Alpha-band rhythms in visual task performance: phase-locking by rhythmic sensory stimulation

Oscillations are an important aspect of neuronal activity.
Interestingly, oscillatory patterns are also observed in behaviour,
such as in visual performance measures after the presentation of a
brief sensory event in the visual or another modality. These
oscillations in visual performance cycle at the typical frequencies
of brain rhythms, suggesting that perception may be closely linked
to brain oscillations. We here investigated this link for a
prominent rhythm of the visual system (the alpha-rhythm, 8-12 Hz)
by applying rhythmic visual stimulation at alpha-frequency (10.6
Hz), known to lead to a resonance response in visual areas, and
testing its effects on subsequent visual target discrimination. Our
data show that rhythmic visual stimulation at 10.6 Hz: 1) has
specific behavioral consequences, relative to stimulation at
control frequencies (3.9 Hz, 7.1 Hz, 14.2 Hz), and 2) leads to
alpha-band oscillations in visual performance measures, that 3)
correlate in precise frequency across individuals with resting
alpha-rhythms recorded over parieto-occipital areas. The most
parsimonious explanation for these three findings is entrainment
(phase-locking) of ongoing perceptually relevant alpha-band brain
oscillations by rhythmic sensory events. These findings are in line
with occipital alpha-oscillations underlying periodicity in visual
performance, and suggest that rhythmic stimulation at frequencies
of intrinsic brain-rhythms can be used to reveal influences of
these rhythms on task performance to study their functional roles.