You can teach an old dog new tricks, according to researchers at Dartmouth University.
Graduate student Alex Schelgel, first author on a paper in the Journal of Cognitive Neuroscience, notes that the brain continues to change — for the better — in adults, as long as the adult continues learning.
The researchers are using the brain’s white matter to study brain function.
While most people equate gray matter with the brain and its higher functions, such as sensation and perception, white matter, which makes up about half the brain by volume, serves as the brain’s communications network.
The gray matter, with its densely packed nerve cell bodies, does the thinking, the computing, and the decision-making, the researchers said. Projecting from these cell bodies are the axons — the network cables — that constitute the white matter. Its color derives from myelin, a fat that wraps around the axons, acting like insulation.
“This work is contributing to a new understanding that the brain stays this plastic organ throughout your life, capable of change,” Schlegel said.
“Knowing what actually happens in the organization of the brain when you are learning has implications for the development of new models of learning, as well as potential interventions in cases of stroke and brain damage.”
To see if white matter could change as part of a long-term learning process, the researchers asked 27 Dartmouth students to enroll in a nine-month Chinese language course between 2007 and 2009, which allowed Schlegel to study their white matter in action.
While many neuroscientists use magnetic resonance imaging (MRI) in brain studies, Schlegel turned to a new MRI technology, called diffusion tensor imaging (DTI). He used DTI to measure the diffusion of water in axons, tracking the communication pathways in the brain.
Restrictions in this diffusion can indicate that more myelin has wrapped around an axon.
“An increase in myelination tells us that axons are being used more, transmitting messages between processing areas,” Schlegel said. “It means there is an active process under way.”
The study data suggest that white matter myelination was seen among the students, proving there is a structural change that goes along with the learning process.
The work demonstrates that significant changes are occurring in adults who are learning, according to the researchers, who note the structure of their brains undergoes change.
“This flies in the face of all these traditional views that all structural development happens in infancy, early in childhood,” Schlegel said. “Now that we actually do have tools to watch a brain change, we are discovering that in many cases the brain can be just as malleable as an adult as it is when you are a child or an adolescent.”
Source: Dartmouth College