Analysis of patterns of apraxia and their relationship to lesion site and form of aphasia will be completed on 135 patients. A series of studies based on scans of aphasic patients will examine the relation of lesion to particular aphasia patterns and recovery from aphasia, as well as to brain asymmetry. We will continue to update assessment procedures and to study sex differences in susceptibility to aphasia language functions in aging and dementing subjects will also continue. Studies of syntax will continue with several investigations of receptive processing by agrammatic aphasics in which their output and comprehension profiles are compared as well as their ability to deal on-line with open and closed class vocabulary. Initial data collection will begin with a new cross-modal morphology and syntax battery. In the area of lexical semantics, we plan to initiate a number of concept classification and concept generalization studies. We will continue to collect and analyze data on dissociations among word categories for naming and comprehension. Studies of naming disorders will examine the stability of naming vocabulary in aphasia by test-rates and comparisons. In our examination of written language we will examine the hypothesis that pure word-blindness may be an expression of elevated threshold for all visual percepts. Studies of pragmatics will continue with an examination of right hemisphere damaged patients' appreciation of plausibility and of non-literal implication of messages. Studies of cerebral dominance will emphasize the evaluation of autonamous forms of motor dominance and the biological correlates of non-right handedness.
