Increasing human motor skill acquisition by driving theta-gamma coupling.

Akkad H
Dupont-Hadwen J
Kane E
Evans C
Barrett L
Frese A
Tetkovic I
Bestmann S
Stagg CJ

Learning new motor skills, such as how to play the piano, is important for every-day life. However, little is known about the brain changes that support this learning. Here, we show that driving specific patterns of brain activity in the primary motor area of the brain increases learning in healthy adults. This finding helps us understand more about learning across the brain, and to develop new treatments to help recovery after brain injuries.

Scientific Abstract

Skill learning is a fundamental adaptive process, but the mechanisms remain poorly understood. Some learning paradigms, particularly in the memory domain, are closely associated with gamma activity that is amplitude-modulated by the phase of underlying theta activity, but whether such nested activity patterns also underpin skill learning is unknown. Here we addressed this question by using transcranial alternating current stimulation (tACS) over sensorimotor cortex to modulate theta-gamma activity during motor skill acquisition, as an exemplar of a non-hippocampal-dependent task. We demonstrated, and then replicated, a significant improvement in skill acquisition with theta-gamma tACS, which outlasted the stimulation by an hour. Our results suggest that theta-gamma activity may be a common mechanism for learning across the brain and provides a putative novel intervention for optimising functional improvements in response to training or therapy.

Top left panel shows a coloured graph of brain activity. Top right panel shows cartoon of the electrical stimulation patterns that were delivered to the brain. Bottom panel is a graph showing the effects of brain stimulation on movement learning.
A - Increase in brain activity at 75 Hz is seen when people move their hands (movement onset at black vertical line). B - Here, we used a 75 Hz-6 Hz coupled electrical stimulation pattern to drive activity in the motor cortex of people during learning of a novel motor task. C - In a double-blind, pre-registered replication, active stimulation led to significantly improved learning, quantified as a gain in acceleration, compared with sham stimulation.
2021. eLife, 10:e67355.