LEARNING BY PURE OBSERVATION.
Simply observing a person in the act of learning to move in a new environment is enough to help you unconsciously learn those movements, says new research by Canadian scientists.
More specifically, Andrew Mattar and Paul Gribble, from the University of Western Ontario (UWO), recently found that individuals who watched a video of a person learning to move a robotic arm, performed this same task better than those who didn’t observe the learning process.
This may not come as a surprise to anyone who has learned by watching a professional athlete or expert craftsman. However, what is unexpected is that this learning of complex motor behaviors appears not to be based on conscious thought. Instead, learning through observation involves implicit actions of the brain—a finding that tells us a lot about how we absorb the actions of others.
“One really cool thing this tells us, is that when you’re watching things going on in the world, your brain is always working,” says Gribble, an assistant professor of behavioral and cognitive neuroscience at UWO. “So, even though you don’t know it, your brain is forming internal representations of how things function.”
Mattar and Gribble asked 84 people to sit at a desk in front of a robotic device shaped like a human arm. The 84 subjects were then asked to perform a task involving holding the robotic device while moving towards circles that appeared on the desk. “It was like they were shaking hands with the robot while making rapid movement to new positions,” says Gribble.
However, during the movements, the robot was programmed to apply forces to a person’s arm. “As you tried to move, the robot would push you from your normal straight trajectory,” says Gribble. This produced curved trajectories that the researchers could measure. But, over time people would learn to compensate for the applied forces and make straighter trajectories, a process that involves the brain learning to re-map its control of muscles.
Mattar and Gribble then went on to show a video of people learning to move the robotic arm to a sub-set of subjects. People who watched the video were then tested and found to produce straighter trajectories more quickly than people who didn’t get to see the video. The results are published in April 7, 2005, issue of Neuron.
Interestingly, subjects who were shown a video of people learning unrelated motions did worse, presumably due to their having mentally mapping an inappropriate representation of how the robotic arm worked.
“This really implies that people are building up an internal model of the task,” says Gribble.
To see if this learning by observation was a conscious strategy, Mattar and Gribble made subjects perform math while watching the video, with the intention of distracting their conscious thought patterns. However, this did not reduce their performance, implying that conscious thought is not required.
“In a nut-shell, this suggests that conscious systems are not necessary for someone to improve by observing,” says Mattar, who completed the current study as an undergraduate project at UWO and is now at McGill University.
However, making people move their arms while watching the video did impair their subsequent performance. This finding points to the need for motor systems to be unoccupied for observational learning to occur.
Mattar and Gribble’s findings come on the heels of a recent movement in neuroscience that links motor control – the ability to generate accurate movements under varying conditions – with the observation of actions. This theory has come to life with the discovery of “mirror neurons”, which are activated by both performing and observing the same action.
“Mirror neurons point to a connection between our neural systems for observation and action,” says Mattar. “So we did the experiments because we were interested in whether the link between observation and action could facilitate motor learning,” says Mattar. Motor learning is essentially the ability to adapt to new mechanical environments, like learning to ride a bike. Such learning is thought to involve acquiring neural representations of the way in which mechanical forces affect muscles.
Together the work does raise an intriguing question of whether people need to observe mistakes in order to learn. “My gut instinct is that you probably get more benefit from watching a person progress from being unskilled to skilled,” says Gribble, “but we’re testing this now.”
In the end, “what it all implies is that if you want to maximize your learning you should stay still and let your motor system absorb information,” says Gribble.
UWO Motor Control Lab
Mattar A. A. and Gribble P. L. “Motor learning by observing,” Neuron, 46(1):153-60, April 7, 2005.