Hemispheric dissociations in controlled lexical-semantic processing.
Cognitive mechanisms of semantic priming in individuals with intact cerebral hemispheres were studied using the visual half-field method and lexical-decision tasks. In Experiment 1, unidirectionally associated word pairs were presented in a forward direction (e.g., BEAVER-TAIL) to isolate priming attributable to automatic activation or expectancy-based processing. Forward priming was restricted to the right visual field-left hemisphere, and it occurred only when expectancy-based processing was encouraged in the instructions. Experiments 2 and 3 found backward priming (e.g., TAIL-BEAVER) only in the left visual field, indicating that the right hemisphere contributes to retrospective semantic matching of the target back to the prime. The results suggest that the 2 hemispheres have different roles in controlled processing of semantic relations.
Koivisto
M
M
Department of Psychology, University of Turku, Finland. mika.koivisto@utu.fi
D000328:Adult; D000704:Analysis of Variance; D001245:Association Learning / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003463:Cues; D004292:Dominance, Cerebral / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011578:Psycholinguistics; D017603:Signal Detection, Psychological; D014794:Visual Fields / Q000502:physiology*; D014936:Word Association Tests