a. Hemispheric asymmetry of EEG alpha activity at the wake-sleep transition. Power (top): averaged alpha band power from the right (solid line) and the left (dotted line) hemispheres. ∆ P (second): power difference between the two hemispheres. C(R -L) (third): alpha coefficient (R -L)/(R + L). AVE C(R -L) (fourth): 1-min averaged alpha coefficient. EEG-EOG stages at the bottom. Alpha activity during waking is asymmetric, with the right side predominant.

Contexts in source publication

Context 1

... test specific effects of stage and location, posthoc comparisons using the Tukey test were made. (Figure 1a) and less asymmetric (Figure 2a) during waking. Averaged powers from each hemisphere and region (top) drastically decreased during the period of frequent stages D2 and S, with occasional increases on a contingent recovery of stages W or D1. ...

Context 2

... coefficients (third) made the small amounts of power difference visible as a long-term change superimposed by a short-term fluctuation. Averaged alpha coefficients (fourth) manifested the long-term changes as a reduction in rightpredominant alpha with the occasional ( Figure 1a) and continuous (Figure 2a) left-sided alpha and as a shift of alpha predominance to the anterior region (Figures 1b and 2b). Table 1 summarizes the averaged alpha coefficients of hemispheric asymmetry and regional differences at the four EEG-EOG stages in terms of magnitude and incidence. ...