A new study from Western University shows that the parts of our brain that provide us with our sense of touch are activated when we watch someone else learn a manual skill.
The findings by Heather McGregor and Paul Gribble from Western’s Brain and Mind Institute were published by the prestigious journal Current Biology.
Previous cognitive neuroscience research has proved that observing the actions of others activates many of the same brain areas that are involved in physically producing movement but until this new discovery, investigators like McGregor and Gribble didn’t know how this link between observation and action might facilitate actual learning.
“In our experiments, we showed that learning a new motor skill by watching others complete the task also depends on the neuroplasticity of the somatosensory cortex, which is the part of the brain involved in the sense of touch,” says McGregor, a graduate student in the Paul Gribble Lab and the study’s lead author.
In one experiment, the neuroscientists used electrical stimulation of the nerves in the arm of a study participant to disrupt neural processing in the somatosensory cortex while the participant observed a video of a person learning a new motor skill.
McGregor and Gribble found that when the stimulation was applied to the sensory nerves of the right arm, which was the same arm used by the tutor in the video, the benefits of observation were disrupted. Participants performed more poorly when tested in the new motor skill compared to controls, who received no nerve stimulation. When stimulation was applied to the left arm, no disruption of learning occurred. This suggests that learning by observing depends on activity in that part of somatosensory cortex that deals with the specific limb that was used.
In a second experiment, the team used electroencephalogram (EEG) technology to measure activity in the somatosensory cortex that was produced by stimulation of the sensory nerves in the arm, before and after observing someone else learn a new motor skill. McGregor and Gribble found that activity in the somatosensory cortex was increased after observing someone else learning a new motor skill. In fact, the bigger the change in activity, the better the observer learned the motor skill from observing.
“These experiments add to our understanding of how visual information about the actions of others facilitates motor skill learning and suggests that the somatosensory cortex plays a critical role in mapping visual information about the movements of a tutor’s actions onto the observer’s own motor system for learning,” says Gribble, a professor in Western’s Department of Psychology, who served as senior author of the study.