Live vs. Static Faces: Neural Insights from fNIRS Hyperscanning
Publication Title: Investigating face processing in online interactions via UK–US hyperscanning using fNIRS
Summary
- Question
- This study examined the neural mechanisms involved in face processing during online videoconferencing. Specifically, the researchers aimed to compare brain activity and inter-brain coupling (IBC) — the synchronization of neural activity between two interacting brains — when participants viewed either live video feeds (live-online) or static images (static-online) of their partners’ faces. The researchers hypothesized that the live-online condition would activate social regions of the brain and enhance IBC more than the static-online condition, although they anticipated no difference in activity in the right supramarginal gyrus (rSMG) between the two conditions.
- Why it Matters
- With videoconferencing becoming an essential mode of communication for education, business, and healthcare, understanding how our brains process faces during virtual interactions is increasingly important. Previous studies have shown that live face-to-face interactions elicit unique neural activity patterns linked to social cognition. However, little is known about how these mechanisms translate to online interactions, where subtle social cues, such as facial micromovements and direct eye contact, may be diminished. Insights from this research could help optimize virtual communication platforms and improve social connection in remote settings.
- Methods
- Forty healthy participants (20 dyads) from the UK and US engaged in videoconferencing sessions, viewing either live video feeds or static images of their partners’ faces. The researchers used functional near-infrared spectroscopy (fNIRS), a non-invasive neuroimaging technique that measures brain activity by detecting changes in blood flow, to record neural activity simultaneously at remote laboratories. Participants were instructed to passively gaze at their partner’s face during 15-second task blocks, alternated with 15-second rest periods.
- Key Findings
- The researchers found increased neural activity in brain regions associated with visual processing, such as the occipital-temporal and dorsal visual streams, during the live-online face condition compared to the static-online condition. However, contrary to expectations based on previous in-person studies, the rSMG, a region associated with social cognition and face gaze, did not show significant activation in the live-online condition. Additionally, no evidence was found for enhanced IBC between participants’ angular gyri — brain regions involved in processing social information — during live-online face viewing compared to static-online viewing.
- Implications
- These findings suggest that while live-online faces elicit stronger visual processing than static images, the lack of significant activation in the rSMG and absence of increased IBC may indicate that live-online interactions do not fully replicate the neural dynamics of in-person social interactions. This could be due to the diminished social cues, such as reduced facial micromovements and eye contact, inherent in videoconferencing. Understanding these differences can inform the design of virtual communication tools to better support social engagement and connectedness.
- Next Steps
- The authors recommend further research to explore how other forms of communication, such as verbal interaction or physical gestures, impact neural activity and IBC during online interactions. They also suggest comparing live-online video feeds with pre-recorded videos to better understand the effects of facial dynamism on social cognition. Incorporating physiological monitoring tools in future studies may provide additional insights into the interplay between brain and body during remote social interactions.
- Funding Information
- This research was supported by the Engineering and Physical Sciences Research Council (EPSRC) under the UCL Centre for Doctoral Training in Intelligent, Integrated Imaging in Healthcare (i4Health, EP/S021930/1). Additional support was provided by the Wellcome Trust (Grant No. 212979/Z/18/Z) and the National Institutes of Health (NIH) through grants from the National Institute of Mental Health (NIMH) R01MH111629, R01MH107573, and R01MH119430. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Full Citation
Hakim U, Noah J, Zhang X, Gunasekara N, Hamilton A, Pinti P, Tachtsidis I, Hirsch J. Investigating face processing in online interactions via UK–US hyperscanning using fNIRS. Imaging Neuroscience 2026, 4: imag.a.1101. PMID: 41608057, PMCID: PMC12836396, DOI: 10.1162/imag.a.1101.
This AI-assisted summary has been reviewed and approved by at least one of the study's authors to ensure it accurately reflects the research.
Authors
Uzair Hakim
First AuthorJoy Hirsch, PhD
Last AuthorElizabeth Mears and House Jameson Professor of Psychiatry and Professor of Comparative Medicine and of Neuroscience