The Early Orgins of Autism (Article

Patricia M. Rodier The Early Origins of Autism, Scientific American, 282/2 (February 2000), 56-63. Survey of several significant recent results: A) autists have large structural deficits in the brains stem (very small facial nuclei; absent superior olives; 0.2mm separation layer vs 1.1mm normal size.); B) these structural deficits imply damage of malfunction in fetal development in the 3rd to 4th week, early enough that most women do not even know they have conceived; C) Thalidomide victims have an incidence of autism some 30 times higher than in the general population; D) the low but significantly higher incidence of autism and autistic signs in families indicates that several genes are involved; E) One of the genes, HOXA1 has been identified.
     For me the most interesting finding is the atrophied facial nucleus. This bundle of neurons controls the facial and cranial nerves, and so is involved in facial expressions. Autists have poor or absent facial expressions; and they cannot read facial expressions in other people. This suggests to me that autists do not experience changes in facial expression that accompany changes in emotion; and so they have no subjective experience to relate to other people’s facial expressions. Thus, they do not respond to changes in facial expression, as normal babies do, and so they do not develop appropriate responses to the signs of emotion in other people. Note that Temple Grandin (an autist who has written a book about her life) remarks that she cannot recognise other people’s emotions - she must calculate or estimate them. She must also select the appropriate response expression (facial or verbal) from a consciously assembled catalogue.
     If the recent discoveries are supported in future research, the implications for understanding the relationship between genome and development are profound. Autists have a brain-stem deficit, which results in a behavioural deficit, which results in incorrect or inappropriate interaction with their environment, which results in incorrect (or unsuitable) response from their environment, and so on. It’s a kind of vicious circle. The deficit is augmented by the lack of environmental clues that might trigger the development that would (at least in part) make up for the deficit! One can generalise this idea to other phenomena quite easily. The basic idea is that the genome and the environment must interact correctly for normal development to take place. If the child is incapable of correct responses to the environment, the environment (ie, other people) will not interact appropriately with it, and so it will miss the environmental cues that guide normal development. There is some support for this hypothesis: eg, Downs syndrome children provided with simplified and exaggerated versions of suitable cues can and do develop much further towards normalcy than do children deprived of these cues. In fact, it seems that if they are provided with suitable cues, they usually reach the low-normal range of intellectual and the normal range of social functioning.  Great article. **** (2000)