THE DEVELOPMENT AND TEMPORAL DYNAMICS OF SPATIAL ORIENTING IN INFANTS

Shifts of visual attention can be studied in adults by cueing a partic ular spatial location and assessing the speed of detection of targets presented in the cued location as compared to other locations. A numbe r of studies have used spatial cueing paradigms in an attempt to study attention shifts in infants. However, these studies have employed dif ferent procedures, time courses, measures, and age groups, making comp arison between them difficult. The present experiments were designed t o investigate the effects of varying the cue-target time interval on t he speed and direction of orienting in 2-, 4-, and 6-month-old infants . The results of Experiment 1 indicated that, while 2-month-old infant s showed only weak effects of the cue, 4-month-old infants show facili tation to a cued location when a target appears 200 ms after cue onset , and inhibition of responses to the same location when the target app ears 700 ms after the cue onset. Six-month-old infants showed evidence of inhibition, but not facilitation. One account of this pattern of d ata is that 6-month-olds shift attention faster than do 4-month-olds. This hypothesis was tested in Experiment 2 in which four different cue -target intervals were used with a group of 7-month-old infants. The r esults obtained were consistent with the hypothesis that infants get f aster to shift attention to a spatial location with age. (C) 1996 Acad emic Press, Inc.