Repeated fake images trick your brain into thinking they’re real

Seeing the same picture more than once makes us more likely to believe it reflects reality. That holds for both photographs and AI-generated fakes. Repetition alone boosts perceived authenticity, even when nothing else changes.

A new international study led by Tel Aviv University along with collaborators from Germany, Belgium, and Spain tested this effect in controlled experiments with real and synthetic images.

The study shows how a basic feature of human psychology can shape what we accept as true online. In feeds and stories, the same image may surface across multiple accounts and over several days. Each exposure nudges belief upward, showing that our eyes tend to trust what they recognize.

Familiarity fools us

“The study is based on a well-known psychological phenomenon called the ‘mere exposure effect,’ which suggests that information that we encounter repeatedly is perceived as more credible,” said lead author Guy Grinfeld, a psychologist at Tel Aviv University.

“In our research, we examined whether this effect also applies in the visual domain – specifically with images created using artificial intelligence algorithms.”

This is the first study to demonstrate the mere exposure effect for images; until now, it had only been demonstrated for text. The findings raise concerns about the spread of false visual information on social media and its influence on public perception.

“As we like to summarize it, if until now the proverb went, ‘A lie told often enough becomes the truth,’ our study shows that ‘An image seen often enough becomes reality,” said Grinfeld.

Past research tied repetition to credibility for written claims. This study moves that logic to pictures. It asks a tight question with huge stakes in an AI era: Does mere exposure make visual content feel truer, even when it is fabricated?

Testing real and fake images

Participants viewed a series of images – some authentic photographs, others created by artificial intelligence. Later, they saw a mix of repeated and new images and judged whether each depicted a real object, person, place, or event.

The results were clear: images seen before were rated as more credible than those viewed for the first time. This pattern held whether the image was a genuine photograph or a synthetic fake. Familiarity, not accuracy, drove belief.

One twist stood out – the repetition effect was stronger among the most skeptical participants, those who, on average, rated images as less credible overall.

Even they relied on repetition as a cue; when they had seen an image before, their guard dropped more than expected.

Algorithms amplify fake images

The finding aligns closely with how platforms operate: algorithms prioritize engagement, popular posts recirculate, and communities echo the same visuals across channels.

People may encounter the same image repeatedly, often without context or attribution. With each pass, certainty hardens.

That’s a serious problem in the age of generative tools. It was once easier to “lie” with words than with pictures, but today a convincing image can be created in seconds.

The study shows that once such an image enters circulation, repetition alone can elevate its perceived truth.

Fakes gain power by repetition

The psychology involved in this study shows how brains process risk and noise and how recognition lowers cognitive load.

The mind treats familiar cues as safer and more likely to be true, so in cluttered environments that shortcut helps us cope.

The authors note that the effect does not depend on technical realism. A well-made fake may deceive with detail, but even a mediocre fake can gain plausibility through repetition. This dynamic blurs the line between evidence and mere exposure.

Repetition reshapes reality

Repeated fake image misinformation can shape memory, attitudes, and decisions. It can sway opinions about people and events, seeding false “proof” that resurfaces during crises. Moreover, it can do all that without any single, definitive lie.

Post fewer duplicate images, clearly label synthetic or recycled ones, and strengthen media literacy so repetition is treated as a warning.

“In the era of social networks and digital media, we are constantly and involuntarily exposed to visual information,” Grinfeld said. “Whereas in the past it was easy to lie with words, today AI tools make it just as easy to ‘lie’ with images.”

“Our study reveals a troubling mechanism: people attribute higher credibility to visual information that is repeated, regardless of its veracity. This creates a dangerous combination – repeated exposure to false information can make it seem credible, simply through repetition.”

“The findings raise profound questions about how we process information, especially in an age of visual overload in social and news media.”

The takeaway is simple and unsettling: what we see again and again starts to feel real. That makes repetition a powerful force in public life. And it makes resisting it one of the hardest, most urgent tasks in the information age.

The findings are published in the Journal of Experimental Psychology: Learning, Memory, and Cognition.

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