Effect of visual after-sensations upon brain potential patterning under different degrees of attention.

Abstract

The effect of visual after-sensations upon a brain potentials was detd. under 2 conditions, a high degree and a low degree of attentiveness to after-sensation changes. For the high degree of attention the total duration of [alpha] waves and the mean duration of the bursts during the after-sensation periods were less and the length of time for the first burst to appear after the light went off was greater than for the low degree of attention. These findings indicated a greater effectiveness in altering brain potential patterning of conditions of greater attention. The atten-tional factor contributed at least 35% of the total effect, the functional properties of the retina probably contributing the larger part of the remainder.