Showing posts with label autism. Show all posts
Showing posts with label autism. Show all posts

Wednesday, November 11, 2009

autism spectrum disorders, part deux

Another instance where the question begs to be asked: are handwriting patterns differentiated between autistic and Asperger children?

This study found quality of letter formation in the handwriting of children with ASD to be lower than in normally developing children.  The subject hasn't really been addressed since 2001, when Beversdorf et al identified the significant instance of macrographia in patients with ASD, as compared to age- and IQ-matched control subjects.  Both studies have subsumed autism and Asperger into the ASD umbrella -- just as likely for the purposes of procuring a larger test subject sample as for making their results widely applicable:
"Whereas all subjects with autism spectrum disorder met the diagnostic criteria for autism through their reported behavior during childhood, most subjects had demonstrated significant improvement in function over time, such that the distinction between the various forms of autism spectrum disorder was not as clear. Therefore the more general term autism spectrum disorder is used to describe these patients." (Beversdorf)
The original description of Asperger syndrome in 1944 noted difficulties in motor coordination, specifically in handwriting (Frith; translated 1991).  One year before, Leo Kanner published his first paper asserting that some autistic children were quite agile, performing "hair-raising feats of balancing," while others were clumsy "despite dextrous manipulation of objects" (Frith pg. 95). 

I would love to see a study comparing the different aspects of handwriting using both the Revised Physical and Neurological Examination for Subtle Sign (from the Kennedy Krieger Institute study), and the Autism Spectrum Quotient and Empathy Quotient tests used by Baron-Cohen's group to differentiate autism and Asperger syndrome.  Any cerebellar distinctions between autism and Asperger could be very illuminating...

Tuesday, November 10, 2009

autism spectrum disorders and dsm-v politics

An article in the New York Times this morning by Simon Baron-Cohen addressed the debate in the DSM committee over subsuming the conditions of Autism and Aspergers in the fifth edition of the "psychiatric bible"(promised in 2012).  The committee is deliberating whether or not to eliminate Asperger from the diagnostic manual and characterize its discrete symptoms as a degree of autism in the spectrum (perhaps "intermediate functioning autism").

Autism and Asperger syndrome are both characterized by impaired communication skills, a desire for keenly focused stimuli and strong inclination toward repetition. They are distinguished only by a slower onset of language skills and latency of intelligence in autism, says Baron-Cohen.  He further suggests that this distinction is proving not to be concrete enough, and that the DSM-V committee's struggle with the controversy can be attributed to the lack of physiological distinction of these psychiatric conditions.


I would agree with Baron-Cohen that there is not currently enough genetic distinction between autism and Asperger syndrome to warrant their being entirely separate conditions outside the spectrum disorders umbrella in the DSM-V.  However, I think that defining Asperger syndrome idiosyncratically is important to preserve in the new manual.  Here is why:   

1)  Baron-Cohen mentions his own group's recent identification of 14 Asperger-specific genes,19 genes specific to autism and 7 shared (Chakrabarti et al 2009).  They measured 68 candidate genes in two experiments: the first measured autistic traits in an undiagnosed sample population using the Autism Spectrum Quotient; the second, using the Empathy Quotient.  These two experiments were designed to identify autistic and Asperger cases among the sample:
"We searched for common genetic variants (single nucleotide polymorphisms (SNPs)) on the assumption that autistic traits are continuously distributed in the general population [Constantino & Todd, 2005; Sung et al., 2005]."
"In Experiment 1, autistic traits (measured on AQ and/or EQ) were nominally associated at P<0.05 with SNPs from 19 genes. In Experiment 2, SNPs from 14 genes were nominally associated at P<0.05 with AS."
Six genes were nominally significant in both experiments. This study alone suggests that Asperger syndrome deserves a distinction as a sub-group in the Autism Spectrum Disorders (ASD) category that the DSM-V committee is considering, as opposed to eliminating it entirely, as is also being considered.

The Charkrabarti study is impressive, and the first step in the important attempt to identify the genetic and epigenetic correlates of autism and Asperger separately.  However, there is still an extensive amount of correlative research to be done.  A good amount of this is ongoing through the AutDB Project.

2)  If for no other reason than to preserve the honor of the venerable Hans Asperger.

3)  To keep company the solitary other recognized ASD, Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS).*  Perhaps these could both become sub-groups in the ASD category.

It is noteworthy that a great deal of genetic research already refer to their studies as ASD interactions/links/correlations (PubMed or Google Scholar this).  I am terribly eager to find out whether or not this plays a strong role in the decision of the DSM-V committee.


*High- and Low-functioning autism are not classified as spectrum disorder subgroups, although they should be... and perhaps, one day, will be, provided there is a physiological distinction to be drawn between them, Asperger and PDD-NOS.

Saturday, August 2, 2008

speech, autism and collective consciousness

“…a creature cannot have thoughts unless it is the interpreter of the speech of another.” -Donald Davidson (1975, p. 9)

Initial response: ...what?!

Secondary response:

The man is suggesting that communication through speech is the only means by which a creature is able to generate thought, implying that language is the primary vehicle of thought, rather than vice versa. I think that's dumb. The primary vehicle of thought need not be speech; it could more than conceivably be entirely driven by behaviour.

Follow me for a minute here.

A thought can be a belief. A belief is based on the way things are in the actual world. The way things are in the actual world can be interpreted through the behaviour of creatures in the world. Even if it were true that belief emerged only in those organisms capable of interpreting the behaviour of others, it doesn’t follow that that interpretation need be of speech. Thought could be generated merely on the basis of interpretation of behaviour for which speech is not necessary.

[note: the necessity of internal language is an entirely separate issue...]

Translating this into an example - as my philosophy professors would demand is crucial to my train of thought - say two primitive children witness an avalanche of boulders cascading down a nearby mountain. They may be standing close enough to the avalanche to feel the ground shake, and that a small stone may ricochet from it’s main course and hit one child in the arm. The child, having felt the sting of the stone, generates a thought correlating bounding stones with pain, and that if such a small stone inflicts pain then standing beneath the whole cascade will deliver far worse. The child can then infer that it is a good idea to avoid being in close proximity to avalanches. And... run. The second child, having witnessed the discomfort expressed by and the fleeing of the first, may infer from his behaviour that it is wise to avoid avalanches. The first child generated a thought about avalanches based on the behaviour of the cascading boulders, and the second child generated the same thought based on the behaviour of the first child... with speech being a component of neither scenario.

Yes, it can also be provoked by speech alone if a creature were to be told by another that an approaching avalanche was potentially very harmful. However, provocation of thought about the avalanche through the latter scenario would require that the creature, in order to recognize the implication of an avalanche from only the speech of another creature, must have seen it inflict harm before in the content of the phrase “approaching avalanche” could have any meaning. This doesn't make it less likely that the creature could have a belief about the avalanche as solely regarded through speech. Rather, it suggests that witnessing an avalanche harming someone does not require speech to communicate that one might want to avoid cascading boulders...

The other confound of the "no thought without speech" theory is that it can be used to argue against thought in higher animal organisms, as people actually do make the argument that non-human animals can't communicate through speech [this is another assumption with which I have extensive arguments]. And while I'm a proponent of learning and memory being entirely biochemically and anatomically structured in some processes, there is also a component of consciousness that becomes necessary to explain the acquisition of the kind of behaviour learned in higher animals. There's a communication that occurs between human and animal in instances of learning that are not classical conditioning, which suggests thought in the mind of the animal as it interprets the behaviour of its trainer or owner, or what have you.

And then we have the instance of Davidson's awkward collision with cases of Autism. Since he purports that to be a thinker you must be a speaker interpreting other speakers, it then follows that Davidson must believe that Autistic people - who have monstrous trouble interpreting the minds of others but who can put together their own coherent thoughts (Baron-Cohen 1995; Harris 1991)- are not capable of thought. Which, as you might imagine, perplexes me. Thought, as I categorize its nature, can exist irrespective of lingual communication, and as such, does exist in the minds of autistic beings despite their inability to interpret the mental states of others through their speech. Since Davidson's original argument was way back in 1975, it's a struggle to get my hands on - but am still trying to locate - his response to this more recent confound to speech being the primary vehicle of thought, and thought being nonexistent without interpretation of speech. I imagine him saying something to the like of, "autistic beings do indeed interpret speech, they simply do so incorrectly and so they are able to have thought, but only based on fallacious interpretation." [and yes, he would use the word, fallacious]. Then again, responding as such negates Davidson's other stipulation which is that to be translated into a thought, the speech of another person must be interpreted as the speaker intended.

What I maintain is that when Davidson originally proposed this theory, it was meant to be applied to a confined arena of communication and interpretation... in that one might not be able to have correctly designed thought unless in response to the speech of others.

Here is where I skid off the rail, but where my train gets interesting.

In terms of collective consciousness... it would seem that interpretation of speech were completely devoid of purpose, and that Davidson's theory would be completely null. If we are all linked by consciousness (and that includes non-human animals on the level at which they exhibit it) then interpretation of speech is a useless tool except to distance us from being aware that collective consciousness might exist. So there we have the collective conscious arguing against the utility of speech. Then again, if collective consciousness were a fully functional medium, we would never misinterpret one another's speech... or letters... or online chatter... would we. But by the same token, would autistic beings - under the condition that they might even be able to participate in collective consciousness - cease to have this symptom of not quite being able to grasp the mental states of others as portrayed by their speech or any other means?

So perhaps, if we were, as a species - or as a kingdom of organisms, for that matter - to become aware of our collective conscious, would our interpretation of one another improve? Would we disable the function of war? Wouldn't we have a more comprehensive understanding of the international economic dynamics such that "globalization" and recession could be side-stepped entirely? Would sociology even be necessary?

And there you have it. Thought as independent of interpreting speech. Davidson, I like you. Don't say dumb shit.

Monday, March 17, 2008

empty thoughts IV

4. Whyyyyyyy is it obvious that because autistic children have an impairment in only a particular type of reasoning that one type evolved separately from the other? Explain to me how this is in any way a solid framework to make this broad of a conclusion with any certainty.

Thursday, February 28, 2008

empty thoughts III

3. Fiona Scott and Simon Baron-Cohen conclude that the deficit in autism is due to an impairment of psychological reasoning, as opposed to logical or analogical reasoning. This seems to suggest a deficit in “mindblindness,” not Gestalt perception, as addressed by the article. Because mindblindness is defined by Baron-Cohen in another article as an inability to be aware of what is in another person’s mind, it becomes a separate issue from Gestalt perception entirely. The logical and analogical tests demonstrated that autistic children can reason with representations of representations, and identify relation between relations, which suggests that their perceptive grouping is intact, which is clearly not the case. I don’t get it.

The authors say that their evidence shows the deficit to be due to m-representation; the inability to represent and agent’s attitude toward something. They do not speak of which of their results support this, but continue to say that autism is more likely due to the child’s inability to represent mental states...metarepresentation? What is this jump they are making to conclude that this is an impairment of psychological reasoning? It makes more sense to me that an inability to represent mental states would reflect a deficit in analogical reasoning.

I would have appreciated a more direct response to their three main hypotheses. Speculating the three intelligence paradigms of logical, analogical and psychological reasoning were a strong approach to the question of whether autistic children are impaired selectively in psychological and not in non-social tasks. However, I think the importance of their conclusions was missed, and their discussion generally lacking, and did not address the relation of their various tests to their hypotheses... Neither do they definitively support or object to Cosmides’ theory which is the title of their paper. It seems that since Scott and Baron-Cohen concluded that social intelligence has evolved separately from non-social intelligence, they would discuss Cosmides’ theory that intelligence evolved to solve social problems.

so basically, my disappointment reflects that which I typically hold toward psychology papers... pity.

Sunday, February 3, 2008

empty thoughts I

1. one of the keystone deficits of autism is the inability to filter visual/auditory stimuli into hierarchical importance. evolutionarily speaking, i wonder what it is about “goal-, ancestral- and expertise-derived criteria” that is lost on these victims. a way in which autistic people cope with this lack of filtering is to focus obsessively on a single thing to override all the other stimuli they cannot make sense of at once. why do they preferentially focus on inanimate objects (banging head against the wall, counting toothpicks, etc.) when animate objects are more crucial for survival? Is there support for the counter hypothesis (“no mechanisms for deploying attention to animate objects”)?

*New et al 2007. Category specific attention...