Individual and developmental differences in disengagement of fixation in early infancy

The current study investigated whether individual and developmental differe nces in look duration are correlated with the latency for infants to diseng age fixation from a visual stimulus. Ninety-four infants (52 3-month-olds, 42 4-month-olds) were tested in a procedure that measured ocular reaction t ime to shift fixation from a central target to a peripheral target under co nditions in which the central target either remained present ("competition" condition) or was removed from the display ("noncompetition" condition). L ook duration was correlated with disengagement latency; longer-looking infa nts were slower than shorter-looking infants to shift fixation to the perip heral target on competition trials, but not noncompetition trials. Results were similar for 3- and 4-month-olds, although 3-month-olds showed slower l atencies on all trials. Furthermore, long-looking infants were not consiste ntly slower, but rather showed greater variability in their response latenc ies under conditions that required disengagement of fixation. The results s upport the position that developmental and individual differences in look d uration are linked to the development of the neural attentional systems tha t control the ability to disengage, or inhibit, visual fixation.