Brain Zap Trial Shows Gamma Stimulation May Rewire Social Brains in Gaming Disorder

Gaming disorder has long been treated as a problem of willpower, environment, or design tricks baked into the games themselves. But a growing body of neuroscience points somewhere deeper: the brains of people with gaming disorder appear to interact with others differently, and those differences may be measurable, and perhaps modifiable, with electricity. A new randomized controlled trial from researchers at Shanghai Mental Health Centre, Shanghai Jiao Tong University School of Medicine, and collaborators in Hunan, China, reports that a high-intensity form of transcranial alternating current stimulation, or HI-tACS, changed the way brains synchronize between two people during competitive tasks, and nudged gaming cravings in the right direction. The study, published in BMC Psychiatry, is among the first to test whether a brain stimulation technique can act on interpersonal brain synchronization, a neural signature of how two minds engage with each other in real time.

The concept at the heart of the study is called interpersonal brain synchronization, or IBS. When two people interact, whether cooperating on a task or competing against each other, their brain activity patterns can become correlated, rising and falling together in ways that reflect the quality of the social exchange. Researchers measure this using functional near-infrared spectroscopy, or fNIRS, a non-invasive optical technique that tracks changes in oxygenated and deoxygenated hemoglobin in the outer layers of the cortex. By recording two participants simultaneously and calculating the correlation between their hemodynamic signals in specific regions of interest, scientists can quantify how strongly two brains are coupling during a shared task. Previous work has linked atypical IBS to social interaction difficulties in several psychiatric conditions, and the team behind the new trial reasoned that gaming disorder, which is characterized by impaired social function and heightened gaming cravings in the International Classification of Diseases 11th Revision, might also involve disrupted interpersonal neural coupling.

To test whether that coupling could be changed, the researchers designed a randomized, double-blind, sham-controlled trial, registered at ClinicalTrials.gov as NCT06208358. They recruited 60 men with gaming disorder in Hunan, China, and randomly assigned them to an active HI-tACS group of 30 participants arranged in 15 dyads, or a sham group of 30 participants also arranged in 15 dyads. The active group received 10 sessions of HI-tACS over two weeks, while the sham group received a sham intervention designed to mimic the experience without delivering the same neural modulation. The use of dyads is central to the design: because IBS is a property of two interacting brains, the intervention had to be evaluated in pairs of participants performing social tasks together, rather than in isolated individuals. The trial was approved by the Institutional Review Board of the Shanghai Mental Health Center and carried out in accordance with the Declaration of Helsinki, with all subjects providing informed consent.

The stimulation itself deserves explanation. Transcranial alternating current stimulation applies a weak oscillating electrical current to the scalp, and when the frequency of that current matches a natural brain rhythm, it can entrain or amplify neural oscillations in the underlying cortex. Gamma-frequency stimulation targets the fast oscillations associated with cognitive control, attention, and social cognition. The high-intensity variant used in this trial delivers stronger currents than conventional tACS devices, with the aim of reaching deeper or more robustly modulating cortical circuits. The technique is distinct from transcranial direct current stimulation, which applies a steady current, and from repetitive transcranial magnetic stimulation, which uses magnetic pulses. By entraining gamma activity, the researchers hoped to influence the prefrontal and temporoparietal circuits that support social interaction and craving regulation in gaming disorder.

The primary outcomes were gaming cravings, measured with validated scales, and fNIRS-based IBS during structured competition and cooperation tasks performed by the dyads. The researchers analyzed the data using linear mixed models, a statistical framework well suited to repeated-measures designs in which participants are nested within dyads and measured before and after the intervention. The models tested for a Time by Group interaction, which would indicate that the active and sham groups changed differently over the course of the trial. The analysis followed an intention-to-treat approach, and the team controlled for multiple comparisons using false discovery rate procedures at the region-of-interest level, with additional single-channel analyses providing finer spatial resolution.

The craving results were suggestive but statistically delicate. Linear mixed models revealed a significant Time by Group interaction effect on gaming cravings, with an F statistic of 4.95 on 1 and 52.5 degrees of freedom and a p value of 0.03, indicating that the two groups’ craving trajectories diverged over the intervention period. However, the post-hoc comparisons did not reach statistical significance, meaning the researchers could not confirm precisely which group changed relative to which at the pairwise level. This pattern, a significant omnibus interaction without significant post-hoc tests, is common in trials of this size and suggests that the craving effect, while promising, requires replication in larger samples before any clinical claim can be made. The authors are careful to frame the findings as initial neurophysiological evidence rather than proof of therapeutic efficacy.

The interpersonal brain synchronization results were more spatially specific and, in some ways, more surprising. In the competition task, IBS showed significant Time by Group interaction effects at the single-channel level in two regions: the right temporoparietal junction, with F of 10.56 on 1 and 25 degrees of freedom and p equal to 0.04, and the left ventrolateral prefrontal cortex, with F of 11.50 on 1 and 21.6 degrees of freedom and p equal to 0.03. The direction of the effects was intriguing: after the intervention, IBS decreased in the active group and increased in the sham group. At first glance, a decrease in synchronization might seem undesirable, but the interpretation is subtler. Elevated between-brain coupling is not automatically a marker of healthy interaction; in some contexts, excessive synchronization may reflect rigid or hyper-coordinated neural dynamics. The reduction observed in the stimulated group may indicate a normalization of neural coupling toward more flexible patterns of social engagement.

Perhaps the most clinically resonant finding came from an exploratory correlation analysis. The researchers found that the reduction in IBS in the right temporoparietal junction was associated with participants’ increased perceived social support, as measured by the Perceived Social Support Scale. The right temporoparietal junction is a hub of the social brain, consistently implicated in theory of mind, the capacity to attribute mental states to others, and in perspective-taking during competitive and cooperative exchanges. If reduced synchronization in this region tracks with feeling more socially supported, it lends weight to the idea that the neural changes induced by HI-tACS are not merely artifacts of stimulation but relate meaningfully to participants’ lived social experience. This link between a laboratory neural measure and a real-world psychosocial construct is exactly the kind of bridge the field needs if brain-based interventions are to translate into functional recovery.

The trial is not without limitations, and the authors acknowledge them. The sample consisted exclusively of 60 men, which limits generalizability to women and to the broader population of people with gaming disorder. The craving result lacked significant post-hoc support, and the IBS findings emerged at the single-channel level in the competition task, warranting confirmation in independent cohorts. The two-week, ten-session protocol raises questions about the durability of any neural changes, and the study did not establish whether reduced IBS in competition predicts long-term reductions in gaming severity. Still, the randomized, double-blind, sham-controlled design, the preregistration, the dyadic fNIRS methodology, and the intention-to-treat analysis represent a methodological step forward for a field where many brain stimulation studies are small, unblinded, or exploratory.

The broader significance of the work lies in its reframing of what treatment for gaming disorder might look like. Cognitive behavioural therapy remains the most common psychological approach, but it does not directly target the neural circuits of social interaction, and pharmacological options are limited. If interpersonal brain synchronization is indeed a modifiable mechanism, brain stimulation could become a tool not just for reducing cravings but for restoring the social function that gaming disorder erodes. The Shanghai team’s findings offer the first randomized controlled evidence that gamma-frequency HI-tACS can shift between-brain coupling in the temporoparietal and prefrontal regions of people with gaming disorder, and that these shifts relate to how socially supported participants feel. Larger trials with longer follow-up, mixed-sex samples, and clinical outcome measures will determine whether this approach can move from an intriguing neurophysiological signal to a genuine therapeutic option. For now, the study opens a provocative possibility: that the social difficulties of gaming disorder are written in the synchrony between brains, and that synchrony can be retuned.

Subject of Research: High-intensity transcranial alternating current stimulation effects on interpersonal brain synchronization and gaming cravings in gaming disorder

Article Title: Effects and mechanism of High-Intensity transcranial Alternating Current Stimulation (HI-tACS) for social interaction and cravings in gaming disorder: a randomized controlled trial

Article References: Huang, C., Wang, Z., Zeng, Y., Shan, H., Lu, J., Chen, Y., Du, J., Jiang, H., Deng, M., Chen, T., Li, S., Su, H., Zhao, M., & Zhong, N. (2026). Effects and mechanism of High-Intensity transcranial Alternating Current Stimulation (HI-tACS) for social interaction and cravings in gaming disorder: a randomized controlled trial. BMC Psychiatry. https://doi.org/10.1186/s12888-026-08576-y

Image Credits: AI Generated

DOI: 10.1186/s12888-026-08576-y

Keywords: gaming disorder, HI-tACS, transcranial alternating current stimulation, interpersonal brain synchronization, fNIRS, temporoparietal junction, ventrolateral prefrontal cortex, craving, social interaction, randomized controlled trial, brain stimulation, social support