Normal readers have an upper visual field advantage in change detection

Abstract

The ability to detect change has not been well studied in children. A research paradigm was used involving search for a change made to one of four letter targets, presented twice, with a gap of 250 ms. Sixty-one schoolchildren, aged 7.3 - 12.9 years, participated in the study. The duration of the first presentation was such that each child was detecting change at a rate of 71% correct. The mean duration was 0.91 s (SD = 0.58 s), with older children not significantly faster in detecting change. In the second phase, using the duration established in the first phase, the effect of cue condition on detection was studied. An upper visual field advantage for change detection was clearly evident for uncued trials. The most likely explanation derives from the masking produced by the reappearance of the four targets, which interferes with the process of change detection. The greater dorsal pathway representation of the lower visual field implies greater masking there, yielding better change detection in the upper visual field.