Diminution of cortical visually evoked potentials during the following eye-movement in the cat

Six cats with brainstem transection at the pretrigeminal level were used. Visually evoked potentials (VEPs) to a diffused flash were recorded in the marginal, suprasylvian, ectosylvian and sigmoid gyri under three situations: the eyes were motionless in the position of rest, the eyes followed a moving object, and the eyes moved spontaneously. In the marginal and ectosylvian gyri the VEPs were smaller in the second situation, compared to the first and third. It is concluded that the VEP reduction is not produced by the eye-movement itself, but by the process of selective attention to the followed stimulus.