Fig. 4.
Attentional modulation of alpha power. A, Grand average (n = 17) normalized alpha power differences between attend-left and attend-right trials. For each channel, alpha power was averaged across time during the cue period (left, t = −1.2 to 0 sec) or during the stimulus period (right, t = 0 to 2.44 sec). B, Grand average alpha power differences between ipsilateral and contralateral attention conditions, collapsed across left and right parietal channels. C, AMIα, calculated from Eq. 2, during the cue period (left) and stimulus period (right). p values over individual bars are the result of t tests used to determine if was significantly greater than zero. Comparisons between conditions in Experiment 2 are also shown by brackets and associated p values. All displayed p values were corrected for multiple comparisons. AMI indicates attentional modulation index.