Entrainment of local synchrony reveals a causal role for high-beta right frontal oscillations in human visual consciousness

Abstract

Prior evidence supports the critical role of oscillatory activity in cognitive function, but are cerebral oscillations simply correlated or causally linked to specific aspects of visual cognition? Here, EEG signals were recorded on humans performing a conscious visual detection task, while they received brief rhythmic or random noninvasive stimulation patterns delivered to the right Frontal Eye Field prior to the onset of a lateralized target. Compared to random patterns, rhythmic high-beta patterns led to greater entrainment of local oscillations (i.e., increased power and phase alignment at the stimulation frequency), and to higher conscious detection of contralateral targets. When stimulation succeeded in enhancing visual detection, the magnitude of oscillation entrainment correlated with visual performance increases. Our study demonstrates a causal link between high-beta oscillatory activity in the Frontal Eye Field and conscious visual perception. Furthermore, it supports future applications of brain stimulation to manipulate local synchrony and improve or restore impaired visual behaviors.