AUDITORY EVOKED RESPONSES FROM EXPOSED HUMAN CORTEX

Average responses to clicks were recorded in seven patients from the human cortex exposed during surgery for treatment of focal epilepsy. The early components of the evoked activity were one or two positive waves 10-25 μV in amplitude and 26-40 msec in latency. These responses were obtained from the posterior part of the superior temporal gyrus and the parietal and frontal operculum. Direct recording from the superior surface of the temporal lobe was not carried out. Average responses to click were also recorded from the scalp and were compared with the auditory responses from the cortex. It was concluded that the early scalp deflections usually represent myogenic potentials, while the late components of the responses are a mixture of myogenic and neurogenic potentials. © 1968.