Figuring out how to pedal a bike and memorizing the rules of chess require two different types of learning, and now for the first time, researchers have been able to distinguish each type of learning by the brain-wave patterns it produces.
When neurons fire, they produce electrical signals that combine to form brain waves that oscillate at different frequencies. Our ultimate goal is to help people with learning and memory deficits, notes Miller.
The neural signatures could help identify changes in learning strategies that occur in diseases such as Alzheimer’s, with an eye to diagnosing these diseases earlier or enhancing certain types of learning to help patients cope with the disorder, says Roman F. Loons, a graduate student in the Miller Lab and first author of the paper. Power Institute research scientist Scott L. Bract and former MIT postdoc Evan G. Antzoulatos, now at the University of California at Davis, are co-authors.
Brain waves from earlier studies
When the MIT researchers studied the behavior of animals learning different tasks, they found signs that different tasks might require either explicit or implicit learning. In tasks that required comparing and matching two things, for instance, the animals appeared to use both correct and incorrect answers to improve their next matches, indicating an explicit form of learning.
What’s more, the researchers found, these different types of behavior are accompanied by different patterns of brain waves.
The alpha2-beta waves increased with learning during explicit tasks, then decreased as learning progressed. The researchers also saw signs of a neural spike in activity that occurs in response to behavioral errors, called event-related negativity, only in the tasks that were thought to require explicit learning.
“This showed us that there are different mechanisms at play during explicit versus implicit learning,” he notes.
Future Boost to Learning
The neural signatures could also help detect disorders such as Alzheimer’s disease at an earlier stage, Loons says. The one learning system is down; you have to rely on another one.
Miller says that the brain wave study indicates a lot of overlap in these two systems. They share a lot of the same neural networks.