The "eye" in imagination: Restricting eye movements influence imagined actions


Humans use their eyes and hands in a coordinated way during the performance of goal-directed action – the eyes usually precede the hand to the target to assist in error detection and correction. A version of this eye-hand coupling may also be maintained when we imagine performing these actions. That is, even if the body is not moving during motor imagery, the eyes tend to maintain a movement pattern consistent with the pattern seen during actual performance. These eye movements may functionally support (or be the expression of) the accurate imagination of the body movement. To test this hypothesis, we examined the role of eye movements in imagined and executed actions in a Fitts' reciprocal pointing task. Participants were asked to imagine and execute reciprocal aiming movements in two conditions. In one of these conditions, no instructions were given regarding eye movements. In the other condition, participants were asked to fixate their eyes on a central circle. The primary finding was that the eye fixation instructions only affected movement times in the imagination task. Specifically, whereas movement times in the execution task were similar when participants could freely move their eyes or were instructed to centrally fixate, movement times in the imagination task were longer when participants were instructed to fixate than when they could freely move their eyes. Therefore, only imagined actions were affected by restricting the eye movements indicating a functional role for eye movements during imagination.

Acknowledgments: NSERC