Posts tagged autism
Can the Cotard’s syndrome tell us something about the self? A person suffering from Cotard’s syndrome is likely to claim that he/ she is dead- can such a delusional experience make us appreciate what self is what it isn’t – and more importantly how the sense of self can go awry in some phenomena?
Anil Ananthaswamy, in his exquisitely written book ‘ The Man Who Wasn’t There‘ beautifully illustrates how Cotard’s and other such weird and not so weird phenomena can shed light on the true nature of self (provided the self exists and there is something it is like to have a self- more about this later).
The book is beautifully written, weaving narratives of actual patients suffering from various disorders, with cutting edge research in the field and at all times tying it back to the nature of the self.
Although the eight chapters talk about eight different phenomena- ranging from Cotard’s to deperosnalisation to Autism to schizophrenia to out-of-body experiences and ecstatic epilepsy to BIID ( or having a desire to amputate ones limbs) and Alzheimer’s – there doesn’t seem any discontinuity- nor does it seem as if disparate phenomena are being talked about. With self being the focus, each of these is used to approach the self from a different angle.
I am reminded of the parable of blind men and the elephant – whereby each blind men could only grasp one part of the elephant. Self is such an elephant in the room. The various chapters do advance our understanding of the self and fortunately, this time, the sum is greater than the sum of the parts, and we are indeed able to get a sense of the elephant/self!
It would be naive to assume that Anil would have solved the problem of self where great philosophers or scientists of past and present have failed to do so- but he does gives tantalizing glimpses of what the answer might me and at least brings us up to speed with what is being thought of in the philosophical / scientific circles.
The power of the book comes from its very approachable and readable writings style and the humane treatment of its subjects. Whether its the isolation felt by a BID sufferer who has no means of getting his limb amputated legally or the strangeness felt by those suffering from deperosnailsation, Anil makes the stories vivid- loud and clear in one’s mind;s eyes.
The book is also chock full of interesting facts- some of which I was already familiar with, but got an opportunity to brush up on the latest happenings in the filed, others were new to me – for example I hadn’t realized that people with Cotard’s are typically depressed or that people remember more about their life from between 10 and 30 years (the reminiscence bump) and many such nuggets.
The book is immensely readable and holds your attention from chapter to chapter. I was almost felling bad about having finished it as I wanted more of the treats to continue. In a week in which we lost Oliver Sacks, it takes some solace to discover that there are others who are keeping the tradition alive.
Both the erudition , humanity and narration of Anil is superb. While reading the book, I thought he was himself a prominent neuroscientist- its only post reading it I realized he is a science journalist and has also written a best seller in physics. Surprising how brilliant people are able to make their mark in whatever field they chose to focus on. Quiet coincidentally I had also reviewed ‘Subliminal’ by Leonord Mlodinow- who is also a physicist but has written a good book rooted in psychology.
My advice to readers of this blog- if you loved Sacks, if you loved VS Ramachandran, or even if you didn’t or haven’t heard about them, do give this book a read- you are going to love the easy style- yet a lot of substance. I, for one , am eagerly looking forward to Anil’s next read.
A new study by Ruthsatz and Urbach is doing the rounds nowadays. That study has nothing to do with Autism or ADHD per se. The study focuses on child prodigies and finds that they have high levels of intelligence, enhanced working memory and that they pay attention to details.
What the study also found was high level of autistic relatives and high scores on Autism spectrum for the prodigies. The relation between autism and prodigiousness was mediated by the endo-phenotype ‘paying attention to detail’ and none of the other symptoms of ASD seemed to play a role.
Many savants also are high on ASD and have exception working as well as long term memory. There too they pay excessive attention to details and are fascinated by speical interests.
On the other hand there is gathering literature that suggests that the ADHD kid is basically on the creative side of the spectrum – restless, trying multiple strategies, having diffused and peripheral attention, and to an extent novelty and sensation seeking.
Also, if one thinks about that for a minute, autism and ADHD seem to be opposed on a number of dimensions. The three basic features of ADHD are 1) inattentiveness and distractibility vs too much focus and fascination for an object shown by Autistic kid 2) impulsiveness vs restricted and repetitive motions and interests of the autistic kid and finally 3) hyperactivity vs restrained interactions and communications of the autistic kid.
There is also some data from fly models that suggest that autism and ADHD are opposites in a sense.
I may even go ahead and stick my neck and say that while autism is primarily characterized by emotion of Interest/ fascination/ attention ; ADHD is characterized by emotion of Wonder/Awe/surprise.
One theory of autism suggests that the social and communicative difficulties arise as the child hides in a cocoon to prevent over-stimulation and sensory overload; a theory of ADHS says that the child is under-stimulated and needs stimulants like Ritalin to achieve baseline of activation and sensory stimulus.
Another popular theory of autism posits that it arises primarily due to ‘weak central coherence’, or inability to see the context/ gestalt/ ‘the big picture’. The ADHD kid on the other hand is hypothesized to use a lot of peripheral attention and daydreams missing what is being centrally taught in the classroom.
And that brings me to the root of the differences in my opinion; while the Autism spectrum is characterized by a local processing style, the ADHD-psychotic spectrum is characterized by a global processing style.
Some clarifications are due here. I believe ADHD to fall on the psychotic spectrum and have been proposing the autism and psychosis as opposites on a continuum model for close to eternity.
Also, when I say global/local processing styles I dont restrict the application to perception alone, but extend it to include cognitive style too.
There is a lot of work that has been done on global/ local processing styles with respect to perception, using Navon letter tasks and it is fairly established that normally people lean towards the global processing style.
Forrester et al extend this to cover there GLOMOSYS system that posits two basic types of perceptual/cognitive style- global and local.
It is instructive to pause and note here that psychosis is associated with a global processing style while autism with attention to details.
It is also instructive to pause and note that similar to autism-psychosis continuum , it seems Intelligence and creativity are also in a sense opposed to each other. Also while creativity is associated with broad cognitive style that is divergent; intelligence is conceived of as narrow and focused application of abilities.
That brings me to my final analogy: while autistic kids may have pockets of intelligence and savantism and may be driving the evolution of intelligence; it is the ADHD kids who are more likely to be creative and are driving the evolution of creativity.
The romantic notion that psychosis is the price for creativity may not be untrue.
Joanne Ruthsatz, & Jourdan B. Urbach (2012). Child prodigy: A novel cognitive profile places elevated general intelligence,
exceptional working memory and attention to detail at the root
of prodigiousness Intelligence DOI: 10.1016/j.intell.2012.06.002
Jens F¨orster, & Laura Dannenberg (2010). GLOMOsys: A Systems Account of Global Versus Local Processing Psychological Inquiry, DOI: 10.1080/1047840X.2010.487849
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
It has been this blog’s thesis that autism and its milder form autism spectrum disorders (ASD) are diametrically opposed to psychosis and its milder form schizotypy. In no area is this more apparent than in the perception or attribution of minds to others. It thus gave me immense pleasure to read this new article by Wegner et al that looks at how the perception of others’ mind is affected in different sub-clinical conditions like ASD, Schizotypy and Psychopathy.
Wegner et al review a great deal of literature to come to the conclusion that others’ mind perception is a two dimensional construct and that we typically attribute mind to an entity depending on whether the entity can experience like us and whether they have goals and agency like us. Thus people can differ in the perception of either Agency or Experience when they attribute mind to an entity. Also b reviewing the available literature they came to the hypothesis that ASD folks should attribute less of agency , but perhaps equal experience to other humans and other entities as compared to controls; Schizotypals on the other hand have been shown to attribute more of mind and in particular agency to other entities than human. They also hypothesized that owing to lack of empathy the psychoptahs might perceive all animals/humans as lacking experience and thus mind-deficient to an extent and subject to manipulation.
They used online surveys to ascertain scores on ASD, schizotypy and psychopathy and correlated that with mind perception and attribution inclinations. How they assessed mind perception was by letting the subjects ascribe perceived experience and perceived agency to nine entities viz. baby, dead woman, dog, God, man , robot, Superman, tree and woman. They performed a confirmatory factor analysis that confirmed that indeed mind perception has two components- Experience and agency.
They got results in line with their hypothesis. ASD folks did not differ in ascribing Experience to fellow humans but did differ in ascribing agency. Schizotypals on the other hand ascribed too much agency to Robots/animals etc; and in general attributing min dto even things like tress , god and dead woman. Psychopaths on the other hand showed reduced ascription of Experience to other humans as well as animals. As an interesting aside, psychopaths attributed more mind to superman perhaps self-identifying with the fictional character
Thus, though mind perception in both ASD and Schizotypy is distorted it is tilted one way in autism and the other way in psychosis. With clinical populations the authors hope to get even stronger results. I am pleased because finally people have started taking the autism is opposed to psychosis paradigm seriously and have started doing research around it that is leading to fruitful results and confirmations.
Another new study that I came across recently and would like to link to found that VPA (valproic acid) treated mice were indeed an apt model of autism in mice and had the same brain correlates and signatures as in Autistic people. It is worth noting that VPA/sodium valproate is used to treat psychosis and I have pointed earlier too how this indicates that autism and psychosis are di\ametrically opposed. It is good that we are getting multiple confirmations of the important autism-psychosis opposition theory.
Gray, K., Jenkins, A., Heberlein, A., & Wegner, D. (2010). Distortions of mind perception in psychopathology Proceedings of the National Academy of Sciences, 108 (2), 477-479 DOI: 10.1073/pnas.1015493108
I have written previously about CNV’s and how de novo CNV’s have been recently shown to correlate with disorders like autism and schizophrenia. I have also been militantly proposing that autism and psychosis are diametrically opposed disorders and have been gladdened to find that recent CNV data support that hypothesis. I reported how 16p11.2 duplications were associated with schizophrenia while micro-deletions at same site associated with autism. I also reported how a larger study which looked at multiple CNVs found the same reciprocal effects on CNV sites for autism and schizophrenia, thus bolstering the hypothesis that these are diametrically opposed.
By now you might be wondering what all this has to do with ADHD? Well, for one, early this year I started expanding my model and started conceptualizing ADHD as opposed to Autism in childhood and ADHD thus as belonging to psychotic spectrum; I mused that perhaps the same genetic vulnerability that leads to ADHD in childhood could lead to the manifestation of psychosis in teenage/adulthood. Its worthwhile noting that both ADHD and Psychosis are highly correlated with creativity.
So I could not stop my exuberance at finding that CNVs at another site 16p13.11 has been implicated in ADHD and the duplications are present in both ADHD and Schizophrenia. Also, as per the same study , ADHD children carry a large number of de novo CNV’s – a pattern similar ro Autism/schizophrenia. Some, for example the Neuroskeptic, have taken the same loci of CNVs to mean that these CNVs just confer a general risk of maladaptation, but I think they are missing the forest for the trees. The pattern points to the diametrical model and how CNvs are one mechanism in which tug-of-wars are played (whether evolutionary variation or parent-offspring or between paternal and maternal genomes).
Let me explain what I mean by tug-of-wars. Say you have a evolutionary trade-off between exploration and exploitation, with one extreme being useful in some extreme environmental niche (say food is abundant) and the other strategy useful in the opposed environmental niche (say food is scare) . The trait that gets stabilized should have a bell cure distribution so that the a species can survive even if environment leans toward one extreme. The way to archive this could be by having distribution of frequency of different alleles; or it can be via CNV mechanism. You may have some gentic loci for exploration and have a single popular gene allele that codes for exploration at that loci and CNVs that cause deletions here will lead to more exploitation while CNVs that are duplications will lead to more exploration. Thus, by CNV mechanism one can have more of good thing or less of a good thing, good depending on context (i.e context says what is ‘good’).
To take the example of 16p13.11 – it seems it is somehow related to mental retardation/ creativity/intelligence. A deletion at this site causes mental retardation/multiple congenital anomalies.=, while duplications have benign effects. I would conjecture that duplications (associated with ADHD and schizophrenia) may actually increase intelligence/ creativity. That woudl fit with the diametrical model and the finding that ADHD kids are more creative nd develop language more readily than autistic kids of same age.
I am pasting the background and findings from the abstract below:
Large, rare chromosomal deletions and duplications known as copy number variants (CNVs) have been implicated in neurodevelopmental disorders similar to attention-deficit hyperactivity disorder (ADHD). We aimed to establish whether burden of CNVs was increased in ADHD, and to investigate whether identified CNVs were enriched for loci previously identified in autism and schizophrenia.
Data for full analyses were available for 366 children with ADHD and 1047 controls. 57 large, rare CNVs were identified in children with ADHD and 78 in controls, showing a significantly increased rate of CNVs in ADHD (0·156 vs 0·075; p=8·9×10?5). This increased rate of CNVs was particularly high in those with intellectual disability (0·424; p=2·0×10?6), although there was also a significant excess in cases with no such disability (0·125, p=0·0077). An excess of chromosome 16p13.11 duplications was noted in the ADHD group (p=0·0008 after correction for multiple testing), a finding that was replicated in the Icelandic sample (p=0·031). CNVs identified in our ADHD cohort were significantly enriched for loci previously reported in both autism (p=0·0095) and schizophrenia (p=0·010).
To some the fact that ADHD had the same loci as both Autism and Schizophrenia may speak against there being a diametrical relation; however the same was claimed when initially it was found that autism and schizophrenia CNVs were at the same loci; only after looking at the nature of CNV’s (whether duplications or deletions) were the researchers able to identify the diametrical nature of the CNV’s
I haven’t read the full paper yet (waiting for someone to send me the paper) and as and when I get my hands on the full paper, I’ll update this blog post with more details.
Williams, N., Zaharieva, I., Martin, A., Langley, K., Mantripragada, K., Fossdal, R., Stefansson, H., Stefansson, K., Magnusson, P., & Gudmundsson, O. (2010). Rare chromosomal deletions and duplications in attention-deficit hyperactivity disorder: a genome-wide analysis The Lancet DOI: 10.1016/S0140-6736(10)61109-9