Posted on Monday 18th November 2013
Against the intuitive notion that information flows in a continuous, steady-state fashion from our sensory channels, this research demonstrates that humans sample visual information in discrete time windows oscillating at around 5-10 Hz. Prior studies speculate that the brain’s strong oscillatory activity in the same frequency range is responsible for this rhythmic nature of the human visual system. However, no study has yet demonstrated how ongoing brain oscillatory activity impacts on visual processing and therefore little is known about the neural mechanisms underlying this intriguing phenomenon.
Recording brain oscillations with EEG and brain activity with fMRI at the same time during human participants performed a visual perception task the authors are the first to unravel the neural mechanisms behind the rhythmic phenomenon of human vision. Specifically they show that an on-going brain oscillation at 7 Hz impacts on visual perception via dynamically opening and closing the time windows for information transfer between lower sensory and higher attentional processing regions in the human brain. These results represent a major scientific advance as they unravel the neural underpinnings that might be responsible for the rhythmic nature of our visual system.