Regional cerebral blood flow correlates of a dichotic listening task.

This investigation was designed to test the hypothesis that ear advantage on a dichotic listening (DL) task of pitch discrimination reflects asymmetries in the metabolic activities of the temporal lobes. Fourteen normal subjects, with either a left-ear advantage (LEA) (n = 9) or a right-ear advantage (REA) (n = 5) on the DL task, underwent measurements of regional cerebral blood flow (rCBF) during a resting baseline condition and during performance on the DL task. For both groups, the DL task was associated with selective and significant increases in rCBF to the contralateral posterior temporal lobe. Our finding of selective rCBF activation with dichotic stimulation may have potential implications for an understanding of the functional organization of the cerebral hemispheres.