Oculomotor control and occipital alpha activity: a review and a hypothesis

Findings relating occipital alpha rhythm with the visual system appear to be difficult to interprete. This is due to the fact that the discrimination between oculomotor control monitored by visual input and monitored by other factors — a distinction which is independent of the presence or absence of visual stimulation — has been widely neglected. A review of the available evidence leads to the conclusion that the inflow of visual information itself has no relation with occipital alpha activity. Blocking occurs only when such information serves also as a monitoring principle in oculomotor position control. Some implications of this hypothesis especially in relation to the concept of alertness and arousal in tasks demanding a high level of visual attention, such as car driving, are discussed.