The same brain systems that humans used 200,000 years ago for day-to-day survival are the same brain systems we use today to learn abstract concepts, like momentum, energy, and gravity, which have only been formally defined in the last few centuries.

Scientists say we do this by “repurposing.”

“This is why humans have been able to move ahead and innovate—because we can use our brain for new purposes.”

Published in the journal Psychological Science, researchers used neural-decoding techniques to identify specific physics concepts that advanced students recalled when prompted.

The brain activation patterns while thinking about the concepts indicated that all of the students’ brains used the ancient brain systems the same way. Further, the patterns revealed how the new knowledge was formed—by repurposing existing neural systems.

The findings could be used to improve science instruction, says Robert Mason, a senior research associate in the psychology department at Carnegie Mellon University.

“If science teachers know how the brain is going to encode a new science concept, then they can define and elaborate that concept in ways that match the encoding. They can teach to the brain by using the brain’s language.”

For the study, researchers recruited nine advanced physics and engineering students. Each student’s brain was scanned while they were shown a set of 30 familiar concepts, such as gravity, entropy, inertia, refraction, and velocity.

Using a machine learning program, the scientists were able to identify which of the 30 concepts a student was thinking about because the thought of each concept created its own brain activation pattern. They also could break down the patterns into the different neural pieces used to build the full concepts.

The research showed for the first time how learning physics concepts is accomplished by repurposing neural structures that were originally used for general everyday purposes. More specifically, the brain is able to learn physics concepts because of its ability to understand the fundamental concepts of causal motion, periodicity, energy flow, and algebraic (sentence-like) representations.

Brain systems that process rhythmic periodicity when hearing a horse gallop also support the understanding of wave concepts in physics. Similarly, understanding gravity involves visualizing causal motion, like an apple falling from a tree; energy flow uses the same system as sensing warmth from a fire or the sun; and understanding how one concept relates to others in an equation uses the same brain systems that are used to comprehend sentences describing quantities.

“This is why humans have been able to move ahead and innovate—because we can use our brain for new purposes,” says coauthor Marcel Just, professor of psychology. “Human brains haven’t changed much over a few thousand years, but new fields like aeronautics, genetics, medicine, and computer science have been developed and continuously change. Our findings explain how the brain is able to learn and discover new types of concepts.”

The Office of Naval Research funded the work.