Archive for February, 2012
Abundant evidence exists that psychosis is more prevalent in urban areas as compared to rural areas. The fact that living in the city makes one vulnerable to psychosis is not up for debate – but healthy debate ensues about the mediating mechanisms.
Last year, Zammit et al claimed that the high incidence of psychosis in urban settings is a result of greater social fragmentation in urban areas.
Today I came across a study [pdf] that had nothing to do with psychosis and came up with this novel hypothesis that the mediating mechanism may be global versus local focus or processing style. If that seems farfetched, bear with me for a while.
First a bit of background, the new study was referenced by Christian Jarrett in a BPS research digest blog post in which he lucidly shows that it has been found that living in urban areas has been found to be associated with a propensity for global processing style (seeing the forest); while living in rural areas has been found to be associated with a local processing style (focusing on the trees and missing the forest).
The study itself is pretty straight forward; in one of the local/global task it used the famous Ebbinghaus illusion (see image) to measure the amount of bias towards global vis-a-vis local processing.
In the second task it used large, composite (global) shapes/letters made of small, parts (local) which were also themselves shapes/letters and then measured whether one was more drawn in making inferences/similarity based on global percepts or the local figurine.
The study measured this global vs. local bias in Himba society (Namibia) members who had varying level of exposure to urban environments as well as Japanese and British urbanites. What they found was that living in urban areas/ exposure to urban areas was significantly predictive of whether you would lean more towards more global mode of processing. The authors link this with more ‘visual clutter’ in the cities necessitating a global style of processing.
Christian mentions in passing the fact that autistic people have a very local bias of processing and are marked by weak central coherence; what he perhaps doesn’t realize is that psychotics, which have been conceptualized to lie diametrically opposed on a continuum from autistic, have a global processing bias and a strong central coherence.
Badcock and Crespi, and I even before them, have been crying from the rooftops to conceptualize psychosis and autism as diametrical disorders – and some investigators have paid heed. Suzzana N et al [pdf] have recently shown that as conceptualized by Badcock and Crespi , Autistics and Psychotics are actually at opposed ends of local vs global processing.
We refer particularly to Crespi and Badcock (2008), who make the novel claim that the autism and positive schizophrenia spectra are diametrically opposed. They argue that individuals with autistic traits and individuals with positive symptoms of schizophrenia (e.g., magical ideation, unusual perceptual experiences and paranoia) should exhibit opposite cognitive profiles. The current investigation focuses specifically on their claim that autistic and positive schizophrenia traits contrastingly affect preference for local (i.e., piecemeal) versus global (i.e., integrative) processing.
Crespi and Badcock (2008) argue that while autistic traits are associated with a preference for local over global processing, positive schizophrenia traits are associated with a preference for global over local processing. That is, these authors claim that while individuals with autism show a tendency to focus on detail or process features in their isolation, individuals with traits of positive schizophrenia show a tendency to look at the ‘bigger picture’ or process features as an integrated whole. Although a preference for local processing fits theoretically with the tendency of individuals with autism to notice minor features or changes to the environment that are often overlooked by others (Hayes 1987), the link between traits of positive schizophrenia and a preference for global processing is less obvious. It is hypothesized though, that a global processing style could contribute to the complex delusions and enhanced creativity for individuals with positive schizophrenia (Nettle 2006; Oberman and Pascual-Leone 2008), as well as the tendency of these individuals to make ‘‘loose” associations between words and between aspects of the environment (Maher 1983; Spitzer 1997; Spitzer et al. 1993). Importantly, the effect of such loose associations is that one thought does not logically relate to the next, and thus these associations may be strongly linked to the hallucinations and delusions experienced by individuals with positive schizophrenia. However, while there are potential links of local and global processing to features of autism and positive schizotypy, the preferred processing styles for individuals with autistic and schizophrenic traits are yet to be examined together in the one investigation. Therefore, the current study aims to provide the first complete empirical test of Crespi and Badcock’s claim regarding local-global processing.
And this is exactly what they found. They used an embedded figural task to assess the global vs. Local bias and their results showed that indeed psychosis prone individuals had a more global style of processing.
Now one thing I am good at is putting two and two together and the moment I saw the new study correlating global style with urban living, a lot of pieces fell into place. Form the above it is apparent that global processing style may be an intermediate mediating factor that leads to association between urban living and psychosis.
What neural mechanism may be involved?
To quote from the Suzzana et al paper again:
The contrasting preferences for local versus global processing are identified with differences in brain connectivity in particular (Crespi and Badcock 2008). Reference is made to both structural (intrahemispheric and interhemispheric) and functional connectivity. Specifically, Crespi and Badcock argue that the preference for local over global processing displayed by individuals with autistic traits, compared to controls or individuals low on autistic traits, is a result of increased connectivity within neural regions relative to decreased connectivity across regions (Courchesne and Pierce 2005a, b; Happe´ and Frith 2006). Crespi and Badcock then argue that schizophrenia is associated with decreased connectivity within neural regions relative to an increased connectivity across brain regions (Colger and Serafetinides 1990; Siekmeier and Hoffman 2002), leading individuals with traits of positive schizophrenia to favor a global (over local) processing style, compared to controls or people low on these traits. These differences in brain connectivity for autism and positive schizophrenia are said to be mediated, at least in part, by genomic imprinting.
While genomic imprinting may be one mechanism, maybe there is something about exposure to urban environments (maybe it’s ‘visual clutter’) that also has a similar effect on pruning of synapses and unduly affect local pruning at the cost of pruning between widely separated regions thus leading to global processing bias.
Instructive to pause here and note that in children they start with local bias and around 6 year of age revert to global bias that adults typically have and this is mediated by synaptic pruning. See this open access PLOS one article.
Thus, it seems Psychosis and the City are intimately connected; and that, this is because, to live in a city, you need to (de)focus on ‘the big picture’.
Caparos, S., Ahmed, L., Bremner, A., de Fockert, J., Linnell, K., & Davidoff, J. (2012). Exposure to an urban environment alters the local bias of a remote culture Cognition, 122 (1), 80-85 DOI: 10.1016/j.cognition.2011.08.013
Crespi, B., & Badcock, C. (2008). Psychosis and autism as diametrical disorders of the social brain Behavioral and Brain Sciences, 31 (03) DOI: 10.1017/S0140525X08004214
Zammit, S., Lewis, G., Rasbash, J., Dalman, C., Gustafsson, J., & Allebeck, P. (2010). INDIVIDUALS, SCHOOLS AND NEIGHBOURHOODS; A MULTILEVEL LONGITUDINAL STUDY OF VARIATION IN INCIDENCE OF PSYCHOTIC DISORDERS Schizophrenia Research, 117 (2-3), 181-182 DOI: 10.1016/j.schres.2010.02.223
Russell-Smith, S., Maybery, M., & Bayliss, D. (2010). Are the Autism and Positive Schizotypy Spectra Diametrically Opposed in Local Versus Global Processing? Journal of Autism and Developmental Disorders, 40 (8), 968-977 DOI: 10.1007/s10803-010-0945-7
This post originally appeared on my Psychology Today blog “The Fundamental Four” on 13th Dec. 2011. This is cross-posted from there.
Some days back, Vaughan Bell of Mind Hacks blog linked to a blog post from Sabrina, of the Notes from Two Scientific Psychologists blog, and they both lamented the fact that modern psychology has a pre-dominantly western slant and speculated what might have been the case had psychology been developed under Korean influence (where for example Mind is ‘Maum’ or composed of feelings, motivations etc as opposed to being cognitive in nature).
In the West, and, specifically, in the English-speaking West, the psychological aspect of personhood is closely related to the concept of “the mind” and the modern view of cognition. But, how universal is this conception? How do speakers of other languages think about the psychological aspect of personhood?
In Korean, the concept “maum” replaces the concept “mind”. “Maum” has no English counterpart, but is sometimes translated as “heart”. Apparently, “maum” is the “seat of emotions, motivation, and “goodness” in a human being” (Wierzbicka, 2005; p. 271). Intellect and cognitive functions are captured by the Korean “meli” (head). But, “maum” is clearly the counterpart to “mind” in terms of the psychological part of the person. For example, there are tons of Korean books about “maum” and body in the same way that there are English texts on “mind” and body.
Today I wish to extend the debate and focus specifically on how psychology might have been if it had been developed under Indian influence.
Firstly, instead of focusing on the somewhat dubious mind-body duality, we would be focussed on the more fruitful matter-consciousness duality.
As per the Samkhyaa (or Number- based) system of Indian philosophy (the oldest philosophical tradition), the world is composed of two distinct fundamental realities. The first is Purush (sentient pure consciousness) and the second is Prakriti (insentient Nature) and these two are not reducible to each other. This is very strong form of dualism.
The Purush is supposed to deform the Prakriti and this interaction leads to Prakriti splitting into 24 tattvas (or 24 basic elements) and that is the reason we see such diversity in nature.
Before you lose patience and leave as to what this has to do with personhood and mind, just bear with me for one more minute.
The prakriti gives rise to Mahat Tatva or Buddhi (intellect) as the first of the 24 elements. This is the subtlest aspect of a life form. Buddha or enlightened one derives from being at this stage.
From Mahat rises Ahamkar or Self and I. This is of three forms – sativk (stable; I, the observer) , rajasik ( in motion; I, the doer) and tamasik (stationary; I, the unchanging) .
From Ahamkar arises Mann (feelings) and Chitta (unconscious memories and precepts).
The ‘antahkaran‘ or the equivalent of subjective aspect of personhood i.e. what is referred to as Mind in English is made up of these 4 element - Chitta (unconscious memories, precepts etc) , Mann (feelings) , Ahamkar (sense of I or selfhood) and Buddhi (Intellect or reason).
Thus the second difference, if Psychology had evolved in India, would have been that Mind would not be predominantly cognitive and conscious in nature , but will have had unconscious aspects, as well as conscious aspects of feeling, willing and deciding.
To continue on the Samkhya evolution (from subtle towards grosser aspects of personhood), Mann gives rise to 5 Sense organs (gnyana indriyas) and 5 Action organs (karma indriyas); while chitta gives rise to 5 Mahabhut (matter forms) and 5 tanmatras (matter qualities).
Here I believe is where modern Psychology has heavily gone astray. Most scientists conceive of brain as an information processing tool and lean towards sensation, perception and believe that brain evolves basically for these purposes and action or movement is secondary; thus the focus on the 5 sense organs – those of vision, audition, somatosensation (touch), olfaction (smell) and gustatory (taste).
Psychology harps about these 5 sense organs but is silent on the agentic conception of the person/ life form whereby it is movement for which brains have evolved. A stray scientist like Daniel Wolpert or C H vanderwolf makes the case for primacy of movement and action , but that voice is easily lost in the cacophony surrounding research on vision and other senses.
Indian psychology/ philosophy/ religion puts action organs at equal footing with sense organs and implicitly imply that brains or mind is for both sensation/perception as well as for action/motion.
The five karmendreyas (action organs ) are mouth (from whose movement speech flows), hand (to handle tools) , feet (for locomotion), excretory organs (for pushing out the residues) and reproductive organs ( to inject / take inside reproductive material from a partner.
Thus, I guess the greatest contribution that Indian culture would have made to psychology would have been by making it more even handed towards both research paradigms focused on sensations and perceptions as well as research paradigms focused on action and motion.
What unique perspective does your culture/ religion offer on the sense of person-hood, the cultural nature of mind or the framing of the mind-body problem. Let us get as many insights from other cultures as possible and loosen the grip of WEIRDism on Psychology.
c: copyright: 2011 Sandeep Gautam