The effects of selective and anticipatory attention on alpha blocking were examined by presenting an 8 sec. warning tone followed .4 sec. later by a second tone which alternately commenced 1) a control series of passive listening, 2) a simple reaction time task, or 3) a discrimination reaction time task. No differences in alpha activity were noted in the period of auditory anticipation following the onset of the warning signal or during the process of selection after the reaction signal.

Significant differences in conditions were noted only in the period after the response had been made. It was suggested that the presence of an overt response, combined with a complexity factor, may explain the reduction in amount of alpha activity after the response occurs.