Prestimulus EEG parameters during recognition of a significant photic stimulus.

Abstract

1. Successful performance of activity by a human operator in recognizing a meaningful photic stimulus and the quality of that activity (duration of recognition) are reflected in the set of spatiotemporal parameters of the prestimulus EEG. 2. The functional state of the CNS preceding optimal recognition during operant rest and 70% effectiveness of activity is characterized by an average level of spatial synchronization of potentials within the neocortex of the two hemispheres and by the lowest level of spatial synchronization between potentials in symmetrical regions of the two hemispheres, compared with states before a long recognition time or nonrecognition of the stimulus. 3. The average abundance of frequencies from 0.2 to 30 Hz in prestimulus potentials of the majority of neocortical formations studied, together with increased power of fast waves in the central and occipital regions of the right hemisphere are characteristic of optimal recognition.