This proposal represents a maturation of my interest in schizophrenic thought disorder, and my commitment to a multidisciplinary approach to its study. The program I describe here will provide me with fundamental skills in psycholinguistics and cognitive psychology which are directly relevant to research on schizophrenia, and which have not yet been applied in this field. Schizophrenics' use of language has been characterized as lacking in contextual constraint. Psycholinguists distinguish between various loci of contextual effects in language processing, identifying a lexical stage (access to a word's meaning) and postlexical stages. Maher has described a failure to actively suppress contextually irrelevant associations in schizophrenia, and attributes this to a deficit in postlexical processing. I have proposed an alternative, non-competing hypothesis which suggests that disturbances may also arise within lexical processing which account for similar results. In Phase I of this program, I will develop a parallel distributed computer model of language processing. Variables will be sought which can be manipulated in actual psycholinguistic experiments, and which distinguish between the effects of stimulus persistence and postlexical events on the processing of context. In Phase II, I will perform experiments with normal and schizophrenic subjects using chronometric lexical priming techniques, to test predictions which arise from these computer simulations. Positive findings in patients will be correlated with clinical variables, in order to explore the use of these techniques for diagnostic assessment. Work in Phases I and II will be directed to the testing of specific hypotheses concerning schizophrenic language dysfunction. This will not only allow me to explore the functional characteristics of thought disorder, but will also provide me with a training in theoretical and methodological techniques which will be of general value in psychiatric research.
| Cohen, J D; Braver, T S; O'Reilly, R C (1996) A computational approach to prefrontal cortex, cognitive control and schizophrenia: recent developments and current challenges. Philos Trans R Soc Lond B Biol Sci 351:1515-27 |
| Cohen, J D; Servan-Schreiber, D (1993) A theory of dopamine function and its role in cognitive deficits in schizophrenia. Schizophr Bull 19:85-104 |
| Cohen, J D; Servan-Schreiber, D (1992) Context, cortex, and dopamine: a connectionist approach to behavior and biology in schizophrenia. Psychol Rev 99:45-77 |
| Servan-Schreiber, D; Printz, H; Cohen, J D (1990) A network model of catecholamine effects: gain, signal-to-noise ratio, and behavior. Science 249:892-5 |
| Cohen, J D; Dunbar, K; McClelland, J L (1990) On the control of automatic processes: a parallel distributed processing account of the Stroop effect. Psychol Rev 97:332-61 |
