The major objective of this research is to investigate, in the normal brain, the hemispheric for semantic functions which may be impaired in thought disorders. The proposed studies will use visual half-field stimulation to investigate semantic facilitation and inhibition processes in the left and right hemispheres of normal individuals. The primary hypothesis is that the left hemisphere processes meaning in a focal manner, by facilitating relevant meanings and inhibiting those deemed irrelevant, while the right hemisphere maintains facilitation for a set of semantically related meanings without inhibition. The role of attentional selectivity in semantic processing in each cerebral hemisphere will be examined in three series of experiments. In Series 1, lexical priming paradigms will be used to investigate the role of semantic expectancies in producing semantic inhibition and facilitation. In Series 2, the """"""""negative priming"""""""" paradigm will be used to investigate facilitatory and inhibitory processes produced when one of two simultaneously presented words is the focus of visual attention. In Series 3, semantic facilitation and inhibition are examined in higher order cognitive tasks which required judgments of meaning. It is predicted that semantic facilitation will occur in both cerebral hemispheres, but that inhibitory processes, which depend upon attentional selection, will be restricted to the left hemisphere. It is important to understand the neurological basis of these functions, since breakdowns in the normal interplay of semantic facilitation and inhibition could produce some schizophrenic symptoms (e.g., loose associations).

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29MH043868-05
Application #
2245897
Study Section
Cognition, Emotion, and Personality Research Review Committee (CEP)
Project Start
1988-05-01
Project End
1993-04-30
Budget Start
1992-05-01
Budget End
1993-04-30
Support Year
5
Fiscal Year
1992
Total Cost
Indirect Cost
Name
Syracuse University
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
002257350
City
Syracuse
State
NY
Country
United States
Zip Code
13244
Rende, R; Weissman, M; Rutter, M et al. (1997) Psychiatric disorders in the relatives of depressed probands. II. Familial loading for comorbid non-depressive disorders based upon proband age of onset. J Affect Disord 42:23-8
Richards, L; Chiarello, C (1997) Activation without selection: parallel right hemisphere roles in language and intentional movement? Brain Lang 57:151-78
Richards, L; Chiarello, C (1995) Depth of associated activation in the cerebral hemispheres: mediated versus direct priming. Neuropsychologia 33:171-9
Chiarello, C; Maxfield, L; Richards, L et al. (1995) Activation of lexical codes for simultaneously presented words: modulation by attention and pathway strength. J Exp Psychol Hum Percept Perform 21:776-808
Chiarello, C; Richards, L (1992) Another look at categorical priming in the cerebral hemispheres. Neuropsychologia 30:381-92
Chiarello, C; Richards, L; Pollock, A (1992) Semantic additivity and semantic inhibition: dissociable processes in the cerebral hemispheres? Brain Lang 42:52-76
Richards, L G; Chiarello, C (1990) Typicality effects in artificial categories: is there a hemisphere difference? Brain Lang 39:90-106
Chiarello, C; Burgess, C; Richards, L et al. (1990) Semantic and associative priming in the cerebral hemispheres: some words do, some words don't ... sometimes, some places. Brain Lang 38:75-104