Proceedings of the Annual Meeting of the Cognitive Science Society

The context dependent nature of language processing requires the synchronization of several subprocesses over time. One claim which follows is that de-synchronization is likely to disturb language processing.Aphasia is a language disorder which arises following certain types of brain lesion. Many theories of aphasia are competence based theories and do not address aspects of performance which can be affected under conditions of processing degradation. The discussion in this pajjer will focus on de-synchronization as a possible explanation for aphasic language comprehension problems.HOPE, a computer model for single sentence comprehension, provides a tool to systematically study the effects of various hypothesized de-synchronization problems on different language processing levels and on overall comprehension performance. HOPE includes a neural-like architecture that incorporates a grammar which functions in a predict/feedback manner. It illustrates one way in which serial-order input can map into synchronous, parallel subprocesses that can effectively produce normal sentence comprehension performance.Using H O P E , the study of explicit de-synchronization effects on a cover set of stimuli sentences suggests error patterns to be sought in neurolinguistic evidence. Within a subset of a cover set of stimuli,simulation results from a slowed propagation lesion experiment will demonstrate how timing problems can result in observed aphasic comprehension performance.