Assessing and defining explicit processes in visuomotor adaptation

Reaching with a visuomotor distortion in a virtual environment leads to reach adaptation in the trained hand, and in the untrained hand. In the current study we asked if reach adaptation in the untrained (right) hand is due to transfer of explicit adaptation (EA; strategic changes in reaches) and/or implicit adaptation (IA; unconscious changes in reaches) from the trained (left) hand, and if this transfer changes depending on instructions provided. We further asked if EA and IA are retained in both the trained and untrained hands. Participants (n = 60) were divided into 3 groups (Instructed (provided with instructions on how to counteract the visuomotor distortion), Non-Instructed (no instructions provided), and Control (EA not assessed)). EA and IA were assessed in both the trained and untrained hands immediately following rotated reach training with a 40° visuomotor distortion, and again 24 hours later by having participants reach in the absence of cursor feedback. Participants were to reach (1) so that the cursor landed on the target (EA + IA), and (2) so that their hand landed on the target (IA). Results revealed that, while initial EA observed in the trained hand was greater for the Instructed versus Non-Instructed group, the full extent of EA transferred between hands for both groups and was retained across days. IA observed in the trained hand was greatest in the Non-Instructed group. However, IA did not significantly transfer between hands for any of the three groups. Limited retention of IA was observed in the trained hand. Together, these results suggest that while initial EA and IA in the trained hand are dependent on instructions provided, transfer and retention of visuomotor adaptation to a large visuomotor distortion are driven almost exclusively by EA.

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Gaze locations affect explicit process but not implicit process during visuomotor adaptation

Journal of Neurophysiology ◽

10.1152/jn.00044.2014 ◽

2015 ◽

Vol 113 (1) ◽

pp. 88-99 ◽

Cited By ~ 14

Author(s):

Miya K. Rand ◽

Sebastian Rentsch

Keyword(s):

Visuomotor Adaptation ◽

Visuomotor Rotation ◽

The Gaze ◽

Visuomotor Transformations ◽

Explicit Processes ◽

Target Hand ◽

Hand Coordination ◽

Implicit And Explicit ◽

Explicit Process

The role of vision in implicit and explicit processes involved in adaptation to novel visuomotor transformations is not well-understood. We manipulated subjects' gaze locations through instructions during a visuomotor rotation task that established a conflict between implicit and explicit processes. Subjects were informed of a rotated visual feedback (45° counterclockwise from the desired target) and instructed to counteract it by using an explicit aiming strategy to the neighboring target (45° clockwise from the target). Simultaneously, they were instructed to gaze at either the desired target (target-gaze group), the neighboring target (hand-target-gaze group), or anywhere (free-gaze group) during aiming. After initial elimination of behavioral errors caused by strategic aiming, the subjects gradually overcompensated the rotation in the early practice, thereby increasing behavioral errors (i.e., a drift). This was caused by an implicit adaptation overriding the explicit strategy. Notably, prescribed gaze locations did not affect this implicit adaptation. In the late practice, the target-gaze and free-gaze groups reduced the drift, whereas the hand-target-gaze group did not. Furthermore, the free-gaze group changed gaze locations for strategic aiming through practice from the neighboring target to the desired target. The onset of this change was correlated with the onset of the drift reduction. These results suggest that gaze locations critically affect explicit adjustments of aiming directions to reduce the drift by taking into account the implicit adaptation that is occurring in parallel. Taken together, spatial eye-hand coordination that ties the gaze and the reach target influences the explicit process but not the implicit process.

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Differential motor learning via reward and punishment

Quarterly Journal of Experimental Psychology ◽

10.1177/1747021819871173 ◽

2019 ◽

Vol 73 (2) ◽

pp. 249-259 ◽

Cited By ~ 2

Author(s):

Yanlong Song ◽

Siyuan Lu ◽

Ann L Smiley-Oyen

Keyword(s):

Loss Aversion ◽

Visual Target ◽

Visuomotor Adaptation ◽

Explicit Learning ◽

Prediction Errors ◽

Model Free ◽

Explicit Processes ◽

Multiple Processes ◽

Sensory Prediction ◽

Reward And Punishment

Visuomotor adaptation involves multiple processes such as explicit learning, implicit learning from sensory prediction errors, and model-free mechanisms like use-dependent plasticity. Recent findings show that reward and punishment differently affect visuomotor adaptation. This study examined whether punishment and reward had distinct effects on explicit learning. When participants practised adapting to a large, abrupt visual rotation during reaching for a virtual visual target, visual feedback of the cursor was not provided. Only performance-based scalar reward or punishment feedback (money gained or lost) was used, thereby emphasising explicit processes during adaptation. The results revealed that punishment, compared with reward, induced faster adaptation and greater variability of reaching in the initial phase of adaptation. We interpret these findings as reflecting enhanced explicit learning, likely due to loss aversion.

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