title: Effector movement triggers gaze-dependent spatial coding of tactile and proprioceptive-tactile reach targets.
abstract: Reaching in space requires that the target and the hand are represented in the same coordinate system. While studies on visually-guided reaching consistently demonstrate the use of a gaze-dependent spatial reference frame, controversial results exist in the somatosensory domain. We investigated whether effector movement (eye or arm/hand) after target presentation and before reaching leads to gaze-dependent coding of somatosensory targets. Subjects reached to a felt target while directing gaze towards one of seven fixation locations. Touches were applied to the fingertip(s) of the left hand (proprioceptive-tactile targets) or to the dorsal surface of the left forearm (tactile targets). Effector movement was varied in terms of movement of the target limb or a gaze shift. Horizontal reach errors systematically varied as a function of gaze when a movement of either the target effector or gaze was introduced. However, we found no effect of gaze on horizontal reach errors when a movement was absent before the reach. These findings were comparable for tactile and proprioceptive-tactile targets. Our results suggest that effector movement promotes a switch from a gaze-independent to a gaze-dependent representation of somatosensory reach targets.
authors.affiliation: Department of Psychology, Justus-Liebig University Giessen, Otto-Behaghel-Strasse 10F, 35394 Giessen, Germany. Electronic address: stefanie.mueller@psychol.uni-giessen.de.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Mueller
authors.affiliation: Department of Psychology, Justus-Liebig University Giessen, Otto-Behaghel-Strasse 10F, 35394 Giessen, Germany. Electronic address: katja.fiehler@psychol.uni-giessen.de.
authors.forename: Katja
authors.initials: K
authors.lastname: Fiehler
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D011434:Proprioception / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D014110:Touch / Q000502:physiology*; D055815:Young Adult
keywords: Gaze-dependent; Movement; Proprioception; Reaching; Reference frames; Touch