| Abstract: | Examined performance patterns and concurrent EEG spectra in 4 Ss (mean age of 30.5 yrs) performing a continuous visuomotor compensatory tracking task in 15–20 min bouts during a 42-hr sleep deprivation study. During periods of good performance, participants made compensatory trackball movements about twice per second, attempting to keep a target disk near a central ring. Results indicate that autocorrelations of time series representing the distance of the target disk from the ring center showed that during periods of poor performance marked near-18-sec cycles in performance again appeared. There were phases of poor or absent performance accompanied by an increase in EEG power that was largest at 3–4 Hz. These studies show that in drowsy humans, opening and closing of the gates of behavioral awareness is marked not by the appearance of (12–14 Hz) sleep spindles, but by prominent EEG amplitude changes in the low theta band. Further, both EEG and behavioral changes during drowsiness often exhibit stereotyped 18-sec cycles. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
