Abstract
Visuomotor abilities, such as crossing a busy road or intercepting a ball, continue to improve until late childhood - but what drives these improvements is unclear. We tested whether development of visuomotor skill in childhood might in part be explained by improvements in the ability to account for visual and motor uncertainty. 6 to 10-year-olds and adults performed a time-limited rapid reaching task. In the main task, participants had to locate a hidden target within a set time (2s). Every 0.1s a dot would appear, randomly drawn from a bivariate Gaussian distribution centred on the target, until a reach was initiated. Participants were divided into two groups, one receiving a smaller distribution of dots (reliable cues), and one a larger distribution (unreliable cues). To maximise their score, subjects had to minimise the variance of their endpoint reaches around the target by trading-off time spent sampling visual information about the target's location, and time spent moving to 'catch' it. As such they had to trade-off between visual and motor uncertainty. To estimate each individual's gain-maximising (ideal) strategy, we also measured variance in (a) visual localisation and (b) movement precision for all possible sampling vs. movement time trade-offs. The trade-off at which total visuomotor variance was lowest was taken as their ideal strategy. While adults' sampling/movement times matched the ideal strategy in both visual cue-reliability conditions, young children consistently moved before gathering sufficient visual information. This is in line with previous studies suggesting that unlike adults, children are more likely to follow fast, 'risk-seeking' visuomotor strategies at cost to their performance (Dekker & Nardini, 2016; Jones, et al., in prep), rather than weighting visual and motor information appropriately.
Meeting abstract presented at VSS 2017