Recovery from cerebral blindness: Evoked potential and psychophysical measurements

In a case of cerebral blindness diagnosis was established and hysterical blindness was ruled out by evoked potential (EP) measurements with grating patterns. The prominent feature of these measurements was that EPs were present in normal configurations when the patient said she saw the pattern and they were absent when she claimed no vision. EPs and psychophysical measurements showed concurrent changes during the patient's recovery. These measurements suggest that the neural substrates which determine psychophysical responses and EPs are either identical or equally vulnerable.