Anodal transcranial direct current stimulation over premotor cortex facilitates observational learning of a motor sequence.

Motor skills, including complex movement sequences, can be acquired by observing a model without physical practice of the skill, a phenomenon known as observational learning. Observational learning of motor skills engages the same memory substrate as physical practice, and is thought to be mediated by the action observation network, a bilateral fronto-parietal circuit with mirror-like properties. We examined the effects of anodal transcranial direct current stimulation (tDCS) over premotor cortex, a key node of the action observation network, on observational learning of a serial response time task. Results showed that anodal tDCS during observation of the to-be-learned sequence facilitated reaction times in the subsequent behavioral test. The study provides evidence that increasing excitability of the action observation network during observation can facilitate later motor skill acquisition.