REGIONAL COUPLING OF BRAIN FLOW AND NEURONAL ELECTRICAL ACTIVITY IN HUMAN VISUAL CORTEX: A COMPARISON OF PET AND VEP.

Cerebral blood flow and visual evoked potential responses were compared in a series of normal volunteers using a stimulus which graded response magnitude in a predictable fashion. The responses determined by either method were graded simularly, thus demonstrating coactivation of cerebral blood flow and electrical activity. The principal determinant of response magnitude appeared to be the number of elements in the visual field; luminance had little or no importance.