EXCEED THE SPACE PROVIDED. The goal of the proposed research is to investigate the sources of rCBF effects obtained in studies of syntactlc processing. Previous studies in this laboratory and elsewhere have documented different patterns of rCBF in different groups of subjects on protocols testing syntactic processing in sentence comprehension. The research proposed here will determine whether these different pattems of rCBF reflect different non-linguistic processes that are employed to different degrees by different groups of subjects, or whether they reflect true differences in the localization of particular syntactic operations. The hypotheses that will be tested are: 1. Previously identified variation in rCBF comprehension will be replicated. 2. These changes are due to differences in in performing the sentence comprehension !HI-OHMANGF ,511_'(_) (organtzatlon, city, state) Massachusetts General Hospital, Boston, MA Sargent College, Boston University,_ Boston, MA KEY PERSONNEL. <Gee instructions on Page 11. Use continuation pages Name David Caplan, M.D., Ph.D. M.G.H. Nathanial Alpert, Ph.D. M.G.H. Gloria Waters, Ph.D. B.U. changes associated with the use of visual mental task in different groups as needed to provide the required Organization syntactic processing in sentence images and short-term memory of subjects. inlormation In the format shown below. Role on Project P.I. Investigator Investigator ========================================Section End===========================================