In George Orwell’s dystopian novel, 1984, Winston Smith works in the Ministry of Truth retouching photographs to remove people from the record of history. A recent psychology study suggests that these manipulations may change more than the historical record, they could affect our collective memories of what actually happened.
In the study, led by Italian psychologist Dario Sacchi, participants were shown two photographs; one from the 1989 Tiananmen Square protests and another from a 2003 protest in Rome against the Iraq war.
What they didn’t know was that some participants saw doctored versions of either one or both of the photographs. The image on the left demonstrates that a crowd was added to the Tiananmen Square image. With the Rome photo police and aggressive-looking demonstrators were added to the image of peaceful protesters.
To test whether people perceived the photos as genuine or not without giving the game away, the researchers asked participants how familiar they were with the image.
Both groups rated the Tiananmen Square photo as equally familiar, suggesting few picked up on the changes.
Interestingly, participants rated the altered Rome photo as less familiar, but when given a chance to comment, no-one suggested it was fake, with some suggesting that their memory of the protest being peaceful, rather than the photo, must be mistaken.
The participants were then asked to answer questions about the events from their memories of what happened.
Those who saw the altered Tiananmen Square image remembered more people being there, those who saw the Rome image remembered it as more violent, more negative, and recalled more property being damaged and confrontations with the police.
When the experiment was run again, participants additionally rated themselves as less likely to attend a demonstration in future.
The study has obvious implications for propaganda and the paper spends much time discussing the possible impact of doctored photos on public opinion.
Combined with some earlier studies that suggest that people often believe initial false news reports even when they’re aware of them being falsified, you can see how the media has a powerful influence over our remembered realities.
Mind Hacks 
There’s a phenomenon amongst the cryptozoologically inclined concerning a widely remembered photo of a ‘thunderbird’ that doesn’t seem to exist. Of course, this field of study is largely the province of, how to say this…kooks. Hmm, no HTML tags in your comments? Guess you’ll just have to use Google.