How the human brain lies to us

By Maggie Koerth-Baker at 10:20 am Wednesday, Aug 17

Even in important moments, our brains are not as good at creating accurate memories as we think they are.

This clip from the World Science Festival features two stories that show how easily the brain can be manipulated. In the first, writer Jonah Lehrer describes how he remembers his cousin ruining his 8th birthday party (except, that, he later found out, this incident never happened). The second is significantly more rattling, as Harvard psycholigst Daniel L. Schacter describes a case of mistaken identity that could have led to an innocent man being tried for rape.

This tendency of the brain to naturally distort memories has been studied in relation to what people believe they remember about September 11th. It turns out, even memories that we think of as being seared into our brains aren't as accurate as they're often treated as being, writes Greg Bousted in a piece for Scientific American. Human memory simply isn't that reliable.

Memories of tragic public events have been of interest to researchers for years. Dubbed as “flashbulb memories” for their extraordinary vividness of detail and photographic recall, these emotionally charged memories are described as being “burned” into one’s mind. Knowing exactly where one was or what one was doing during the assignation of John F. Kennedy, the Challenger disaster, or now, the September 11 attacks has become a quintessential phenomenon of the past few generations. In 1977, a pair of Harvard psychologists studied the reported memories of the JFK assassination. Participants had “an almost perceptual clarity” for recalling when they learned about the assassination and during the immediate aftermath, noting even trivial details with impressive accuracy. The researchers concluded that flashbulb memory is more detailed and accurate than memories of ordinary daily events. The defining characteristic of these types of emotionally charged, shared memories is that one’s confidence in their accuracy tends to be unshakable. But does that really make them more accurate?

In an attempt to answer that, Duke University’s Jennifer Talarico and David Rubin conducted a study on the day after the 9/11 attacks. They gave volunteers a questionnaire about their memories of the morning of September 11 as well as some other unremarkable event a day earlier. They later followed up with the questionnaires at several intervals up until almost a year later. What the researchers found is that the memories of the individuals’ goings-on during the events of September 11—the vivid and picture-like ones—were in fact no better than their recall of, say, lunch the day before. Like most memories, they predictably declined in accuracy over time.

I certainly have very detailed childhood memories that, upon reflection, can't possibly be true—in particular, I remember cooking soup for my mom while she was sick in an apartment that we moved out of somewhere around the time I was 4 years old. Obviously, she didn't actually let a toddler stand over the stove with chicken soup. But my brain "remembers" it. Maybe, at the time, that was simply something I wanted to do and my brain mixed that desire up with later memories of cooking in other, similar, kitchens.

What false memories has your brain concocted up?