Abstract
Information about another person’s movement kinematics obtained through visual observation activates brain regions involved in motor learning. Observation-related changes in these brain areas are associated with adaptive changes to feedforward neural control of muscle activation and behavioural improvements in limb movement control. However, little is known about the stability of these observation-related effects over time. Here we used force channel trials to probe changes in lateral force production at various time points (1 min, 10 min, 30 min, 60 min, 24 h) after participants either physically performed, or observed another individual performing upper limb reaching movements that were perturbed by novel, robot-generated forces (a velocity-dependent force-field). Observers learned to predictively generate directionally and temporally specific compensatory forces during reaching, consistent with the idea that they acquired an internal representation of the novel dynamics. Participants who physically practiced in the force-field showed adaptation that was detectable at all time points, with some decay detected after 24 h. Observation-related adaptation was less temporally stable in comparison, decaying slightly after 1 h and undetectable at 24 h. Observation induced less adaptation overall than physical practice, which could explain differences in temporal stability. Visually acquired representations of movement dynamics are retained and continue to influence behavior for at least one hour after observation.
New & Noteworthy Little is known about the durability of motor learning that occurs by observing someone else’s movements. We used force channel probes in an upper limb force-field reaching task in humans to compare the durability of learning-related changes that occured through visual observation to those after physical movement practice. Visually acquired representations of movement dynamics continued to influence behavior for at least one hour after observation.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Funding sources: This work was supported by the Canadian Institutes of Health Research (CIHR grant PJT-153447 to PLG). CJF was supported by a BrainsCAN postdoctoral fellowship from the Canada First Research Excellence Fund (CFREF) and a postdoctoral fellowship from the Natural Sciences and Engineering Research Council of Canada (NSERC).
Conflict of Interest: Authors report no conflict of interest.
