Playing against robots during a game of table tennis can be a brain teaser, as brain scans reveal that there are differences in how we respond to human opponents versus machines.
Amanda Studnicki, a four-year varsity tennis veteran in college and captain of her high school tennis team, had been preparing for this moment for years. She realized that all she had to do was think small, like the size of a ping pong ball.
As a graduate student at the University of Florida, Studnicki spent weeks practicing table tennis with dozens of opponents. However, her opponents were not ordinary players, but rather had a science-fiction look with a cap of electrodes attached to their heads and a backpack streaming off them. The purpose was to investigate how our brains respond to the demands of a high-speed sport like table tennis and what difference a machine opponent makes.
Studnicki and her advisor, Daniel Ferris, found that the brains of table tennis players react differently when facing human versus machine opponents. The anticipation of a serve from a ball machine caused players’ brains to scramble, while with human opponents, the neurons hummed in unison, seemingly confident of their next move due to obvious cues.
These findings hold significant implications for sports training, highlighting the importance of human opponents in providing a level of realism that cannot be replicated with machine helpers. With the increasing prevalence and sophistication of robots, a better understanding of our brain’s response to artificial opponents could be instrumental in making these machines more naturalistic.
“Robots are getting more ubiquitous. You have companies like Boston Dynamics that are building robots that can interact with humans and other companies that are building socially assistive robots that help the elderly,” points out Ferris. “Humans interacting with robots is going to be different than when they interact with other humans. Our long term goal is to try to understand how the brain reacts to these differences.”
For years, Ferris’s lab has researched the brain’s response to visual cues and motor tasks, such as walking and running. Seeking to delve into the study of complex, fast-paced actions, Ferris brought Studnicki, with her tennis background, into the research group. Tennis proved to be the ideal sport to address these questions with, but the tech they had on hand initially struggled to capture the oversized movements, particularly high overhand serves.
“So we literally scaled things down to table tennis and asked all the same questions we had for tennis before,” Ferris adds.
Despite the smaller movements involved in table tennis, the researchers had to account for the rapid head movements that occur during a match. As a result, Ferris and Studnicki doubled the number of electrodes typically found in a brain-scanning cap to 120, with each additional electrode serving as a control.
By utilizing these numerous electrodes to scan players’ brain activity, the researchers were able to focus on the parieto-occipital cortex, an area of the brain responsible for converting sensory information into movement.
“It takes all your senses – visual, vestibular, auditory – and it gives information on creating your motor plan. It’s been studied a lot for simple tasks, like reaching and grasping, but all of them are stationary,” Studnicki adds. “We wanted to understand how it worked for complex movements like tracking a ball in space and intercepting it, and table tennis was perfect for this.”
After analyzing numerous hours of play against both Studnicki and the ball machine, the researchers made a noteworthy discovery. When facing a human opponent, players’ neurons worked in unison, as if they were communicating in the same language. Conversely, when playing against a ball-serving machine, the neurons in their brains were not in sync with one another. In neuroscience terminology, this lack of synchronization is referred to as desynchronization.
“If we have 100,000 people in a football stadium and they’re all cheering together, that’s like synchronization in the brain, which is a sign the brain is relaxed,” explains Ferris. “If we have those same 100,000 people but they’re all talking to their friends, they’re busy but they’re not in sync. In a lot of cases, that desynchronization is an indication that the brain is doing a lot of calculations as opposed to sitting and idling.”
The research team believes that the players’ brains were more active while anticipating robotic serves because the machine did not provide any cues about what was going to happen next. It is evident that our brains process these two experiences in distinct ways, indicating that training with a machine might not replicate the same experience as playing against a human opponent.
“I still see a lot of value in practicing with a machine,” Studnicki adds. “But I think machines are going to evolve in the next 10 or 20 years, and we could see more naturalistic behaviors for players to practice against.”
Image Credit: Frazier Springfield
