Neuromagnetic oscillatory brain responses
First, we compared the oscillatory ssVEF responses in cortical source
space between the two pre-cue conditions, in which subjects had to
attend the central fixation cross or two peripheral flickering rings.
Thereby, the dipoles on the canonical cortex surface that captured
significant oscillatory ssVEF power different from background noise were
determined by the F-ratio test (see Methods) for each pre-cue condition,
separately. Figure 2 shows the power spectra and ssVEF topographies for
both pre-cue conditions, and the spatial distribution of significantly
oscillating cortical sources for the “attend to fixation cross” and
“attend to both rings” conditions, respectively. Only cortical sources
that exceeded the critical threshold of the F-ratio test are shown
(critical minimum F ratio: F(2, 62) = 9.03, pfdr
corrected < 0.001 for the central fixation condition; F
ratio: F(2, 62) = 10.12, pfdr corrected <
0.001 for the peripheral rings condition). Both pre-cue conditions
resulted in ssVEF responses in V1, and V2 in both hemispheres, whereas
attending to the peripheral flickers activated more extended ssVEF power
modulations in right occipito-parietal, and hMT+ areas including a small
part of the right pre-cuneus.