The more interested you are in a topic, such as politics or sports, the more likely you may be to form "false memories" about events related to that topic, according to a new study.

In the study, people were asked whether they remembered certain events, including some that really happened and some that didn't. The researchers found that only 10 percent of people in the study said they remembered an event that did not really happen — or in other words, they had a false memory — in relation to topics that they were not interested in. In contrast, 25 percent of people in the study had false memories about events in relation to topics they were interested in.

"Most people are pretty confident in their own memory for events, but this research shows that false memory is a lot more frequent than many people realize," said study co-author Ciara Greene, a psychologist at the University College Dublin in Ireland. [5 Strange Facts About Memory]

"In terms of daily life, the take-home message here may be to understand that someone who remembers an event differently from you isn't necessarily lying — someone's memory may be faulty, and it might be yours," Greene said.

In the study, the researchers asked 489 people to rank seven topics from the most to the least interesting. Those topics were football, politics, business, technology, film, science and pop music, according to the study, which the researchers will present on Thursday (Sept. 1) in Barcelona, Spain, at a meeting of the British Psychological Society.

The researchers asked each person to read four news stories about events that were related to the topic they ranked as the most interesting, and four stories about events related to the topic they rated as the least interesting. In each case, three of these events really did occur, but the fourth one was made up. For example, in the "science" category, the fictional story was about recent rediscovery of a supposedly extinct bird species in Senegal. However, in truth, the species is very common in that country and is in no danger of extinction.

The researchers then asked the people to indicate if they remembered each of the four news events by choosing one of the following options: "I remember this," "I remember this differently" or "I do not remember this."

It turned out that people tended to remember the stories from the topics they said they were more interested in, compared with topics they were not interested in. However, the participants also tended to store more false memories related to the topics they were interested in, compared with topics they were not interested in, the researchers found.

This finding "is counterintuitive, interesting and definitely worthy of further scientific examination," said Elizabeth F. Loftus, a psychologist and false-memory expert at the University of California, Irvine, who was not involved in the study.

Moreover, the researchers found a similar effect if a person knew a lot about a certain topic, rather than just being interested in it. In that case, he she or was also more likely to form false memories about the subject, compared with topics that he or she did not know much about. [Top 10 Mysteries of the Mind]

It is not clear why having a strong interest or deep knowledge of a topic is linked to a greater risk of forming false memories about the subject. However, the more people know about a topic, the more memories related to this topic they have stored in their brains, the researchers said. Therefore, when a person encounters new information on this topic, that information may trigger traces of similar memories that are already stored in the brain, Greene said.

"This can result in a sense of familiarity or recognition of the new material, leading to the conviction that the information has been encountered before and is in fact an existing memory," Greene told Live Science. In other words, this new material or information may "feel" familiar and therefore the person may assume it must be true, he said.

Learning more about how false memories work may help protect against the harmful effects of them, such as when eyewitness accounts of crimes are faulty, the researchers said.

Originally published on Live Science.