title: Hand-eye coordination relies on extra-retinal signals: evidence from reactive saccade adaptation.
abstract: Execution of a saccadic eye movement towards the goal of a hand pointing movement improves the accuracy of this hand movement. Still controversial is the role of extra-retinal signals, i.e. efference copy of the saccadic command and/or ocular proprioception, in the definition of the hand pointing target. We report here that hand pointing movements produced without visual feedback, with accompanying saccades and towards a target extinguished at saccade onset, were modified after gain change of reactive saccades through saccadic adaptation. As we have previously shown that the adaptation of reactive saccades does not influence the target representations that are common to the eye and the hand motor sub-systems (Cotti J, Guillaume A, Alahyane N, Pelisson D, Vercher JL. Adaptation of voluntary saccades, but not of reactive saccades. Transfers to hand pointing movements. J Neurophysiol 2007;98:602-12), the results of the present study demonstrate that extra-retinal signals participate in defining the target of hand pointing movements.
authors.affiliation: Laboratoire de Neurobiologie de Cognition, UMR CNRS 6155, Université de Provence, F-13331 Marseille, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Cotti
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vercher
authors.forename: Alain
authors.initials: A
authors.lastname: Guillaume
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D000704:Analysis of Variance; D005403:Fixation, Ocular / Q000502:physiology; D006225:Hand / Q000502:physiology*; D006801:Humans; D009068:Movement / Q000502:physiology*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology*; D012160:Retina / Q000502:physiology; D012438:Saccades / Q000502:physiology*