Visual evoked response to patterned stimuli and potentials emitted during the stimulus runs were investigated using an omission procedure and a guessing method. Visual stimuli were square patterns presented either to the lower, upper, left or right visual half field. Brain electric activity was recorded with occipital and vertex electrodes. Stimulation of the lower half field evoked characteristic pattern specific responses. On the other hand, the polarity reversals at the upper half field stimulation were rather rare. At the occipital records there were no emitted peaks. During the omission procedures fairly often a triggered alpha activity appeared. Under both conditions, a characteristic positive peak appeared at the vertex with 150 msec mean latency. There were no similar evoked peaks with comparable latency. At the vertex, a late positive component appeared mainly under the guessing conditions.
|Pages (from-to)||no. E 065|
|Journal||Electroencephalography and Clinical Neurophysiology|
|Publication status||Published - Jan 1 1977|
ASJC Scopus subject areas
- Clinical Neurology