What we imagine learning from watching others: how motor imagery modulates competency perceptions resulting from the repeated observation of a juggling action.

Although motor learning can occur from observing others perform a motor skill (action observation; AO), observers' confidence in their own ability to perform the skill can be falsely increased compared to their actual ability. This illusion of motor competence (i.e., 'over-confidence') may arise because the learner does not gain access to sensory feedback about their own performance-a source of information that can help individuals understand their veridical motor capabilities. Unlike AO, motor imagery (MI; the mental rehearsal of a motor skill) is thought to be linked to an understanding of movement consequences and kinaesthetic information. MI may thus provide the learner with movement-related diagnostic information, leading to greater accuracy in assessing ability. The present study was designed to evaluate the effects of MI when paired with AO in assessments of one's own motor capabilities in an online observation task. Two groups rated their confidence in performing a juggling task following repeated observations of the action without MI (OBS group; n = 45) or with MI following observation (OBS+MI; n = 39). As predicted, confidence increased with repeated observation for both groups, yet increased to a greater extent in the OBS relative to the OBS+MI group. The addition of MI appeared to reduce confidence that resulted from repeated AO alone. Data support the hypothesis that AO and MI are separable and that MI allows better access to sensory information than AO. However, further research is required to assess changes in confidence that result from MI alone and motor execution.

The "eye" in imagination: The role of eye movements in a reciprocal aiming task.

Humans not only perform a variety of actions, but they also simulate or imagine themselves performing those actions. When individuals physically execute goal-directed hand movements, eye movements typically precede the hand movements to the target to enhance movement accuracy. Studies have also revealed that eye movements emerge during motor imagery. Although eye-hand coordination is clearly important for the execution of a goal-directed movement, less is known about the role or expression of eye movements in an imagined movement. The present experiments were designed to investigate the role of eye movements during an executed and imagined reciprocal aiming task. Participants executed and imagined reciprocal aiming movements under conditions in which they were allowed to freely move their eyes or were told to fixate at a fixation point. Speed-accuracy trade-offs consistent with Fitts' Law were observed across all conditions suggesting that eye movements were not necessary to execute or imagine movements. Movement times were longest, however, in the imagination task when the eye movements were restricted to the central fixation point, suggesting that eye movements might assist with the accuracy or calibration of the imagination process. Analysis of eye movements during the no fixation imagination task revealed that the eye movements during imagination mimicked the executed hand movements when gaze was not restricted. Overall, these results suggest that although the ability to make eye movements was not necessary for action execution or motor imagery, the use of eye movements likely enhancing the accuracy of motor imagery for this task.