The Frontal Cortex

Over at Neurophilosphy, there's a wonderful post on "confabulatory hypermnesia," or severe false memory syndrome:

In the journal Cortex, researchers describe the case of a patient with severe memory loss who has a tendency to invent detailed and perfectly plausible false memories (confabulations) in response to questions to which most people would answer "I don't know", such as the one above. They have named this unusual condition confabulatory hypermnesia, and believe that theirs is the first study to document it.

For example, when asked about his brother's job, he told the researchers that "Remy is an artist who works in variety shows", confusing his brother with his son, who actually does work as an artist in variety shows; when asked "What month is it?", he answered "The end of December", when it was in fact April; to the question "What happened in May 1968?", he responded with "It was the beginning of of the workmen's revolution; the government opposed Africa"; when probed about what he thought would be the most important advance in space exploration in the next 10 years, he he replied "We will land on the Moon and...see if it is habitable"; and when asked to tell the researchers what he would be doing that evening, he presponded with "I'll have dinner with my wife and then watch the television news", despite the fact that he was hospitalized at the time, and that there was no television on his ward.

Most strikingly, LM confabulated plausible answers to questions about both his personal life and public events, which would normally elicit from most people an answer of "I don't know". When the researchers asked him "Who won the Palme d'Or at the Cannes Film Festival in 1980?" he replied "Fernandel"; when asked what he had for dinner on Tuesday two weeks ago, he answered "Steak with french fries"; and when asked "Do you remember what you did on March 13th, 1985?" he replied "We spent the day at the Senart Forest."

Sounds rather bizarre, right? We like to believe that our memories are honest and accurate and that our confabulations aren't, well, confabulations. But we're wrong on both counts. We all have a lot more in common with LM than we'd like to believe.

Look, for instance, at memory reconsolidation. Although we tend to imagine our memories as immutable impressions, like a data file stored on a computer hard drive, our memories are actually part of a ceaseless process. Every time we remember anything, the neuronal structure of the memory is delicately transformed, a process called reconsolidation. (Freud called this process Nachtraglichkeit, or "retroactivity".) The memory is altered in the absence of the original stimulus, becoming less about what you remember and more about you. This is why even flashbulb memories - those recollections that seem permanently etched into the hippocampus - are so inaccurate, as this paper makes clear:

On September 12, 2001, 54 Duke students recorded their memory of first hearing about the terrorist attacks of September 11 and of a recent everyday event. They were tested again either 1, 6, or 32 weeks later. Consistency for the flashbulb and everyday memories did not differ, in both cases declining over time. However, ratings of vividness, recollection, and belief in the accuracy of memory declined only for everyday memories. Initial visceral emotion ratings correlated with later belief in accuracy, but not consistency, for flashbulb memories. Initial visceral emotion ratings predicted later posttraumatic stress disorder symptoms. Flashbulb memories are not special in their accuracy, as previously claimed, but only in their perceived accuracy.

We're no better when it comes to confabulations. Consider this moral scenario, which was first invented by Jonathan Haidt, at the University of Virginia. Julie and Mark are siblings vacationing together in the South of France. One night, after a lovely day spent exploring the local countryside, they share a delicious dinner and few bottles of red wine. One thing leads to another and Julie and Mark decide to have sex. Although she's on the pill, Mark uses a condom just in case. They enjoy themselves very much, but decide not to have sex again. The siblings promise to keep the one night affair secret and discover, over time, that having sex has brought them even closer together. Did Julie and Mark do something wrong?

If you're like most people, your first reaction is that the brother and sister committed a grave sin. What they did was very wrong. When Haidt asks people to explain their harsh moral judgment, the most common reasons given are the risk of having kids with genetic abnormalities and the possibility that sex will damage the sibling relationship. At this point, Haidt politely points out that Mark and Julie used two types of birth control and that having sex actually improved their relationship. But the facts of the case don't matter. Even when their arguments are disproved, people still cling to the belief that having sex with your brother or sister is somehow immoral. In other words, they confabulate reasons to justify their moral intuition.

Eventually, of course, people run out of reasons. That's when people start saying things like "Because it's just wrong to have sex with your sister" or "Because it's disgusting, that's why!" Haidt calls this state "moral dumbfounding". We know something is morally wrong⎯sibling sex is a terrible idea⎯but we can't rationally defend our verdict. According to Haidt, this simple story about sibling sex illuminates the two separate processes at work inside the mind. On the one hand, we've got an unconscious stuffed full of powerful emotions and visceral instincts, which generate the initial verdict. In the case of Julie and Mark, it refuses to believe that having sex with a sibling is morally permissible, no matter how many forms of birth control are used. In the case of LM, it sent out a mistaken signal that a memory existed when it did not. So what does our consciousness do? It has to explain the verdict and justify the feeling of remembering. It provides us with reasons and details, but those confabulations all come after the fact.