title: Sleep deprivation and task performance

text:
# Question
Title: Sleep deprivation and task performance
Case: In case of an adult, the average adult sleep time required is 7.5 to 8 hours. Suppose the person (aged between 23-29) has slept only 6 hours, or less than the average time (7.5 to 8 hours).

1. Does sleep deprivation lasting for a day cause mood swings in that particular day?
2. Do we loose grasping abilities due to sleep deprivation?
3. Does sleep deprivation affect our reasoning abilities?

# Answer
## Does sleep deprivation cause mood swings?

Few studies have focused on mood changes in healthy subjects following sleep deprivation. It seems that **there is evidence for sleep deprivation causing mood changes on the subsequent day, but there is no evidence for or against it causing mood swings.**

Hart et al. (1987) found significantly higher self-reported hostility for sleep-deprived medical residents compared with controls, but did not report an effect size. A later study compared college students' self-reported moods between "morning/evening person" and total/partial sleep deprivation, and reported general support for mood changes in morning persons, but not in evening persons (Selvi, Gulec, Agargun and Besiroglu, 2007).

## Does sleep deprivation impair grasping?

A reasonable search of Google Scholar, Web of Science and Scopus did not reveal any research on the association between sleep deprivation and grasping behaviors as such. One study of surgical residents reported that **sleep-deprived residents made more errors and took more time to complete a surgical simulation**, the "Minimally Invasive Surgery Trainer VR", mostly involving grasping behavior (Eastridge et al., 2003).

## Does sleep deprivation affect reasoning?

Reasoning is by far the most well-studied domain with respect to sleep deprivation. **Sleep deprivation seems to have a substantial negative effect on many aspects of reasoning.** Pilcher and Walters (1997) reported that sleep-deprived college students not only performed worse on Watson-Glaser Critical Thinking Appraisal, but also rated their concentration and effort as higher than controls following total sleep deprivation. Herscovitch, Stuss and Broughton (1980) found that partial sleep deprivation was associated with decreased strategic flexibility on the Wisconsin Card Sorting Task. Hart et al. (1997) reported that partially sleep-deprived medical residents retained less information and exhibited slower responses on a set of cognitive tasks.

## References

* Eastridge, B. J., Hamilton, E. C., O’Keefe, G. E., Rege, R. V., Valentine, R. J., Jones, D. J., ... & Thal, E. R. (2003). Effect of sleep deprivation on the performance of simulated laparoscopic surgical skill. The American Journal of Surgery, 186(2), 169-174.
* Hart, R. P., Buchsbaum, D. G., Wade, J. B., Hamer, R. M., & Kwentus, J. A. (1987). Effect of sleep deprivation on first-year residents' response times, memory, and mood. Academic Medicine, 62(11), 940-2.
* Herscovitch, J., Stuss, D., & Broughton, R. (1980). Changes in cognitive processing following short-term cumulative partial sleep deprivation and recovery oversleeping. Journal of clinical and experimental neuropsychology, 2(4), 301-319.
* Pilcher, J. J., & Walters, A. S. (1997). How sleep deprivation affects psychological variables related to college students' cognitive performance. Journal of American College Health, 46(3), 121-126.
* Selvi, Y., Gulec, M., Agargun, M. Y., & Besiroglu, L. (2007). Mood changes after sleep deprivation in morningness–eveningness chronotypes in healthy individuals. Journal of sleep research, 16(3), 241-244.
> 2 votes

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Tags: intelligence, performance, sleep, mood
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# Question
Title: What are effective strategies for increasing concentration and motivation when doing seemingly passive activities such as reading journal articles?
### Background

Unfortunately I am not a specialist in Cognitive Science I am just a regular CS student who has big interest in cognitive science.

I want to share with you some interesting observation I am sure all of us familiar with it, however I wonder whether there are some researches about this observation.

As a student I have to do some kind of activities all the time it can be **reading papers**, **solving exercises**, **talking with classmates**, **thinking about problem in research**. The problem is I find all these activities very different in terms of engagement.

Let us consider **solving exercises**. This is an activity with a high level of engagement. When you do this you are very concentrated, I noticed that all my mental force are concentrated on this activity. I don't pay attention what happens around. I do hear and see people. However I don't pay attention to them, and I cannot control this state it happens unintentionally/ I wish I could go in this flow when I want, but I cannot. However I know what to do in order to get into this flow, just calm sit down get some exercises and try to solve it.

On the other hand **reading papers** has less engagement. I usually I set a goal to every day to read a paper (among all other tasks I plan to do every day) even when I don't need to read (of course there are days when I have to spend all day reading papers). The problem is when reading papers I need really quiet place, I get easily annoyed by talking people around me, the best place I found so far is library, but what really makes me crazy is not only people can shatter your peace but my mind doesn't want to concentrate on reading. I very often found myself daydreaming about something when reading paper in this case I have to reread few last paragraphs, just because my mind didn't get them.

(Some thought about academical writings)I thought, what the reason of this problem, maybe we can start to write papers in different way, let say papers without obvious conclusion and result such that to cause you to think about it to derive the conclusion by yourself, maybe the best way to write two version of papers one is open ended and the second with results.

So far, I use the following technique to be concentrated when reading papers, before reading try do something with high engagement, **solving exercise**, **programming** a while and them start reading the paper.

### Questions

* **What are effective strategies for increasing concentration and motivation when doing seemingly passive activities such as reading journal articles?**

# Answer
All truly great thoughts are conceived while walking.
~ Friedrich Nietzsche, *Twilight of the Idols*
Movement promotes cognitive performance. Either take breaks and exercise, as you already do, or set up your reading in a way that allows you to move while you read:

* take your book or paper in your hand and walk around in your room or garden while you read, or take it to the park; here is a how-to, if you need one: http://www.wikihow.com/Read-While-Walking, and you can find a lot of essays on "Reading while Walking" through Google
* some books are available as audiobooks and easy to walk or exercise to
* buy or build a standing desk and stand while you read or type; even though you don't move around much, your posture is more healthy and you need more muscle to stand than slouch, so you are in fact active in a less obvious way
* sit on a big exercise ball; similar to standing, this induces you to move around a bit more and use more of your musculature; but keep your regular chair and move back to once you get tired, because slouching on an exercise ball is even worse for your back than on a chair with a supporting back
* knead something with your hands; there are special balls and other objects for this, like therapy putty, hand exercise kits etc.
* chew gum; see Does chewing gum mentally help basketball players make foul shots?

Some of my emotional unrest while reading and writing day in, day out comes from the fact that reading and writing are lonely, unsocial activities. Being a person who feels most alive when interacting with others, I simply cannot bring myself to work at home or alone in an office. I find working in the university library to be a partial solution for my need for human company.

The quiet atmosphere doesn't distract me, the other people working there even amplify my own motivation, indeed the relaxed and quiet movements of those taking a break or picking up books gives me enough necessary distraction from my own wandering thoughts to remain focussed on my reading (similarly, I'm unable to sleep in a quiet room, I need the window open and outside sounds to listen to, for my mind to stop circling the same thoughts for many sleepless hours).

And of course you can talk and smile to the other people to the degree that you find comfortable. I often chose a place at an occupied table when I take a break in the cafeteria, smile at people that I meet on my way to the restroom, help those who look lost. At home I would eat alone and look at the wall even when I don't work.

I also like to have the window open and children playing outside. What you like, you'll surely know yourself.
> 6 votes

# Answer
**Increasing Concentration**

A method that is geared espeacially towards reading scientific texts is SQ3R. SQ3R is short for *survey*, *question*, *read*, *recite* and *review*. So instead of "just reading" a text, one is supposed to

* survey it first to grasp the basic outline by reading the abstract, introduction or table of contents
* formulate questions as to what it is that one learns from the text

After these two steps you start "really reading" the text, which is the 3R- part of the method. After reading a passage, pause and summarize what you have learned. You can be critical and evaluate the things with respect to a certain criteria (e.g.: how much evidence does the author provide?).

Maybe you don't even have to take this method too literally. You might want to switch the order of the steps a little, or only do some of the things mentioned. Thinking about my way of reading papers, I often do some of the things, but not all of them. But that is of course just my personal experience.

**Increasing Motivation**

This is maybe the harder part of your question. Goal Setting Theory (Locke & Latham, 2002) might work. According to the theory, setting a specific and challenging goal leads to better performance than a vage and easy goal. In addition, setting a *proximal learning goals* is recommended, when "the knowledge or skill for attaining a goal is unknown" (Latham & Locke, 2007, p.293). This could be appropriate for a student reading papers, as he is probably not already familiar with the material. Setting a proximal goal also goes well with the notion of reading only a small protion of the text and then summarizing it (the 3R- part from above) as opposed to a more distal goal like: "I want to understand this paper". Using Goal Setting Theory amounts to a form of extrinisc motivation. It does not necessarily get you into a flow. So maybe this is not what you wanted when you asked the question. But after all, having to read a lot of papers as a student is an externally prescribed task.

References:
<sub> Latham, G. P., & Locke, E. A. (2007). New developments in and directions for goal-setting research. European Psychologist, 12(4), 290-300. PDF
Locke, E. A., & Latham, G. P. (2002). Building a practically useful theory of goal setting and task motivation: A 35-year odyssey. American psychologist, 57(9), 705. HTML </sub>
> 8 votes

# Answer
A.I.R. == Attention. Interest. Repetition.

A.I.R. is a mnemonic for a technique. If the subject is dryasdust but you need to get over the 'getting-started-hump' or you have a busy schedule using A.I.R. in 5 to 20 minute bursts adds up quickly. The 'trick' is for those 5 minutes you force yourself to be interested in the subject at hand. Like an actor you just pretend. The mind soon follows the behavior. Once you start to unlock the 'secrets' of the subject with enforced interest, motivation usually takes care of itself.

Attention is similar in that it is much easier to concentrate if you know in advance you only have to expend the effort for a short period of time. No dread, no crushing burdens on limited time and resources. Of course, attention benefits from practice and controlling disruptions, but again, the short bursts really help overcome many of the mental roadblocks.

Repetition is the key to building strong memories and linking the learned concepts in useful ways in thought to your expanding knowledge base. A.I.R. pretty much made sure I always at least muddled through coursework I had little aptitude for and that really reduced my stress. As a student, when it got really busy I would just keep a short list of A.I.R. subjects on a post-it note. That way I was less likely to miss the opportunities that occur frequently throughout everyday for quick A.I.R sessions. A.I.R. is about being efficient. Stuck in traffic? waiting in line? empty time slot between obligations? waiting for service? on the can? ...? The brain, speaking from my experience only of course, burns copious amounts of glucose in a day and it seems to get better MPG (Miles Per Glucose) in short bursts with frequent short pitstops. The difference on the outcome for exams was always noticeable if A.I.R. was used for the days or weeks beforehand. For me the A.I.R. technique has been useful over the years for rapidly evaluating new areas of potential interest. An occasional A.I.R. session on old subjects never hurts. Just remember A.I.R.
> 0 votes

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Tags: motivation, performance, positive-psychology, attention, concentration
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# Question
Title: Which schools of psychotherapy are most credible to a hard scientist?
There is a problem in all therapies that if the client doesn't have faith or trust in the therapist then it is unlikely that anything can be achieved. Therefore effective therapy for an extreme skeptic relies on convincing them that the therapist does indeed have some talent and ability.

Consider a profile that has something akin to the following views on common therapies:

> When looking at psychotherapy and therapists the list of different "types" seems endless. On the one end, "Freudian" or "Psychoanalysis" is widely discredited quakery. Carl Jung believed in "synchronicity", which puts him firmly in the quack bin. Plenty of other therapist start talking "spirituality" and so again, sadly are filed under "not proper scientific medicine".

If someone has the above attitude to therapy and psychotherapy, what sort of therapist is going to be most credible? We are talking about finding a credible therapy for someone who would self describe as a skeptic, atheist, scientist, etc.

# Answer
For several reasons, Cognitive Behavioral Therapy (CBT) should have a good fit for someone who has a skeptic and scientific outlook on life.

1. There is a large body of research showing that **CBT is effective** (see e.g., Hofmann et al. 2012). Obviously, this also depends on the kind of disorder. And of course, other forms of therapy can be effective too. However, for some disorders, CBT may be more effective than other therapies. For example, in a recent randomized trial, CBT was more effective in treating Bulimia Nervosa (Poulson et al., 2014) than psychoanalytic therapy (the other main form of psychotherapy). By and large, most empirical evidence we have about psychotherapy regards CBT. Despite your premise that the question is not about effectiveness, I believe that **a skeptic would love that.**
2. CBT is informed by and has inspired much **basic research about the cognitive processes** that may underlie different disorders. For example, there is much research about attentional processes in affective disorders (e.g., MacLeod et al., 2002). **A skeptic should value this.**
3. Another way to frame this is to say that CBT is scientific in the sense that it is based on **testable theories and disorder models**. In contrast many concepts in psychoanalysis, such as resistance or repression may be criticized as unfalsifiable (Popper, 1963). Again, **a skeptic should prefer a more scientific therapy form**.
4. A **core technique in CBT is to question wrong beliefs and assumptions**. CBT has a very rational, thought-focused way of explaining an dealing with problems (some say overly). A central tenet of CBT is that people often hold wrong (self-defeating) beliefs about the world and that they engage in schematic thought processes (e.g. someone who has social phobia may have "catastrophizing" thoughts about how others might react to him in public and therefore avoid such situations). **Questioning such beliefs should be right up a skeptic's alley.**
5. Conducting **behavioral experiments** to collect evidence about oneself is an **important therapeutic tool in CBT** (e.g., Brennet-Levy et al. 2004). Whereas psychoanalytical approaches strongly rely on the interpretation of clients' (unconscious) conflicts, CBT encourages people to collect data about their thoughts and behaviors and to conduct experiments that clarify important questions about themselves. **Skeptics should love this facts-driven approach.**
6. Whereas psychoanalytic therapies are focused on trying to solve core, unconscious intrapersonal conflicts (brought from the past) in (mostly) long therapies, **CBT is problem- and behavior-focused and short. A skeptic should like this pragmatism of CBT**.
7. Even though your question highlights the **role of the therapist**, this is actually **not an important feature of CBT**. CBT relies on structured therapeutic manuals, and not so much on talent or personality of the therapist. In fact, CBT may be effective if conducted via the internet (Andersson et al., 2009), or even in the form of self-help books (Anderson et al., 2005). **A skeptic should value that CBT is focused on technique and not on the therapist.**

**References**

Andersson, G. (2009). Using the Internet to provide cognitive behaviour therapy. Behaviour Research and Therapy, 47, 175–180. doi:10.1016/j.brat.2009.01.010

Anderson, L., Lewis, G., Araya, R., Elgie, R., Harrison, G., Proudfoot, J., et al. (2005). Self-help books for depression: how can practitioners and patients make the right choice. British Journal of General Practice, 55, 387-392.

Bennett-Levy, J., Butler, G., Fennell, M., Hackmann, A., Mueller, M., Westbrook, D., & Rouf, K. (2004). Oxford Guide to Behavioural Experiments in Cognitive Therapy. Cognitive Behaviour Therapy: Science and Practice.

Hofmann, S. G., Asnaani, A., Vonk, I. J. J., Sawyer, A. T., & Fang, A. (2012). The Efficacy of Cognitive Behavioral Therapy: A Review of Meta-analyses. Cognitive therapy and research, 36, 427–440. doi:10.1007/s10608-012-9476-1

MacLeod, C., Rutherford, E., Campbell, L., Ebsworthy, G., & Holker, L. (2002). Selective attention and emotional vulnerability: assessing the causal basis of their association through the experimental manipulation of attentional bias. Journal of Abnormal Psychology, 111, 107–123.

Popper, K.R. (1963). Conjectures and Refutations. London: Routledge and Kegan Paul.

Poulsen, S., Lunn, S., Daniel, S. I. F., Folke, S., Mathiesen, B. B., Katznelson, H., & Fairburn, C. G. (2014). A Randomized Controlled Trial of Psychoanalytic Psychotherapy or Cognitive-Behavioral Therapy for Bulimia Nervosa. American Journal of Psychiatry, 171, 109–116. doi:10.1176/appi.ajp.2013.12121511
> 20 votes

# Answer
Cognitive Behavioral Therapy. It started as a pure-conditioning school, but it later on took on evidence from studies in cognition. It's the school that holds the most science behind it. Some of its history can be found at its wikipedia page:

> Although the early behavioral approaches were successful in many of the neurotic disorders, they had little success in treating depression.\[109\]\[110\]\[118\] Behaviorism was also losing in popularity due to the so-called "cognitive revolution". The therapeutic approaches of Albert Ellis and Aaron T. Beck gained popularity among behavior therapists, despite the earlier behaviorist rejection of "mentalistic" concepts like thoughts and cognitions.\[109\] Both of these systems included behavioral elements and interventions and primarily concentrated on problems in the present. In initial studies, cognitive therapy was often contrasted with behavioral treatments to see which was most effective. During the 1980s and 1990s, cognitive and behavioral techniques were merged into cognitive behavioral therapy. Pivotal to this merging was the successful development of treatments for panic disorder by David M. Clark in the UK and David H. Barlow in the US.\[110\] Over time, cognitive behavior therapy became to be known not only as a therapy, but as an umbrella term for all cognitive-based psychotherapies.\[109\] These therapies include, but are not limited to, rational emotive therapy, cognitive therapy, acceptance and commitment therapy, dialectical behavior therapy, reality therapy/choice theory, cognitive processing therapy, EMDR, and multimodal therapy.\[109\] All of these therapies are a blending of cognitive- and behavior-based elements. This blending of theoretical and technical foundations from both behavior and cognitive therapies constitute the "third wave" of CBT,\[114\] which is the current wave.\[114\] The most prominent therapies of this third wave are dialectical behavior therapy and acceptance and commitment therapy.\[114\]
> 3 votes

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Tags: clinical-psychology, psychoanalysis
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# Question
Title: Are you more successful if you publicly commit to pursuing a difficult goal?
If you have an ambitious goal, does it help to publicly commit to that goal? For example, if someone is training for a long distance triathlon but doesn't know whether he/she will be able to pull it off or not. This person could tell his/her friends about my goal or post it on Facebook. What consequences does it have for people, if they do that? On the one hand, it might push them more, because they don't want to be embarrassed in front of others if they fail. On the other hand, this is a pretty negative focus and might be distractive.

# Answer
Ok, I found something. Gollwitzer and colleagues (2009) have published an interesting paper on this question.

First of all, they say that, yes, publically stated intentions should lead to commitment, because the person wants to act in way that is consistent with the communicated intentions (e.g., Cialdini, Wosinka, Barrett, Butner, & Gornik-Durose, 1999). Second, public intentions should increase accountability (Lerner & Tetlock, 1999), which should also lead to an commitment effect.

However, they show that sometimes this can go wrong. Such public commitments may often be made in domains that are highly identity relevant and may thus be a means to reach some overarching goal. For example, committing to a triathlon may serve the goal of being a successful athlete. Now, **symbolically**, publicly committing to triathlon training may already help reaching this identity goal (because other people take notice of this effort). And thus ironically, it may be less necessary to **actually** reach the goal and diminish goal striving.

In line with these ideas they found that

> Identity-related behavioral intentions that had been noticed by other people were translated into action less intensively than those that had been ignored (Studies 1–3). This effect was evident in the field (persistent striving over 1 week’s time; Study 1) and in the laboratory (jumping on opportunities to act; Studies 2 and 3), and it held among participants with strong but not weak commitment to the identity goal (Study 3). Study 4 showed, in addition, that when other people take notice of an individual’s identity-related behavioral intention, this gives the individual a premature sense of possessing the aspired-to identity

I should boast with the finished triathlon on Facebook only afterwards, I guess.

**References**

Cialdini, R.B., Wosinka, W., Barrett, D.W., Butner, J., & GornikDurose, M. (1999). Compliance with a request in two cultures: The differential influence of social proof and commitment/consistency on collectivists and individualists. Personality and Social Psychology Bulletin, 25, 1242–1253.

Gollwitzer, P. M., Sheeran, P., Michalski, V., & Seifert, A. E. (2009). When intentions go public: Does social reality widen the intention-behavior gap? Psychological Science, 20, 612–618. doi:10.1111/j.1467-9280.2009.02336.x

Lerner, J.S., & Tetlock, P.E. (1999). Accounting for the effects of accountability. Psychological Bulletin, 125, 255–275.
> 8 votes

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Tags: social-psychology, motivation, goals
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# Question
Title: How valid are reaction times collected from online studies?
Online studies promise the possibility of greatly increased numbers of and variability in populations to study, but there are many potential concerns and need for validation, and diving in head first seems imprudent.

Here, I am interested in the ability to collect **response time** data online compared to a standard computer setup (e.g., a PsychToolbox or E-Prime based study with keyboard input, not a response box) in an on-site experiment booth. While these studies have their own limitations, such as being insuitable for experiments where very high fidelity RT data is critical to the study, I am merely interested in whether online studies differ significantly from them.

* **Are online RTs different from on-site RTs within tasks?**
* **Is the theoretical floor on online RTs in general different from that of on-site RTs?**

# Answer
> 12 votes
Short answer: The data is likely to be noisier, the absolute reaction time can't be trusted, but given enough power (which is easy to obtain on the Internet) relative reaction time differences should be similar to those in the lab. However, web-based reaction time studies might pose other problems, because you have less control over stimulus presentation and about how participants behave.

Long answer: There is some research that has looked at Internet-based collection of reaction time data using different software approaches. The number of papers is small, but they converge in the conclusion that there will be more noise, but that it can be quite useful depending on the specific research question.

**The effect of additional noise**

Some noise stems from the fact that hardware and software is widely different "in the wild". For example, using a JAVA - applet Eichstaedt (2001) has shown much variation in reaction times depending on different PCs. Some of this variation between computers is based on factors that add some constant to the reaction time on a specific machine. These constants don't matter if you do within-subjects reaction time comparisons as they are common in cognitive paradigms. Other factors will add random noise. For example, some keyboards only transmit responses with some frequency (e.g. every 20 ms.). Thus, the timing resolution will be bound to this limit. Also, other software running in the background may result in random noise. Nevertheless, given enough trials and enough participants this random noise may be a manageable nuisance.

In fact, using simulations, Brand and Bradley (2012) have found that adding a random 10 to 100 ms delay to response times reduced statistical power only by 1-4% across a range of different effect sizes.

Research that has compared response times collected with online and lab-technologies suggests similar conclusions. For example, using the Flash-based ScriptingRT Schubert et al. (2013, Study 1) have shown that

> the SDs of \[reaction times\] stayed below 7 ms in all three browsers. That value is comparable to many regular keyboards and standard reaction time software. In addition, the constant added by measuring in ScriptingRT was about 60 ms. This result suggests that researchers using ScriptingRT should thus focus primarily on differences between RTs and be cautious when interpreting absolute latencies.

From Study 2:

> ScriptingRT resulted in both longer response latencies and a larger standard deviation than all other packages except SuperLab and E-Prime in one configuration. Nevertheless, in absolute terms, the SD of 4.21 is comparable to what was standard for keyboards for a long time \[16\]. It is thus clear that any test with ScriptingRT should be well powered and used to assess primarily paradigms with a large effect size.

Similarly, comparing JavaScript and Flash-based data collection Reimers and Stewart (2014) concluded that, in general,

> within-system reliability was very good for both Flash and HTML5—standard deviations in measured response times and stimulus presentation durations were generally less than 10 ms. External validity was less impressive, with overestimations of response times of between 30 and 100 ms, depending on system. The effect of browser was generally small and nonsystematic, although presentation durations with HTML5 and Internet Explorer tended to be longer than in other conditions. Similarly, stimulus duration and actual response time were relatively unimportant—actual response times of 150-, 300-, and 600-ms response times gave similar overestimations.

**Replications of cognitive paradigms with online samples**

Several papers have used online data-collection to replicate well known effects stemming from lab-based research.

For example, Schubert et al. (2013) replicated the Stroop-Effect with online-vs. lab technology and found that the size of the effect was independent from the Software used. Using JAVA, Keller et al. (2009) replicate a the results of a self-paced reading paradigm from the psycho-linguistic literature. The most comprehensive replication project has been published by Crump et al. (2013) who replicate Stroop, Switching, Flanker, Simon, Posner Cuing, attentional blink, subliminal priming, and category learning tasks on Amazon's Mechanical Turk.

**Other challenges and limitations**

There are several other challenges and limitations associated with online response time collection

* A different question is the accuracy with which stimuli can presented online. There will be limits to time resolution (see, e.g., Garaizar et al. 2014, Reimers & Stewart, 2014, Schubert et al., 2013) and visual differences (color and resolution) depending on hardware and environmental light
* Often online samples will be more diverse with regards to age and education, some may have difficulties understanding difficult instructions. Also, in an online study it is easier to abandon boring RT-tasks than in the lab (Crump et al., 2013)
* Participants' hardware may be confounded with other variables, thus that there might be confounds in the absolute reaction times because a systematic RT constant may added to certain demographic groups. This is not a problem for reaction time differences within participants. However, correlations of absolute reaction times with personality variables may be spurious (as warned by Reimers and Stewart (2014)

**References**

Brand and Bradley (2012). Assessing the Effects of Technical Variance on the Statistical Outcomes of Web Experiments Measuring Response Times. Social Science Computer Review, 30, 350–357. doi:10.1177/0894439311415604

Crump, M. J. C., McDonnell, J. V., & Gureckis, T. M. (2013). Evaluating Amazon’s Mechanical Turk as a Tool for Experimental Behavioral Research. PLoS ONE, 8, e57410. doi:10.1371/journal.pone.0057410

Eichstaedt, J. (2001). An inaccurate-timing filter for reaction time measurement by JAVA applets implementing Internet-based experiments. Behavior Research Methods, Instruments, & Computers, 33, 179–186. doi:10.3758/BF03195364

Garaizar, P., Vadillo, M. A., & López-de-Ipiña, D. (2014). Presentation Accuracy of the Web Revisited: Animation Methods in the HTML5 Era. PLoS ONE, 9, e109812. doi:10.1371/journal.pone.0109812

Keller, F., Gunasekharan, S., Mayo, N., & Corley, M. (2009). Timing accuracy of Web experiments: A case study using the WebExp software package. Behavior Research Methods, 41, 1–12. doi:10.3758/BRM.41.1.12

Reimers, S., & Stewart, N. (2014). Presentation and response timing accuracy in Adobe Flash and HTML5/JavaScript Web experiments. Behavior Research Methods, 1–19. doi:10.3758/s13428-014-0471-1

Schubert, T.W., Murteira, C., Collins, E.C., Lopes, D. (2013). ScriptingRT: A software library for collecting response latencies in online studies of cognition. PLoS ONE 8: e67769. doi:10.1371/journal.pone.0067769

# Answer
> 7 votes
There are a few factors that could contribute to differences between online versus in-lab reaction time measurement.

**Hardware variation**

Participants in an online experiment will use their own computers to complete the task, which will result in lots of variation in hardware. Many studies have looked at how hardware variations affect response time measurement, and generally find that hardware variations can cause differences in the range of 10-100ms for a single response (e.g. Plant & Turner, 2009).

**Software variation**

Online studies and lab studies tend to be conducted with different software, since most of the standard lab-based software can't be used to make an online experiment. A popular option for online experiments is JavaScript & HTML. Reimers & Stewart (2014) measured the error in JavaScript response time measurements, and generally found it to be around 25ms, with some variation across different hardware and software. de Leeuw & Motz (2015) ran an experiment in which subjects completed a visual search task in the lab using both a JavaScript and MATLAB (Psychophysics Toolbox) version of the experiment, and found that JavaScript measured response times that were about 25ms slower. However, both JavaScript and MATLAB had equivalent variance in the measurements and both software systems were equally sensitive to experimental manipulations of the visual search task at the sample sizes used for the experiment.

**Online versus in the lab**

Hilbig (in press) randomly assigned participants to complete an experiment in the lab using standard lab software (E-prime), in the lab using a web browser, or online at a location of the participant's choice. They measured response times in a standard lexical decision task, and found that there were no significant differences among the three groups. The effect was on the order of 120-220ms. The effect is relatively large (d' ~ 1.5), but given the current literature there is no reason to doubt that it would.

**Does it matter?**

The last part of the answer is: does it really matter if response times collected online are noisier than those collected in the lab? It turns out that even for pretty noisy measurements, moderate sample sizes will counteract the additional noise of the measurement. Reimers & Stewart (2014) simulated the sample size necessary to find an effect of 50ms with and without the additional noise in response times caused by using online methods. They found that only about 10% more subjects were needed in their model to have an equivalent likelihood of detecting the effect. Ulrich & Giray (1989) came to a similar conclusion in a different modeling context.

**References**

* de Leeuw, J. R., & Motz, B. A. (2015). Psychophysics in a Web browser? Comparing response times collected with JavaScript and Psychophysics Toolbox in a visual search task. *Behavior Research Methods*. doi:10.3758/s13428-015-0567-2
* Hilbig, B. E. (in press). Reaction time effects in lab- versus web-based research: Experimental evidence. *Behavior Research Methods*. doi:10.3758/s13428-015-0678-9
* Plant, R., & Turner, G. (2009). Millisecond precision psychological research in a world of commodity computers: new hardware, new problems? *Behavior Research Methods*, *41*(3), 598-614.
* Reimers, S., & Stewart, N. (2014). Presentation and response timing accuracy in Adobe Flash and HTML5/JavaScript Web experiments. *Behavior Research Methods*
* Ulrich, R., & Giray, M. (1989). Time resolution of clocks: Effects on reaction time measurement - Good news for bad clocks. *British Journal of Mathematical and Statistical Psychology*, *42*, 1-12.

# Answer
> 3 votes
We cover a discussion on this in an article we've submitted for peer-review. Here is the preprint.

I will cite this stackExchange question/answers in the manuscript (post peer review now) as there are some lovely discussions going on, and doubtless, more to follow.

Tangentially relevant to this discussion is a simulation we did in the paper exploring how not knowing screen refresh impacts on stimulus timing (consider that if RT *starts* being recorded from a stimulus presentation, error in stimulus timing mucks around with RT):

> We tested this appearance issue in a simulation where we varied the duration of visual stimulus, starting at a random time during the refresh cycle (10,000 virtual presentations per stimulus duration). Figure 5 shows the likelihood of short duration stimuli being shown at all, or being shown for the wrong duration, or starting / stopping at the wrong time (https://github.com/andytwoods/refreshSimulation; available to run / tweak online here http://jsfiddle.net/andytwoods/0f56hmaf/).

Below is the abstract:

> This article provides an overview of the literature on the use of internet-based testing to address questions in perception research. Internet-based testing has several advantages over in-lab research, including the ability to reach a relatively broad set of participants and to quickly and inexpensively collect large amounts of empirical data. In many cases, the quality of online data appears to match that collected in laboratory research. Generally speaking, online participants tend to be more representative of the population at large than laboratory based participants. There are, though, some important caveats, when it comes to collecting data online. It is obviously much more difficult to control the exact parameters of stimulus presentation (such as display characteristics) in online research. There are also some thorny ethical considerations that need to be considered by experimenters. Strengths and weaknesses of the online approach, relative to others, are highlighted, and recommendations made for those researchers who might be thinking about conducting their own studies using this increasingly-popular approach to research in the psychological sciences.

# Answer
> 1 votes
Depending on how you collect the data, reaction times collected "online" will likely be different from those collected "on-site". When considering reaction times, it is important to decide if the reaction time is being used as a trigger, as the time to a response, or the difference in the time to response.

Consider an experiment which displays a random series of images for a 1/2 second each and the analysis consists of averaging the images that resulted in key presses. If your online system introduces a 1 s delay, you will not be averaging the images that led to the keypress, but the random image after it.

Consider an experiment which displays a random series of images for a 1/2 second each and every once in a while a target image is displayed and the analysis focuses on average amount of time it takes to react to the target image. In this case your reaction time will be 1 second longer than it should be and your data will be effectively meaningless.

Consider an experiment which displays a random series of images for a 1/2 second each and every once in a while one of two target images is displayed and the analysis focuses on difference in the average amount of time it takes to react to the target image. In this case the reaction time to each target will be 1 second longer than it should be, but the difference in reaction will be accurate. If in this experiment, in addition to the 1 s delay, there is also a variable delay (e.g., a Gaussian jitter with mean 0 and variance 1 s). This jitter will add noise to the data and make seeing small difference difficult. This noise, however, will average out across the trials and participants.

As with most psychological measures, the experimenter can trade fidelity of the measurement, number of measurements on each participant, and number of participants against each other. Online studies give up fidelity, and to an extent number of measurements on each participant, for large numbers of participants.

In a lab with a dedicated button box on fast dedicated hardware response latencies of under 1 ms are possible with tiny jitters. This of course ignores the human subject making the response. Wagenmakers et al (2005) suggest jitter of about 100 ms in the best case. Adding keyboard and network jitter of 100 ms (which would be pretty bad) means the online experiment would need 2x increase in the number of subjects to have the same statistical power; if the variance is twice as big (which happens when you add two independent sources of noise with equal variance), you need an N 2 times bigger to have the same standard error of the mean.

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Tags: measurement, experimental-psychology, methodology, internet
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# Question
Title: What are the practical uses of ontologies?
I have read many papers and books about ontologies, and I am trying to figure out that how they are used in a real project. For example, how can the ontology for a soccer player robot can be defined and used with a cognitive architecture in order to make it intelligent?

Are ontologies relations between terms in that domain of knowledge (for example relation between the ball and foot word, and physical rules definition and their relation with the foot and ball movement) or relations between tactics, strategies and different mixture of tactics?

Are there any clear examples of ontology usage in real projects and their combining usage with the cognitive architectures like ACT-R for augmenting the cognitive architecture?

# Answer
> 3 votes
Interesting question. "Ontology" is often used in confusing and polyvalent ways, so let's start by clearing up the terminology very quickly for those who aren't intimate with the various different meanings.

## What does "ontology" mean?

Broadly, *ontology the field* is the philosophical study of being. *An ontology* is a method for establishing what beings or entities *may* exist (cf. epistemology's whether we should believe they exist), how they may be grouped, and the relations they may have.

In information and computer science, "ontology" is used in a related, but not identical sense to refer to formally defined sets of types, properties and the relationships between them. To answer your question, then, relations compose *part* of an ontology, but ontologies do not comprise sets of relations and nothing but sets of relations. From the Wikipedia page:

> **An ontology is a description (like a formal specification of a program) of the concepts and relationships that can formally exist for an agent or a community of agents.** This definition is consistent with the usage of ontology as set of concept definitions, but more general. And it is a different sense of the word than its use in philosophy. -- Tom Gruber, Toward Principles for the Design of Ontologies Used for Knowledge Sharing.

<sub>(Gruber updated the definition in 2007, but it is not so much different as an extension.)</sub>

## Ontologies and ACT-R

ACT-R defines a basic ontology with the entities **modules, buffers and pattern-matchers**, ways to group entities within their type (e.g., **perceptual-motor vs. memory modules**), and the relations between them.

We use ontologies to abstract away from particular data structures. The **ACT-R cognitive architecture both implies and specifies an ontology, and we can use that ontology to extend ACT-R, or make ACT-R talk to other architectures** which may not have any data structure overlap with ACT-R. Oltramari et al. (2014) provides an apt concrete ("real"?) example. They coupled ACT-R to the SCOPE knowledge management system, where they use concrete information science ontologies in order to extend ACT-R to use abstract philosophical ontologies.

> In general, ACT-R models only employ as much knowledge as required to perform well-defined cognitive tasks. By and large, they can be seen as “monadic” agents, whose knowledge bases are limited, partially reusable and sporadically portable across experimental conditions. On the contrary, in order to replicate high-level contextual reasoning and pattern recognition in humans, large amount of common-sense knowledge should be available to ACTR: **to overcome these limitations, we propose to equip ACT-R with a specific module for processing ontologies \[philosophical sense\], i.e. semantic specifications of a given domain or application (Guarino, 1998) \[information science sense\]**, which are generally used in combination with inference engines for deductive reasoning. Since the ACT-R declarative module supports a relatively coarse-grained semantics based on slot-value pairs, and the procedural system is not optimal to effectively manage complex logical constructs, a specific extension is needed to make ACT-R suitable to fulfill knowledge-intensive cognitive tasks like context-driven spatial reasoning. Accordingly, **we engineered an extra module as a bridging component between the cognitive architecture and an external knowledge-base system KBS, SCONE** (Fahlman, 2006).

## References

* Oltramari, A., Vinokurov, Y., Lebiere, C., Oh, J., & Stentz, A. (2014, March). Ontology-Based Cognitive System for Contextual Reasoning in Robot Architectures. In 2014 AAAI Spring Symposium Series.

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Tags: cognitive-modeling, computational-modeling
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# Question
Title: What is the most comprehensive model of executive control?
Wikipedia has a nice summary of the various models of executive function, but what is the most comprehensive one? That is, the one that accounts for the most cognitive variations among subjects and can be applied to the most tasks.

# Answer
Currently, **the most comprehensive cognitive model of executive functions would have to be the model proposed by Miyake et al. (2000)**.

<sub>(It is probably best not to confuse being *the most comprehensive cognitive model* with being a *strong explanation*, because the executive functions remain one of the most poorly understood areas of cognition, but it's a very *useful* model.)</sub>

## Miyake-Friedman Model

> This individual differences study examined the separability of three often postulated executive functions—**mental set shifting (“Shifting”), information updating and monitoring (“Updating”), and inhibition of prepotent responses (“Inhibition”)**—and their roles in complex “frontal lobe” or “executive” tasks.

This influential model has engendered thousands of papers applying it to explain many different findings and domains. Psychometric research using confirmatory factor analysis (Duan, Wei, Wang and Shi, 2010) found support for three shifting, updating and inhibition factors, and Friedman et al. (2006) reported evidence for the factors' discriminant validity by comparing it with the Wechsler IQ scale. Practical support for the model has also come from research on ADHD, as reviewed in Wilcutt et al. (2005), and attentional problems in school settings (Friedman et al., 2007).

Finally, the NIH Toolbox Cognition Battery also includes an executive functions test informed by the Miyake and Friedman model, which recently received strong support in a review by Zelazo et al. (2013):

> In the current study, **we sought to assess the reliability and validity of new measures of EF and attention that are part of the NIH Toolbox CB**. New versions of the DCCS and the flanker task were designed to provide assessments of two aspects of EF, cognitive flexibility (Toolbox DCCS) and inhibitory control in the context of visual selective attention (Toolbox Flanker). Together with a separate measure of working memory (see Tulsky et al., Chapter 5, this volume), **these measures capture the three aspects of EF identified by Miyake et al. (2000)** in their work with adults.
>
> Overall, **results reveal excellent developmental sensitivity across childhood, excellent test–retest reliability, and excellent convergent validity (except for the Toolbox Flanker, which showed adequate convergent validity among 8–15 year olds).** Correlations between the new NIH Toolbox measures and corresponding convergent measures were generally quite high, although for younger children, they were higher for the DCCS than for the flanker measures.

**Overall, the tripartite Miyake and Friedman model is extremely well-supported by both the literature and praxis.** If a more comprehensive cognitive model of executive function exists, I am not aware of it.

## References

* Duan, X., Wei, S., Wang, G., & Shi, J. (2010). The relationship between executive functions and intelligence on 11-to 12-year-old children. Psychological Test and Assessment Modeling, 52(4), 419-431.
* Friedman, N. P., Haberstick, B. C., Willcutt, E. G., Miyake, A., Young, S. E., Corley, R. P., & Hewitt, J. K. (2007). Greater attention problems during childhood predict poorer executive functioning in late adolescence. Psychological Science, 18(10), 893-900.
* Miyake, A., Friedman, N. P., Emerson, M. J., Witzki, A. H., Howerter, A., & Wager, T. D. (2000). The unity and diversity of executive functions and their contributions to complex “frontal lobe” tasks: A latent variable analysis. Cognitive psychology, 41(1), 49-100.
* Willcutt, E. G., Doyle, A. E., Nigg, J. T., Faraone, S. V., & Pennington, B. F. (2005). Validity of the executive function theory of attention-deficit/hyperactivity disorder: a meta-analytic review. Biological psychiatry, 57(11), 1336-1346.
* Zelazo, P. D., Anderson, J. E., Richler, J., Wallner‐Allen, K., Beaumont, J. L., & Weintraub, S. (2013). II. NIH toolbox cognition battery (CB): measuring executive function and attention. Monographs of the Society for Research in Child Development, 78(4), 16-33.
> 2 votes

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Tags: cognitive-psychology, cognitive-modeling, executive-function
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# Question
Title: Is there scientific evidence that narcissists cannot be treated?
I've often heard that people affected by narcissism cannot recover.

I can understand that it's a long path and that a narcissist may lack the motivation and so on, but I wonder why cognitive therapy (for example) should be ineffective towards this kind of pathology.

Are there statistics on the treatment of narcissists?

# Answer
> 7 votes
It appears you have heard correctly, at least in a sense: **there are no peer reviewed treatments for narcissistic personality disorder** (NPD) itself. On the other hand, **this does not constitute evidence that narcissists cannot be treated**, either.

A review of the NPD literature by Dhawan, Kunik, Oldham and Coverdale (2010) reported an absence of evidence one way or another in no uncertain terms:

> To determine the most efficacious treatments for NPD without other comorbidities, we performed searches using Narcissis\*, pharmacology, clinical pharmacology, therapeutics, and psychotherapy for reports of controlled trials from January 1980 to August 2008. \[...\] We identified 7 prevalence studies that had used a structured or semistructured interview, 5 of which scored 5/6 using the epidemiologic quality tool. Mean prevalence was 1.06%, and the range was 0% to 6.2%. **We found no studies of treatment meeting our inclusion criteria.**

The prevalence numbers refer to how many people satisfied the DSM-IV-TR NPD criteria. The epidemiological quality tool referred to is defined as follows:

> Articles received 1 point for each of the following: surveying a national population (because personality disorders are more prevalent closer to city centers, this disparity could influence locally obtained samples), obtaining a sample that was representative of the population being surveyed, accounting for nonrespondents, using a valid diagnostic instrument, having adequate training of interviewers, and assessing reliability. Assessment of the above criteria was determined after each question for each study was independently rated by each author. Then the authors met twice and came to a consensus regarding the scoring of each question.

My own review of the 2009-2015 literature did not find any new developments. There simply does not appear to be any treatment studies for NPD, efficacious or otherwise.

## References

* Dhawan, N., Kunik, M. E., Oldham, J., & Coverdale, J. (2010). Prevalence and treatment of narcissistic personality disorder in the community: a systematic review. Comprehensive psychiatry, 51(4), 333-339.

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Tags: abnormal-psychology, clinical-psychology
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# Question
Title: Are presence questionnaires valid in a between-subjects design?
Usoh et al. (PDF) applied presence questionnaires (which are usually designed to measure one's feeling of presence in a virtual environment) in both a virtual and a real world environment in a between-subjects design and found no difference in people's sense of presence between the two environments.

While the authors only argue that presence questionnaires are not valid unless they pass a "reality check", i.e. participants self-report a higher feeling of presence in the real environment, *in my opinion*, results might have been very different if they had employed a within-subjects design, exposing participants to both environments and thereby arriving at a relative sense of presence score for each environment.

If this were true, it would imply that such questionnaires are essentially not applicable in between-subject designs, as people would only be able to reliably rate their sense of presence in a particular environment relative to another environment. Hence I've recently asked whether it is valid to treat repeated measures data as both within- and between-subject data and compare the analysis of both to see if there are differences.

But my underlying assumption was questioned by some of the answers, and I posted a follow-up question to ask if it ever makes sense for between- and within analyses of the same data to differ.

> By way of a very contrived example, assume I get subjects to rate on a scale of 1 to 10 how much they like an offer of free beer. In one condition, people are offered one litre of beer for free, in the second condition, people are offered two litres of beer for free. If I ran this experiment with a between-subjects design, I would personally assume that there isn't any discernible difference between the two conditions, because - hey, free beer! But as a within-subjects design, I think I stand a reasonable chance of seeing an effect, because more free beer is better than less free beer.

One comment has asked for the question to be migrated to here so, to give the whole thing a more cog-sci spin, my intent here is to question my (admittedly intuitive) assumption that people can not relate their absolute sense of presence to a number from 1-7, but can relate their relative sense of presence compared to another environment. Is there any research other than Usoh's paper on presence in particular, or are there similar phenomenon in other measurement instruments?

# Answer
The underlying question here is: **Does the context of a questionnaire affect the answer?**

I think you already answered the question yourself. **Yes it does**.

Let's make the comparison even more extreme:

1. Please rate on a scale of 1 (not at all) to 7 (very) how happy you would be if you won 1 million dollars because you were the 1 millionth customer of a super market.
2. Please rate on a scale of 1 (not at all) to 7 (very) how happy you would be to win 100 dollars because you were the 1 millionth customer of a super market.

Now imagine you would have been asked only the second question. Will the answer on the second question be affected by the fact that there was question 1? Very likely.

For an excellent introduction to research about such context effects and other survey-related phenomena check out "Self-reports: How the questions shape the answers." by Norbert Schwarz (1999).

Schwarz summarizes several ways in which ***pragmatic* aspects** of questions affect answers in questionnaires. There is an important distinction with regard to how people construct the meaning of such questions. On the one hand, there is the literal meaning of the question, its semantic content. On the other hand, there is also the pragmatic meaning of a question, which involves an assessment about the intention of the person (the researcher) who has asked the question. (What is implied? Also called the implicature). To infer this pragmatic meaning, people rely on several communication norms or "maxims" (Grice, 1975).

The maxim that is most relevant here is the **maxim of relation**:

> a maxim of relation enjoins speakers to make their contribution relevant to the aims of the ongoing conversation. In research situations, this maxim licenses the use of contextual information in question interpretation and invites respondents to relate the question to the context of the ongoing exchange. (Schwarz, 1999, p. 94)

So in the context of question 1 (1 million dollars/presence in environment 1/2 liters of free beer), the pragmatic meaning of question 2 (100 dollars/presence in environment 2/1 liters of free beer) may be interpreted as comparative (compared to the first option, who much do you like it?) and the answer may be different that than when it is asked in isolation.

Another way in which the context may affect the answer is that the implied meaning of the scale anchors change (What means "very happy" vs. "not at all happy"?). An example of research that has investigated such issues is the research on **shifting standards** in stereotyping (e.g. Biernat & Manis, 1994). For example, if you judge woman X with regard to aggressiveness, she may be rated as "highly aggressive" in the context of other women (because the stereotype is that women are low in aggressiveness). However, if the question is asked in the context of men, she might be rated lower in terms of aggressiveness (also because of the stereotype that women are less aggressive). The point is that the inferred meaning of the scale anchor "very aggressive" changes based on the context the question is asked in.

**References**

Biernat, M., & Manis, M. (1994). Shifting standards and stereotype-based judgments. Journal of Personality and Social Psychology, 66, 5–20. doi:10.1037/0022-3514.66.1.5

Grice, H. P. ( 1975). Logic and conversation. In P.Cole & J. L.Morgan ( Eds.), Syntax and semantics: Vol. 3. Speech acts (pp. 41– 58). New York: Academic Press.

Schwarz, N. (1999). Self-reports: How the questions shape the answers. American Psychologist, 54, 93–105. doi:10.1037/0003-066X.54.2.93
> 5 votes

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Tags: measurement, survey
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title: Why "fractional" anisotropy?

text:
# Question
Title: Why "fractional" anisotropy?
Why is Fractional Anisotropy (FA), a measure in diffusion tensor imaging, called "fractional"? I'd have thought "local", i.e. voxel-wise, would have been the correct way to qualify the anisotropy that is calculated from the tensor model, so why fractional?

# Answer
> 3 votes
Like *lea*'s comment indicated, FA is called "fractional" anisotropy simply because it's the degree of anisotropic diffusion, i.e., a ratio (Soares, Marques, Alves and Sousa, 2013).

> Fractional Anisotropy is **a normalized measure of the fraction of the tensor's magnitude due to anisotropic diffusion**, corresponding to the degree of anisotropic diffusion or directionality and ranges from 0 (isotropic diffusion) to 1 (anisotropic diffusion).

**References**

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Tags: measurement, neuroimaging, fmri
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# Question
Title: How valid is Lumosity's Brain Performance Index and what normative information is available?
### Background

There is a test called Lumosity's Brain Performance Index. A sample profile of scores might be:

```
Speed           680
Memory          707
Attention       277
Flexibility     304
Problem Solving 900
Overall BPI     573

```

I'm interested in how to interpret a profile of scores.

### Questions

* What validity information is available for the BPI?
* What normative information is available for BPI? In other words, how could the sample profile of scores be interpreted both absolutely and relative to other groups of people?

# Answer
**General thoughts on brain training**: Lumosity is a commercial tool that aims to improve brain functioning. In general, I am sceptical of the potential for "brain training programs" to improve cognitive functioning in a generalised way (e.g., see this Nature discussion). Practice is powerful, but tends to be domain specific. So if you want to become skilled in brain training tasks, then do brain training exercises, but if you want to become skilled in a particular domain of life, then study and get experience in that domain. While I can see the value in researching the topic, I can also see the potential for sellers of "brain training" programs to exploit people's concerns about their mental shortcomings or about fears of mental deterioration with ageing.

**Normative data**: From what I can gather from this review, Lumosity has lots of normative data based on existing users which you can use to compare your performance. However, I imagine this is proprietary information that they would be reluctant to publish in a useful form.

There was an unpublished report I found by Cruz et al based on a small sample of young adults. The following summarises Table 2:

```
Number of days        4.75 ± 3.18
Number of sessions    10.79 ± 9.31
Median (IQ R )        9.00 (2.25‐17.75)
Minimum‐Maximum       0 ‐ 34
Overall BPI           676.93 ± 323.94
Lumosity points     173.43 ± 158.89

```

**Validity of the BPI**: The website writes:

> Your Overall BPI is your average BPI across each of the four cognitive areas: attention, memory, processing speed and cognitive control.

It also states

> "We then evaluate your game scores and use a proprietary algorithm to derive your BPI"

Performance on almost all cognitive tasks are intercorrelated to some extent, and if you take the average, or preferably the first principal component, of a battery of cognitive tasks, it will tend to have a general factor, which will have some loading on g. Of course, if the tests are of a particular type, this might lead to different outcomes.

I could not find any validity data on the website whereby BPI scores are correlated with other measures. Thus, it is unclear what relationship BPI has with other ability measures, or IQ for example.

In general, practice effects on cognitive tests are seen as a source of error variance. What a test measures after people have taken the test many times may be very different. In particular, the degree to which the test correlates with a domain general quality of interest may be reduced. Instead, the test may start to reflect a domain specific adaptation. Also, if people differ in the amount of practice, this would compound the measure of a domain general ability.

**Overall thoughts**: In general, the target market for Lumosity's product seems to be consumers. In contrast, tests like the WAIS or the CANTAB have a target market which is researching and applied psychologists. In the consumer market, it is typical for companies to use "proprietary algorithms" and for there not to be a test manual with extensive validity data. While this might make commercial sense, it limits the scientific value of such instruments.

### References

* Cruz, A., Canelas, A., Machado, F., Pedreira, J., Barroso, J., Beir\\~ao, L., Freitas, L., Belo, L., Seabra, M., Portero, M. & others (). Brain Fitness--Clinical Trial to Measure the Effect of Cognitive Training in Brain’s Capabilities. PDF
> 27 votes

# Answer
Because it has been a few years since Jeromy's original answer, and because I just read a very apt article, I will venture an update on the state of the field with respect to the BPI's validity. Overall, despite more research into brain training and Lumosity, there is little to no peer-reviewed evidence supporting the Lumosity BPI's validity, nor evidence that an average consumer should expect practical cognitive improvements from Lumosity games.

## Testing the BPI

A very recent test of the BPI's validity was published by Shute, Ventura and Fe (2015), who compared participants practicing *Portal 2* with participants practicing *Lumosity* games; the Lumosity players served as active controls. Portal 2 measures included (1) total number of levels completed, (2) average number of portals shot, and (3) average time to complete levels; Lumosity was measured by BPI. They reported no evidence of transfer effects for measures of either problem solving or spatial abilities in the Lumosity condition, and partial support for transfer in the Portal 2 condition only on spatial abilities.

> Hypotheses 2 and 3 test pretest to posttest gains on specific problem solving and spatial test scores within each condition. We computed paired t-tests for each measure in each condition. For hypothesis 2 (problem solving gains), we found no significant gains for the Portal 2 condition, from pretest to posttest, for any specific problem solving measure. **We also did not find any significant pretest-to-posttest gains for the Lumosity condition across any of the problem solving measures.** Results provide partial support for hypothesis 3 (spatial gains). Participants in the Portal 2 condition showed pretest to posttest improvement on the MRT, t(1, 39) = −1.80, p \< .05; Cohen's d = .30 under a one-tailed test. Additionally, Portal 2 players' VSNA scores significantly differed from pretest to posttest, t(1, 40) = 2.42, p \< .05; Cohen's d = .44. There was no significant improvement for Portal 2 players on the SOT test. **For participants in the Lumosity condition, there were no significant pretest-to-posttest improvements on any of the three spatial tests.**

## Brain training

A rigorous study by Redick et al. (2013) suggested that the initial research on brain training generally, and thus the basis for Lumosity (mentioned by name in the paper), may have been compromised by design limitations and lack of theoretical grounding, and criticizes those studies for struggling to adequately explain often mixed results. They reported three relevant findings from their own validation study of dual *n*-back working memory training:

> Our study yielded three main findings. First, subjects improved with practice on both the dual n-back and visual search tasks. Second, training group subjects showed no transfer to any of the ability measures, in keeping with the prediction outlined in Figure 4D. Third, dual n-back trained subjects reported subjective improvements in various aspects of cognition in the absence of any objective evidence for change.

## Concluding remarks

The jury is still out on brain training more generally and on when, where and whether it may be useful (e.g., Deveau et al., 2014; Mayas, Parmentier, Andrés and Ballesteros, 2014). However, the Lumosity BPI appears to have little to no scientific validity as a cognitive training method for average consumers.

## References
> 9 votes

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Tags: cognitive-psychology, intelligence, test, brain-training
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# Question
Title: Is the weight of neural inputs in the human brain as central as it is for neurons in an artifical neural network?
As an example of an artificial neural net (ANN), a neural processing unit (NPU) is able to encode previous (learned) information by storing a weighted resistance for each input. Since ANN's are biologically inspired, I was wondering whether the neurons in the human brain also have a mechanism to set the resistance for electrical current that flows through the neuron. If not, how is information (long term storage) encoded in the brain (for example, a familiar word like "house")?

# Answer
> 4 votes
The general biological term for this kind of mechanism is synaptic plasticity. Synapses are the biological structure that allow neurons to communicate via the exchange of neurotransmitters. The strength of the synapse (the effectiveness of the link between the neurons) can be modified over time.

One important kind of modification is long-term potentiation, first reported by Bliss and Lømo in 1973. They demonstrated that short term bursts of activity in a neural pathway can cause long term augmentation of the post-synaptic response. In artificial neural network terms, they were able to demonstrate something akin to an increase in the connection strength between two neurons.

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Tags: neuroscience, neural-network, electrophysiology
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# Question
Title: What is the phenomenon that one can recognize a movie after seeing a scene for a fraction of second called?
I have experiences that while I was walking around the street, I saw a scene on a TV for a fraction of second, and I instantly recognized the correspondent movie. This is very interesting since at the time I didn't fully comprehend what I saw, but the name of movie came up anyway.

What is this very fast recollection phenomenon called? What is the type of memory involved? Where can I learn more about this cognitive function?

# Answer
> 3 votes
The subliminal recollection is called involuntary memory retrieval.

This triggers an implicit memory.

Further reading:

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Tags: perception, memory
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# Question
Title: Spontaneity as object of investigation in the cognitive sciences
What are known studies, experiments, thoughts and literature on spontaneity? I am looking for anything relating to questions like "What does it mean for someone to be spontaneous?" or "What factors are involved in being spontaneous?" or anything else.

EDIT: aspects of creativity, improvisation in the arts are not meant, but spontaneity in the way of life or in daily behavior. Excuse being unprecise.

I appreciate any hints.

# Answer
These should get you started, relating to spontaneous behaviour of humans in society, in contrast to normality behaviour:
> 4 votes

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Tags: reference-request, terminology
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# Question
Title: What cognitive processes occur during a mental exhaustion or 'burnout'?
Mental burnout - or mental exhaustion is not very pleasant, when one feels completely overwhelmed, something 'snaps' and it is hard to concentrate and maintain motivation. What are the cognitive processes that occur during a burnout? What processes allow for recovery?

# Answer
> 7 votes
One of the older theories suggested that a person literally runs out of brain-fuel when they hit the wall (Baumeister et al, 1998). They called this state "ego depletion" and it refers to the kind of mental burnout you are talking about. There is currently a lot of research activity on this topic because we (psychologists) assumed for over a decade that some resource was depleted in the brain but have found no evidence for any such resource. Newer theories suggest that people go through a kind of motivational cycle in which people tend to approach longer-term goals with delayed rewards (e.g., doing homework) for some period of time, followed by pursuit of shorter-term goals with immediate rewards (e.g., eating, leisure, etc.; see Kurzban et al, 2013 for a great discussion).

Thus, people with high self-control are people who spend relatively more time engaging in "labor" and impulsive people spend relatively more time pursuing leisure. The cyclical nature of motivation has clear adaptive qualities and the burnout that you feel after working for long periods is thought to be your brain doing exactly what it is designed to do: keep you from neglecting short term goals which are/were just as essential for survival as long-term goals. This is in direct contrast with the brain-fuel idea, which models burnout as self-control failure. See the Inzlicht article for a critique of brain-fuel models.

One interesting area of work that is related to all of this comes from the ADHD literature. The drugs developed to treat ADHD have demonstrated a clear connection between dopamine activity in the frontal lobes and the ability to persist in pursuing labor goals. It might be tempting to think that dopamine is the phantom brain-fuel we've been looking for, but note that the brain has no problem producing dopamine (i.e., it doesn't "run out"). Nobody has really pursued this, but it will be interesting to see how psychologists integrate the role of dopamine and frontal lobe functioning into self-control models. The Barkley reference below is an old one, but it is a good review of ADHD research that is relevant to this topic.

Barkley, R. A. (1997). Behavioral inhibition, sustained attention, and executive functions: constructing a unifying theory of ADHD. Psychological bulletin, 121(1), 65.

Baumeister, R. F., Bratslavsky, E., Muraven, M., & Tice, D. M. (1998). Ego depletion: is the active self a limited resource?. Journal of personality and social psychology, 74(5), 1252.

Inzlicht, M., Schmeichel, B. J., & Macrae, C. N. (2014). Why self-control seems (but may not be) limited. Trends in cognitive sciences, 18(3), 127-133.

Kurzban, R., Duckworth, A., Kable, J. W., & Myers, J. (2013). An opportunity cost model of subjective effort and task performance. Behavioral and Brain Sciences, 36(06), 661-679.

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Tags: cognitive-psychology, cognitive-neuroscience, stress, mental-exhaustion
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# Question
Title: How to measure precision in classical test theory framework?
What methods or approaches exist or might be developed to measure precision of measurement in a classical test theory framework? *Standards for Educational and Psychological Testing* (American Psychological Association, 2014) talks about precision of measurement in several places, but does not seem to provide any references.

Also, to what extent is precision of measurement in IRT theory similar to or different from absolute agreement in score (as opposed to inter-rater reliability or test reliability as measured by alpha) in CTT?

# Answer
# 'Precision' in classical test theory

Most accounts of classical test theory do not have a notion of precision as such, but occasionally, *reliability* may be called precision instead. The relationship is probably most concisely illustrated with the standard dartboards. This is also explained on the Wikipedia Item Response Theory page, but as you can see, in CTT, precision is to reliability what accuracy is to validity.

<sub>(Wikipedia Reliability article juxtaposed with a Tufts University guide.</sub>

## Origin of 'precision' in classical test theory

Cronbach (1951) suggested Coombs (1950) as the origin of the reliability/precision confusion.

> Coombs (6) offers the somewhat more satisfactory name "coefficient of precision" for this index which reports the absolute minimum error to be found if the same instrument is applied twice independently to the same subject. A coefficient of stability can be obtained by making the two observations with any desired interval between. A rigorous definition of the coefficient of precision, then, is that it is the limit of the coefficient of stability, as the time between testings becomes infinitesimal.

I'm not entirely sure if I'm interpreting the secondary question right, but IRT precision is a measure of precision under IRT, and ICC is a measure of reliability under CTT. The main difference is that CTT expresses reliability as a single value, while IRT expresses precision for different values of the underlying trait. This isn't specific to absolute agreement, though, so maybe I'm misunderstanding.

## References
> 3 votes

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Tags: measurement, methodology, test, statistics, reliability
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title: Reading words without pronunciation

text:
# Question
Title: Reading words without pronunciation
I have been trying to practice speed reading, and found the removal of subvocalization technique, but it seems almost impossible to understand words without pronouncing them in my head.

I think our brain is wired in a way that words are first converted in speech, and then we really understand them. Is it possible to rewire the brain to skip the speech process and start understanding words without experiencing a voice in head?

So far, I have come across the following exercises:

* Keep your speech centre busy while reading (e.g., keep repeating "1,2,3,4" or "a,e,i,o,u" in head while trying to understand what words mean).
* Think by visualizing words in your head without sound.
* Visualize the name of the object or action seen, without pronouncing it.

So far, I have made no progress, but this might be more difficult than learning a new language. Maybe I need to be patient and keep practicing these, but are there other better methods, exercises?

# Answer
Your initial intuition, that eliminating subvocalization makes understanding more difficult, seems to be consistent with empirical evidence. Slowiaczek and Clifton (1980) investigated the effect of eliminating subvocalization on reading comprehension, and concluded the following.

> In these experiments, reading for meaning was severely impaired when subvocalization was suppressed. Listening comprehension was also reduced by suppressing subvocalization, but the effect was much smaller. We conclude that there was a general interference effect from the secondary task, but that the significantly greater interference effect for reading was due to the specific function of subvocalization in reading.

In general, all of the methods listed for suppressing subvocalization could also be understood as forms of articulatory suppression. Under the influential Baddeley and Hitch model of working memory, the phonological loop subsystem is believed to facilitate long-term learning in part via articulatory rehearsal, and articulatory suppression corresponds to tasks which interfere with this function.

## References

* Slowiaczek, M. L., & Clifton, C. (1980). Subvocalization and reading for meaning. Journal of Verbal Learning and Verbal Behavior, 19(5), 573-582.
> 2 votes

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Tags: cognitive-neuroscience, language, reading, working-memory
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# Question
Title: Where does the distinction between motives and goals lie in activity theory?
Activity has an hierarchical structure, and can be analyzed at different levels: *activities*, *actions* and *operations*. (Leontiev 1974)

<sub>(source: interaction-design.org)</sub>

The top level is activity itself, oriented towards its *motive*. At a lower level lie conscious *goal*-directed *actions* that must be undertaken to fulfill the object. Goals can be decomposed into sub-goals, and so forth, meaning actions can have a hierarchical structure of their own. At the lowest level lie automatic processes which happen subconsciously, called *operations*. This is how actions are eventually carried out.

**I'm not entirely sure where the distinction lies between motives and goals.** A motive is an object that meets a certain need of the subject, while actions are goal-directed processes that must be undertaken to fulfill the object. (Kaptelinin 2009)

It seems like as long as a certain action has some underlying higher motive it is only part of an activity, while as no higher motive can be identified it should be considered an activity instead.

* Do you arbitrarily decide on what to define the activity, and what to define as the underlying actions?
* How does e.g. a potential underlying motive for all actions as 'survival' fit into this picture?

<sub> Leontiev, Aleksei N. (1974). The Problem of Activity in Psychology. Soviet Psychology, 13, 4-33.
Kaptelinin, Victor & Nardi, Bonnie A. (2009). Acting with Technology: Activity Theory and Interaction Design. The MIT Press </sub>

# Answer
> 4 votes
I think the confusion arises because the hierarchy of "activity" as described in that figure exist in the context of an ontology that is closer to dynamical perception-action cycles than to the evolutionary information processing ontology typically used in cognitivist approaches.

> The world is structured; it comprises discrete objectively existing entities, that is, objects. Subjects’ interaction with the world is also structured; it is organized around the objects. Objects have their “objective” meanings, determined by their relationship with other entities existing in the world (including the subject). In order to meet their needs, the subject has to reveal the objective meaning of the objects, at least partly, and act accordingly. — interaction-design.org, section 16.3.2.1

**Activities** are relations between **subjects** and **objects** (as in interests), so **motives** *are* objects. They exist in the sense that the grammar of a language exists, and are independent of any one person. **Goals** relate individual conscious processes (e.g., decision-making and planning) to these motives in order for the subject to concretely attain their object, and **actions** relate individual behavior to the goals.

However, these are only facets of the same continuously evolving system. There is therefore no way to describe an action without reference to an object and motive in an activity theoretical sense. In activity theory, all behavior is directed towards some motive as a matter of definition, and it is the motive which defines the activity. Motives entail goals, goals entail conditions, and reciprocally the other way around in a continuous dynamically evolving cycle.

> **The motive is the object that the subject ultimately needs to attain.** For instance, in some cultural contexts people reaching a certain age need to learn how to drive a car (and get a driver’s license); it is a general prerequisite of being a fully functional member of society. Learning how to drive a car is an activity which is organized as a multi-layer system of sub-units directed at getting a driver’s license. **Actions are conscious processes directed at goals which must be undertaken to fulfil the object.** Goals can be decomposed into sub-goals, sub-sub-goals, and so forth. For instance, one may decide to enroll in a driving school, purchase instructional materials, make a schedule of theoretical lessons and practice sessions, etc. **Actions are implemented through lower-level units of activity, called operations. Operations are routine processes providing an adjustment of an action to the ongoing situation.**interaction-design.org, section 16.3.2.2

A potentially helpful tool in understanding this ontology may be to notice the remarkable similarity with the Gibsonian concept of affordances as objectively existing perceptual entities (e.g., Chemero, 2003), only seen from a socio-cultural point of view. The relation between affordance and organism seems closely parallel to the relation between subject and object in activity theory.

Much like ecological psychologists need to define an ontology of objective affordances that define behavior for specific organisms within a specific environment before anything they say makes any sense, activity theorists need to define an ontology of objective motives for specific subjects within a specific socio-cultural context. Unlike EP, **activity theory does not appear to provide a concrete way to identify objectively existing motives, nor exactly define the subjects or the socio-cultural context, so AT is ambiguous with respect to any individual case (e.g., a 'survival' motive or goal)**. See also what's comments about AT being implicitly situated within a Marxist context.

## References

* Chemero, A. (2003). An outline of a theory of affordances. Ecological psychology, 15(2), 181-195.

# Answer
> 2 votes
> Do you arbitrarily decide on what to define the activity, and what to define as the underlying actions?

As Christian stated in his answer, there seem to be no concrete (unambiguous) steps to follow. This most likely has to do with Activity Theory being a '**framework for analysis**' rather than a theory in the traditional scientific sense. It thus highly depends on what you choose as the point of analysis.

However, some guidelines exist, as stated on interaction-design.org.

> Revealing the ultimate motives of a person or the fine-grain structure of automatic operations may prove to be difficult, if not impossible. This limitation of Leontiev’s three-layer model as an analytical tool can be overcome **by employing an expansive “actions first” strategy**. This strategy involves starting analysis from the actions layer which relatively easily yields itself to qualitative research methods. In particular, people are usually aware of their goals and can report or express them in a certain way. Then the analysis can be expanded both “up”, to progressively higher level goals and, ultimately, motives, and “down”, to sub-goals and operations. The expanding scope of analysis may not cover the entire structure of the activity in question but be sufficient for the purposes of the task at hand (see also Kaptelinin and Nardi, 2006).

As for the second question:

> How does e.g. a potential underlying motive for all actions as 'survival' fit into this picture?

This question seems to imply that any given action can only be part of one activity system. This is not the case. **Actions can be *polymotivated***, that is, subordinated to several motives and/or higher-level goals at the same time. (Leont'ev A. N., 1978)

<sub> Kaptelinin, V., & Nardi, B. A. (2006). Acting with technology: Activity theory and interaction design. Cambridge, MA: MIT Press Leont’ev, A. N. (1978). Activity, Consciousness, and Personality. Prentice-Hall Englewood Cliffs, Nj. </sub>

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Tags: developmental-psychology
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# Question
Title: Is there a relationship between body composition and intelligence?
Does being fat or thin have any significant effect on cognition? For example, I have observed some very fat people who are extremely intelligent and some very thin people that are not and vice versa. John von Neumann was fat and very smart. Are there any studies on this?

# Answer
A systematic meta-analysis of the relationship between IQ and obesity (Yu, Han, Cao and Guo, 2010) suggested that lower IQ in childhood was associated with later adult obesity via educational level. No evidence of a relationship between IQ and obesity was found for adults.

> Our study and review of the literature overall suggests that there are inverse FIQ/obesity associations, except in pre-school children. **However, after adjusting for educational attainment, this FIQ/obesity association became null**. In the present study, a lower IQ score in childhood is associated with obesity in later adulthood; this relationship is perhaps mediated via educational attainment in later life.

## References

* Yu, Z. B., Han, S. P., Cao, X. G., & Guo, X. R. (2010). Intelligence in relation to obesity: a systematic review and meta‐analysis. Obesity reviews, 11(9), 656-670.
> 7 votes

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Tags: intelligence
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# Question
Title: What are the key dates for the development of operant conditioning?
I am trying to build up a timeline of the development of operant conditioning. So far I have the following

* $1898$ - Thorndike performs experiments using his puzzle box of which Skinner based his work on.
* $1930$ - Skinner invents a similiar box called the "Skinner box" while studying as a graduate student.
* $1938$ - Skinner coins the term "operant conditioning".
* $1947$ - Skinner performs experiments on pigeons.
* $1948$ - Skinner performs experiments on rats.

However, this timeline leaves me skeptical for two reasons.

The first is that the timeline is very stretched out. Skinner invented the box and then it took him 17-18 years to publish his famous studies. What experiments was he performing with his box that weren't as groundbreaking in all those years when his groundbreaking results features a very basic setup?

The second is that Skinner apparently swapped from rats to pigeons in his experiments because they lived longer, learnt faster and were easier to handle yet the according to my timeline the rats experiment took place after the pigeon one (or perhaps not and he just published them in that order).

I suspect my timeline is not quite right (afterall my references are random internet links). My question is what are the (correct) key dates of the development of operant conditioning? Key dates being the events I have highlighted above and any others you think I have missed. I had more references but unfortunately I can only post 2 links due to my reputation.

# Answer
It would have been pretty strange for there to be multi-year gaps in Skinner's publication record, and in fact, Skinner continued to publish every year in both of those periods and beyond (Epstein, 1977). I've provided a link to a list of his publications which includes both periods, but there is no real way to say which of these publications were the 'key' studies for operant conditioning. Hopefully, this will still be of some help.

## References
> 2 votes

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Tags: learning, conditioning, history-of-psychology
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# Question
Title: Does working memory have a role in creativity?
What role does working memory play in creativity?

Creativity in this context being easily measurable creativity, so performance on things like the uses task etc. Divergent thinking is the ability to consciously generate new ideas that branch out to many possible solutions for a given problem. It can be tested using the S-A creativity test (Society For Creative Minds, 1969).

My assumption is that creativity is a form of divergent thinking and working memory is required for divergent thinking. I was wondering if anyone could expand on or dispel this?

# Answer
Takeuchi et al. (2011) had participants in an fMRI perform three tasks in order to measure creativity, working memory and intelligence.

1. S-A creativity test as a measure of creativity (Society For Creative Minds, 1969).
2. Verbal *n*-back as a measure of working memory (Calicott et al., 1999).
3. Raven's Advanced Progressive Matrix as a measure of intelligence (Raven, 1998).

They reported no association between creativity and WM performance after controlling for IQ.

> To our knowledge, this is the first study to investigate the association between individual creativity and functional activity during WM. **Creativity and WM performances did not correlate in this study of young healthy and cognitively intact subjects.** However, congruent with our hypothesis, our findings showed that reduced TID during the WM task in the precuneus (one of the key nodes of the DMN) is associated with creativity measured by the divergent thinking test.

There was no apparent evidence to suggest that performance on a WM task is associated with performance on a divergent thinking task, but the authors proposed a complex argument for the idea of creativity as "diffuse attention," which they argue may share a neural basis with WM (such that they are opponent processes). The evidence for this is indirect and seems difficult to reconcile with the concretely reported independence of WM and creativity performance, however.

## References

* Callicott, J. H., Mattay, V. S., Bertolino, A., Finn, K., Coppola, R., Frank, J. A., ... & Weinberger, D. R. (1999). Physiological characteristics of capacity constraints in working memory as revealed by functional MRI. Cerebral Cortex, 9(1), 20-26.
* Raven, J. Court (1998). Manual for Raven’s progressive matrices and vocabulary scales. Oxford: Oxford Psychologists.
* Society For Creative Minds (1969). Manual of S-A Creativity Test. Tokyo Schinri Corporation. Tokyo.
* Takeuchi, H., Taki, Y., Hashizume, H., Sassa, Y., Nagase, T., Nouchi, R., & Kawashima, R. (2011). Failing to deactivate: the association between brain activity during a working memory task and creativity. Neuroimage, 55(2), 681-687.
> 5 votes

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Tags: cognitive-psychology, memory, working-memory, creativity
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# Question
Title: Are there any open task sets available to assess workload using secondary task measures?
Performance on secondary tasks next to a primary task is sometimes used to assess mental workload (Ogden, Levine and Eisner, 1979). For example, the Stroop test as a secondary task has been evaluated by Gwizdka (2010).

However, a lot of effort goes into setting up these tasks, so I was wondering whether there are any open, ready-made task sets available which would be suitable for this purpose.

Some desirable characteristics I am looking for:

* One task shouldn't be considerably harder than another.
* Performing one task shouldn't take considerably longer than another.
* Overall, one task shouldn't take too long, so the amount of tasks done can also be used as a measurement of mental workload.

<sub> Ogden, G. D., Levine, J. M., & Eisner, E. J. (1979). Measurement of workload by secondary tasks. Human Factors: The Journal of the Human Factors and Ergonomics Society, 21(5), 529-548.
Gwizdka, J. (2010, August). Using stroop task to assess cognitive load. In Proceedings of the 28th Annual European Conference on Cognitive Ergonomics (pp. 219-222). ACM. </sub>

# Answer
> 3 votes
Since you mentioned the Stroop specifically, several versions of the Stroop task are available for Inquisit here.

Randall Engle's lab also maintains a set of validated working memory tasks, which are available on request to researchers. They include full and shortened versions of operation-, symmetry-, reading- and rotation-span for E-Prime 2.0.

Assuming I read the question correctly, any of these should satisfy the requirements.

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Tags: methodology, experimental-psychology, software, human-factors
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# Question
Title: What is the difference between behavioral science and cognitive science?
Is cognitive science a part of behavioral science or vice versa?

# Answer
> 7 votes
**The cognitive sciences are *largely* an element of the behavioral sciences.**

The subject matter of the behavioral sciences is animal or human behavior. It is an interdisciplinary endeavor that involves a diverse set of fields such as psychology, ethology, behavioral genetics, criminology, etc.

The cognitive sciences study how the mind determines behavior via mental processes such as perception, reasoning, emotion, and volition. This also is a multidisciplinary endeavor involving neuroscience, psychology, artificial intelligence, and so on and so forth (see for example Harré, 2002). In the sense that the *ultimate* goal of (most) of the cognitive sciences is to explain behavior, they can be regarded as behavioral sciences. At the same time, it is clear that not all behavioral sciences focus on the mind as their explaining variable. Therefore it is the broader term.

It is important to note, however, that the cognitive sciences may investigate the mind without observing actual behavior in a given study. For example, there may be brain imaging studies without any behavioral measures. As another example, artificial intelligence research may simulate thought processes as a means to understand human reasoning, but conceptualize and measure behavior only in a very abstract sense.

Sometimes, the term "behavioral science" is used more strictly to connote a focus on behavioral experimentation and observation. This usage would exclude some research within the realm of the cognitive sciences.

Finally, there is research that may be regarded as cognitive science that is not a behavioral science in any sense of the term. A case in point is artificial intelligence research that does not aim at simulating or understanding animal or human thinking.

**References**

Harré, R. (2002). Cognitive science: A philosophical introduction. London: SAGE.

# Answer
> 2 votes
The field of cognitive science is sort of a response to behavioral science. Behavioral science focuses on the behavior, or the "output", of an organism. It is based more on observation as a general rule, and attempts to make formulations based on what can be observed. Its methods can be found most often in certain types of therapies and treatments for certain disorders, such as PTSD or phobias. In any case, its primary emphasis is on behavior and behavior change.

Cognitive science, on the other hand, focuses on cognitive processes -- namely, mental states, or the study of the mind. Thus, while behavioral science as a field focuses on animals as well as humans, cognitive science is mostly oriented towards humans. Within cognitive science, we have a bunch of different yet related technological sub-fields: artificial intelligence, computer vision, and robotics, to name a few. To formally study cognitive science, it is helpful to draw from experience in a variety of other subjects (namely formal logic, linear algebra, statistics, computer science, linguistics) that may seem unrelated at first, but actually lend insight into how the mind works as both a biological and computational system.

In the end, behavioral science (for the most part) focuses on the "output" of the organism, and cognitive science (for the most part) focuses on both the "input" and the "output", but it is a bit more curious about the input and what happens in between. If behavioral science emphasizes *behavior*, then cognitive science emphasizes *perception*. Cognitive science is also a bit more theoretical than behavioral science, though there are practical applications, and such applications are made apparent in breakthroughs in artificial intelligence, natural language processing, and even psychological counseling. I think that behavioral science lost traction after the "cognitive revolution" in the 1950s...presumably because people realized that cognitive science indeed had practical applications in science and technology, and wasn't all empirical hogwash. :)

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Tags: terminology
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