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LONG-LOOKING INFANTS ARE SLOWER TO DISENGAGE FIXATION Janet E. Frick, John Colombo, Ten-ill F. Saxon

Department of Human Development, 4001 Dole Center, University of Kansas, Lawrence, KS 66045-2 133

Recent advances in the field of cognitive neuroscience have led to the development of methods for assessing attentional processes in humans that are thought to be controlled by specific neural systems. In particular, this research has identified specific cortical and subcortical areas as being critical for the ability to disengage attention from one visual stimulus and move attention to another stimulus. The purpose of the current study was to investigate whether individual and developmental differences in fixation duration, a measure which has been shown to correlate with measures of perception and cognition, are correlated with the speed with which infants disengage fixation from a visual stimulus. Seventy infants (35 3-month-olds, 35 4-month-olds) completed a procedure that measured their ocular reaction time to shift fixation from a central target to a peripheral target. Following an assessment of their characteristic peak fvration duration, infants were presented with a series of eight trials in which a central stimulus (a black and white static geometric form) was presented until the infant fixated it for one second. of infant midline.

At that time, a peripheral target appeared to the right or left When the peripheral target appeared, the central target either remained

illuminated (“center-on” trials) or was removed approximately 750 rnsec before the appearance of the peripheral target (“center-off’ trials). The dependent measure was the latency to begin to shift f&ion from the central target toward the peripheral target. The overall correlation between infants’ fixation duration and the latency to shill fixation on “center-off” trials was zero. However, the correlation between fixation duration and latency to shift on “center-on” trials was .61 (g < .OOOl). Results were similar for 3- and 4-month- ok%, although 3-month-olds showed slower latencies on all trials. The results support the conclusion that infants with long fixation durations are slower to disengage their visual attention. This finding is consistent with the position that developmental and individual differences in fucation duration may somehow be linked to the development of the neural attentional systems that control the ability to disengage, or inhibit, visual fixation.