Form-specific priming and functional brain asymmetries in perceptual identification.
Word form representations in intact cerebral hemispheres were studied by a lateralized perceptual identification priming task. During the study phase, word forms were primed by displaying words visually in uppercase or lowercase letters. During the test phase, perceptual identification of non-studied baseline words and studied words (presented in same or different lettercase as studied) was tested by displaying targets in the left or right visual field. Experiment 1 showed that the hemispheric pattern of priming effects was dependent on the lettercase at test. For uppercase test items, only the left visual field/right hemisphere was sentitive to study-test changes in lettercase, replicating an earlier result obtained in word-stem completion (Marsolek, Kosslyn and Squire, 1992). However, lowercase test items did not reveal any asymmetries in the form-dependent priming component indicating that in some conditions form-specific representations are computed in the left hemisphere also. No asymmetries were found in the abstract, form-independent component of priming. Experiment 2 revealed that use of explicit memory in the perceptual identification task eliminated the form-specific priming effects and suggested that the results of Experiment 1 were uncontaminated by explicit memory.
Koivisto
M
M
Department of Psychology, University of Turku, Finland.
D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology; D004292:Dominance, Cerebral / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011932:Reading; D014706:Verbal Learning / Q000502:physiology*