Much research has been done on language and communication in children with autism, but the way in which these children acquire language is still poorly understood. Michael Ullman at Georgetown University and his colleagues propose that grammar difficulties experienced by children with autism stem from deficits in one of two kinds of memory. Past research by Ullman and his colleagues has revealed that the use of vocabulary and grammar knowledge relies on two memory systems. Declarative memory, which stores information about facts and events, is used to memorize words and information about those words — for example, that the word pronounced ‘dog’ refers to the furry animal. Procedural memory, which acquires rules and sequences, is crucial for combining words into complex sequences using grammatical rules — knowing, for instance, that ‘man bites dog’ means something very different from ‘dog bites man.’ The researchers are now turning their attention to the acquisition of grammar skills. They hypothesize that children with autism have impaired procedural memory, making it difficult for them to learn grammatical rules. However, the children may compensate for this impairment by using declarative memory, which may often be relatively unaffected by autism. The researchers plan to construct artificial grammars of syllables, which pilot testing has shown can be learned over the course of a few minutes, allowing the researchers to examine the actual process of grammar acquisition. The researchers will expose children with autism and age-matched healthy controls to syllable strings generated by the grammars. They will then examine how much grammatical knowledge the children have learned and whether the children actually learn the rules or simply memorize specific sets of syllables. The researchers believe the findings may clarify the role of the two memory systems in language deficits and compensatory mechanisms in autism. Because the two memory systems have been thoroughly studied in the clinic and using animal models, new information could lead to specific suggestions for pharmacological or behavioral therapies to boost learning in children with autism.