AVERAGE RESPONSES TO CLICKS IN MAN RECORDED BY SCALP ELECTRODES

Abstract

Electric potentials were recorded from scalp electrodes in response to different sensory stimuli and, in particular, to clicks. These electric responses are usually too small to be detected in the electroencephalogram. With the use of an average-response computer, those components of the responses that are time-locked to the delivery of sensory stimuli can be studied. The present study deals with the characterization of average responses to acoustic-click stimuli in man. These responses were compared with evoked responses in subhuman species, and tentatively identified as secondary responses. The effects of the biological structures that separate the brain from a recording site on the scalp was investigated. The conclusion was made that the average click responses obtained from the human scalp are probably secondary cortical responses. This conclusion is based, in part, on two series of experiments: One in which the effects of multisensory stimulation were investigated, and another in which the effects of sleep upon average responses to clicks were studied. (Author)