Proprioceptive information improves the accuracy of reaching when vision is limited
Poster Presentation

Simona Monaco
Department of Psychology, University of Western Ontario, London, ON, Canada, N6A5C2

Greg Kroliczak
Neuroscience Program, University of Western Ontario, London, ON, Canada, N6A5C2

Derek Quinlan
Neuroscience Program, University of Western Ontario, London, ON, Canada, N6A5C2

Patrizia Fattori
Dipartimento di Fisiologia Umana e Generale, Universita` di Bologna, I-40127 Bologna, Italy

Claudio Galletti
Dipartimento di Fisiologia Umana e Generale, Universita` di Bologna, I-40127 Bologna, Italy

Melvyn A. Goodale
Department of Psychology, University of Western Ontario, London, ON, Canada, N6A5C2

Jody C. Culham
Department of Psychology, University of Western Ontario, London, ON, Canada, N6A5C2

     Abstract ID Number: 127
     Full text: Not available
     Last modified: March 21, 2005

Abstract
We investigated reaching accuracy given different degrees of visual and somatosensory information. Eight right-handed participants used their right index finger to quickly reach to either an external target or to the index fingertip of the left hand. Visual information could be absent (Somatosensation Only), available until movement onset (Brief Vision), or available throughout the movement (Full Vision). For external targets, somatosensory information was unavailable (Vision Only). For the fingertip targets, subjects began by either exploring the workspace to place the fingertip on the target (Active Somatosensation) or having the experimenter place the fingertip on the target (Passive Somatosensation). We measured accuracy of the end point (the average deviation of the reaching finger from the target). Increasing visual information improved participants’ accuracy: accuracy was best during Full Vision, somewhat poorer with Brief Vision and considerably worse without vision (Somatosensation Only). In Brief Vision trials, accuracy was higher when somatosensory information was available (for both Active and Passive Somatosensation) than when it was not (Vision Only). In Full Vision Trials, accuracy was comparable regardless of the availability of somatosensory information. These results suggest that somatosensory information can improve the accuracy of reaching but only when visual information is limited.