Abstract
PURPOSE. Visual search studies with adults have demonstrated an asymmetry in that search for a feature-present target amidst feature-absent distracters (R among Ps) is faster and more efficient than the reverse search (P among Rs). Research with infants has suggested that they might exhibit a search asymmetry; however, these studies assessed asymmetry in seconds or minutes, whereas in adults it is assessed in milliseconds. Consequently, whether infants have similar visual search and selective attention mechanisms as in adults is not clear. Adler and Orprecio (2006) have recently demonstrated search performance in infants on the order of millisecond, similar to adults. The present study examined search asymmetry in infants using a visual search paradigm. METHODS. Three-month-olds' saccade latencies to a target in a visual search array were measured as they randomly viewed the following four arrays: feature-present (R among Ps), feature-absent (P among Rs), homogenous Rs and homogenous Ps. All four arrays were presented in set sizes of 1, 3, 5 and 8. RESULTS.Similar to findings with adults, the target in the feature-present array popped-out from amidst the distracters and the saccade latencies were unaffected by increasing set sizes. In contrast, the saccade latencies to the target in the feature-absent array and the homogenous arrays increased with increasing set-sizes. CONCLUSIONS. These findings indicate that infants exhibit a search asymmetry similar to that found with adults. This suggests that the same selective attention mechanisms are functioning in infants and adults. Supported by NSERC 503860 to SAA.
Supported by Natural Science and Engineering Research Council Grant 503860 to SAA