Fig. 2.

(Left) Grand-averaged time-frequency spectrograms of MEG sensors exhibiting significant oscillatory responses, including gamma (64 – 92 Hz, 100 – 250 ms; top), beta (16 – 24 Hz, 225 – 500 ms; middle), alpha (8 – 14 Hz, 225 – 500 ms; middle), and theta (4 – 8 Hz, 0 – 250 ms; bottom). In each spectrogram, frequency (Hz) is shown on the y-axis and time (ms) on the x-axis. Signal power data are expressed as a percent difference from the baseline period with the color scale bar shown to the right of each spectrogram. (Right) Grand-averaged beamformer images (pseudo-t) across all participants for each time-frequency window. Note that the windows stop at 500 ms because this corresponds to the earliest reaction times, and we were interested in visuospatial processing and not decision processes or the motor response