This study investigated the effects of prior experience with contingent or noncontingent stimulation of infants' ability to learn different responses to control perceptual stimulation. In the pretest phase, baseline rates of level movement, panel press and vocal responding were determined for each of the twelve, 6-month-old infants in the study. During treatment sessions, subjects assigned to the contingent stimulation group controlled presentation of auditory-visual stimulation by manipulating a level. An equal number of subjects assigned to the noncontingent stimulation group received the same stimulation noncontingently. In the posttest phase, all subjects were observed in separate tests of (1) learning to panel press, and (2) learning to vocalize to control perceptual stimulus presentation. Results indicate that the long-term effect of prior contingent stimulation is to enhance responding to control environmental stimulation. In contrast, prior experience with noncontingent stimulation interferes with learning to control environmental stimulation. Analyses of attentional behaviors were used to suggest the processes by which previous experience with contingent and noncontingent stimulation influenced subsequent learning to control stimulation. (Author/ED)