Why is response learning bad for the brain?
Dr. West explains that that response learning is associated with less gray matter inside the hippocampus. This part of the brain is in charge of memory and orientation. Orientation is the concept of being aware of your own self in space and time. Interestingly, it's been shown that people with Alzheimer’s disease or depression have similar changes in their brain. These patients also tend to have less gray matter in their hippocampus.
Why does learning type affect the hippocampus?
When someone uses response learning, the striatum grows larger as the hippocampus gets smaller. The reason for this is because when a person is using habits to form memories, they don’t really need to use their active learning mechanisms found in the hippocampus. With less use, the hippocampus can shrink and age in an unhealthy way. Dr. West believes this could be why there is less gray matter in the hippocampus of response learners.