Abstract
Background: While the early development of attentional orienting is well described, basic questions related to infants' attentional windows have not been explicitly investigated. Here we measure whether infants can encode information about objects that they did not fixate into their visual short-term memory (VSTM). Methods: Twenty-five 6-month-old infants (age range: 5;0-7;5, 10 females) participated in a free-viewing eye-tracking study. In each trial, infants were presented with a set of identically shaped, but differently colored items spaced symmetrically around central fixation (set size was varied between participants: 4 or 6). After a 1,000 ms exposure, a randomly chosen pair of neighboring items disappeared. Following a 500 ms delay, the two items reappeared for 2,000 ms, with one changed to a new color (target) and the other unchanged (foil). The sudden offset of the two items was the partial report post-cue, designed to trigger coding from iconic memory into more durable VSTM (Blaser & Kaldy, 2010, Psych Sci). We contrasted infants' performance (preference for the target) on trials where, during the initial exposure, they fixated the items that subsequently became the target and foil ('focal look'), versus trials where they did not ('peripheral look'). Results: Infants' overall (collapsed across set size) performance (59.2 ± 11.7% correct), and performance in 'focal look' trials, (62.9 ± 19.1%) were both significantly above chance (t24=3.93, p< 0.0006, d=0.78; t18=2.95, p< 0.008, d=0.68, respectively). In 'peripheral look' trials, performance was 57.1 ± 17.0%, and importantly, also significantly above chance (t24=2.09, p< 0.048, d=0.42). Conclusion: Infants were able to encode and use information about objects that they did not fixate in a change detection paradigm. To our knowledge, this study is the first to show that infants can extract useful information beyond their target of fixation.
Meeting abstract presented at VSS 2017