Activation of syntax in lexical production in healthy speakers and in aphasia

The lack of a relationship between syntax and naming accuracy suggests that syntax is available, but access is not obligatory. This finding supports theories incorporating non-obligatory syntactic processing, which is independent of phonological access. The semantic error data are best explained within such a theory where there is damage to phonological access and hence to independent syntax. For the aphasia group we identify two types of phonological error, one implicating syntax and phonology, and one implicating phonology only, again supporting independent access to these systems. Overall the data support a model within which syntax is independent of phonology, and activation of syntax operates flexibly dependent on task demands and integrity of other processing routines.