SEEING THE BRAIN AS A CAMERA
Despite the impression that our perceptual experience of the world is seamless and continuous across time, this is likely an illusion. Evidence suggests that information is sampled periodically, like successive snapshots taken by a video camera.
Using Transcranial Magnetic Stimulation (TMS) and Electro-Encephalography (EEG), our research demonstrated that our perception waxes and wanes periodically, fluctuating between favorable and less favorable moments, recurring at particular phases of our brain oscillations.
ATTENTION REORIENTS PERIODICALLY
Reorienting of voluntary attention enables the processing of stimuli at previously unattended locations. Studies have identified a ventral fronto-parietal network underlying attention. Yet, little is known about the role of early visual areas in voluntary reorienting.
Using TMS to interfere with attentional reorienting, we investigated the role and temporal dynamics of visual areas in this process. We demonstrated that reorientation of voluntary attention periodically involves V1/V2 at the theta frequency (5Hz).
VISUAL TPJ FOR VISUAL ATTENTION
The temporo-parietal junction (TPJ) has been associated with various cognitive and social functions, and is critical for attentional reorienting. Attention affects early visual processing. Neuroimaging studies dealing with such processes have thus far concentrated on striate and extrastriate areas.
Using fMRI, we demonstrated that visually-responsive TPJ sub-regions play a critical role in the orienting and reorienting of voluntary and involuntarily attention.