Thumbs up! (or down): Movement imagery may induce changes in cortical movement representation


Movement imagery (MI) is a cognitive motor process that shares common neural networks and mechanisms with movement execution and observation. Consequently, MI may play an important role in motor learning and rehabilitation. Previous research has demonstrated that physical training and training via action observation (in the absence of physical practice) can elicit rapid neuro-plastic changes in the cortical representation of movement (Classen et al., 1998; Butefisch et al., 2000; Stefan et al., 2005). It is unclear if these same rapid cortical plastic changes can be provoked with MI training. To determine if MI training can generate such changes, the dominant direction (i.e. flexion or extension) of TMS-evoked thumb movements was assessed before, in-between, and after five blocks of either MI training (experimental group) or physical training (PT, control group). During training, participants imagined moving or actually moved their thumbs in the direction opposite to the dominant direction of TMS-evoked thumb movements determined prior to the training blocks. It was hypothesized that if MI training can stimulate rapid cortical changes in the representation of the thumb movements (similar to PT) then the dominant direction of movement should shift in the direction of the trained thumb movement. Preliminary results suggest that there are increases in the proportion of TMS evoked thumb movements into the training direction in both the experimental and control groups. These results indicate that MI can generate rapid cortical plastic changes in the motor system.

Acknowledgments: Funded by grants received from the Natural Sciences and Engineering Research Council of Canada. The authors would like to thank Sarah Latter, Talia Shafir, Saba Taravati, and Katrina Innanen for their help with data collection.