Explicit and implicit visuomotor adaptation differ based on the method of assessment


The process dissociation procedure (PDP; action task) and the Verbal report framework (VRF; perceptual task) have been put forth to examine implicit visuomotor adaptation (IA) and explicit visuomotor adaptation (EA). It is unclear if the two methods (PDP vs. VRF) measure similar IA and EA, as the neural processes underlying the control of action versus perception have been shown to be dissociated (Goodale & Milner, 1992). 20 participants were divided into two groups (PDP vs. VRF) and reached in a virtual environment with an aligned cursor (1 block) and a cursor that was rotated 40° CW relative to hand motion (3 blocks). IA and EA were assessed immediately following each of the 4 blocks and following a 5-minute break in which participants sat quietly. The PDP group reached while using any learned strategy (IA+EA), or while not engaging in a strategy (IA). The VRF group verbally reported the number they planned to aim to (EA) before they reached to the target (IA+EA). Both groups adapted to the rotation and showed evidence of IA and EA. However, the groups differed with respect to the stability and extent of IA and EA observed over time. In the PDP group, IA decayed quickly (i.e., following the 5-minute break), while, IA was consistent across blocks and delay interval for the VRF group. The VRF group also had greater EA at all times. Given the different trends in performance between the groups, the PDP and VRF do not assess similar IA and EA.

Acknowledgments: Supported by Natural Sciences and Engineering Research Council of Canada [EKC].