CEREBRAL LATERALIZATION IN RANDOM LETTER TASK IN THE VISUAL MODALITY - A TRANSCRANIAL DOPPLER STUDY

Seven right handed volunteers were studied to determine cerebral later alization patterns for a visually presented random letter task. The su bjects participated in three conditions, which included resting baseli ne, passive fixation (nonlinguistic), and random letter (linguistic) t asks. Mean blood how velocity (MBFV) was recorded using bilateral simu ltaneous transcranial Doppler measurements in the posterior cerebral a rteries in these conditions. The experimental conditions produced an i ncrease in MBFV during both tasks but the linguistic task showed a gre ater change. There was a tendency toward right lateralization with the linguistic compared to the nonlinguistic tasks. There is a physiologi cal correlate of right hemisphere participation in the processing of t he random letter task. (C) 1996 Academic Press, Inc.