title: Direct-effects and after-effects of visuomotor adaptation with one arm on subsequent performance with the other arm.
abstract: Adapting to a novel sensorimotor condition is generally thought to result in the formation of an internal representation associated with the novel sensorimotor transform. While the presence of after-effects following sensorimotor adaptation is taken as evidence that such an internal representation was developed as a result of adaptation, it remains unclear whether the absence of after-effects following sensorimotor adaptation indicates that no internal representation was developed. In the present study, we examined this question by having individuals adapt to a 30° visual rotation with one arm first and testing 1) how the initial adaptation would influence subsequent performance with the other arm under the same visual condition (called direct-effects) or under a normal visual condition (called after-effects); or 2) how the initial adaptation that occurred at one workspace location would influence subsequent performance at another location with the same arm under the same or a normal visual condition. Results indicated that initial adaptation with one arm significantly influenced subsequent performance with the other in terms of direct- but not after-effects and that initial adaptation at one workspace location significantly influenced subsequent performance at a new location with the same arm in terms of both direct- and after-effects, but to different extents. These findings indicate that formation of a neural representation associated with a novel visuomotor transform does not always result in after-effects and suggest that visuomotor adaptation may involve multiple aspects of a neural representation, some of which are effector independent and some of which are effector dependent.
authors.affiliation: Department of Kinesiology, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin wang34@uwm.edu.
authors.forename: Jinsung
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Kinesiology, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Lei
mesh_terms: D000222:Adaptation, Physiological; D000223:Adaptation, Psychological; D000293:Adolescent; D000328:Adult; D001132:Arm; D005260:Female; D006801:Humans; D008297:Male; D011597:Psychomotor Performance; D011601:Psychophysics; D012371:Robotics; D012399:Rotation; D014796:Visual Perception; D055815:Young Adult
keywords: generalization; instance-reliant learning; intermanual; model-based learning; savings