title: The effects of a pre-movement delay on the kinematics of prehension in middle childhood.
abstract: The present study examined the effects of a pre-movement delay on the kinematics of prehension in middle childhood. Twenty-five children between the ages of 5 and 11 years made visually open-loop reaches to two different sized objects at two different distances along the midline. Reaches took place either (i) immediately, or (ii) 2 s after the occlusion of the stimulus. In all age groups, reaches following the pre-movement delay were characterised by longer movement durations, lower peak velocities, larger peak grip apertures and longer time spent in the final slow phase of the movement. This pattern of results suggests that the representations that control the transport and grasp component are affected similarly by delay, and is consistent with the results previously reported for adults. Such representations therefore appear to develop before the age of 5.
authors.affiliation: Department of Psychology, School of Human Sciences, University of Surrey, Guildford GU2 5XH, UK.
authors.forename: Mark F
authors.initials: MF
authors.lastname: Bradshaw
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Watt
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Elliott
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Riddell
mesh_terms: D001696:Biomechanical Phenomena; D002648:Child; D002675:Child, Preschool; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D013997:Time Factors