Monday, 23 September 2013

False memories have an upside

A false memory feels to its owner like a recollection of a real experience, but is in fact a construction of the mind. False memories are prolific because the process of memory is an inherently active, reconstructive process. Human memory then is highly fallible and prone to distortion. This sounds bad. However, in a new paper, Mark Howe and his colleagues show how our propensity for false memories can be advantageous.

Howe's team specifically tested the notion that false memories can be advantageous because they reflect the activation of concepts and ideas related to an earlier experience, which can aid future problem solving. Howe's clever experiment suggests this is particularly the case for memories that pertain to danger and survival.

Thirty adults and thirty children studied lists of ten words at a time and then attempted to recall them. Each list contained words that were all germane to the same topic. Topics were either neutral, such as "paper" or "a table", or related to a survival topic, such as "fire" or "death".

Typically when a person attempts to recall a list of words all related to the same topic they will generate one or more words that fit the theme but were in fact never seen - a kind of false memory. This possibility was important for the next stage of the experiment.

After studying and recalling four word lists, the child and adult participants completed a series of eight word puzzles known as the "remote associates test." Three words are presented and the challenge is to name a fourth word that can be meaningfully paired with all three. An example would be "rocking, wheel, high" with the solution "chair".

The clever twist was that the solution for half of the puzzles was strongly related to the theme of an earlier word list. Crucially, Howe and his colleagues found that children and adults were better at solving a word puzzle if they'd earlier had a false memory for the relevant solution. What's more, this effect was stronger for words pertaining to survival, which hints out how this could be an adaptive process with deep evolutionary roots.

Here's an example so you can see how the process worked. One of the survival word lists featured these 10 words: blaze, flame, inferno, torch, aim, smoke, dragon, log, burn, match. When some of the participants attempted to recall the list, they included the word "fire" - a false memory, since fire wasn't in the list. Later, such participants tended to perform better at the following remote associates word puzzle - cracker, fly, fighter; the answer to which is fire.

In other words, when our memories spread into related concepts, this can lead to false memories - something we usually consider a fallibility - but in fact such false memories have the potential to aid us in future problem solving on a related topic. And this seems especially to happen when the topic is survival related: participants recalled more accurate and more false memories for survival-related word lists, and they found these survival-related false memories more useful than neutral false memories for solving later related puzzles. This suggests memories for survival-related material tend to be particularly interconnected with related concepts.

To finish up, here's the example Howe and his team gave for how false memories could prove useful in a real-life survival situation:
"... the person who misremembers seeing a predator while foraging for food might be more cautious upon their return to that same patch to gather more food than the person who accurately remembers that only signs (e.g., feces, scent) of the predator had been present on an earlier visit. That false memories are an inevitable consequence of a powerful, reconstructive memory system does not make them something to be avoided. Indeed, like many things, memory illusions are neither good nor bad in and of themselves. What determines whether they have a positive or negative consequence depends solely upon how they are later put to use."

Howe ML, Garner SR, and Patel M (2013). Positive Consequences of False Memories. Behavioral sciences and the law PMID: 23843125

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.


Philip M said...

Interesting, highly expansive topic. I don't want to come across as disrespectful but the true/false positive/negative dichotomies raised in slightly limited relation to personal recollections of prior events beg for more rigour. The advantages of reflexive processes involved in “the activation of concepts and ideas related to an earlier experience “ we should agree on. However, this is also limited I suspect, by linear views of time and individuated notions of experience.

Anonymous said...

I understood what you were trying to say until the 'linear views of time' and 'individuated notions of experience' part, could you explain these a little more simply, or what you meant by these? I'm finding that the terminology you are using outweighs your ability to be understood - it would be nice to hear, simply, why you feel this research is flawed. Are you trying to say, that because this is a controlled experiment, everybody was given the same 'experience', the same words to recall etc? And that as a result it may not actually be the case in the 'real world'? I personally think this article is quite enlightening, because the focus has always been on areas where false memories can create a negative situation, such as with eye witness testimony. It's actually refreshing to see where false memory might actually instead be an evolutionary adaptation. Rather than viewing this aspect of memory as a falter of cognitive ability, it's interesting to see a researcher trying to establish a 'reason' why our memory works this way.

Philip M said...

The topic is fascinating and I apologise if I came across as being dismissive in putting across a general response. The point of human memory being highly fallible and prone to distortion is in my own humble opinion one facet of what we could agree to describe as being a fairly common living feature- or one of many 'evolutionary adaptations’.
In short, the more interesting application for this someday would be in traumatic or distressing experience whereby words and other sounds, smells, sights, sensations and perhaps even tastes are logged by a person’s brain in ways that are hard to recall, even harder to find places to describe, and virtually impossible to correspond to real events from the past in terms of saying whether they did actually happen or did not actually happen. It may be more realistic to presume that partial truth or partial falsity is more applicable to human memory, although the premise of something being overtly false but of use is accepted. The reasons for this I wish all researchers luck with in establishing outright.
I would not like to comment in detail on the whole work of Howe et al as I have not read it first-hand. However, although the psyche of pre-historic circumstance may well be one avenue to try and connect with logic in terms of survival; time, or time and space as a whole thing experienced by humans as individuals is mediated by a myriad of social and cultural forms in modern life. The flaw I would suggest is not that a person will never need to draw on survival instincts but human minds are, even by simple and progressive criteria, connected differently within themselves and to one another than they are or were in any worldly situation in which this thought-experiment can be applied.
Critics like myself are ten a penny. People with first-hand experience of the power of false memory and knowledge of sensory perceptions that may not always be reliable are not. I sincerely thank you for engaging and welcome discussion of this in a calm and positive way at any time. Good luck to you and to Howe and the team. As for the ‘individuated notions of experience thing’- it was in part a throwaway under-graduate type comment to make explicit the hoped-for link between what we hold as ideas and concepts in our mind right now, and the notion of something better for future selves and future generations either in the real world, or in the discipline of psychlology.

Luke said...

...I'm pretty sure I'm wrong, because there's no way it could be this obvious... but this doesn't necessarily prove causation, right? "False memory -> Better performance" could just as well be due to a confounding variable just as much as it could be due to causation, I think.
Say for survival topics, people find that it is easier to make word-connections in general. Therefore, they'll tend to make "false memories" more easily, and also perform better on the quiz, too.

Unknown said...

I think you're right to be suspect about the possibility of a direct causal link. However, even without a direct causal link, the researchers' deeper point stands - that the processes (including the activation in memory of related concepts) that give rise to false memories may also aid future problem solving. So in this sense false memories have an upside because they are a marker of those useful concept-activating processes.

Sarah Garner said...

Hi Luke. Thank you for your comment, however I am not sure I agree with your point that we cannot imply causation. This is because our experiment was conducted within-subjects, i.e. the same participants that were primed on some problems, also completed problems that they were not primed on. I believe therefore that it is not simply a case that they 'tend to make more false memories, and then also perform better on the problems', due to the fact that we only found an improvement on the problems where they specifically falsely recalled the answer and no benefit on problems where they were unprimed, or did not falsely recall the false memory.

Anonymous said...

This is really interesting, and quite remarkable really. I think this also has a lot to do with how the brain naturally looks for patterns in things. So with the example when the answer was fire, our brain sees or hears all those words that have to do with fire, so the brain naturally kind of sorts it all out and assumes that "fire" was one of the words. The brain is truly amazing.

Unknown said...

This is pretty interesting and actually makes sense, but when you say, "What's more, this effect was stronger for words pertaining to survival, which hints out how this could be an adaptive process with deep evolutionary roots," I do not think that it really has to do with "deep evolutionary roots." And seeing that in both of the tests the subjects said the word fire, yes our brain makes patterns that are not necessarily there, fire has to do with both puzzles so I think that anybody would naturally bring up that word. I do not think that it really has something to do with "survival" though.

Gracie Kelly said...

I view this topic as being very interesting and I feel that this is related to hypnosis and the changes in perception and memory. There have been many studies that hypnotism can lead to distortions and inaccuracies. Also, hypnosis can create increased confidence in memories that are actually inaccurate. These inaccurate memories are known as pseudo-memories. In addition, I do believe that false memories could be a positive thing and therapeutic for people that have gone through trauma.

Unknown said...

This seems to be very interesting to me as we just talked on this in my Psychology class.Our memory's functions are divided into three main branches: Sensory Memory, Short-term Memory and Long-term Memory.The maintenance rehearsal maintains information in short-term memory.This is the place where information is stored which further passes information to long-term memory for encoding and storage and just in case if it fails, it sends it back to short-term memory. But when in Long-term memory, the process of remembering things work under "clustering". Researchers have claimed that the long-term memory is clustered and associated. Clustering means organizing items into related groups or clusters during recall. So if you're asked to remember the words and the words were: up, down, right,left,below above, front and BLACK then there is maximum possibility that majority of people will miscall "BACK" instead of "BLACK".

Anonymous said...

We were just talking about false memories in my Psych 101 class. We had to remember a group of words relating to the word "cold". However, "cold" was never said, and many people remembered our professor say it. The brain is so fascinating. How can we believe things so vividly that never happened? Parents can even persuade their own children into believing that they had gone Disneyland by planting enough details into their heads.

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