Intensive preparation for the Law School Admission Test (LSAT) actually changes the structure of the brain, according to new research.
Neuroscientists at the University of California, Berkeley, say this preparation bolsters the connections between areas of the brain important for reasoning and could even increase people’s IQ scores.
The results also suggest that LSAT training improves reasoning ability by strengthening the connections between the left and right hemispheres of the brain.
According to associate professor and senior author Dr. Silvia Bunge, deductive reasoning, such as language comprehension, involves a predominantly left-hemisphere brain network. Spatial cognition, on the other hand, taxes a predominantly right-hemisphere network.
The structural changes were revealed by diffusion tensor imaging (DTI) scans of the brains of 24 college students or recent graduates before and after 100 hours of LSAT training over a three-month period.
When compared with brain scans of a matched control group of 23 young adults, the trained students showed increased connectivity between the frontal lobes of the brain, and between frontal and parietal lobes.
The study focused on fluid reasoning, which is the ability to tackle a novel problem, which is central to IQ tests and has been shown to predict academic performance and performance in demanding careers.
“People assume that IQ tests measure some stable characteristic of an individual, but we think this whole assumption is flawed,” Bunge said. “We think that the skills measured by an IQ test wax and wane over time depending on the individual’s level of cognitive activity.”
In the study, the researchers tested for changes in the white matter of the brain, which is the brain tissue that contains the connections between the brain’s neurons.
These connections, called axons, are surrounded by support cells called glia, some of which form myelin that insulates the axons and speeds the passage of signals, the researchers explain. In animal studies, increased myelination and glial support cells are associated with learning.
Using DTI, the researchers followed water movement in the white matter and found the group who went through the LSAT preparation course showed a change in the directionality of water diffusion consistent with increased myelination.
The trained group also showed a reduction in water diffusion near the boundary between the white matter and the gray matter, possibly because of more densely packed glial cells, the researchers hypothesize. While the real cause of the changes in water diffusion is unclear, the researchers note it reflects an alteration in the microstructure of the brain associated with a change in cognitive activity.
“The fact that performance on the LSAT can be improved with practice is not new. People know that they can do better on the LSAT, which is why preparation courses exist,” said Allyson Mackey, a graduate student in UC Berkeley’s Helen Wills Neuroscience Institute, who led the study.
“What we were interested in is whether and how the brain changes as a result of LSAT preparation, which we think is, fundamentally, reasoning training. We wanted to show that the ability to reason is malleable in adults.”
“One thing that gives us confidence in these data is that a lot of these changes are in the tracts that connect frontal and parietal cortex, or between different hemispheres in those areas, and frontal and parietal regions are absolutely essential for reasoning,” Bunge said. “We are seeing the changes exactly where we would expect to see them. And we think that they reflect strengthening of the connections between them.”
The findings were reported in the open access journal Frontiers in Neuroanatomy.