EEG alpha rhythm, intention and oculomotor control.

A replication of Wertheim's (1981) visual pursuit tracking study examined the reactivity of the posterior EEG alpha rhythm to two tracking tasks. Twelve subjects visually tracked a light spot moving in a predictable or an unpredictable path. The EEG was recorded from O1, O2, P3, P4, T5, and T6, referenced to linked mastoids, and power for the alpha frequency band was calculated for 60 s trial epochs. Results showed significantly higher occipital and posterior temporal alpha power during the predictable tracking trials in agreement with Wertheim's findings. The significance of this for his attention/intention model is discussed.