Electrical signs of cortical activity.

A brief introduction to the use of event-related potentials in studies of perception and attention

“…Electroencephalogram (EEG) recordings were the first method developed for direct and noninvasive measurements brain activity from human subjects (Adrian & Yamagiwa, 1935; Berger, 1929; Jasper, 1937, 1948). By noting when stimuli were presented and tasks were performed, early studies examining the raw EEG sought to characterize the changes in the state of electrical activity during sensory processing and the performance of simple-detection tasks (e.g., P.…”

Some Evidence for Multiple Visual Projections to Cortex

“…It has been known for many years that the cerebral cortex will respond to flickering light (1) and indeed, the phenomenon has been used extensively in clinical electroencephalography as an activating technique (2). Whether the sustained following response frequently obtained can be interpreted as a driving of the alpha rhythm is open to some debate, but there can be no doubt that in those individuals showing a response to photic stimulation, the amplitude of the response is maximal at a frequency corresponding to the alpha rhythm (3).…”

The Induction of a Quasi-Dreaming Mental State by Means of Flickering Photic Stimulation1

“…It has long been known that flickering photic stimulation may induce frequency of brain waves which roughly corresponds to the flicker frequency [Adrian, 1947;Adrian and Matthews, 1943;Barlow, 1960;Barlow and Estrin, 1971;Durup and Fessard, 1935;Jasper, 1937;Loomis et al, 1936;Montagu, 1967;Toman, 1941;Vogel et al, 1969;Walker et al, 1944;Walter, 1963;Walter and Walter, 1949], In our laboratory we have found that the same holds true also when the flickering stimulation is applied to a sleeping subject, provided that the light stimulus of the flicker is of appropriate intensity (intense enough to change brain waves but not to awaken the subject).…”