Students and faculty in the University of Chicago Department of Psychology have found the first evidence of a link between neural responses from the motor systems of infants and their overt social behavior. Their research revealed that infants’ brains are able to process and understand the reasons behind the actions of other individuals.

These findings were published on April 12 in Psychological Science, the Association for Psychological Science’s peer-reviewed journal. Courtney Fillipi, a fifth-year doctoral student in development psychology at the University of Chicago, is the lead author of the paper and worked with co-author and UChicago William S. Gray Professor of Psychology Amanda Woodward.

In the study, 36 seven-month-old infants were tested while wearing caps that measured brain activity using electroencephalography (EEG), a test that detects electrical activity in the brain with flat metal discs attached to the scalp. Each infant observed an actor reach for one of two different toys and was then allowed to choose one of the same toys. This process was repeated 12 times for each infant.

The infants’ brain activity predicted their responses to the actor’s behavior. When the infants used their motor system in the brain while observing the actor take one of the toys, the child imitated the actor and took the same toy. When there was no noticeable use of this motor system while observing the actor, the infants did not imitate the actor. According to Filippi, this indicates that infants use their motor systems before they imitate other people’s actions.

“A lot of research has looked at how infants’ brains respond when they observe other people’s actions and consistently find that when they watch other people’s actions, they show this motor system response,” Filippi said. “But what we’ve done, and what makes our work so exciting, is shown that it is not just when they watch any kind of action, but when they watch the action and think really hard about it, when they encode what the action was about.”

In an interview with UChicago News, Woodward said that although their research may not directly translate into new therapies or treatments, it may add to medical advances in the future by shedding light on how the human brain works and develops.

According to Woodward, their research proved her initial hypothesis correct. However, in the course of collecting, analyzing, and writing about the data, the research team came to realize that there are many deeper questions that must be answered that they were not aware of before the study.

“When babies are behaving, a lot of systems in the brain are active,” Woodward said. “We want to know more about how different systems of the brain are interacting and working when infants are trying to understand other people’s actions.”

“One reason to engage in basic science is to better understand the development of the brain and mind,” Woodward said in the interview. “Here we looked at the development of social cognition, social behavior and the motor system, all of which are critical for human development and are often disrupted in developmental disabilities, including autism.”