RT Journal Article
SR Electronic
T1 Alpha fluctuations regulate the accrual of visual information to awareness
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.09.16.298166
DO 10.1101/2020.09.16.298166
A1 Mireia Torralba
A1 Alice Drew
A1 Alba Sabaté San José
A1 Luis Morís Fernández
A1 Salvador Soto-Faraco
YR 2020
UL http://biorxiv.org/content/early/2020/09/16/2020.09.16.298166.abstract
AB Endogenous brain processes play a paramount role in shaping up perceptual phenomenology, as illustrated by the alternations experienced by humans (and other animals) when watching perceptually ambiguous, static images. Here, we hypothesised that endogenous alpha fluctuations in the visual cortex pace the accumulation of sensory information leading to perceptual outcomes. We addressed this hypothesis using binocular rivalry combined with visual entrainment and electroencephalography in humans (42 female, 40 male). The results revealed a correlation between the individual frequency of alpha oscillations in the occipital cortex and perceptual alternation rates experienced during binocular rivalry. In subsequent experiments we show that regulating endogenous brain activity via entrainment produced corresponding changes in perceptual alternation rate, which were observed only in the alpha range but not at lower entrainment frequencies. Overall, rhythmic alpha stimulation resulted in faster perceptual alternation rates, compared to arrhythmic or no stimulation. These findings support the notion that visual information is accumulated via alpha cycles to promote the emergence of conscious perceptual representations. We suggest that models of binocular rivalry incorporating posterior alpha as a pacemaker can provide an important advance in the comprehension of the dynamics of visual awareness.Significance statement Mainstream theories in cognitive neuroscience agree that endogenous brain processes play a paramount role in shaping our perceptual experience of sensory inputs. In vision, endogenous fluctuations in the alpha rhythm have been pointed out to regulate visual inputs to perception. In support of this hypothesis, here we used EEG recordings and visual entrainment to demonstrate that inter-individual differences in the speed of endogenous alpha fluctuations in the brain are causally related to the accrual of visual information to awareness. These findings provide, for the first time, evidence for alpha-gated regulation of the dynamics of alternations in conscious visual perception.Competing Interest StatementThe authors have declared no competing interest.