The application of TMS in Learning
The potential uses for TMS in the study of learning range from a method to map the topography and intensity of motor output maps during visuomotor learning to inducing reversible lesions that allow for the precise temporal and spatial dissection of the brain processes underlying learning (Grafman and Wasserman, 1998).
Ongoing research
A pivotal study by Brown et al. (2009) used repetitive transcranial magnetic stimulation (rTMS) to test the idea that ‘Neural representations of novel motor skills can be acquired through visual observation’ is based on engagement of neural processes for learning in the primary motor cortex (M1). Subjects who observed another person learning to reach in a novel force environment imposed by a robot arm performed better when later tested in the same environment than subjects who observed movements in a different environment. rTMS applied to M1 after observation reduced the beneficial effect of observing congruent forces, and eliminated the detrimental effect of observing incongruent forces. Stimulation of a control site in the frontal cortex had no effect on reaching. The authors concluded that their findings represented the first direct evidence that neural representations of motor skills in M1, a cortical region whose role has been firmly established for active motor learning, also underlie motor learning by observing.
A more-recent study used TMS to investigate the effect of contextual interference on motor learning (Lin et al., 2010). The results supported the hypothesis that random practice of motor skills leads to neural activity in M1, which, in turn, is causally important in developing stronger memory representations of each task (i.e., better motor learning). Such experience-dependent M1 activity in motor learning suggests that in addition to its known role in movement execution, M1 activity is also associated with motor skill learning, particularly when practice variability increases.
References
- Grafman and Wasserman, Neuropsychologia, 1998
- Brown et al., J Cognitive Neuroscience, 2009
- Lin et al., J Motor Behavior, 2010
