Abstract
Eye and hand coordination is essential for everyday activities. Saccadic eye movements play an important role in ensuring that objects of interest are aligned with the foveal region of the retina. Information of eye position can then be used to produce a hand response to the desired location. Developmental abnormalities in the control of saccades may hinder the coupling between eye and hand movements (Wilmut et al., 2006). This study aims to provide better understanding of disorders by assessing oculomotor control throughout normal development. Recent studies have reported immaturities in children's ability to inhibit saccades and maintain fixation (Luna et al., 2004); however, age ranges vary across studies and measuring techniques lack sensitivity compared to modern eye-tracking technology. We investigated age-related differences in the generation of reflexive and voluntary saccades and hand responses during pre-cued and non pre-cued visually guided tasks. Saccades and hand responses were measured from 20 adults (20–26 yrs) and 7 children (9–12 yrs). Participants performed the tasks using their eyes only, hand only and eyes + hand together, to investigate the use of visual information during visuomotor tasks. During the pre-cued condition, children exhibited longer saccade onsets compared to adults; however, saccade onsets significantly decreased during the non pre-cued condition and were similar to adults'. Children's hand responses were also slower during pre-cued conditions indicating tight coupling of the eye and hand. Hand movement times also showed that adults used advance information of the target location more efficiently than children. Eye and hand absolute errors were similar between groups; however children exhibited greater variability. Pre-cued results showed developmental costs in attention disengagement, but not in the inhibition of intrusive saccades. These findings provide insights into the development of eye and hand coordination and maturation of cognitive control and have significant implications in understanding developmental coordination disorders.