Due to saccadic eye movements the retinal image is abruptly displaced
2-4 times a second, yet we experience a stable and continuous stream of
vision. It is known that saccades modulate neural processing in various
local brain areas, but the question of how saccades influence neural
communication between different areas in the thalamo-cortical system has
remained unanswered. By combining transcranial magnetic stimulation
with electroencephalography, we found that saccades were accompanied by
dynamic changes in causal communication between different brain areas in
humans. These changes were anticipatory; they began before the actual
eye movement. Compared with fixation, communication between posterior
cortical areas was first briefly enhanced during saccades, but
subsequently peri-saccadic information did not ignite sustained activity
in fronto-parietal cortices. This suggests that the brain constructs a
spatially stable and temporally continuous stream of conscious vision
from discrete fixations by restricting the access of peri-saccadic
visual information to sustained processing in fronto-parietal cortices.