The Mental Process of Learning Is More Complex Than We Thought
Sometimes two abilities that appear very similar are controlled by two different parts of our brains.
In a new study, scientists found that two mental processes related to physical action take place in separate sections of the dorsal striatum, a part of the brain that’s important for movement. The results could lead to new insights about compulsive habits, authors say, as well as models of learning.
Eric Garr, who graduated with a Ph.D. in psychology and is now a postdoctoral fellow at Johns Hopkins University, was an author on the paper, published in Neurobiology of Learning and Memory. Professor Andrew Delamater (Brooklyn College, The Graduate Center), Garr’s Ph.D. adviser, is also an author.
By studying rodents, Garr and Delamater found that the process of learning how to do a series of actions by trial and error is regulated by the lateral part of the dorsal striatum, or DLS. However, the ability to actually do those actions when motivated by the anticipation of a reward is slightly separated—this is located in the medial part of the dorsal striatum, or DMS.
These findings provide scientists two new advantages. For one, they can use the information about the DLS to validate theoretical models of learning. The results on the DMS, on the other hand, could help researchers looking for therapies for people with pathological cases of compulsive motor routines.
Scientists knew that the dorsal striatum is important for movement and movement dysfunction, but the exact connections between pathways in this part of the brain and certain behaviors are not as clear. The new study showed that these two abilities—learning an action sequence, and carrying it out based on the promise of reward—are related to independent pathways. In fact, Garr and Delamater were able to inhibit certain brain cells to dampen one ability while leaving the other intact.