Other experiments, like this one, looking at signals propagation in pieces of cortex with a cut showed the propagation could somehow circumvent the cut and keep propagating. Again it shows the existence of some local circuits but not necessarily loops.

Do we have a proof of local loops in the cortex? How large a piece of cortex has to be to contain a loop? What are these loops?

# Answer
I've read evidence for single-neuron, two-neuron, and larger loops/cycles throughout the cortex, including intralaminar, interlaminar, and interareal neural loops. But it would take me far too long to back that statement up.

Instead, I offer a list of papers to get you started. I've read all these papers, and they all provide evidence for neural loops in the cortex, especially two-neuron loops. Within these papers, search for "loop", "reciprocal", and, if you're interested in single-neuron loops, "autapse".

### References

> * Alonso, J.-M. (2002) Neural Connections and Receptive Field Properties in the Primary Visual Cortex. The Neuroscientist. 8(5):443-456
> * Feldmeyer, D. (2012) Excitatory Neuronal Connectivity in the Barrel Cortex. Frontiers in Neuroanatomy. 6(24):1-22
> * Rockland, K.S. and Knutson, T. (2000) Feedback Connections from Area MT of the Squirrel Monkey to Areas V1 and V2. The Journal of Comparative Neurology. 425:345-368
> * Thomson, A.M., West, D.C., Wang, Y., and Bannnister, A.P. (2002) Synaptic Connections and Small Circuits Involving Excitatory and Inhibitory Neurons in Layers 2-5 of Adult Rat and Cat Neocortex: Triple Intracellular Recordings and Biocytin Labelling In Vitro. Cerebral Cortex. 12:936-953
> 8 votes

# Answer
Yes, absolutely there are loops, and they can occur on a very small spatial scale.

**Do we have a proof of local loops in the cortex?**

Here are a few papers that describe experimental quantification of small networks (2+ neurons) with recurrent connections in various patterns:

> * Sporns O, Kötter R. 2004. Motifs in Brain Networks. PLoS Biology 2:e369
> * Song S, Sjöström PJ, Reigl M, Nelson S, Chklovskii DB. 2005. Highly Nonrandom Features of Synaptic Local Connectivity in Local Cortical Circuits. Public Library of Science Biology 3:0507–0519
> * Perin R, Berger TK, Markram H. 2011. A Synaptic Organizing Principle for Cortical Neuronal Groups. Proceedings of the National Academy of Sciences 108:5419–5424

**How large a piece of cortex has to be to contain a loop?**

Judging from the experimental evidence I cited, loops of connections can occur on the scale of neighbouring neurons. That means, the smallest piece of cortex that contains a few neurons can contain a loop.

**What are these loops?**

I'm not sure what you're getting at here; if you are asking *why* there are loops, then we can only speculate. But even if connections were made randomly, loops would exist. A better question is *why are there more bidirectional / motif connections than we expect by chance?*
> 4 votes

# Answer
What you're calling "loops" are usually referred to as *Recurrent Neural Networks* (as opposed to *Feedforward Neural Networks*).

Scholarpedia has an article on them, with a bibliography:

> Typically... reviews consider RNNs that are artificial neural networks (aRNN) useful in technological applications. To complement these contributions, the present summary focuses on **biological recurrent neural networks (bRNN) that are found in the brain**. Since feedback is ubiquitous in the brain, this task, in full generality, could include most of the brain's dynamics. The current review divides bRNNS into those in which feedback signals occur in neurons within a single processing layer, which occurs in networks for such diverse functional roles as storing spatial patterns in short-term memory, winner-take-all decision making, contrast enhancement and normalization, hill climbing, oscillations of multiple types (synchronous, traveling waves, chaotic), storing temporal sequences of events in working memory, and serial learning of lists; and those in which feedback signals occur between multiple processing layers, such as occurs when bottom-up adaptive filters activate learned recognition categories and top-down learned expectations focus attention on expected patterns of critical features and thereby modulate both types of learning.

At least in this article (i just skimmed it) it looks like most of the presumed biological neural networks are inferred to exist from models, rather than having actually been found with a microscope.

John's answer lists some papers which sounds like they probably provide more direct evidence.
> 2 votes

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Tags: neuroscience, theoretical-neuroscience, neural-network
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# Question
Title: Can "fire together, wire together" be undone?
Are new connections continuously forged in the adult human brain, or do we just start all wired together and then prune until we have something we like?

# Answer
> 3 votes
Development of patterns of synaptic connection contains elements of both outgrowth and pruning. For example, this paper from zebrafish development illustrates both those mechanisms, which appear to be tightly linked:

> Meyer MP, Smith SJ. 2006. Evidence From in Vivo Imaging That Synaptogenesis Guides the Growth and Branching of Axonal Arbors by Two Distinct Mechanisms. Journal of Neuroscience 26:3604–3614.

In more advanced animals (e.g. cats), there is also evidence for both outgrowth and pruning:

> Callaway EM, Katz LC. 1990. Emergence and Refinement of Clustered Horizontal Connections in Cat Striate Cortex. Journal of Neuroscience 10:1134–1153.

There is also evidence for generation of new neurons in adult humans, which implies that new synaptic connections must be forged to integrate newborn neurons into existing networks:

> Ericsson et al. 1998. Neurogenesis in the adult human hippocampus. Nature Medicine 4:1313-1317.

# Answer
> 5 votes
The phrase "fire together, wire together" comes from an explanation of Hebbian Learning and refers to the adaptation of synapses as a response to the firing of already connected neurons. This is one of several Synaptic Plasticity mechanisms. Two others that exist are Long Term Potentiation (strengthening and creation) and Long Term Depression (weakening and destruction).

All of these mechanisms are still being researched heavily to understand their detail better. However, I hope this gives you a good starting point.

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Tags: neuroscience, theoretical-neuroscience
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# Question
Title: Why can't we understand text without subvocalizating it?
I wonder why can't we understand text the same way we understand pictures?

Everything we see but text we understand without the inner voice, we don't subvocalize/describe a forest, a street or anything. We just understand it.

Why can't reading work the same way? When I look at words I recognize them but they have no meaning until I *read* them in my mind.

Is there even anyone who got rid of subvocalization completely and can read a 300 page book just in one evening understanding pretty everything?

It even works the same the other way around. If I try to *see* a textural representation of some thing like let's say a table, I first have to *say* in my mind. Why is it so? It's really annoying.

```
text > voice (in my mind) > understanding

```

why not

```
text > understanding

```

I also don't get it why people consider this normal. It slows everything down. Imagine you could read a book in a single eventing if not the subvoc. We must do something terribly wrong when learning to read.

I'm not asking about speed-reading because subvoc is not only an issue there - although it is most noticable when reading - but it also interfers when thinking and forces you to *say* your thoughts.

# Answer
> 6 votes
In japanese language, kanjis are more than phonemes but represent an idea. For instance, both tree and spirit have the same sound (ki) and can be written with the hiragana "letter" き. But when kanjis are used tree is 木 while spirit is 気. Therefore, it is possible to read without subvocalizing. We can read as if it was graphics. So, when using kanji is much more like text \> undestanding. But is hard to think doing it purely because we use many words that have no physical meaning such as "as", "such", "meaning" etc.

# Answer
> 3 votes
Visual experience is 2 dimensional, or even 3 dimensional (moving things). Spoken and heard language is one dimensional in the sense that it must be processed in order: either sounds in order or written symbols in order. The ordering is important. Visually, because things move around, there is no 'ordering' of what we see, so the brain developed ways of processing it more holistically. (Consider the well-known description of "what a frog sees".)

Even still, we understand a visual image by having the eye fixate on various points all around it (as revealed by eye-tracking studies, even with animals). And, one can see a few words at a distance and know what they say without hearing words in the mind.

Because writing is intended to stand in place of hearing spoken words, there is really no better way for us to interpret writing, other than to convert it to apparent spoken words and then process it. This is similar to how images taken in ultraviolet, infrared, X-rays, etc are converted to something we can see, and how radio waves are converted to something we can hear. It is just that we handle reading internally.

Separating the interpretation of spoken language from a simulated hearing of it would be a feat. But writing can be made distinct from hearing, if concepts (ideograms) are written instead of sounds - as in Chinese, Japanese and similar writing systems. These written languages are freed from the problems of dialect and change over time: people with many different spoken languages can all read written ideograms just fine.

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Tags: perception, reading
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# Question
Title: Can curiosity be described as an emotion?
Can curiosity be described as an emotion?

On one hand it is definitely an emotion in the sense that is a feeling. IT feels like you want to know something. Furthermore, it can be pleasant or unpleasant according to the circumstances. So there is a basis for thinking that I could. I am wondering if there are good arguments on why it would be problematic to define curiosity as an emotion?

# Answer
The currently accepted model of curiosity is that of Litman. It describes curiosity as a sort of motivating factor:

> Curiosity as a feeling of deprivation (CFD) reflects feelings of uncertainty and tension that motivate information-seeking and problem-solving behavior.

Now we only need to establish a link between motivation and emotional intelligence. In this study, scientists found a link between the two, but came to conclusion that:

> Structural equation modeling indicates that motivation is not a factor of emotional ntelligence but that it is related to the construct particularly through the regulation of emotion and the appraisal of others’ emotions

Edit based on more updated study:

Before we proceed further, I tried to find further proof that curiosity is indeed a motivation. I found confirmation of that here, which categorises curiosity as an intrinsic motivation.

Back on topic, Here is an invaluable resource that I found thanks to mrt: The Psychological Construction of Emotion - Edited by Barrett and Russell

The entire chapter 11 is relevant. It contains lots of relevant citations too (Specially the works of Panksepp). I can't quote all of it because fair use has a limit. I will just post a glimpse:

> In view of the clear evidence linking DA transmission to aspects of motivation, what does this say about dopaminergic involvement in emotion? Is DA irrelevant as an ingredient in emotional states? Not necessarily. Burgdorf and Panksepp (2006) suggested that ventral striatal mechanisms are not related to “pleasure” or “consummatory reward” in the traditional sense, but instead are involved in anticipatory or appetitive energizing effects of stimuli.

The book establishes a difference between hedonic "liking" and dopamine-induced "wanting". \[ Dopamine has been linked to pleasurable simulations as well as aversive stimulations \] Depressed people do not lose their appreciation of pleasurable things like tasty food (quoting the book here), but find no energy in their pursuit of motivational stimuli, exertion of effort, and motivational anticipation.

In conclusion: I would like to propose that being curious is similar to being a foodie, or adventurous. Not sure about lexical term, but there seems to be a need to differentiate between core emotions and their drive.
> 4 votes

# Answer
**Short Answer:**

No, curiosity cannot be described as an emotion.

**Detailed Answer:**

Curiosity is a desire, aspiration for something. An emotion is the affective aspect of consciousness, also known as affect integration. However, curiosity and pretty much *everything* can induce an emotion.
> 0 votes

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Tags: emotion, philosophy-of-mind
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# Question
Title: What is the difference between RR-intervals and NN-intervals in HRV-data?
Heart rate variability (HRV) is often used as a measure of the sympathetic nervous system. One way to quantify HRV is by calculating the Inter-beat interval (IBI), also referred to as the RR-interval. The RR-interval refers to the time between two R-peak of a traditional ECG heart-beat waveform (see Figure 1).

*Figure 1: Two subsequent heart-beats with component names. The RR interval is the time between two subsequent R-peaks. Picture taken from: http://lifeinthefastlane.com/ecg-st-segment-evaluation/*

However, in a review article by Shaffer, McCraty and Zerr (2014) they refer to normal-to-normal (NN) intervals instead. This extends to the statistical measures of the RR intervals, such as SDRR, pRR50 (Urooj, Gupta, Sp & Tandon, 2014), i.e., SDNN and pNN50, respectively (Shafer et al., 2014). **What is the difference between RR-intervals and the NN-intervals?**

---

### References

Shaffer, F., McCraty, R., & Zerr, C. L. (2014). A healthy heart is not a metronome: an integrative review of the heart's anatomy and heart rate variability. Frontiers in psychology, 5, 1040.

Urooj, M., Gupta, S., Sp, V., & Tandon, M. (2014). REFERENCE RANGE OF HEART RATE VARIABILITY AND VALIDATION IN SUBJECTS WITH ASYMPTOMATIC ELEVATED LIVER FUNCTION ENZYMES. International Journal of Current Pharmaceutical Research, 6(4), 49-52.

# Answer
The difference is rather simple. NN-intervals refer to the intervals between **normal** R-peaks. During a measurement, artifacts may arise due to arrhythmic events or faulty sensors, for example (Citi, Brown & Barbieri, 2012). This may lead to abnormal R-peaks, which may in turn distort the statistical measures. To ensure reliable and valid data, only normal R-peaks are selected. Alternatively, the abnormal R-peaks can be corrected.

In practice, however, RR-intervals and NN-intervals are synonymous (Tarvainen, 2014; Wiki). The use of "NN-intervals" is merely used to emphasize that normal R-peaks were used.

---

### References

Citi, L., Brown, E. N., & Barbieri, R. (2012). A real-time automated point-process method for the detection and correction of erroneous and ectopic heartbeats. IEEE transactions on biomedical engineering, 59(10), 2828-2837.

Tarvainen, M.P. (2014). Kubios HRV version 2.2: User's Guide.

https://en.wikipedia.org/wiki/Heart\_rate\_variability
> 5 votes

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Tags: methodology, data, workload, heart-rate-variability, ecg
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# Question
Title: How do deaf people get feedback on their speech?
When we speak, our ears give us feedback on the same. This, presumably, helps in learning a language and adjusting the volume of our speech. How do deaf people get this feedback to learn a new language or adjust the volume of their speech?

# Answer
> 0 votes
Many "deaf" individuals still have some functional hearing. Even in the case of a total loss of hearing, there are proprioceptive cues that provide useful feedback for speech production. The typical way of teaching pre-lingually deaf children how to speak involves hours of one-on-one time with a speech-language pathologist. The child learns to speak by placing their hand on the throat/mouth of the instructor and feeling the vibrations and movements of the articulators. There is also software that process speech in near real-time and helps the talker adjust their speech to match a target pattern. These same techniques could be used for the post-lingually deaf. That said, I think it is pretty rare for post-lingually deaf individuals to learn a second spoken language.

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Tags: hearing, speech
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# Question
Title: Increasing pitch perception of the same auditory stimuli
I was trying to work up a small clip of repeating *beep* sounds I recorded from a mobile game. This series of sounds, when played, gave an unmistakable perception of increasing pitch with every rendition of the *beep*. I recorded the sound and plotted a spectrogram of the sound, and also a frequency spectra of the first and the last rendition in a series of 10 repetitions (which should apparently have the largest difference in the pitch perception). What was surprising, is that, visibly, on the spectrogram, and also on the frequency spectra, they were exactly the same. Using an enhanced autocorrelation function too, the two repetitions hardly had any gross differences.

Since this is primarily based on visual differences in the plots, there could be subtle shifts which would not be visibly apparent. But in listening, there is a very noticeable rise in pitch, which seems less probable to be a consequence of subtle shifts of the autocorrelation-maxima. **Why then does this seem to be the case? Is it only a subtle shift that I am unable to appreciate or is it something more higher-order than that?**

The pictures contain the spectrogram of the sound in question, the autocorrelation plots (which I understand to be more neurally relevant then the freq spectra) for the highlighted window (the plot with the blue heading) and a similarly placed window around the last repetition (the plot with the white heading). Do let me know if any further information is required. I don't know how can I get the sound uploaded in here.

*I am unsure if the provided spectra are rendered non-informative due to ambient noise, for the recording has been done in a noisy environment using a laptop mic. All analysis via Audacity.*

# Answer
> 2 votes
Ignoring your pictures for a second, it sounds like what you are referring to is pitch circularity. Diana Deutsch was a pioneer in this area. The key is that generating these sounds is tricky and that unless you inspect the "correct" dimensions of the stimuli you will not see the differences.

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Tags: cognitive-neuroscience, theoretical-neuroscience, computational-modeling, sensation, hearing
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# Question
Title: How beneficial is attending a funeral in the process of grieving and why?
Is there any established literature that indicates that attending a funeral aids in the grieving process? I would like to know if funerals pay a critical role in the grieving process and what makes them important.

# Answer
> 4 votes
So I had a quick look into your question (not my area). It turns out there is long established journal called "Death Studies" that focuses specifically on "bereavement and loss, grief therapy, death attitudes, suicide, and death education".

From a quick search on Google Scholar for "funerals grieving", I found an article by Romanoff (1998) that looked like it might provide a starting point. That said, it's not especially empirical (i.e., it is not an RCT evaluating the effectiveness of funeral attendance).

For example, to quote the text:

> Funeral rituals are symbolic enactments that provide meaning- ful and affirming experiences for the bereaved. Funeral rituals mediate the transition of the deceased from life to death, and mediate the transition of the bereaved from one social status to another (Pine, 1989). They provide opportunities for the public display of grief, structures for the delimitation of grief, vehicles for affirming the relationship of the deceased to the community, and the continuity of the community in his or her absence (Fulton, 1988) . During this time of transition, members of the social group tend to the bereaved in an outpouring of human support that tran- scends social status ( Turner, 1969) . Postfuneral bereavement rituals, while rare in American culture (McGoldrick et al., 1991), provide structure to the grieving and full incorporation into a new social status ( Goldberg, 1981) .

### References

Romanoff, B. D. (1998). Rituals and the grieving process. Death studies, 22(8), 697-711.

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Tags: social-psychology, emotion, well-being
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# Question
Title: Can you practice and improve physical activities only by thinking?
By physical activities I mean any kind of task, work, sport, you have to use your body.

Not always have the time to do some task or even the possibility (need some equipment, not great situation). I try to imagine myself doing what I intend to practice. Example: some katas (karate movements), sign language, arts&crafts. Is like I imagine how will it be so when I can do it, I can do it better.

Do I need to practce the real movements to improve or by thinking I have enough?

# Answer
> 4 votes
My general understanding is that thinking about executing the motor tasks in your mind can improve skill. It's not as good as actually practicing the task. I'm not sure exactly how conclusive the literature is on what moderates the effectiveness of mental practice. However, presumably, the nature of the task, the nature of the mental activities performed, your current skill level, and so on, should be relevant.

Perhaps check out Driskell et al (1994) for a review and a meta-analysis. It has a more nuanced treatment. Specifically, they define the relevant act as "mental practice":

> Mental practice is the symbolic, covert, mental rehearsal of a task in the absence of actual, overt, physical rehearsal.

So, it's not just any kind of thinking.

# References

Pascual-Leone, A., Nguyet, D., Cohen, L. G., Brasil-Neto, J. P., Cammarota, A., & Hallett, M. (1995). Modulation of muscle responses evoked by transcranial magnetic stimulation during the acquisition of new fine motor skills. Journal of neurophysiology, 74(3), 1037-1045. https://www.researchgate.net/profile/Aidan\_Moran/publication/228118007\_Does\_Mental\_Practice\_Enhance\_Performance/links/00b49527e74ea53a69000000.pdf

# Answer
> 5 votes
Yes. In one famous experiment,a college basketball team was divided into three groups.

Group 1 was supposed to show up to practice shooting baskets for a week on a daily basis.

Group 2 was asked to "think about" practicing shooting baskets during the alloted time, without showing up.

Group 3 was asked to "forget about" basketball for the week.

After the one week period, Group 3 showed no improvement in shooting baskets.

Group 1 improved meaningfully.

Group 2 improved almost as much as group 1, and way more than group 3.

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Tags: learning, performance, motor, imagery
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# Question
Title: What are the main differences between the FreeSurfer volumetric approach and the statistical parametric mapping from SPM?
In modern research of brain volume and function there are two main players. FreeSurfer which is free of cost and open source and the older, but more frequently used, statistical parametric mapping that itself is also opensourced but is typically used within Matlab, which is closed source.

What should I have in mind while deciding which one to pick for my research?

# Answer
> 0 votes
Freesurfer is great for mapping cortical thickness using anatomical MRI data, while SPM can be used to compare two populations, voxel-by-voxel. This is useful for PET imaging. For example you can see where in the brain amyloid uptake occurs in alzheimer's patients, vs healthy controls.

Our lab uses Freesurfer to process functional MRI data, so I don't have any experience using SPM for this. I will say though that probably the main difference is that many of the Freesurfer processes are simple via command line in UNIX, while SPM has a easy-to-use graphical interface.

SPM however also has command line functionality, so if you are comfortable with that, you might want to explore that. The bottom line is that you will just have to experiment with both programs to find what works for you. Methodologically, both tools should give you the same results, so it's really just a matter of preference, and depends on what you are studying.

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Tags: neuroimaging, spm
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# Question
Title: Brain Right hemisphere is random and left hemisphere is linear? really?
For long I've seen uncountable number of blogs, websites, tutorials, booklets about career-guide, self-improvement, meditation, parenting etc. claiming;

1. "Right hemisphere loves to work random, creative way; in contrast left-hemisphere loves to follow instructions and discipline."
2. "Right hemisphere takes part in lateral-thinking; in contrast left-hemisphere takes part in vertical thinking."
3. "Right hemisphere deals with pictures, visions, senses, feelings etc; in contrast, Left hemisphere deals with formula, equation, numbers, names, letters, calculations etc."
4. "Right hemisphere works in nonlinear, meshy manner; in contrast, Left hemisphere works in linear, rigid, sequential way.
5. "Right hemisphere see the whole, big-picture. Left hemisphere see one part only".

etc.

Some example here , here, here , here, here, here et cetera.

Thus I developed a concept about behavior of 2 hemisphere.

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**Now While I was going through following research article (of 2000):**

Cerebral specialization and interhemispheric communication by M. Gazzaniga (pdf) ,

I stuck on a diagram telling the *exact opposite*.

(URL: https://d1gqps90bl2jsp.cloudfront.net/content/brain/123/7/1293/F16.medium.gif)

(I've slightly edited the screenshot to enlarge the text and utilize the whitespace).

The only thing of the paper maches with popular view, is; the right hemisphere is taking important part in understanding pictures, geometric shapes, extrapolating to fill a gap in an image, etc.

But according to this diagram; actually *Left hemisphere* is site for viewing the 'big-picture' of a subject ('living things'), finding 'similarity' (sings, eats, has a etc). Also From personal experience, the way of thinking shown as relational-map at left hemisphere, is the cause of 'randomness' in me, so that I keep many books and files scattered while working; or was broken line (que) in school to collect a grass or stone. The thing shown at left side forces me to collect various objects and arrange them... not the rightward one. Also I zone-out too-much and day-dream because of the left-one... not the right-one.

In contrast, clearly the right-hemisphere in this diagram, is processing information in much rigid, linear or sequential, disciplined way; and looking a small-part... not the big-picture.

So, please could anyone explain me, why should I still have to consider left hemisphere as a rigid linear servant and right-hemisphere as rulebreaker daydreaming artist?

---

(P.S. most of these popular-series's tell that Right hemisphere is intuitive and Left hemisphere is logical. But I can't believe this because I can't separate logic and intuition. Logic is the bridge between intuition and reality.)

# Answer
> 6 votes
You shouldn't. It is one of those stubbornly persistent myths. It is almost entirely false. It is true that in some tasks one half of the brain is more prominent (although even in supposed classic cases like speech both halves are actually involved, just one half more than the other).

But the idea that one half of the brain is logical and the other intuitive or emotional is simply false. At most, one half the brain is slightly more prominent in processing some tasks that may be perceived by us as more logical or more intuitive, but that is really as far as it goes.

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Tags: cognitive-psychology, lateralization, brain
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title: Function of heart neural network?

text:
# Question
Title: Function of heart neural network?
I have found articles the try to give a possible biological neural network for the movement of limbs, neurons in the eyes, etc. Is there an explanation on how the neural network that controls the heart works?

# Answer
The heart isn't really "controlled" by the nervous system in the same way, say, the limbs are. Heart muscle cells (cardiac myocytes) beat with a steady rhythm even in complete isolation. Collections of isolated cardiac myocytes will beat synchronously. The beating of the heart is controlled internally by two bundles of specialized cardiac myocytes, the sinoatrial node being the primary controller and the atrioventricular node regulating how the beat changes between the upper and lower chambers of the heart.

Although the heart beating it controlled internally, the nervous system does have an influence. This comes more generally from the sympathetic and parasympathetic nervous system, which control how our bodies respond to various levels of arousal and stress. These systems influence many parts of the body, but they influence the heart by "instructing" the sinoatrial node to alter its rate of beating. This is controlled primarily by the vagus nerve, if you are wondering about the specific neural anatomy. That nerve is involved in a wide variety of tasks, but it is particular important for the sympathetic and parasympathetic systems.
> 3 votes

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Tags: neuroscience, reference-request, neural-network
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title: Why baby animals seem "cute" to us?

text:
# Question
Title: Why baby animals seem "cute" to us?
I understand why babies seem cute to us from an evolutionary point of view: They need our protection and love to grow, so it's beneficial for them to look good for us, or at least their parents, since that makes them more likely to be taken care of.

But why does this pattern repeat with baby animals? It seems that small puppies or kitten appear cute to a large number of people, so how does that make evolutionary sense? Do they remind us of our babies? Did domestic animals evolve to be "cute" in order for us to take care of them?

# Answer
What you are referring to is broadly known as baby schema. However, does this not only apply to human babies, but actually to most mammals which need (parental)care. Certain features in the mammal trigger the release of hormones, which in turn will/can trigger caretaking behaviour in humans. The hormone release is associated with the eye and head shape. The reason behind this “phenomenon” is to provide and warrant for the safety and well-being of the baby (evolutionary benefit). Of course, this works also with the non-parents of the mammal, which provides that the animal baby’s well-being is also ensured if the parents are not available to do it. Also, the cuteness does not only apply to humans, but is very interspecific, hence the reason why we sometimes here about babies being raised by wolves, or orphan kitten being cared after by a dog.
> 5 votes

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Tags: perception, evolution
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# Question
Title: Does Computer science has any role to play in Cognitive science?
Does Computer science(or computationalism) has any role to play in Cognitive science or Creativity studies?

# Answer
> 2 votes
Yes. Computer science is one of central disciplines of cognitive science. In fact, the dominant, central dogma of modern (i.e., the last 50 years) cognitive science is that cognition *is* computation. This SEP article elaborates on this thesis:

http://plato.stanford.edu/entries/computational-mind/

Even if you don't think that cognition is computation, you would still likely think that computer science is relevant to cognitive science insofar as CompSci is necessary for computational modeling of any phenomena. For example, some dynamical systems theorists would use computational, dynamical models of cognitive processes, even if they aren't claiming that the mind is *computing* differential or difference equations. (Just like we might use differential equations to model hurricanes, even if we maybe don't think the hurricane itself is computing the equations.)

I'm less sure of what is considered "creativity studies", exactly, but I can imagine that computer science would be relevant. For example, CS -- and linguistics -- is definitely interested in questions like "How are an infinite number of expressions created from finite means?" Different kinds of grammars -- like regular grammars vs context-free grammars -- have different 'creative' powers. Creativity here is more defined in purely formal terms, as opposed to perhaps the semantic/artistic terms that you may have in mind. But, I and many others would argue, formal creativity and semantic/artistic creativity are intimately related.

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Tags: cognitive-psychology, cognitive-neuroscience, computational-modeling, creativity, metacognition
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# Question
Title: How to generate ipsative scores from a test with normative Likert-type items?
Some constructs in psychology are sometimes conceptualised ipsatively. I.e., where the sum of the scales adds up to a constant (e.g., personal values; coping styles). The aim of such measures is often to show the relative position on such scales. In some cases, such scales are created by their response format (e.g., participants respond to questions that require some form of rank ordering of constructs). However, it is also possible to score tests with normative items (e.g., 20 items each on 1 to 5 scale, measuring 4 constructs) in an ipsative way.

However, I recently ran into confusion about exactly how such ipsatised scores should be computed. I can think of a few different ways (e.g., subtracting the mean across all items from each item; dividing scale scores by sum of scale scores; saving residuals where scale is predicted by total score, etc.). I imagine many of these approaches yield similar variables. However, if you need to write a paper using ipsatised scores, you need to justify your particular approach.

**Is there a standard way of performing ipsatisation on scales made up of normative likert-type items?**

# Answer
Baron (1996) writes:

> Scores on a multi-scale measure are ipsative when raw scale scores sum to a constant for any individual. An ipsative score can be thought of as the normative equivalent controlled for overall total score across scales.

Meade (2004) describes perhaps the most common form of ipsatisation based on normative scores as "deviational ipsative" (Radcliffe, 1963):

> normative data (e.g., Likert scales) can be made to be ipsative by simply subtracting the grand mean of each individual’s scale scores (averaged across all scales) from each of his or her individual scale scores (i.e., ipsatized data, Cattell, 1944; additive ipsative data (AID), Chan & Bentler, 1993);

But it seems that there are range of other ways to create ipsative scores (i.e., that satisfy the formal requirement).

* The above substraction method can also involve dividing by the within-person population standard deviation.
* Save the residuals of a regression model predicting each scale from the mean of all scales

I ran quick comparison on some personality data and it seemed like the residual regression and the deviation approach achieved very similar results (see R code at the bottom of post. Thus, it makes sense that the simpler to calculate deviation approach is often applied.

### References

* Radcliffe, J. A. (1963). Some properties of ipsative score matrices and their relevance for some current interest tests. Australian Journal of Psychology, 15(1), 1-11.
* Meade, A.W. (2004). Psychometric problems and issues involved with creating and using ipsative measures for selection. Journal of Occupational and Organizational Psychology (2004), 77, 531–552.
* Baron, H. (1996). Strengths and limitations of ipsative measurement. Journal of Occupational and Organizational Psychology, 69(1), 49-56.

### R code

```
> # load some personality data
> library(psych)
> data(bfi)
> scales <- c("a1", "a2", "a3")
> names(bfi) <- tolower(names(bfi))
> bfi <- bfi[,scales]
> bfi <- na.omit(bfi)
> head(bfi)
      a1 a2 a3
61617  2  4  3
61618  2  4  5
61620  5  4  5
61621  4  4  6
61622  2  3  3
61623  6  6  5
> # calculate overall mean
> bfi$omean <- apply(bfi[,scales], 1, mean)
> # calculate ipsative scores based regression residuals
> bfi$res_a1 <- resid(lm(a1 ~ omean, bfi))
> bfi$res_a2 <- resid(lm(a2 ~ omean, bfi))
> bfi$res_a3 <- resid(lm(a3 ~ omean,bfi))
> # calculate devaiation ipsative scores
> bfi$dev_a1 <- bfi$a1 - bfi$omean
> bfi$dev_a2 <- bfi$a2 - bfi$omean
> bfi$dev_a3 <- bfi$a3 - bfi$omean
> # check that both satisfy ipsatisation requirement
> all(round(apply(bfi[,paste0("res_", scales)], 1, sum), 6) == 0)
[1] TRUE
> all(round(apply(bfi[,paste0("dev_", scales)], 1, sum), 6) == 0)
[1] TRUE
> # Examine similarities between approaches (see diagonal)
> round(cor(bfi[paste0("res_", scales)], bfi[paste0("dev_", scales)]), 3)
       dev_a1 dev_a2 dev_a3
res_a1  0.981 -0.729 -0.711
res_a2 -0.716  0.999  0.065
res_a3 -0.718  0.067  0.971

```
> 1 votes

---
Tags: personality, methodology, statistics, test
---


# Question
Title: Manipulating the difficulty of guessing a correlation
I am trying to generate correlations between random variables (two dimensional) with a defined linear relationship (in the $r$ sense), but with different visual patterns when plotted. I am trying to create a 'guess the correlation' task where I can systematically manipulate the difficulty for an observer to guess the linear relationship.

What I am doing now is given a correlation $r$ I generate the first and second values, $X\_1$ and $X\_2$, with $n$ samples from the standard normal distribution. Then from there I make $X\_3$ a linear combination of the two $X\_3 = r X\_1 + \sqrt{1-r^2}\\,X\_2$

Then: $Y\_1 = \mu\_1 + \sigma\_1 X\_1, \quad Y\_2 = \mu\_2 + \sigma\_2 X\_3$

And now $Y\_1$ and $Y\_2$ have a correlation $r$.

For manipulating the difficulty I've been playing with the parameters of the distribution and $n$, however, I am not satisfied with the results.

Any idea on how to systematically increase the difficulty of the task? (i.e., adding outliers, for instance etc).

Note: Difficulty is a cognitive/psychology question rather than a statistical one. I intend to test the notion of difficulty empirically (i.e., under a specific parameter combinations, people tend to do worse). The idea is to generate plots with varying parameters for a given correlation value (i.e., changing the number of points, the variance, outlier, functional form? etc). What are the parameters and what would be a systematic way to manipulate them.

# Answer
> 2 votes
You will probably need to do pilot testing to ascertain the difficulty of a given correlational task.

From pilot testing, you would need to quantify the difficulty of the task. One option would be the mean discrepancy between actual and predicted correlation. However, there would be other metrics of both degree of error and difficulty.

I would hypothesise that the easiest correlations to guess based on scatterplots would be strong linear relationships involving bivariate normal distributions and lots of data (e.g., n \> 1000).

There are a whole bunch of things that you could try to make the task more difficult. Here's what comes to my mind:

* Outliers (both outliers that increase the correlation and outliers that decrease the correlations); vary the number of outliers in a particular region; combine outliers that increase and decrease the correlation; make outliers even more extreme
* Non-linear relationships (e.g., mixtures of linear and another function such as quadratic, cyclical, stepwise; power functions, logistic fucntions, circular, etc.)
* bimodal distributions on one or both variables
* Highly skewed distributions on one or both variables
* Fewer data points
* data that yield correlations only a little bit above or below zero
* where there is a function like a quadratic, make the x depend on y rather than y depend on x.

More generally, I think that practice and feedback effects will also be relevant. I.e., it may be relevant to ascertain whether the differences in difficulty with novices also correspond to relative differences in difficulty with participants who have been exposed to the full range of items you have generated.

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Tags: cognitive-psychology, measurement, experimental-psychology
---