title: The influence of target context and early and late vision on goal-directed reaching.
abstract: The online visual control of movement involves contributions from 2 processes: a process early in the trajectory concerned with comparisons between actual and expected sensory consequences and another process late in the trajectory that reduces the discrepancy between the position of the hand and the target. This experiment was designed to determine how early and late visual controls are impacted by the illusory characteristics of the target in a rapid reaching task. Participants performed 500 ms movements to the vertices of Müller-Lyer figures with the availability of full vision on the majority of trials. However, on a fraction of the trials, movements to the targets were performed with either early vision (first 200 ms of movement), late vision (last 200 ms of movement) or no vision. Although participants undershoot the targets under all target and visual conditions, the impact of the target configuration was greatest when vision was available during only the final portion of the movement trajectory and least when only early vision was available for limb regulation. Aiming bias under full-vision and no-vision conditions was intermediate. These findings indicate that visual context has a greater impact on late discrete limb regulation than on early dynamic control of the limb trajectory.
authors.affiliation: School of Sport and Exercise Sciences, Faculty of Science, Liverpool John Moores University, Liverpool, UK.
authors.forename: James
authors.initials: J
authors.lastname: Roberts
authors.forename: James J
authors.initials: JJ
authors.lastname: Burkitt
authors.forename: Bas
authors.initials: B
authors.lastname: Willemse
authors.forename: Alison
authors.initials: A
authors.lastname: Ludzki
authors.forename: James
authors.initials: J
authors.lastname: Lyons
authors.forename: Digby
authors.initials: D
authors.lastname: Elliott
authors.forename: Lawrence E M
authors.initials: LE
authors.lastname: Grierson
mesh_terms: D000328:Adult; D005260:Female; D006040:Goals; D006225:Hand / Q000502:physiology; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time; D014785:Vision, Ocular / Q000502:physiology*; D055815:Young Adult