8/05/2009

Normal-IQ ASD adults show smaller false memory effect: could context blindness be responsible?

This study is somewhat out of date (2005), and anyone interested is probably already aware of it. But I'm writing about it here because it ties in with a lot of the ideas I've talked about in earlier posts.

This study from Ohio State University supports the "caetextia" theory that high-functioning people with ASD have problems understanding context and using it to draw inferences. Furthermore, that's hard for them in more than just social situations.
"Autistic people usually can't grasp the full meaning, or context, of a situation," [Ashleigh Hillier] said. "This often leads to difficulties in social settings, as making inferences from what someone else says or thinks is extremely difficult for an autistic person."
In an earlier study, Beversdorf and colleagues found that non-autistic adults were more likely than autistic adults to falsely remember hearing a word presented to them in a list of similar words. In 2005, they found that the same was true for images of geometric shapes. Non-autistic adults remembered a "lure" object--similar in shape, size, arrangement, and color to members of the set--as being in the set when it actually was not. Autistic adults were much less likely to make this error.
"This suggests that autistic people may have trouble with using context," Beversdorf said. "The image on the lure slide was so similar to the images shown in the original group of slides that it was fairly difficult to determine if it was part of the first group.
"Whether they were aware of it or not, the non-autistic people had used the context of the original group of slides – the shape, size and color of these images – to decide if they had previously seen the lure image. This same use of context doesn't seem to happen in the autistic brain, which may relate to the altered brain circuitry in autism."
This makes sense to me. In my experience, people with ASD tend not to draw inferences that are as obvious (to the rest of us) as "2+2=4." The same may be true for other disorders--for instance, dyspraxia. My stepmother was staggered when, after she taught me how to make coffee by straining it into a cup and by using a coffeemaker, I said I didn't like the straining method because it made the coffee turn out weak. The obvious inference--that the coffeemaker worked the same way as the strainer and the only difference was the amount of water I put in--escaped me. When she said "You're a smart girl, think about it," it still didn't occur to me. More examples will be discussed when I think of them...

Is there a connection here to the abnormal visual processing discussed in a previous post? (http://mosaicofminds.blogspot.com/2009/08/could-visual-processing-problems-cause.html#comments). Maybe some people with ASD don't "see context" at a cognitive level because at the visual level, they have trouble resolving local details into a context in the first place?