Differential Integration of Visual and Proprioceptive Representations for Perception Versus Action
Open Access
Author:
Patterson, Jacqueline Rose
Area of Honors:
Kinesiology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Robert L Sainburg, Thesis Supervisor Jessica Lynn Schultz, Thesis Honors Advisor
Keywords:
vision proprioception limb position drift movement specification
Abstract:
Previous work (Brown et al., 2003) has shown that limb position drifts when individuals make repetitive movements in the absence of visual feedback. Regardless of the extent of drift, distance and direction of the repetitive movements are maintained. Currently, we examine how individuals program new movements following drift based on visual and proprioceptive maps. We hypothesize that limb drift reflects a misalignment of intact visual and proprioceptive maps. In a VR environment, participants made continuous movements with their dominant right hand between two targets positioned 15 cm apart, paced by a two Hertz metronome. After five cycles, cursor feedback of hand was removed for the next 44 cycles, which induced an average drift in hand position of roughly five centimeters. Kinematic analysis indicates differential programming, with movement direction specified by the visual input of the initial, last-seen position and movement distance specified by proprioceptive input of the current, drifted hand position. We conclude that limb position drift arises from a progressive misalignment of intact visual and proprioceptive maps. Integration of these maps is attained differently for perception versus action: uncertainty in positional sense results in drift while movements maintain accuracy.
