A recent study published in the journal NeuroImage suggests that when people collaborate on a video game, their brain activity aligns, but this synchronization does not necessarily result in better performance. The findings indicate that the way human brains link up during teamwork is highly complex. This provides evidence that shared brain patterns might not directly cause successful collaboration.
When people interact, their brain waves often start to match up in real time. This phenomenon is known as inter-brain synchrony. To study this, scientists use a technique called hyperscanning, which allows them to record the brain activity of multiple people at the exact same time. Previous research provides evidence that this mental alignment happens during cooperative tasks, like playing games or solving puzzles.
Two specific areas of the brain are highly active during social interactions. The prefrontal cortex handles complex cognitive functions, such as planning, decision-making, and understanding what other people are thinking. The right temporoparietal junction acts as a central hub for social skills, specifically helping individuals take another person’s perspective.
A team of scientists from Nanyang Technological University in Singapore, including S.H. Jessica Tan, S.P. Jessie Leuk, and Wei-Peng Teo, designed a project to explore the causal relationship between brain alignment and teamwork. The authors wanted to know if brain synchrony directly causes better cooperation, or if it is just a byproduct of interacting.
To test this, the research team used a technique called transcranial magnetic stimulation. This method uses brief magnetic fields to temporarily speed up or slow down neural activity in targeted brain regions. By altering activity in the right temporoparietal junction, the researchers hoped to see if changes in this social brain area would affect how well two people collaborated.
The researchers recruited 33 pairs of same-gender strangers for the experiment. Each pair participated in three separate sessions involving a classic puzzle video game, Tetris. During each session, the participants played the game both individually and collaboratively for seven minutes.
In the individual version of the game, each person controlled their own falling blocks. In the collaborative version, the pair shared a single game screen. One person was strictly responsible for moving the blocks left and right, and the other person was responsible for rotating the blocks.
The participants were not allowed to speak to each other during the cooperative game. This rule forced them to anticipate their partner’s next move and rely on turn-taking. By restricting verbal communication, the scientists could observe non-verbal teamwork in action.
To measure brain activity, the scientists used a technology called functional near-infrared spectroscopy. This non-invasive method uses sensors placed on the head to shine near-infrared light through the skull. By measuring how that light is absorbed, the sensors can track changes in blood flow to different parts of the brain. The researchers placed these sensors over the participants’ prefrontal cortex and right temporoparietal junction.
During two of the three sessions, one randomly selected person in each pair received a brief, safe burst of magnetic brain stimulation before the game started. One session used an uninterrupted stimulation pattern known to temporarily slow down brain activity in the right temporoparietal junction. Another session used a pulsing pattern designed to temporarily boost activity in that same area. The third session served as a baseline, meaning no stimulation was applied.
The brain scans revealed that the participants experienced much stronger brain synchrony when they played Tetris together compared to when they played alone or rested. This synchronization was notably stronger in the prefrontal cortex than in the right temporoparietal junction.
Modulating the right temporoparietal junction with magnetic stimulation did not change how well the participants played together. The stimulation also did not change the level of brain synchrony between the partners. The scientists noted that altering the brain activity of just one person might not be enough to disrupt a shared interaction, as the other person’s brain might naturally adapt to maintain the social connection.
The data also revealed a surprising pattern regarding game performance. The researchers measured success by looking at the number of block rows completed, as well as the number of combination moves made. Combination moves occur when multiple rows are eliminated at exactly the same time.
The authors found a negative relationship between brain synchrony in the prefrontal cortex and the number of combination moves the pair achieved. Essentially, pairs who exhibited higher levels of mental alignment actually performed worse at setting up complex, high-scoring moves. This suggests that high neural alignment does not always guarantee a successful outcome in strategic tasks.
The participants also filled out questionnaires about their partners before and after the games. The responses showed that participants consistently rated their partners as more likable after collaborating. This positive social feeling occurred regardless of how poorly they performed or whether they received brain stimulation.
Several factors limit how these findings can be applied to real-world interactions. The study required participants to play Tetris across three different sessions, which likely allowed them to learn the game and adapt to their partner’s style over time. This learning effect could influence how their brains synced up during later sessions.
The equipment used for the study also relied on a limited number of sensors, tracking only specific parts of the brain. Future research could benefit from using more advanced scanning techniques that observe the entire brain at once. This would help map out exactly how different neural networks respond to social interaction and magnetic stimulation.
It is also possible that the observed brain synchrony was partially caused by both participants watching the exact same falling blocks on a screen. When two people look at identical visual inputs, their brains can process the information in similar ways, which can mimic the appearance of a deeper social connection.
To separate genuine social synchrony from shared visual processing, scientists suggest adding a control condition in future studies. For instance, participants could watch a recording of a game without actually playing together. This would help verify if the brain alignment is truly based on teamwork.
The negative relationship between brain synchrony and game performance highlights the need to reevaluate how we understand mental alignment. Higher brain synchrony is often assumed to mean better teamwork and information sharing. This new evidence suggests that the function of inter-brain synchrony is highly nuanced.
Higher levels of synchronization tend to emerge during teamwork, but they might reflect the cognitive effort required to figure out a partner’s strategy rather than successful execution. More studies are needed to unpack the exact reasons why brain waves align and how this biological process affects human relationships.
The study, “Inter-brain synchrony during collaborative gaming: an investigation using theta-burst stimulation at the right temporal-parietal junction,” was authored by S.H. Jessica Tan, S.P. Jessie Leuk, and Wei-Peng Teo.