More about executive functions
The executive functions encompass planning, attention and organizing, next to Cognitive shifting and short-term memory. The concept covers the faculty which enables effective – complex human – functioning. The executive functions reside in the ‘prefrontal’ cortex, which, in right-handed people, is situated in the front (‘pre’) of the ‘frontal’ left lobe of the brain. In humans this system is most developed and represents an estimated 29% of the cells in the cortex, as opposed to 17% in chimpanzee’s and about 3% in cats. They concern, therefore, eminently human functions. It’s very difficult to navigate everyday life with impaired executive functions, as it is for instance for people with dementia.
At first glance it’s peculiar that only one of the three cognitive styles can be subsumed under the executive functions, e.g. Cognitive shifting. The most plausible idea is to consider autism the result of anomalies affecting three core cognitive processes: global–local processing (necessary for adequate Central coherence), social cognition (of which Theory of Mind is a part) and executive functioning. (See the excellent article by Happé & Frith.) Each of the cognitive styles would then belong to another core process.
If this idea of three distinct anomalous processes is correct, it becomes more understandable why there is so much variation in the manifestations of autism. In this dimensional perspective it becomes easier to conceive of one of these core processes exhibiting larger imperfections than the others. I.e. someone who is socially rather competent, but confused in behavior and orientation, while someone else acts just in the opposite way – both being autistic.
Also it would become more comprehensible why the general statement about cognitive styles is that there’s always at least one affected and one or two others may not be.
One should keep in mind, however, these three processes influence each other. So one can say: lack of social insight will not be caused by weak executive functioning but may still be exacerbated by it.