The Influence of Motor Imagery on Postural Sway: Differential Effects of Type of Body Movement and Person Perspective

Abstract

The present study examined the differential effects of kinesthetic imagery (first person perspective) and visual imagery (third person perspective) on postural sway during quiet standing. Based on an embodied cognition perspective, the authors predicted that kinesthetic imagery would lead to activations in movement-relevant motor systems to a greater degree than visual imagery. This prediction was tested among 30 participants who imagined various motor activities from different visual perspectives while standing on a strain gauge plate. The results showed that kinesthetic imagery of lower body movements, but not of upper body movements, had clear effects on postural parameters (sway path length and frequency contents of sway). Visual imagery, in contrast, had no reliable effects on postural activity. We also found that postural effects were not affected by the vividness of imagery. The results suggest that during kinesthetic motor imagery participants partially simulated (re-activated) the imagined movements, leading to unintentional postural adjustments. These findings are consistent with an embodied cognition perspective on motor imagery.

Keywords: embodied cognition; motor imagery; postural control.

Figure 1.

A: Sway path length (mm) for the six conditions. Significant (p < .05) contrasts between conditions are denoted with an asterisk (*). Error bars denote standard errors of the mean. B: Mean power frequency (Hz) for the six conditions. Significant (p < .05) contrasts between conditions are denoted with an asterisk (*). Error bars denote standard errors of the mean.