Watch Wimbledon tennis champion Roger Federer practice his forehand stroke and you see hundreds of repetitions that contribute to his often breathtaking winning returns during a match. Practice past the point of mastery appears to "lock in" the memory of a skill, a Brown University study shows.
Teaching a visual perception task for 20 additional minutes after learning reached a plateau showed the benefit of practice past the point where volunteers mastered the task. This over-learning appeared to solidify the memory of the task even when it was followed by a new task that otherwise would have interfered, according to a 2017 study in Nature Neuroscience.
Musicians practicing, actors rehearsing, and students studying for a test all seem to benefit by a similar principle that "practice makes perfect" and added repetition makes it last. The assignment of extra behavioral practice of a conversational skill to a client with social anxiety is based on a similar assumption that practice above and beyond what is necessary helps the skill sink in. The Brown study had a total of 183 volunteers learn to distinguish images with and without a pattern when they were presented one after the other.
“These results suggest that just a short period of over-learning drastically changes a post-training plastic and unstable [learning state] to a hyper stabilized state that is resilient against, and even disrupts, new learning,” wrote the team led by corresponding author Takeo Watanabe, a professor of Cognitive Linguistic and Psychological Sciences at Brown.
The researchers tried to assess the neural basis for this effect with the help of a brain imaging method (magnetic resonance spectroscopy) that measured the activity of the excitatory neurotransmitter, glutamate, and the inhibitory neurotransmitter, GABA, in the visual cortex receiving area at the back of the brain, in a small subset of volunteers. Their results showed that the over-learners had an increase of GABA relative to glutamate during a window of time following the task, suggesting to the authors that neural inhibition preserved the memory of the task against interference by a second task. The regular learners showed no such effect.
“If you want to learn something very important, maybe over learning is a good way,” Watanabe said. “If you do over learning, you may be able to increase the chance that what you learn will not be gone.”
Shibata, K. and others (2017. Over learning hyper stabilizes a skill by rapidly making neurochemical processing inhibitory-dominant. Nature Neuroscience 20, 470–475 (2017) doi:10.1038/nn.4490
Brown University, Practice makes perfect, and 'overlearning' locks it in. https://news.brown.edu/articles/2017/01/overlearn