# Question
Title: What is the difference (in a recording) between speech and a sound? What makes the difference to the brain?
How does the brain cognitively differentiate between speech and a sound within a recording? I am asking this theoretical question for speech synthesis, i.e. Making a voice with just waves (no recordings). Is this even possible?

# Answer
Speech is sound and the brain will recognise the sound as speech. As for the possibility of creating the sound of speech without recordings using sound waveforms I would say that is off topic here and would be a question for sound creators.

The subject of recognising speech from sounds is a big subject but to give a starting point here are a few pointers for further reading and research, depending on what area you want to look at more.

## Neurological basis of Speech Perception

Heald & Nusbaum (2014) gives a brief outline of the neural processes involved.

> One view of speech perception is that acoustic signals are transformed into representations for pattern matching to determine linguistic structure. This process can be taken as a statistical pattern-matching problem, assuming realtively stable linguistic categories are characterized by neural representations related to auditory properties of speech that can be compared to speech input. This kind of pattern matching can be termed a passive process which implies rigidity of processing with few demands on cognitive processing. An alternative view is that speech recognition, even in early stages, is an active process in which speech analysis is attentionally guided. Note that this does not mean consciously guided but that information-contingent changes in early auditory encoding can occur as a function of context and experience. Active processing assumes that attention, plasticity, and listening goals are important in considering how listeners cope with adverse circumstances that impair hearing by masking noise in the environment or hearing loss. Although theories of speech perception have begun to incorporate some active processing, they seldom treat early speech encoding as plastic and attentionally guided. Recent research has suggested that speech perception is the product of both feedforward and feedback interactions between a number of brain regions that include descending projections perhaps as far downstream as the cochlea.

They also define **active** and **passive** processes

> The distinction between active and passive processes comes from control theory and reflects the degree to which a sequence of operations, in this case neural population responses, is contingent on processing outcomes (see Nusbaum and Schwab, 1986).

**Figure 1A-C \[Source: Heald & Nusbaum (2014)\]**

> A **passive process** is an open loop sequence of transformations that are fixed, such that there is an invariant mapping from input to output (MacKay, 1951, 1956). Figure 1A illustrates a passive process in which a pattern of inputs (e.g., basilar membrane responses) is transmitted directly over the eighth nerve to the next population of neurons (e.g., in the auditory brainstem) and upward to cortex. This is the fundamental assumption of a number of theories of auditory processing in which a fixed cascade of neural population responses are transmitted from one part of the brain to the other (e.g., Barlow, 1961).
>
> By contrast, **active processes** are variable in nature, as network processing is adjusted by an error-correcting mechanism or feedback loop. As such, outcomes may differ in different contexts. These feedback loops provide information to correct or modify processing in real time, rather than retrospectively. Nusbaum and Schwab (1986) describe two different ways an active, feedback-based system may be achieved. In one form, as illustrated in Figure 1B, expectations (derived from context) provide a hypothesis about a stimulus pattern that is being processed. In this case, sensory patterns (e.g., basilar membrane responses) are transmitted in much the same way as in a passive process (e.g., to the auditory brainstem). However, descending projections may modify the nature of neural population responses in various ways as a consequence of neural responses in cortical systems. For example, top-down effects of knowledge or expectations have been shown to alter low level processing in the auditory brainstem (e.g., Galbraith and Arroyo, 1993) or in the cochlea (e.g., Giard et al., 1994). Active systems may occur in another form, as illustrated in Figure 1C. In this case, there may be a strong bottom-up processing path as in a passive system, but feedback signals from higher cortical levels can change processing in real time at lower levels (e.g., brainstem). An example of this would be the kind of observation made by Spinelli and Pribram (1966) in showing that electrical stimulation of the inferotemporal cortex changed the receptive field structure for lateral geniculate neurons or Moran and Desimone’s (1985) demonstration that spatial attentional cueing changes effective receptive fields in striate and extrastriate cortex.

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## Linguistic Speech Perception

The following information was sourced from an article by John Kingston (Professor in the Department of Linguistics, University of Massachusetts) in 2013.

**Links below are for Free PDF files - DOIs are provided in the references section in case of future breaks in links**

> According to the motor theory of speech perception (Liberman, et al., 1967; Liberman & Mattingly, 1985; Liberman & Mattingly, 1989), listeners recognize speech sounds by emulating their articulation in their heads. The sound is recognized when the acoustic properties of the emulation match those of the speech sound heard...Now, this is embodied cognition in that the cognitive act of perceiving a speech sound consists of emulating the speaker’s articulatory behavior mentally, i.e. behaving in the mind as the speaker would in the world.
>
> ...
>
> According to the direct realist theory of speech perception (Fowler, 2006), no such emulation nor embodied cognition is necessary to perceive speech sounds because the speaker’s articulatory behavior in pronouncing them so structures the acoustic properties of the speech signal that the listener can identify the unique articulation that produced those properties. In other words, the acoustic properties are specific information about the articulations that produced them...This is extended cognition because no mental act is required to extract information from the speech signal’s acoustic properties. The information is instead present and patent within those properties and no analysis is required to turn those properties into information. All the cognitive work, other than simply being around to hear the sounds, is done outside the listener’s head.

Kingston says that there are empirical and theoretical challenges to both the motor theory’s and direct realism’s accounts of speech perception, stating that speech perception is neither emboedied or extended; however he did not elaborate on this.

### Source

Kingston, J., (2013). *Why speech perception is neither embodied nor extended cognition* \[Online\] Available at http://blogs.umass.edu/jkingstn/2013/12/

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## References

Barlow, H. B. (1961). *Possible principles underlying the transformations of sensory messages* In: Sensory Communication, ed W. Rosenblith (Cambridge, MA: MIT Press): pp 217–234. ISBN-13: 978-0262518420 DOI: 10.7551/mitpress/9780262518420.003.0013

Fowler, C. A. (2006). *Compensation for coarticulation reflects gesture perception, not spectral contrast*, In: Perception & Psychophysics. 68(2): pp 161-177. DOI: 10.3758/BF03193666 PMID: 16773890

Galbraith, G. C., and Arroyo, C. (1993). *Selective attention and brainstem frequency-following responses*, In: Biological Psychology 37(1): pp 3–22. DOI: 10.1016/0301-0511(93)90024-3

Giard, M. H., Collet, L., Bouchet, P., and Pernier, J. (1994). *Auditory selective attention in the human cochlea*, In: Brain Research 633(1-2): pp 353–356. DOI: 10.1016/0006-8993(94)91561-x

Heald, S. L. M., and Nusbaum, H. C., (2014). *Speech perception as an active cognitive process* In: Frontiers in Systems Neuroscience Vol.8 DOI: 10.3389/fnsys.2014.00035 PMCID: PMC3956139
URL: http://journal.frontiersin.org/article/10.3389/fnsys.2014.00035

Liberman, A.M., Cooper, F.S., Shankweiler, D.P., & Studdert-Kennedy, M. (1967). *Perception of the speech code*, In: Psychological Review. 74(6): pp 431-461. DOI: 10.1037/h0020279 PMID: 4170865

Liberman, A.M., & Mattingly, I.G. (1985). *The motor theory of speech percepton revised*, In: Cognition. 21(1): pp 1-36. DOI: 10.1016/0010-0277(85)90021-6 PMID: 4075760

Liberman, A.M., & Mattingly, I.G. (1989). *A specialization for speech perception*, In: Science 243(4890): pp 489-494. DOI: 10.1126/science.2643163 PMID: 2643163

MacKay, D. M. (1951). *Mind-like Behaviour in artefacts*, In: The British Journal for the Philosophy of Science 3(12): pp 352-353 DOI: 10.1093/bjps/II.6.105

MacKay, D. M. (1956). *The epistemological problem for automata*, In: Automata Studies (AM34), eds C. E. Shannon and J. McCarthy (Princeton: Princeton University Press): pp 235-252
ISBN-13: 978-0691079165 Retrieved from http://www.jstor.org/stable/j.ctt1bgzb3s.14

Moran, J., and Desimone, R. (1985). *Selective attention gates visual processing in the extrastriate cortex*, In: Science 229(4715): pp 782–784. DOI: 10.1126/science.4023713

Nusbaum, H. C., and Schwab, E. C. (1986). *The role of attention and active processing in speech perception*, In: Pattern Recognition by Humans and Machines: Speech Perception (Vol. 1), eds E. C. Schwab and H. C. Nusbaum (San Diego: Academic Press): pp 113–157.
DOI: 10.1016/B978-0-12-631403-8.50009-6

Spinelli, D. N., and Pribram, K. H. (1966). *Changes in visual recovery functions produced by temporal lobe stimulation in monkeys*, In: Electroencephalography and Clinical Neurophysiology 20(1): pp 44–49. DOI: 10.1016/0013-4694(66)90139-8
> 5 votes

# Answer
While speech is certainly sound, the brain will not always recognize speech sounds as speech. This is clear when one constructs speech from just sine waves as it reveals how the brain goes about understanding meaningfully linguistic signals.

Sine wave speech is constructed by using the first 3 prominent frequency bands (ie. formants) in a speech signal and replacing them with time-varying sine wave components. Cognitively when a listener is faced with sine wave speech without knowledge that it is speech, he or she often fails to understand it. More shockingly individuals often fail to hear it as an example of speech. Indeed, unless you have the expectation that it is speech, it is often mistaken as birds whistling or computer generated nonsense sounds. However, you can engender understanding with the knowledge that it is language. Presumably this is because the expectation that is it speech, allows a listener to bring to bear the vast amount of knowledge they possess about language to interpret the sinewave speech signal. The idea that expectations play a large role in speech understanding is supported by the view of speech perception held by Heald & Nusbaum (2014):

> ...even in early stages, \[speech perception\] is an active process in which speech analysis is attentionally guided. Note that this does not mean consciously guided but that information-contingent changes in early auditory encoding can occur as a function of context and experience. Active processing assumes that attention, plasticity, and listening goals are important in considering how listeners cope with adverse circumstances that impair hearing by masking noise in the environment or hearing loss. Although theories of speech perception have begun to incorporate some active processing, they seldom treat early speech encoding as plastic and attentionally guided. Recent research has suggested that speech perception is the product of both feedforward and feedback interactions between a number of brain regions that include descending projections perhaps as far downstream as the cochlea...

Here are helpful online resources to understand what is cognitively occurring in speech understanding broadly as well as in the context of sine wave speech:

http://www.haskins.yale.edu/featured/sws/sws.html https://www.mrc-cbu.cam.ac.uk/people/matt.davis/sine-wave-speech/
> 1 votes

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Tags: perception, speech
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# Question
Title: Low crystalized intelligence- failure to transfer skill from Hippocampus to cortex?
We know that when we process some information or solve some problem, we need to pull information from long term memory to working memory. There are few factors known to me that can cause a failure during retrival:

1. Working memory shortage
2. poor temporal context
3. The memory was never transferred to long term memory to begin with

Low working memory is something that can be easily diagnosed with Dual n-back tests.

A study on anterograde amnesic patients have shown that they do not appear to have poor temporal order (5), which indicates that maybe temporal context is not to blame when people forget things. However, it is possible that this does not apply on all cases.

This leaves the third possibility: that short term memories do not always get transferred to long term memories. Is this a possibility? If yes, then why does it happen?

---

Sources:

1. Types of memory
2. Role of working memory
3. Temporal context
4. How is information transferred into long-term memory?
5. Anterograde amnesia and temporal order
6. Dual n-back test

# Answer
First we need to establish the link between crystallized intelligence and the types of memory. Long term memory can be divided in two parts: Procedural and declarative.

Episodic memory is recollection of events, semantic memory is recollection of learned facts, and procedural memory includes priming, classical conditioning, skill based learning etc and does not require intentional or conscious recollection of an experience (1).

Among these types, Howard and Kahana's model of temporal context theory is only applicable to the declarative branch (2).

The answer to the question depends on which type of problem solving we are talking about. All three types of memories get used during learning. Problem solving requires skill based learning. But we must also remember a lot of facts in order to solve certain real world problems. Practical experiences also come in handy. However, if we can recall all the related facts but still fail to solve a problem, that indicates poor skill-building. According to Cattell‘s (1971, 1987) Gf-Gc theory, fluid intelligence causes crystallized intelligence (5). therefore, low fluid intelligence might be a reason behind poor skill based learning.

"failure to transfer skill from Hippocampus to cortex" is not likely to happen because skills do not seem to have any short-term and long-term phases. Excerpts from a recent study (6):

> We have shown that when people adapt to successive and opposing sensorimotor transformations, they fail to consolidate learning of the first even when the two transformations or tasks are separated by 24 hr.

From a meta-analysis (4):

> This implies that a procedural memory may never become fully stable and instead remains vulnerable to interference. When exposed to task B, participants may have retrieved the procedural memory associated with task A and modified it, ‘overwriting’ the memory for task A with information relevant to task B............ It implies that learning a new skill leads to the automatic destruction of another skill. It would never be possible to have skill in more than one task! Our ability to acquire multiple skills may depend upon having contextual cues available to signal the switch from one task to another.

This theory proposes that our procedural memory has a completely different type of contextual cue system, one that cannot differentiate between multiple skills as efficiently as episodic memory can. This theory also explains why ADHD is such a barrier in learning.

Now we can guess what type of memory is involved in skill learning: When a new skill is being formed by Gf, it is likely utilizing the info available in short term memory to do so. When a skill is being recalled, It goes to working memory for utilization.

In conclusion: Forgetfulness indicates inefficiency in declarative memory, while poor skills might indicate low Gf and/or poor attention span.

Questions remaining:

1. What causes inefficiency in declarative memory?
2. How to strengthen our procedural memory? Can practice help?
3. Why do people who find it easier to learn through practical and struggle to grasp abstract concepts?

But these questions deserve new topics.

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Sources:

1. Green REA, Kopelman MD. Neural organization of memory andmemory impairments. In: Trimble MR and Cummings JL, eds. Contemporary behavioural neurology. Boston: ButterworthHeinenman, 1997; 139–152.
2. https://pdfs.semanticscholar.org/5b83/58754a92cf648f3c5ccea7f34df62bba1e74.pdf
3. https://www.cambridge.org/core/journals/journal-of-the-international-neuropsychological-society/article/interdependence-of-episodic-and-semantic-memory-evidence-from-neuropsychology/1A97EFA24F2CDED16D12964AD5EE67F9
4. http://www.cell.com/current-biology/pdf/S0960-9822(04)00937-6.pdf
5. http://ir.uiowa.edu/cgi/viewcontent.cgi?article=2639&context=etd
6. http://www.cns.atr.jp/~kawato/Ppdf/CaithJNS04.pdf
> 2 votes

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Tags: long-term-memory, episodic-memory, temporal-context, amnesia
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# Question
Title: Is it possible to objectively measure the amount of pleasure a person is experiencing?
I'd like to know if it's possible to quantify somebody's "fun meter". Maybe by measuring the amount of endorphin produced. Because every person is unique, I don't expect that amount to make another person feel exactly as much satisfaction, but I'm ready to be proven wrong.

Are there any existing methods to objectively measure pleasure?

# Answer
> 5 votes
This is a very general answer to your question. And let me say upfront that I don't know about any measurement instruments for pleasure. However, I would like to emphasize that pleasure, just as about any psychological phenomenon, has to be considered a *latent construct*. What this means is that it cannot be measured directly, but only indirectly and imperfectly through a bunch of indicators. It is actually important to have more than one indicator in order to estimate how reliable the measurement is. Since you asked wether it is possible to measure pleasure or not, my answer is yes.

The question then becomes what the indicators are, that allow one to measure the amount of pleasure someone is experienceing. They should be derived from a theory about what pleasure is. In the reference that @GregMcNulty gives in the comments, for instance, the amount of pleasure is measured predominantly by activity in the prefrontal cortex. But it is also stated that "From a biological perspective, pleasure is not a unitary experience in the brain. It’s not just one region that is activated when we find pleasure in something or someone." That's speaking to the notion of having more than one indicator.

Whatever way you do it, though, you will have to come up with a good theory on what pleasure is and then find indicators. And with a construct as complex as pleasure, it is important to keep in mind that you will always have measurement error.

# Answer
> 1 votes
You could also choose a wider path by measuring a person emotion, and deduce a level of pleasure from these results. There are three useful components in order to record an emotion :

* The behavioral component is mostly turned towards face analysis. The user may not be aware of his face change, but he may control it... So it's not the perfect objective tool. There are computer-based softwares to analyse such emotions from a face analysis.
* The cognitive component consists basically to ask how the person feel through robust questionnaires. There are several questionnaires involving emotional terms or not. However, this is a very subjective source.
* The physiological component may be a quite relevant resource for you as it is objective: the person is not able to control his physiological response. There are numerous different physiological responses of emotional change, but I would rather choose the galvanic skin reponse (GSR). However, this will objectivly bring forward an emotional response, without being able to qualify it.

Therefore, it is important to use a combinaison of these resources in order to get an objective way of assessing pleasure.

# Answer
> 1 votes
There are different kinds of "well being". However, regarding pleasure, I'd rather suggest measuring the level of dopamine released, instead of endorphins. Watch this: dopamine release comparison. Anyways, there are other neurotransmitters that produce euphoria, such as endorphins and endocannabinoids. Music, food and sex induce dopamine release, but aerobic exercise "runner's high" is related to endorphins, as well as endocannabinoids. Additionally, alcohol and other CNS depressants and anaesthetics such as "laughing gas" (nitrous oxide) do produce euphoria too, so the phenomenon of pleasure is certainly difficult to define in a biological way.

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Tags: cognitive-psychology, neuroscience, measurement, emotion, methodology
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title: Why Bayesian Cognitive Modeling?

text:
# Question
Title: Why Bayesian Cognitive Modeling?
Recently i read an article on Bayesian Program Synthesis. It says that Bayesian cognitive modelling would help AI systems to learn from few examples in comparison to deep learning. But i was not able to understand the advantages of using Bayesian vs other formulations in cognitive modeling. I would like to understand why this Bayesian approach stand out ? What are the drawbacks of current approaches to cognitive modeling ?

# Answer
Here's a quick answer from general background knowledge, not from any specific knowledge of "Bayesian Program Synthesis (BPS)"

In general, Bayesian models can use strongly informed priors or diffuse "could be anything" priors. Strong priors specify that a lot of parameter values are very unlikely, while a few other parameter values are possible descriptions of the data. With a strong prior, it takes relatively little data to winnow down the possibilities (i.e., faster learning). Weak priors allow for a much broader range of possibilities, but it takes a ton of data to narrow down the possibilities (i.e., slower learning).

Many Bayesian models of mind use strong priors. Such models come pre-set with particular structure or parameter dependencies that are tuned for the type of problem that needs to be learned. This is not "cheating;" the prior is a crucial part of the theory. Another example comes from computer vision: Figuring out what objects and lighting produced a pixelated 2D image can only be done by assuming strong prior knowledge of the types of objects and types of illumination "out there" in the world, otherwise it's an unsolvable problem. An introductory article is **here** or **here** (specifically, see the section on "Prior Knowledge" starting on p. 17).

Deep learning, however, is (as far as I know) a generic approach that can learn just about any possible relationship among variables. The cost of this weak prior is that it takes a ton of training to narrow down the parameter distribution.
> 7 votes

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Tags: cognitive-modeling, intelligence, computational-modeling, bayesian
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# Question
Title: Human memory - remembering sequences of letters vs numbers
There are 10 digits and 26 letters. In computer science you'd need 4 bits to store a digit value and 5 bits do store a letter value.

Does the same apply to human brain? Is a statistical person able to remember more digits than letters, or is there no difference? Or maybe it varies from person to person?

# Answer
I am not sure I completely understood your question but I will try to answer it. Different numbers and different letters can be easier or harder to remember based on the order, meaning that, depending on their sequence, it can be either way. Ex. a r d q is easier to remember than 9 4 6 0 but z n k r is harder to remeber than 9 8 3 0. This is because the letters are used in the English language in a way that allows you to make them into a certain sound but only if you have the right letters.

I hope that was helpful (even though it has been almost two years),
> -1 votes

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Tags: cognitive-psychology, memory
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# Question
Title: Intrapersonal drawbacks of landscaped open spaces
Preparing a dissertation, I would be interested in finding studies/articles concerning work conditions in open space offices.

Regarding what is expected and advocated by the benefits, I would currently hypothesize that this environment has a negative impact on long-term individual motivation, and it is more difficult to concentrate and to avoid preemption. If I find some clues in this direction, my first and current plan would be something like:

1. The benefits wanted by companies in terms of group:

* Team cohesion
    * Fluidity of communication (see theory of information processing) and knowledge sharing
    * Motivation (by collective emulation and cohesion and/or better hierarchical surveillance)
2. Disadvantages

* Leveling / erasing of people (intrinsic individual characteristics are flattened into a group mean, probably the resulting form of the most influential and extrovert behaviors)
    * Distraction: a single person can create a unplanned meeting (whatever personal/professional topics) or a game (for example starting throwing a single soft ball) that will degenerate into massive service interruption (because nobody is really in charge of that, and hierarchy may think it is part of cohesion)
    * Insecurity\* and lack of autonomy, loosing ability to create a personal space of withdrawal) (\* in this context, insecurity would be related to this quotes "These openings would foster a sense of insecurity related to the failure to exercise a comfortable grip on his/her personal space/sphere, especially in some situations where the distance with the hierarchical instance is lower." translated from one of my book)

Particularly, and for now, I would be interested by reading researchers that may have studied directly or indirectly any of:

* open space drawbacks
* productivity (before/after comparison)
* knowledge sharing before/after (before/after comparison)
* intimacy feeling/private sphere respect before/after (before/after comparison)
* concentration/focus (before/after comparison)
* spontaneous criticisms in small "human sized" desk (3-4 persons) versus "keep it for me" and have bad feelings concerning troublemakers because it may be herder to spot a problem in front of a bigger audience
* accumulated distraction moments (before/after comparison)
* etc.

I have some books in my native language but they are not related directly to these questions, and I find it hard to get some English literature.

Could you suggest some pointers or books or methodology on how you would find such articles ?

Thanks,

# Answer
> 1 votes
A partial answer to the question.

Literature about **before/after comparisons** may be found searching for the phrase "**office redesign**".

For example:

McElroy, J. C., & Morrow, P. C. (2010). Employee reactions to office redesign: A naturally occurring quasi-field experiment in a multi-generational setting. *Human Relations*, 63(5), 609–636.

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Tags: social-psychology, io-psychology
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# Question
Title: How do features of the work environment such as type of pen or color of paper influence productivity and workplace well-being?
**Background:** Recently I have been doing mathematics a whole lot,and I have noticed that my output varies wildly from many external factors,but mostly it is the enviorment I am working in. Namely one of the most unexpected things is that most my output depends on the quality of pen I am using and kind of notebook I am writing in. Last day I went to buy new notebooks and I laid my eyes upon one with especially distinguishing blue-white color scheme,and in my mind it was already set that it will be notebook I will write abstract algebra into,and truly while using that notebook I feel really motivated, it feels like the color of it and the subject of abstract algebra are intertwined in my brain.

**Questions:**

* What is the phenomena called where features of the work environment such as type of pen or color of paper influence productivity or workplace well-being?
* How can such features be used to improve productivity?

# Answer
Environment can be highly motivating through positive and negative forces. The conditions of the world motivated the scientists of the Manhattan project to violate some of their ethics and risk destroying the world in order to create the atomic bomb. Likewise also the oppressed scientist some of which where Jews who were forced into labor on the same project destroyed and sabotaged their work in order to prevent the weapons control by the Nazi's. Then also the USSR was not capable of creating an atomic bomb because of their culture conformity to a specific tenant of Bolshevik and Stalinism stating the atom cannot be subdivided. Galileo also comes to mind yet slaves built the pyramids. These principles of being open free to create, having every comfort of home and preference then motivated in a social and personal way free from tyranny of governmental and cultural oppression allow people to do their best work.

Freud would say your maternal or paternal figure may have wore a blue and white dress during a birthday party or Christmas or other extremely positive event in your childhood which caused you to associate those colors with successes. Which no one could prove unless you happen upon some memory of why those colors are important to you. Likewise also you (or someone else) may have had success with some kind of work or test with a specific kind of pen or pencil. This irrational association connecting certain operating items and conditions with success is fundamental to the human condition.

See below paper for further information:

> Effects of Perceived Work Environment on Employees’ Job Behaviour and Organizational Effectiveness
>
> A.K. Srivastava
>
> The study examined the effect of two constituents of work environment (i.e. physical and psychosocial on employees’ job satisfaction and performance, and organizational effectiveness in a sample of 360 technical supervisors and operating core personnel. The analyses revealed that participants who perceived their work environment as to be adequate and favourable scored comparatively higher on the measures of job satisfaction, performance, and perceived organizational effectiveness. The two constituents of work environment were also found causing significant variance in employees’ job behaviour and their perception of organizational effectiveness. Regression analyses revealed that among the various components of work environment, working condition, welfare provisions, interpersonal relations, and trust and support predominantly contribute to employees’ job behaviour and organizational effectiveness. The results also specified that psycho-social environment in work-place exert more impact on employees’ job behaviour and organizational effectiveness than the physical environment does.
> 2 votes

# Answer
> What is the phenomena called where features of the work environment such as type of pen or color of paper influence productivity or workplace well-being?

Ergonomics.

Definition: According to the Penguin Dictionary of Psychology (Reber & Reber, 2001, p. 248), ergonomics is "the science of the 'fit' between jobs and persons, the study of the relationship between an individual's anatomy, physiology and psychology and the demands of particular forms of work".

> How can such features be used to improve productivity?

I would rather say: How do such features improve productivity?

Answer: By reducing or eliminating superfluous effort or even noxious effects on health while going after work tasks. In practice, according to Sonntag (2001, p. 568), this can be achieved through the "identification of regulation requirements and cognitive demands" as well as the "identification of regulation obstacles in industrial work" (ibid.). Many theoretical assumptions behind such an approach are outlined by Leitner and Resch (2005) as well as by Hacker (2003). In short, *regulation obstacles* refers to the psychic regulation of work activity. Even more details can be found in Rau (2004).

References:

Hacker, W. (2003). Action Regulation Theory: A practical tool for the design of modern work processes? *European Journal of Work & Organizational Psychology*, 12(2), 105. https://doi.org/10.1080/13594320344000075

Leitner, K., & Resch, M. G. (2005). Do the Effects of Job Stressors on Health Persist Over Time? A Longitudinal Study With Observational Stressor Measures. *Journal of Occupational Health Psychology*, 10(1), 18–30. https://doi.org/10.1037/1076-8998.10.1.18

Rau, R. (2004). Job Strain or Healthy Work: A Question of Task Design. *Journal of Occupational Health Psychology*, 9(4), 322–338. https://doi.org/10.1037/1076-8998.9.4.322

Reber, A. S., & Reber, E. S. (2001). *The Penguin dictionary of psychology* (3rd ed). London ; New York: Penguin Books.

Sonntag, K. (2001). Psychological Approaches to OSH Research—An Evaluation of 20 Years of Psychological Research on Industrial Safety and Health in Germany. *International Journal of Occupational Safety and Ergonomics*, 7(4), 561–573. https://doi.org/10.1080/10803548.2001.11076508
> 1 votes

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Tags: terminology, io-psychology, educational-psychology
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# Question
Title: Can memorising a new thing erase existing memories?
> Homer: But every time I learn something new, it pushes out something old. Remember that time I took a home wine-making course and forgot how to drive?
>
> Marge: That's because you were drunk.

Yeah, but all jokes aside, when all other conditions are equal, does memorising a new thing increase the chance of losing existing memories that are not directly related to the new memory (different subjects)?

If there is no OS that keeps track of data (i.e.,file system), and each program writes small data anywhere on a large hard disk it wants, as the data grows, the chance of overwriting existing data will increase. And even if OS keeps track of data, when there is no more space it must delete some existing files.

# Answer
Although this is quite an old question, I thought I would add additional information regarding this topic for consideration.

As already noted, the storage capacity of the human brain is certainly very impressive. However, there are also some interesting quirks to human memory worth noting.

> does memorising a new thing increase the chance of losing existing memories that are not directly related to the new memory (different subjects)?

No -- and in fact, when something approaching the phenomenon you are describing occurs, quite the opposite appears to be true.

Before I clarify this, it's important to note that one should not think of memory as something that is "lost" in the same way that one might record over a VHS cassette tape and lose the old content in the process.

When one encodes new information ("learns a new factoid"), there is a greater chance of that new information adversely affecting their ability to retrieve and recall semantically related memories.

Memory interference is more likely to occur with similar material than different material.

Two main types of interference are thought to affect memory:

**Proactive interference.** Previously learned information affects our ability to recall newly learned information.

**Retroactive interference.** Newly learned information affects our ability to recall earlier learned information.
In effect, what you might observe is precisely the opposite of what you are suggesting in your original question: when you memorise information about a "different subject" you are in fact less likely to "lose existing memories" relative to memorising information about the "same or similar subject".

Again, it's important to recall that you're not actually overwriting or erasing the older memories, but more likely merging them together and confusing them with other memories.

This has relevance to how one might chose to structure their learning e.g. revise for exams. After revising organic chemistry, one might derive greater benefit from subsequently revising a foreign language, rather than say, following it with inorganic chemistry.

So, as it relates to your Simpsons reference, the following would be more likely to be correct:

> Remember that time I took a home wine-making course and forgot how to drive brew beer?

Below is a screenshot from a introductory psychology textbook detailing describing the role of interference in forgetting. It also refers to empirical research supporting the phenomenon:

From: "A Level Psychology Through Diagrams" By Grahame Hill (My apologies, I had to use my undergrad textbooks in a bonfire when I was homeless and had been reduced to eating catfood)
> 8 votes

# Answer
This is true if you do have a hard disk of 20GB, but the human memory is large enough.

> You might have only a few gigabytes of storage space, similar to the space in an iPod or a USB flash drive.
>
> Yet neurons combine so that each one helps with many memories at a time, exponentially increasing the brain's memory storage capacity to something closer to around 2.5 petabytes (or a million gigabytes)

http://www.scientificamerican.com/article/what-is-the-memory-capacity/
> 4 votes

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Tags: memory, long-term-memory
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# Question
Title: Does language learning improve or worsen the ability to remember and process information?
In an interview with a Czech neurologist Syka, I've heard that much of the mental health (such as the ability to reason, communicate and process information) in older age mainly depends on the amount of informational ballast we create. The argument states that with this additional information, we unnecessarily wear some of the basic mental mechanisms out (Even though there's no the effect of "too much memories"). Does knowledge of more languages tend to improve or worsen these mental skills?

# Answer
> 6 votes
What I do not quite understand is: What is (according to Syka) "useless information" and how should we "avoid" this kind of information?

Let me try and answer this as follows: During our lifetime, our brain undergoes "synaptic pruning", which lasts from childhood into puberty. Basically, the brain gets rid of "unused" synapses to make space for more complex structures according to the principle of "use it or lose it". It has been hypothesised that sleep has a similar function in that it helps decrease the strength of synapses in order to save energy and not store what you may have referred to as "information ballast" (Synaptic Homoestasis Hypothesis). The creation of new synapses continues throughout our life, which is why there is (some) neural plasticity even in old adulthood. Thus, the brain itself knows how to get rid of irrelevant information (i.e. whatever it does not use) and is receptive to learning even in old age.

What is more, the brain grows with its tasks. So if you avoid learning new tasks, your brain will effectively decline and so will most cognitive skills (working memory, executive functions, processing speed, reasoning etc.). Likewise, our brain does not easily transfer skills from one task to general cognition. If you start doing Sudokus 5h a day, you will improve your Sudoku skills, but not your general ability to reason, for instance. Thus, to the contrary, it seems that what best maintains cognitive functioning in old age is continued engagement in cognitively challenging activities (see Park 2014) rather than the avoidance of new information.

With multilingualism, there is currently a hot debate about its benefits for cognition. For one, it has been shown that bilinguals have a smaller lexicon (per language) than monolinguals - but generally, vocabulary keeps increasing over the lifespan, so I would not worry about that. Ellen Bialystok is a strong defender of the "bilingual advantage", arguing that cognitive skills are even better preserved in bilinguals than in monolinguals, and she provided cross-sectional data showing that symptoms of dementia are delayed by 4 years in bilinguals as compared to monolinguals. The group of Kenneth Paap challenges these findings, arguing that there is no bilingual advantage see Vaughn 2015 for a discussion, but there is little to no evidence suggesting a *disadvantage* for cognitive ability in bilinguals. Starting to learn a new language in adulthood is even more promising, as it has been shown to promote grey matter increase in areas also responsible for cognitive functions that are known to decline in old age (see Antoniou et al., 2013).

In summary, I do not know of "information ballast" impairing basic mental mechanisms, but knowing more than one language has certainly not been shown to decrease your mental health.

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Tags: learning, memory, long-term-memory, language-processing, aging
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# Question
Title: What terms describe "schema" at various stages of acceptance?
According to WordNet 3.0, quoted at TheFreeDictionary.com, in psychology, *schema* means "an internal representation of the world; an organization of concepts and actions that can be revised by new information about the world".

Within psychology, specifically as applied to learning or education, are there terms to describe schemata at different stages of acceptance, e.g.:

* schema present in an individual
* schema currently being added or adjusted by an individual
* potential "schemata/patterns/ideas" out in the world not yet encountered by the individual

Are there specialized terms to distinguish these?

# Answer
> 2 votes
I don't know of separate terms to differentiate 'schema present in an individual' from 'potential "schemata/patterns/ideas" out in the world not yet encountered by the individual', but with regard to 'schema currently being added or adjusted by an individual', I can at least offer some related terms.

* *Accommodation* is the process by which schemata are adjusted most generally.
* With respect to identity status, which might be considered self-schemata, one's status is classified as in *moratorium* during periods of active adjustment. I find James Marcia's theory useful often, because it differentiates individuals in terms of two factors:

1. Whether they have a sense of personal identity
    2. Whether they have attempted to scrutinize and develop their personal identities

I'm only wary of dichotomizing these factors, which might be better understood as dimensions (I doubt whether anyone is truly at an absolute zero)...but that's slightly tangential, as it's somewhat easier to imagine schemata being completely stable or absent in a meaningfully dichotomous sense.

# Answer
> 2 votes
I'm not able to directly answer your question, but I would suggest you take a look at some of the ideas association with Lev Vygotsky (wikipedia is as good a place to start as any).

Schema theory is a relatively static idea - schemata exist as simplified internal representations of an external reality, and are symbolic, much like the memory of a computer. I'm not sure, for that reason, if there should be any term for your `potential "schemata/patterns/ideas" out in the world not yet encountered by the individual`, because a schema is nothing more than a representation (although see Plato's theory of forms).

In Vygotskian theory (or cultural-historical psychology), on the other hand, knowledge is seen as something that emerges from the interaction between a person, the people they encounter, and their broader social and cultural environment.

I know I can't do justice to these ideas myself, but I offer them as a starting point to better understand the concepts you're getting at in your question.

Sorry about all the wikipedia links.

A very good starting point is the following book. It should be retrievable quite easily over the Internet.

Vygotsky, L. S. (1978). *Mind in society: the development of higher psychological processes*. Cambridge: Harvard University Press.

# Answer
> 1 votes
It may not be possible to answer this question in terms of "schema", simply because of its theoretical underpinnings. Eoin has already pointed out this limitation in his/her answer to this question.

However, concepts for describing both psychic representations of "the world" in the individual and "their potential … out in the world not yet encountered by the individual" (citation of the question) are available in the terminology of Activity Theory (Leont’ev, 1978). Namely, the concepts of *personal sense* (in the individual) and *meaning* (potentially reflected by the individual and concretized/found/passed on in the social system/society/culture).

According to Leont’ev (1978), the psychic representation of things, their personal sense, and their meaning are the three formative moments of human consciousness.

Furthermore, Aleksej Nikolaevič Leont’ev was a major exponent of the Cultural-Historical School of Psychology and a student and co-worker of L. S. Vygotsky in Sovjet Russia.

### References

Leont’ev, A. N. (1978). *Activity, Consciousness, and Personality*. Engelwood Cliffs: Prentice Hall.

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Tags: cognitive-psychology, learning, terminology, ideation
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# Question
Title: Erik Erikson: "We live in a continuous process of making the present 'former' "
I'm reading Identity: Youth and Crisis and I was particularly struck by this passage:

However, I'm completely lost by the idea that we are in constant process of making the present into the past - I don't believe I've seen this idea before, and I had an ever harder time trying to find it explained anywhere.

**What does Erikson mean by "constant process of making the present 'former' " ? What is he referring to here?**

# Answer
> 2 votes
You should have quoted a bit more, because he was getting to the punchline. It is a bit metaphorical, but I think he is basically saying that it is not possible to have a "pure experience". We always have some individual context for everything, including our own past thoughts.

Another wrinkle is that everything that we think about is already in the past. We can't walk and chew experiences at the same time, so to speak.

Take a good look at what Buddhism says about this sort of thing - it is a 2500 year old technology for dealing with and understanding psychological reality. You could just study nonduality (research term: **Persistent Non-Symbolic Experience**) and get there faster.

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Tags: developmental-psychology
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# Question
Title: How do mammals estimate the speed of moving objects?
Has there been any research on how mammals predict the speed of moving objects? In particular, how do they integrate top-down information? For instance, do they have greater difficulty estimating the speed of a fast-moving sloth more than a moving mouse?

# Answer
> 3 votes
Two areas in the visual cortex are associated with the perception of velocity, namely:

1. The primary visual cortex (V1) and
2. The middle temporal area (MT or V5).

Both V1 and MT contain neurons that respond strongly to motion in a particular direction and also have selective responses to a particular speed. Direction and speed together define the velocity vector, *i.e.*, these V1 and MT neurons are velocity-tuned. The velocity tuned neurons in V1 typically project to velocity tuned cells in MT. While V1 contains approximately 25% velocity-tuned neurons, those in the MT neurons are nearly all velocity-tuned (Bradley & Goyal, 2008).

Now this is all bottom-up processing. You basically ask as well whether top-down issues play a role. I do not think so. The visual system is basically split in a dorsal 'what' and a ventral 'where' stream (Fig. 1). The 'what' system identifies a target and the 'where' system (containing MT) determines location and velocity. As far as I know, there is no feedback from the dorsal stream onto the ventral one to affect velocity processing.

Fig. 1. Dorsal (parietal) and ventral (temporal) streams. source: Lehky & Sereno (2007)

**References**
**-** Bradley & Goyal, &Nature Rev Neurosci (2008); **9**: 686-95
**-** Lehky & Sereno, \*J Neurophysiol (2007); **97**(1): 307-19

# Answer
> 4 votes
@AliceD gave a great answer on the bottom up pathway. Let me add some top-down processing bits into the picture, since that's what you are asking.

First of all, at a perceptual level, motion perception is biased by prior expectations and strength of motion signal. E.g., see:

* Stocker, A. A. and Simoncelli, E. P. (2006). Noise characteristics and prior expectations in human visual speed perception. Nature Neuroscience, 9(4):578-585. http://dx.doi.org/10.1038/nn1669

The neural activity of MT (and behavior) is known to be modulated by attention. E.g., see:

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Tags: cognitive-psychology, neuroscience, reference-request, vision
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# Question
Title: Do we perceive contrast colour patterns easily because of adaptation?
I can understand that colours are just manipulation of our brain to light rays of different wavelength and energy. We perceive patterns better at higher contrast. Do we perceive patterns better at high contrast because of adaptive processes in our brain, *i.e.*, do we habituate to the colours?

For example, consider a black board; we find texts written by white chalk easier to see than if it was written by blue chalk. Is white chalk on black board a form of adaptation of our brain, or it is always preferred by the brain in comparison to blue? In terms of wave mechanics, the white chalk may cause greater disturbance in the light waves travelling from the black board to our eyes. Please don't consider the case of any eye defects.

# Answer
> 4 votes
**Short answer**
Contrast is hardwired in the visual system and can be explained by retinal and brain connectivities without the need for adaptive processes. My answer pertains to *adaptation* at the *neurophysiological level*. In other words, *short-term neural adaptation in the retina or the visual cortex* are not necessary components for color-contrast coding in the visual system.

**Background**
According to the model of Hering, color contrast in trichromatic species (such as most humans) is basically established between three sets of opponent systems: yellow-blue, red-green and the achromatic channel (dark-bright), and depicted in Fig. 1. The opponent system is established in the brain by cells in the visual cortex responding to both colors of a pair, but one color (e.g. blue) excites and the other (yellow) inhibits the cell, or *vice versa*. These systems are basically established by funneling the color information of opponent colors from the primary sensory neurons (the photoreceptive rods and cones) to color sensitive cells in the visual cortex (Gouras, 2009). In effect, we cannot perceive a yellowish blue, or a reddish green, because these colors are opponent colors in a pair.

Fig. 1. Hering model of color opponency. source: Mark Green

Because of this, the primary color-pairs yellow-blue and red-green yield excellent contrast, because in the brain the opponent response of cells will cause the edge to be sharply defined. Likewise, the achromatic channel yields high-contrast acuity. Mixed colors will impinge on this system not in an ON/OFF way, but in a gradient. For example, in your example, the blue chalk will be visualized through the yellow-blue opponent channel. On a black background, color contrast will be established against the achromatic channel. The highest possible contrast would be delivered with the blue chalk on a yellow background such that the blue-yellow opponent system could be used (*e.g.* blue chalk on a yellow 'white' board :-). However, blue chalk on a blackboard had to be contrasted using the yellow-blue against the achromatic channel, which are phsyiologically not opponent systems and therefore yield less sharp contrast.

Another reason is foveal tritanopia: the fovea has the highest resolution for perceiving fine detail. There are no short wave cones (blue cones) in the very center, the area of maximum resolution (Williams *et al*., 1981), so presumably it is impossible to see blue with the area of the retina with the highest contrast acuity.

Note that while the aforementioned Hering model does not depend on adaptation, many illusions do depend on adaptive processes in the color system, most notably after-images.

**References**
**-** Gouras, Color Vision. In: *Webvision. The Organization of the Retina and Visual System* (2009)
**-** Williams *et al*., *Vis Res* (1981) **21**(9): 1341–56

# Answer
> 2 votes
@AliceD: All of this is very accurate. However, I would like to add that the idea of adaptation in colour perception is not entirely off the mark. What is being described in @AliceD 's reply pertains to the processes in the visual cortex, but of course the colour signal needs further processing before it can be perceived consciously. What is certainly universal is the contrast perceived between the primary colour-pairs you mentioned (because the cones in the retina block the cones of the respective opposite colour), but there is evidence that finer contrasts - for instance between different shades of blue - are acquired through culture. In Russian, there are two words for blue - a darker and a lighter shade, but they lack a common word to denote a general concept of "blue" as in English. Studies (although not entirely consistently) have shown that, therefore, Russian speakers are better at distinguishing finer contrasts among shades of blue (see Paramei, 2005). So there appears to be some (cultural) learning to how we perceive colour contrasts.

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Tags: neuroscience, perception, vision, neurophysiology, sensation
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# Question
Title: What is the effect of Daylight Saving Time on attentiveness and productivity?
This weekend the clocks were set an our later (in some countries), such that the daylight lasts an hour longer in the evening. This has several reasons, among which a reduction in energy consumption and it is preferred by people who's work depends on daylight (wiki). Moreover, the clock will be more in sync with the natural sleep cycle which ought to improve well being (see figure).

However, because of Daylight Saving Time (DST), you do not only lose 1 hour of sleep that night, the entire day has shifted an hour. Subsequent nights, you'll thus likely experience that you go to bed an hour early.

**Does this hour of missed sleep and shift in day affect your wakefulness and attentiveness (and overall productivity at work)?**

# Answer
## Short answer

The amount of sleep that people get affects people attentiveness and their productivity to a large extent, as discussed by Rosekind et al. (2015). When switching to DST, many people experience a loss of sleep (Barnes and Wagner, 2009) which can last up to a week and potentially longer (Harrison, 2013). This lack of sleep may explain the fact that more occupational accidents occur and productivity on the work floor drops (Barnes and Wagner, 2009; Coren, 1996).

## Long answer

**Sleep and attention**

Rosekind et al. (2010) did a research on the effect of sleep and productivity in a general sense. In their introduction, they described the following:

> The prefrontal cortex is an especially important part of the brain for such functions as temporal memory and divergent thinking tasks (Harrison & Horne, 2000b), as well as control of emotional responses and attention (Johnson & Proctor, 2004). Consistent with this contention, empirical research indicates that sleep is an important determinant of alertness and attention deployment and control (Dijk, Duffy, & Czeisler, 1992; Flower et al., 2003; Jewett & Kronauer, 1999; Smith, McEvoy, & Gevins, 2002).

Following, in their study, they compared alertness and task performance of people (1) with good sleep, (2) who are at risk of losing sleep, (3) with insufficient sleep syndrome (ISS) and (4) who suffer insomnia. The results indicated that the people who sleep well always significantly outperformed the insomniacs. Effects of different sizes were found between the insomniac, at-risk and ISS group, depending on the measure.

**DST**

With sleep loss, attention and productivity is thus negatively effected. But do people lose sleep because of DST? Harrison (2013) researched the effect of DST on sleep and related behaviors and, in his abstract, states that:

> Relative ease in adjustment of sleep patterns is assumed by the general population but this review suggests that the scientific data challenge a popular understanding of the clock change periods. The start of daylight saving time in the spring is thought to lead to the relatively inconsequential loss of 1 h of sleep on the night of the transition, but data suggests that increased sleep fragmentation and sleep latency present a cumulative effect of sleep loss, at least across the following week, perhaps longer.

The negative effect is not limited to the shift of the clock in the spring:

> The cumulative effect of five consecutive days of earlier rise times following the autumn change again suggests a net loss of sleep across the week. **Indirect evidence of an increase in traffic accident rates, and change in health and regulatory behaviours which may be related to sleep disruption suggest that adjustment to daylight saving time is neither immediate nor without consequence.**

Another study by Barnes and Wagner (2009) also showed that people slept shorter after DST and that there was an increased amount of accidents in the immediate Monday after, compared to before the switch to DST. **No significant differences in amount of sleep or accidents were found after the autumn switch from DST to normal time.**

The loss of sleep is not only a problem for productivity on the job. In a Canadian study (Coren, 1996), the amount of traffic incidents were investigated over several years around the switch to DST. Three Mondays were compared: 1 week before DST, Monday immediately after DST and the Monday 1 week later. Results shows that the amount of accidents significantly increased directly after the switch to DST, and a week later (although the effect size is smaller). .

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**References**

Barnes, C. M., & Wagner, D. T. (2009). Changing to daylight saving time cuts into sleep and increases workplace injuries. Journal of applied psychology, 94(5), 1305.

Coren, S. (1996). Daylight savings time and traffic accidents. New England Journal of Medicine, 334(14), 924-925.

Harrison, Y. (2013). The impact of daylight saving time on sleep and related behaviours. Sleep medicine reviews, 17(4), 285-292.

Rosekind, M. R., Gregory, K. B., Mallis, M. M., Brandt, S. L., Seal, B., & Lerner, D. (2010). The cost of poor sleep: workplace productivity loss and associated costs. Journal of Occupational and Environmental Medicine, 52(1), 91-98.
> 2 votes

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Tags: sleep, attention, human-factors, health-psychology
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# Question
Title: Are there parts of the brain which don't change over a lifetime?
We know that during our lifetime the brain develops new neural connections. In addition, there is pruning of neural connections. These phenomena together are called neuroplasticity.

Is there any research on part(s) of the brain that are fixed in terms of structure and other properties? In other words, **are there regions in the brain where neuroplastic changes do not occur**?

# Answer
> 4 votes
First off, 'neuroplasticity'is a broad term. Although structural changes are the most visible form of neuroplasticity, for example neurogenesis and axon outgrowth, generally subcellular changes are also taken into the definition of plasticity as well, for example the strengthening of synapses that occurs at the molecular level:

> **Neuroplasticity** occurs at different levels: structural plasticity (new neurons born, growth and shrinkage of neurons), functional synaptic plasticity (enhancing/diminishing the functional connection between neurons) and all the molecular and cellular mechanisms that accompany these changes

Secondly, the '*is there an exception to the rule*' questions are notoriously hard to answer, as most scientific research reports pertain to the publishing of positive data (descriptions of neuroplastic changes in areas of the brain).

To cite Aguire:

> ...\[A\]s long as there are neurons, there is a potential for neuronal plasticity...

Hence, given the broad definition of neuroplasticity, I dare to state that it basically occurs in every brain region. In some more than others, however. The hot spots in the brain where neurogenesis takes place even in the adult brain, e.g. the hippocampus, are obviously the prime examples of high potential for gross plastic changes to occur.

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Tags: neuroscience, neurophysiology
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# Question
Title: What is the bias called when listening to the same sound repeatedly?
When people are made to listen to the same sounds repeatedly, it can trigger placebo effects, *i.e.*, they think they've heard something new or different the $ Nth $ time around, when in fact they haven't.

What is the name of this "bias"? And are there any research papers on it?

I've stumbled across the 'Focusing Effect' but I don't think that's what I'm looking for

# Answer
**Short answer**
In psychophysics, positive hit-rates on zero-intensity stimuli are called *false positives*.

**Background**
In **psychophysics**, it is a common phenomenon where subjects say they perceived something, while no stimulus was in fact being presented. Such responses are called **false positives** (Running, 2015).

In Fig. 1, I have posted a psychometric curve on a so-called stimulus detection task, where the subject (in this case myself) had to identify vibratory stimuli. The x-axis is stimulus level (arbitrary units) and the y-axis shows *P*, or the fraction correct (0 being 0% and 1 being 100% correct). At high stimulus levels (right side of the graph) I faithfully detected all stimuli.

At zero stimulus-intensity, however, no stimulus was presented, and such trials are sometimes called **catch trials**. In this case, only a visual cue appeared on the screen, as in all trials, to notify the subject a trial was starting. You can see I pressed the '*Yes, I can feel it button*' in nearly 5% of the catch trials, while there was no stimulus presented at all. Subjects (too) willing to reach low thresholds (thus favorable outcomes) may tend to be trigger happy, and hit the '*Yes* button too often.

On another note, false positives tend to creep up in case of pathologies. In my field of research, blind people with retinal implants subjected to a visual detection task with electrical stimulation of the retina may report perceiving implant-evoked stimuli, while in fact they are perceiving random phosphenes caused by neurophysiological changes in their retinae, or visual cortex. Likewise, hearing-impaired folks may perceive spontaneous auditory sensations referred to as tinnitus. When subjected to auditory detection tasks in audiometric testing, they may perceive tinnitus sensations and hit the 'Yes' button while in fact no auditory stimulus through the headphones was presented.

Fig. 1. Psychometric curve

**Reference**
**-** Running, Atten Percept Psychophys (2015); **77**(2): 692-700
> 1 votes

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Tags: perception, terminology, bias, hearing, placebo
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title: Why does appreciation make us happy?

text:
# Question
Title: Why does appreciation make us happy?
Why does one crave facebook likes or a pat on the back. Our actions are always governed by this phenomenon, and I don't understand why.

# Answer
From a biological viewpoint, these experiences are associated with the release of neurotransmitters like dopamine and oxytocin, which activate the "reward pathway" of the brain that is associated with feelings of happiness and mood alleviation. Since these are pleasurable experiences, we crave more and more of it, which is why a lot of our actions are governed by it.

**References**:

The Science of Happiness. (2016). More Good Deeds. Retrieved 19 April 2017, from https://www.moregooddeeds.org/blog/2017/1/20/the-science-of-happiness

Fehlhaber, K. (2012). The Reward Pathway Reinforces Behavior - Knowing Neurons. Knowing Neurons. Retrieved 19 April 2017, from http://knowingneurons.com/2012/10/31/the-reward-pathway-reinforces-behavior/

Icahn School of Medicine | Neuroscience Department | Nestler Lab | Brain Reward Pathways. (2017). Neuroscience.mssm.edu. Retrieved 19 April 2017, from http://neuroscience.mssm.edu/nestler/brainRewardpathways.html

Know your brain: Reward system. (2015). Neuroscientifically Challenged. Retrieved 19 April 2017, from http://www.neuroscientificallychallenged.com/blog/know-your-brain-reward-system
> 3 votes

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Tags: emotion, personality
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# Question
Title: At what time in a psychophysical test are catch trials preferably presented?
I am designing a tone-in-noise detection task (specifically a high frequency N0Spi task). For various reasons I need to use a yes-no paradigm and the method of constant stimuli. I am severely limited on the number of trials that can be presented (total of 20 trials) and the presentation order must be the same for all subjects. The subjects will be completely naive and be unfamiliar with the stimuli.

I was thinking of giving them two "practice" trials: one with a clearly audible signal (if they knew what the signal sounded like) and one that is noise alone. I would provide feedback on these trials in the case of an incorrect response. Is there any literature on if the signal or no signal trial should come first? In a run of 20 trials, is there an optimal number of catch (no signal) trials? Is there an optimal place in the track to put these catch trials?

# Answer
> 2 votes
**Short answer**
Based on the experimental restrictions provided in the question and comments, my best bet would be to include 6 catch trials and to randomly present them from trial 6 and onward. Trials 1 & 2 are reserved for training purposes, trials 3 - 5 I would reserve for above-threshold stimuli.

**Background**
First a problem breakdown as I understand it from the question and the comments:

* A Yes/No task is performed using method-of-constant stimuli;
* Dynamic stimulus range is known and expected outcomes are available;
* The detection rate is important, whereas a 50% threshold or psychometric curve are not of interest;
* Zero-stimulus ('catch') trials are a necessary component to validate the method in the normal-group;
* No pilot experiment can be performed to validate the methods in a small group of controls;
* Two practice trials are needed (stimulus-tone alone; noise-alone);
* Critical bottle neck: 20 trials per run

So - here is my suggestion, based on my experiences.

First off, in a yes/no task there's anything possible from correct rates from 0% to 100%. To have a reasonably estimate of the correct rate at a certain constant stimulus, multiple trials are necessary. With one trial you only get 0% or 100% correct - such a binary approach may make sense, but it will add substantial jitter. With four trials, you basically end up with correct-rate increments of 25%. Not too bad, but not pretty either. One subject error and the outcome will be substantially affected. With 8 trials, you are left with steps of 12.5%. From my point of view, **8 trials** is the least you should have to have a reasonable estimate with some precision and to allow the subject to make an error without too much of an affect on the outcome.

From a more practical standpoint, you are left with 18 trials per run per subject (?), namely 20 trials minus two practice runs. At the minimum, from my stand point, you should use 3 stimulus levels: zero-intensity (catch trials) and two above detection-threshold stimuli to spread your chances of finding a statistical difference. I would recommend one far-above detection threshold ('High' condition), where also your impaired group will reach correct rates \>50% and one low level ('Low) where your impaired group will score \<50% to have a condition that will make a positive outcome (difference control-impaired) guaranteed.

This means 18 trials for three conditions: 'Catch'; 'Low'; 'High'. That means 6 trials per condition, leaving you with correct-rate increments of 16.7%. Not too bad.

Now, where to put those catch trials into the picture?

I would personally enforce the paradigm to start with the two practice trials (first the tone, then noise) and then have at least the first two or three trials above threshold; best thing to do is have the 'High' condition first for two times, then the 'Low' and start randomizing from there. Again, this is all personal opinion, based on my experience that **dis-ambiguating the test protocol** is paramount. There's nothing worse than a confused subject. By having 2 well-above detection threshold stimuli (the same as training trial #1 I guess) the task is clear cut. If you start off with a catch trial after training they will likely be confused ('I didn't hear a tone!?' ; 'Should I press the button?').

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Tags: measurement, methodology, psychophysics, experiment-design
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# Question
Title: How is the biological error signal in predictive coding computed?
I am quite inspired by the results obtained by PredNet, which implements a predictive coding model using artificial neural networks. They compute the *prediction error* as a simple subtraction, and then split the positive and negative into two different feature maps.

Within the predictive coding framework it is believed that biological brains also uses the prediction error to communicate between different areas. **How is this error signal computed in biological brains?**.

**Update**

I am especially interested in the mechanical aspects, such as *how doe does the brain compare a prediction with the true signal?*. Synthetic approaches generally just use a pixel-wise error, and I am wondering if the brain does something analogously.

# Answer
> 2 votes
I provided an answer to a similar question here that limitedly deals with the role of biological prediction errors.

Here's an excerpt of that answer:

> ...to answer this properly, we must first make it clear that there are potentially dozens, hundreds, or an arbitrarily high number of other "prediction error types" in use by the brain. Here are just a few major ways, hypothetically:
>
> * Lots of different neurotransmitters (e.g. dopamine)
> * The opening/closing of various ion channel species that regulate the membrane potential
> * Synaptic vescicles/receptors
> * Neuronal firing rates (as in bursting, a rapid succession of action potentials)
> * Temporal coding (relative firing times to the firing of other neurons)
> * And I can think of 10 other more-subtle and harder to explain possibilities, but that are just as important, off the top of my head
>
> Keep in mind that each neuron also seems to have its own differentiated mechanisms for, both, interpreting and signaling prediction error. This complicates things further. For instance, one neurotransmitter may communicate prediction error to one particular neuron, but has no effect (or a different effect) on a different neuron. It may even be that neurotransmitter X must be present while temporal code Y happens for the event to be interpreted as a prediction error.

The study of biological mechanisms for prediction error is a very complicated thing that has no simple interpretation, as opposed to what you find in artificial approaches (presumably, like your PredNet example). While we have not yet uncovered how the brain computes or uses these mechanisms to encode and communicate prediction errors across neurons, what is obvious is that the brain has to be doing some kind of prediction error coding. However, if we try to oversimplify what the brain is doing, we are likely to not have a very intelligent model. The fragility of predictions, susceptibility to error from data complications, and limited nature of current artificial intelligence implementations lends to the idea that there is a lack of good ideas about how to implement and fully utilize prediction error.

The work I do is of a theoretical nature so your question is right up my alley. I have some unique ideas on how various biological prediction errors may work, but it requires a lot of background to understand. Unfortunately, I also have not published my ideas so they are definitely not peer reviewed. That makes me somewhat reluctant to mention my personal ideas as an answer.

It's possible that a kind of prediction error is used in all the listed mechanisms to fine tune the respective properties. Each mechanism likely has a unique role that is central to intelligence- from not only prediction errors encountered in the environment, but even to intrinsic behaviors and being able to predict the outcome of its own actions.

# Answer
> 2 votes
**TL;DR**: We don't know whether the brain really uses predictive coding or not. But neurally computing an error signal on a small scale is possible (see below).

Predictive coding is an *hypothesis* for a putative signal-processing mechanism used in vertebrate brains. As things stand presently (2017), mapping the hypothesis of predictive coding onto known neural structures and responses is a matter of active research (e.g. Choi et al. 2016, Zmarz & Keller 2016, Roth et al 2016).

On a small-scale neural level, an error signal could be partially computed through converging an excitatory "prediction" signal and an inhibitory "evidence" signal onto a single neuron. This is only a partial error signal, since it is rectified by the spiking threshold of the post-synaptic neuron.

The main issue is that the forward and backwards pathways need to follow very precise wiring patterns, and be quite tightly aligned, for the simple formulations of predictive coding to work. That doesn't mesh well with intuitions of what is biologically reasonable.

There are some approaches to map a predictive coding framework onto other mechanisms that may be more biologically plausible (e.g. Spratling 2008).

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Tags: vision, neural-network, communication, signal-processing, encoding
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# Question
Title: How often are complex networks and graph theory useful in computational neuroscience?
Complex networks and graph theory seem like they would be important for computational neuroscience, but they don't come up in the literature as often as I would expect. I'm wondering how frequently they are utilized and what specific ways they tend to be applied.

# Answer
In my opinion as a computational neuroscience researcher, graph theory has not made major inroads into computational neuroscience because we don't have good evidence for what graphs characterise brains.

For example, my research revolves around how patterns of connections between neurons within local cortical circuits relate to information processing mechanisms performed by those circuits. But it's only very recently (e.g. Ko et al. 2011, Cossell et al. 2015, Markram et al. 2015, Lee et al. 2016) that we have detailed experimental data to build a connection graph on a very small scale.

The "small-world" concept was highly influential in neuroscience for a few years, but it turns out that "small-world" doesn't tell you anything much about the computations performed by a network, or even tell you anything much about it's detailed structure.

The work of Sporns (2004) and others have been applied to large-scale experimental data characterising connections between cortical areas. But again, the network motifs that come out from these experimental data sets statistically don't tell us much about what is going on computationally, or even how these areas connect to each other on a fine scale. The problem here is one of physical resolution of the techniques used.

Some aspects of random matrix theory apply to the sorts of networks that we can build, simulating what we know about connections within the brain (e.g. Rajan & Abbott 2006, Muir & Mrsic-Flogel 2015). Much of random matrix theory doesn't apply however, since graphs of realistic networks are non-Hermitian and can be quite constrained.
> 6 votes

# Answer
Graph theory and complex networks are central to many works involving fMRI (, ), whole brain models (, ), protein interaction graphs (, ), and some EEG studies of consciousness (, , ). The problem is that neuroscience is a very wide field that emcompases many different specific questions, most of which are pointed at small features that dont envolve huge networks.
> 1 votes

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Tags: cognitive-neuroscience, cognitive-modeling, computational-modeling, mathematical-psychology
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# Question
Title: Does anxiety produce adrenaline or does adrenaline make the person anxious?
Its obvious that both are related(adrenaline and anxiety) but which causes which? What (I think) I know:

* Anxiety accelerates the hearth rhythm due to the feeling of fear. It makes the body believe that there is a need to spend an enormous amount of energy getting away(someway) so it cuts the blood flow in the cognitive parts of the brain and sends more blood to the other muscles, it also releases adrenaline in the blood due to the increasing need of energy(even if there is no real need).
* Adrenaline, (when released) makes the hearth rhythm increase and gives some "extra" power to the muscles by cutting the blood flow in the brain and giving it to the muscles. With the lost of blood flow in the brain the person loses a considerable part of the cognitive capacity (among other things), causing the person to have some feelings (like anxiety) and unreal thoughts.

Resuming my question: Anxiety results in a release of adrenaline, but adrenaline also makes the brain malfunction causing some feelings like anxiety. It makes sense but it is an infinite cycle. What is the false (and why), or if both are true then how does it ends?

# Answer
> 13 votes
Sorry for the delay getting to an answer - the holidays have been super busy for me this year.

If you feel up to it, definitely check out the link @ChuckSherrington posted in the comments. That has more information than you'll need for a while.

Getting down to business: The answer to your question is **both**!

Since your question assumes that both are related and affect each other, I won't go into how they do that.

However, to clear up some misconceptions:

## It's not a 1-to-1 cycle.

That is, the "amount" of anxiety *reduced* by reducing adrenaline is **not** the same as the amount of adrenaline reduced by reducing anxiety. Similarly, the amount of anxiety created by inducing adrenaline is small compared to the amount of adrenaline created by inducing anxiety.

## There are other factors at work

This is where the "parasympathetic" thing comes in. The human nervous system is actually two systems (broken up into the `Central Nervous System (CNS)` and the `Peripheral Nervous System (PNS)`, though the PNS is often broken down further).

One of the component parts of the `PNS` is the Autonomic Nervous System. This carries out the largely unconscious functions of daily life: breathing, heartbeat, digestion, etc. It is further split into two components: the `Sympathetic Nervous System (SNS)` and the `Parasympathetic Nervous System (pSNS)`.

A very rough and reductionist analogy would be to say that these two, together, are like two springs one either side of a ball (or something) - they keep each other regulated and in balance.

The `SNS` is responsible for very fast, excitatory activity. Fight or flight, for example. *The adrenal response is part of the sympathetic nervous system.*

The `pSNS` is a lot slower. One of it's primary functions is to return the body to a relaxed state after it was provoked in an excited state.

From the wiki-books article @ChuckSherrington posted:

> While an oversimplification, it is said that the parasympathetic system acts in a reciprocal manner to the effects of the sympathetic nervous system; in fact, in some tissues innervated by both systems, the effects are synergistic.

So as you hopefully have seen, as normal-functioning humans (which, to live, you must have both a SNS and a pSNS; it's not a question), you have a modulation response which keeps the adrenal response (the base response to a threatening stimulus that prepares the body for fast action) from getting out of hand.

Now, lastly, a disclaimer of sorts:

The link between neural activity and thoughts is tenuous at best! Many people are involved in many flame wars over the link between neural activity and phenomenology (experienced reality). The most direct view, and a very common one (from what I can tell) is the view that neural activity is reality itself. That is, our existence, our lives, our individual personalized reality, *is neural activity itself*.

But you will have to decide that question for yourself, because this is not a philosophy question/answer.

What's important is that the link between having thoughts and having feelings is not well understood. So adrenaline may make you nervous, but it may give Susie Randomgirl a panic attack (believe it or not, I know someone who can work themselves into a panic attack, every time - and they still don't get that they do it to themselves).

# Answer
> 2 votes
I don't think a causal relationship between the two has been established yet. I did read about an experiment conducted by Ulrich Bolm Androff, where the blood samples 10 physicians and psychologists were collected at 2 different times, once after they gave a public speech and once at the same time, on another day, and it was found that levels of epinephrine were found to be higher at the time directly after the speech was given. This does show a corelation between an anxiety inducing situation and levels of epinephrine, however, causal relationship cannot be established.

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Tags: emotion, physiology
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# Question
Title: The explanation behind the taboo behind rape/sexual assault versus acceptance of violence
I'm new here, so I apologise if this question doesn't fit the parameters required for this site, but I couldn't find a more appropriate stackexchange site to post it.

In TV shows, films, news and other forms of media, there is a very big taboo against portraying rape be it fictional, or a footage of the event. I can understand the sensitivity regarding the latter, but when we instead consider violent scenes, or footage of violence - our tolerance seems much higher. News channels, for example, conveyed the footage of a soldier being burned alive by ISIS in a cage. But depicting a video of a man inappropriately touching a woman would invite a huge backlash. To a lesser extent, this issue also extends to violence against women being portrayed in media (taking hollywood as an example, it is very rare that they convey violence against women, and if they do it is far less severe than that against men). This last point referring to violence which is not necessarily sexual in nature against women is not the main point of my question, but rather an observation which may or may not be relevant for an answer.

To summarise, what are the psychological reasons for our 'acceptance' of very severe violence in media whilst there is a strong taboo against comparatively less severe sexual assaults. (e.g. in Game of Thrones, compare the torture of Theon Greyjoy to the criticism of the implied offscreen rape of Sansa).

# Answer
Depiction of violence towards women triggers sadism in us much more effortlessly than other kinds of violence or torture. A recent study on correlation between violent videogames and violent attitude found no link between the two. But there are plenty of studies that show direct link between consumption of violent pornography and aggression towards women. Here is a meta study with tons of citations: http://aurora.umn.edu/pdf/ResearchOnPornography.pdf

Sadism is different from psychopathy. Psychopaths are apathetic, sadists are not. A recent study on sadism shows that sadists rated the pain experienced by the victim as more intense than the non-sadists did.

Inability to form emotional disconnection and higher awareness of the victim's suffering together can explain why we people triggered by sexual violence way more easily than non-sexual violence. From the famous Milgram experiment to very recent studies like this one:http://journals.sagepub.com/doi/abs/10.1177/0956797613490749 clearly show us that everyday sadism is very common. However, I don't know why sexual violence triggers sadism in us more easily than non-sexual torture.
> 2 votes

# Answer
You said

> In TV shows, films, news and other forms of media, there is a very big taboo against portraying rape be it fictional, or a footage of the event.

I don't know where in the world you are, but there have been many soaps and other TV shows depicting rape with varying responses. Here in the UK there have been rapes portrayed in all of the soaps I can think of. Coronation Street April 2001 is one example. There has also recently been the 3rd series of Broadchurch which dealt with rape and it's aftermath from the victim's point of view.

With static or moving images, possession of extreme pornography is illegal in the UK and showing an real rape or sexual assault recorded on CCTV within a TV programme or movie would be also be considered to be in bad taste.

As far as movies are concerned there are also a great number of movies containing rape of varying explicitness from mild to extreme. The Accused (1988) even won a fair few awards including an Oscar and a Golden Globe.

There have been a fair few movies which have been banned in some countries and some of the bans have been lifted in others. As for reasons for viewer backlash, maybe it is down to the sensitivity with which the subject matter is dealt with. This is open to opinion and therefore the answer to this would be off topic for this site.

## Severity of sexual assault

You also said

> there is a strong taboo against comparatively less severe sexual assaults. (e.g. in Game of Thrones, compare the torture of Theon Greyjoy to the criticism of the implied offscreen rape of Sansa).

I have not watched Game of Thrones and therefore I don't know what you are referring to, but a point I would like to make from the standpoint of someone who supports those who have been raped and sexually assaulted, although I cannot find any studies at the moment to reference, from the experiences of those I have supported, there is only one severity of sexual assault and all sexual assaults are as severe as each other when looking at potential psychological damage.
> 0 votes

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Tags: social-psychology
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title: Chunking: more chunks or more items?

text:
# Question
Title: Chunking: more chunks or more items?
I'm working on a game that's designed to exercise the player's short-term memory. In the core game loop, I present the user with a random set of items (anywhere from 3 to 30), and after they click start, ask them to regurgitate that set of items.

The items themselves are simple but arbitrary / semantically meaningless, eg. four colours (red/blue/green/yellow), or four arrows (up/down/left/right).

As I increase the game difficulty, what I want to know is: is it more difficult for humans to memorize *more groups* (eg. five groups of two items each), or smaller groups with *more items* (eg. two groups of five items each)?

I recall learning that short-term memory is generally seven items (plus or minus two, eg. 5-9 items) but I'm not sure how grouping/chunking affects that.

# Answer
> 3 votes
I think you're misunderstanding the concept of chunking. If the items are arbitrary with no connection to each other, chunking will do you no good since grouping them is meaningless and thus you're still memorizing the individual items in the groups instead of the groups themselves. This paper from Brady et al. goes into depth about the limits of working memory, I also recommend looking up the references mentioned. Here is a relevant passage about the definition of chunking from that paper:

> Cowan (2001) defined a chunk as a group of items where the intrachunk associations are greater than the interchunk associations. In other words, in the sequence FBICIA the letters F, B, and I are highly associated with each other and the letters C, I, and A are highly associated with each other, but the letters have fewer associations across the chunk boundaries. Thus, observers are able to recall the sequence using the chunks FBI and CIA, effectively taking up only two of the four chunks that people are able to store in memory (Cowan, 2001; Cowan, Chen, & Rouder, 2004). By comparison, when the letters are random, say HSGABJ, they are more difficult to remember, since it is more difficult to chunk them into coherent, associated units.

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Tags: short-term-memory
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# Question
Title: To what degree does environment govern the severity of symptoms in schizophrenia?
From what I understand about the physiology of schizophrenia it is thought to be caused by chemical imbalances resulting from genetic factors, fueled by environmental factors. I've garnered that environmental factors can play a large role in how a person reacts to the disease.

As an example: a person with a genetic predisposition towards schizophrenia is raised in an abusive household with his parents yelling everyday, they will definitely become angry and more stressed out, which one might assume would lead to their eventual psychotic break. Is this 100% correct? Another person who might be less stressed out, probably raised in a normal family, could potentially experience troubling symptoms before a complete psychotic break. Is this a valid assumption or observed pattern in those who suffer from the disease?

So, if environmental factors can contribute to the onset of schizophrenia, could the removal of these factors lessen the symptoms? Take for example Jared Loughner, he will be spending life in prison. With time away from society, with the stresses of life removed, and (given the correct medication), could incarcerated schizophrenia patients' symptoms be ameliorated by this change in social situation?

Any info on this?

# Answer
I think reading about the genain quadruplets should give you a clear idea of the effect of environment on schizophrenia. Basically, the quadruplets had a genetic disposition to this disorder and all 4 siblings were admitted at some point or another to the National Institute of Mental Health as schizophrenic. However, there were differences in the severity of the disorder in all 4 siblings due to the way they were treated by their parents, showing that despite genetic dispositions to a disorder, environmental factors do affect the severity of it.
> 1 votes

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Tags: neuroscience, abnormal-psychology, schizophrenia
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# Question
Title: Does the split brain disprove a materialistic mind?
According to materialism, the conscious mind is the product of the brain. Thus, if the brain is split in half such that the two hemispheres cannot communicate with each other, then there are three possibilities:

1. Both hemispheres gain their own conscious mind.
2. Only one hemispheres has a conscious mind.
3. A single conscious mind operates across both hemispheres.

Within a materialistic paradigm, #3 is impossible. There cannot be unified control without communication between the two hemispheres.

Option #1 is false according to this article,

> A new research study contradicts the established view that so-called split-brain patients have a split consciousness. Instead, the researchers behind the study, led by UvA psychologist Yair Pinto, have found strong evidence showing that despite being characterised by little to no communication between the right and left brain hemispheres, split brain does not cause two independent conscious perceivers in one brain. Their results are published in the latest edition of the journal Brain.

and this answer.

> So I conclude from \[sic\] this quick literature review that Joseph ascribes the presence of two minds based on something that can be explained at a more basic level, and hence by a more simple model, namely disinhibited motor control. Given the principle of parsimony, I conclude his observations were right, but that his conclusions were not.

Option #2 is false according to this answer. The answer state consciousness does not transfer to one half, but continues to operate in both halves.

> If by continuity you mean, "a feeling that I am who I was before the operation, (perhaps with some changes)", then it seems that each hemisphere would separately maintain continuity, in the same way patients after massive strokes and other sudden brain injuries don't usually feel "they are a different person".

Thus, only option #3 is viable according to the available data.

If option #3 is indeed the only possible explanation, yet is impossible according to materialism, then the materialistic explanation for the conscious mind is false.

A fourth possibility is there is an alternative communication pathway that is not severed, as hinted at by this answer.

> Keep in mind that there are many other pathways between the hemispheres besides the Corpus Callosum - such as thalamocortical circuits, those via the midbrain and brainstem and of course external sensorimotor feedback.

Is option #3 the only viable option, or do the halves somehow communicate in a different way?

# Answer
> 6 votes
The question title reads:

> Does the split brain disprove a materialistic mind?

The simple answer being **no**, nothing disproves that - the brain harbors the mind (*e.g.*, Lilienfeld & Arkowitz, 2008).

Now you mention that two hypotheses on split-brain patients are false, namely...

> 1. Both \[hemispheres\] gain their own conscious mind.
> 2. Only one \[hemisphere\] has a conscious mind.

...and I agree with them being incorrect hypotheses as suggested in the linked pages.

Now you proceed with...

> \[Does a\] single conscious mind operates across both \[hemispheres ?\]

Importantly, you state yourself that...

> \[...\] there are \[...\] other pathways between the hemispheres besides the corpus callosum - such as thalamocortical circuits \[...\] and those via the midbrain and brainstem \[...\].

So from my perspective, up until now you have answered your own question whether one single mind operates across two hemispheres in split-brain patients. Anyway, to illustrate some additional interhemispheric commissures besides the callosal pathway, see Fig. 1. This shows that '*split-brains* are in fact not entirely split; only the main causeway is severed.

Now there are wild stories about split-brain patients having a dual consciousness, including the paper by Joseph (1998) where the author speculates that one of his patients "*...was possessed of two minds*" based on the frustrations experienced by this person because his motor skills were erratic. Andrew & Akelaitis (1945) explain that split-brain patients can display *diagnostic dyspraxia* by an unbalanced inhibitory influence of the dominant hemisphere over the non-dominant side, explaining the uncoordinated behavior on the non-dominant side. These symptoms generally diminish over time, as the brain deploys alternative inter-hemispheric routing of communications.

Fig. 1. Interhemispheric pathways are indicated by numbers 1, 2, 3 and 4. source: Urbanski *et al*. (2014)

**References**
**-** Andrew & Akelaitis (1945) *Am J Psychiatr*; **101**(5): 594-9
**-** Joseph, *J Clin Psychol* (1988); **44**(5): 770-9
**-** Lilienfeld & Arkowitz, *Sci Am Mind* (February 2008)
**-** Urbanski *et al*., \*Front Integr Neurosci (2014)

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Tags: cognitive-modeling, neurophysiology, theory-of-mind, brain, pathology
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# Question
Title: Is "Schizophrenic" considered to be a derogatory or offensive term?
In US English, *"Schizoid"* is considered a derogatory term, while *"patient/person with Schizoid Personality Disorder"* is the "politically correct" term (and more accurate).

For this reason I wanted to be sure, is calling someone *"Schizophrenic"* (assuming the diagnosis is correct) considered offensive in any way? Is is more "correct" to use the full *"patient/person with schizophrenia"*?

# Answer
> 8 votes
You never know what's gonna offend *someone*...That being said, "hallucinations in people with schizophrenia" does seem the safer option, but "schizophrenics" (not capitalized) is used plenty often. Here's an interesting Google result:

> Schizophrenics Anonymous (SA) is a self-help group for persons who have schizophrenia or a schizophrenia-related illness.

I don't see them using "schizophrenics" outside of the title though, which further supports the use of "persons / people with schizophrenia". This follows a general guideline: one should avoid defining people by their afflictions and emphasize their personhood foremost. It might seem trivial with occasional use, but conflating a condition with an object category (person) might affect perception of those people, including their self-perceptions / identities, since these are largely matters of emphasis already.
<sup>(This is armchair theorizing without references...or any arms on the chair...Please edit or comment with any support or disagreement.)</sup>

# Answer
> 1 votes
In general, help groups and health authorities recommend avoiding labels such as "epileptics, schizophrenics, etc." and suggest "people with epilepsy/schizocphrenia, etc." "John is epileptic" can have negative connotations and also labels a person as being different, whereas "John has epilepsy" can be taken as John is a person (first and foremost) who happens to have epilepsy. He is not defined by his illness. However, in a clinical or scientific context, for example in a study report, I don't believe this is important; so it depends on the readership.

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Tags: abnormal-psychology, terminology, clinical-psychology
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