Imagine stepping into a store, CCTV cameras discreetly angled over aisles and doorways. You know you’re being watched, but does it matter? You shrug off the thought and browse. Yet, somewhere beneath your conscious awareness, something fundamental shifts. Your brain, ever vigilant, begins to perceive the world differently.

This subtle and involuntary shift has been investigated closely by a new study. Researchers from the University of Technology Sydney (UTS) have found that knowing you’re under surveillance doesn’t just change behavior—it alters how your brain processes faces and gaze direction. The results, while intriguing, hint at deeper implications for public mental health in a world increasingly under mass surveillance.

A Faster Mind Under Watchful Eyes

Led by Associate Professor Kiley Seymour, the research team worked with 54 participants to investigate how surveillance impacts a core function of human perception: the ability to detect another person’s gaze. This skill is a cornerstone of social interaction, honed by evolution to help us identify threats, friends, and subtle social cues.

“We know CCTV changes our behavior, and that’s the main driver for retailers and others wanting to deploy such technology to prevent unwanted behavior,” Seymour explained. “However, we show it’s not only overt behavior that changes — our brain changes the way it processes information.”

In the study, participants exposed to conspicuous CCTV became hyper-aware of faces. They could detect facial stimuli almost a full second faster than those who weren’t under surveillance. This hyper-awareness happened automatically, without the participants even realizing it.

Seymour described the effect as “marked, highly significant, and imperceptible.” Even when participants reported no concern about being monitored, their brains acted as though they were on high alert.

Why Does This Matter?

The ability to rapidly detect faces and interpret gaze direction is essential for navigating social life. “Information conveyed in faces, such as gaze direction, enables us to construct models of other people’s minds and to use this information to predict behavior,” Seymour said.

But there’s a darker side to this heightened vigilance. The brain’s hyper-sensitivity to gaze is a common feature of mental health conditions like social anxiety disorder and psychosis. In these conditions, people may become irrationally preoccupied with the idea of being watched. The new findings suggest that the mere presence of surveillance could amplify these tendencies, potentially affecting mental health on a broader scale.

As surveillance becomes more pervasive — in stores, on streets, and even in schools — the cumulative mental load on society may be profound.

“Given the increasing level of surveillance in society and the ongoing debates around privacy reform,” Seymour said, “the study’s findings suggest the need for closer examination of the effects of surveillance on mental processes and on public health more broadly.”

A Hidden Cost of Modern Life?

Surveillance is often justified by promises of security and safety. Yet, the study raises a provocative question. What if the price of security is an unseen burden on our minds?

In the late 18th century, philosopher Jeremy Bentham proposed the Panopticon. The idea was a prison design where all inmates could be observed by a single corrections officer, without the inmates knowing whether or not they are being watched. Bentham asserted that the mere possibility of observation was enough to keep them in line by means of self-regulation. In the modern world, with surveillance cameras dotting every corner, the Panopticon has become a reality. But here the walls are invisible, and the prisoners are all of us.

The UTS study doesn’t advocate for abandoning surveillance. But it urges a deeper consideration of how these invisible eyes might shape us, not just consciously, but in the silent circuitry of our brains.

“Whilst this investigation was specifically focused on unconscious social processes, future investigations should explore effects on the limbic system more broadly, which would have more general implications for public mental health and the importance of privacy,” Seymour said.

The findings appeared in the journal Neuroscience of Consciousness.