Abstract
Visual search is facilitated when half of the distractors are presented in advance and can be actively inhibited – the preview benefit (Watson & Humphreys, 1997). We investigated the developmental course of this top-down inhibitory control by measuring the preview benefit in children of middle to late childhood. In order to evaluate whether this process followed a similar trajectory to more traditional measures of top-down cognitive control, children also completed executive function (EF) tasks assessing switching, inhibition (Shape-School Extended; Ellefson & Espy, 2005), and verbal/ spatial memory tests (Working Memory Test Battery for Children; Pickering & Gathercole, 2001). Our results show that a preview benefit is observed at small display sizes for 6 and 8 year old children, but that it is not present at larger display sizes. The preview benefit emerges fully in 12 year-old children at all display sizes. Children of all age groups searched baseline single feature, conjunction and preview search tasks more slowly than adults and produced more errors. Both the response times and the number of errors decreased with age. None of the EF measures correlated with the strength of the preview benefit. This suggests that: a) top-down inhibition does not develop until late childhood, b) preview search at small display sizes is mediated by different processes than at large display sizes, and c) top-down inhibition applied in time-based visual selection is different from inhibition during search, and from inhibition measured by current EF tasks. Overall, these results show that the attentional mechanisms involved in inhibitory time-based selection develop over the age range of 8 to 12 years.
Meeting abstract presented at VSS 2014