Fig. 3: MEG responses to steady-state visual stimulation.
From: Anticipatory and evoked visual cortical dynamics of voluntary temporal attention
a Topography of visually responsive channels across participants (top five channels selected for each session based on 20 Hz trial-average SSVER power). Grayscale indicates the proportion of sessions across participants (n = 20 sessions) in which the channel was selected as visually responsive. b Illustration of cartoon time series from five trials (gray) and their average (black). High phase coherence across trials results in high ITPC and trial-average power (top); low phase coherence across trials results in low ITPC and trial-average power (bottom), despite the same single-trial power. c–e Time frequency spectrograms (group means of n = 10 participants) of (c) trial-average power reveals a strong 20 Hz signal at the probe flicker frequency. Trial-average power depends on two factors: (d) the power on single trials and (e) phase coherence across trials, or ITPC. The trial-average power at 20 Hz was more strongly reflected in ITPC than in single-trial power.
