Observing responses, visual preferences, and habituation to visual stimuli in infants

Two experiments investigated the effects of moving visual stimuli on observing responses of 2- to 6-month-old infants. Stimulation consisted of a blinking light which randomly changed position in a 4×4 light matrix. In Exp. I, 60 infants were randomly assigned to one of five groups. Four experimental groups were given 24 presentations of a light which either remained stationary or moved among 4, 8, or 16 positions. The fifth group received no light until the last four trials, when they were shown the light moving among 8 positions. In Exp. II, infants' visual preferences were examined by repeatedly presenting two lights simultaneously. Thirty infants were randomly assigned to one of three groups. Group (4, 1) was shown the 4-position and stationary lights, Group (16, 1) the 16-position and stationary lights, and Group (16, 4) the 16- and 4-position lights.Results from Exps. I and II indicate infants initially fixate longest on stimuli with intermediate position change, and these fixations tend to habituate over trials. Infants were also found to prefer lights which changed position to a stationary light, with the greatest preference occurring on the early trials when the light varied among 4 matrix positions and on the late trials when the light varied among 16 positions. Finally, evidence from Exp. II but not from Exp. I indicates that lights with many position changes produce less habituation than lights with few position changes.