The development of endogenous orienting: control over the scope of attention and lateral asymmetries

This study examined the development of endogenous orienting in children ages 6, 10, and 14 years and in adults. Participants were asked to respond with a button press to targets appearing in the left or right visual field. Cues that correctly or incorrectly indicated the target's location preceded the appearance of targets at stimulus onset asynchronies (SOAs) of 100 and 800 msec. Cues that signaled a target's appearance, but not its location, were also included. In addition to raw reaction times, orienting effects, benefits, and costs were examined. Two main findings emerged: First, for all participants except the youngest children effect sizes increased with increasing SOA. The absence of an SOA effect in the youngest group is interpreted as evidence of their difficulty in voluntarily adjusting the scope of their attentional focus. In addition, field asymmetries changed with the age of the respondent: 6-year-olds showed a right-field advantage, 10-year-olds failed to show any laterality differences, and 14-year-olds and adults responded more quickly to targets in the left than in the right field. This finding is consistent with developmental data on a number of cognitive processes, and is interpreted within a developmental framework of right-hemisphere dominance for spatial orienting (cf. Mesulam, 1998).