In this paper, it is hypothesized that many of the behavioral abnormalities found in autistic persons result from deficits in fundamental cognitive abilities. Memory and attention are the most likely candidates. The memory deficit may be primarily one of retrieval, possibly exacerbated by an encoding deficit However, both types ol memory deficit are probably the result of a (Rimary deficit in attention. This is supported by the observation that the autistic memory deficit resembles that following frontal lobe, rather than mediotemporal lobe, damage. This and other evidence is used to draw a parallel between autism and frontal lobe syndrome. In light of this analogy, how a primary deficit in the fundamental cognitive ability of attention may be responsible for the more secondary autistic deficits in memory and more advanced forms of cognition, such as language acquisition, symbol manipulation, rule extraction, and social interaction, is explored.

A connectionist model is presented that used a hebbian learning rule to acquire knowledge about an artificial grammar (AG). The validity of the model was evaluated by the simulation of two classic experiments from the A G learning literature. The first experiment showed that human subjects were significantly better at learning to recall a set of strings generated by an A G , than by a random, process. The model shows the same pattern of performance. The second experiment showed that human subjects were able to generalize the knowledge they acquired during A G learning to novel strings generated by the same grammar. The model is also capable of generalization, and the percentage of errors made by human subjects and by the model are qualitatively and quantitatively very similar. Overall, the model suggests that hebbian learning is a viable candidate for the mechanism by which human subjects become sensitive to the regularities present in AG's. From the perspective of computational neuroscience, the implications of the model for implicit learning theory . as well as what the model may suggest about the relationship between implicit and explicit memory, are discussed.