Does Survival Processing Increase Memory Accuracy?
Have you ever been in a life or death experience? Walked across a bear in the woods? Almost been eaten by a tiger? Gotten in a car crash? Did you find your memory of this event to be clear and accurate, possibly almost like slow motion? Have you made that mistake again, or been more careful in similar settings? Recent studies have shown that the human memory system evolved to afford us a survival advantage (Nairne et al. 2008.) This functional analysis of memory explains that the purpose of memory is to remember the best way to survive. Humans need to accurately remember what situations pose a threat to them so they can successfully avoid those situations in the future.
However, memory is also quite malleable. Memory can be easily misremembered or altered, and is not always an accurate expression of an event. False memories, which are events that are remembered even though they never actually occurred, are actually quite common. The Deese-Roediger-McDermott paradigm (DRM paradigm) is often used to induce false memories. The DRM paradigm is a list of words, either verbal or visual, that all relate to one word not listed. As an example, the list could contain words like “bed, sheets, snooze, alarm, pillow, nap.” All of these words concern sleeping, but the word “sleep” would not be on this list. “Sleep” would be the critical item, and the word that many people will falsely remember to be part of the list, even though it wasn’t. There is an example of a DRM paradigm below, if a visual presentation is easier to understand. The process of creating a false memory includes a participant reading this list, but not told to remember the words or try to memorize them. Later one the participant will be given a surprise free-recall test on the words. Many misremember that sleep was on the list, even though it was not, because of its similarity to other words on the list. The memory of “sleep” being on the list is the false memory that is created.
So, if memory is more accurate during situations of survival, is there less of a chance of creating false memories in survival situations? This is the question researchers Henry Otgaar and Tom Smeets sought to figure out. Their article, entitled “Adaptive Memory: Survival Processing Increases Both True and False Memory in Adults and Children” looks at the prevalence of accurate and false memories in different contexts, and for different ages. Children were specifically included to find out if the kids had a different relationship with false memories than adults did, specifically if the adaptation to survival processing is innate to humans or part of a developmental trend.
The researchers set up three experiments within their larger experimental scheme. The first experiment tested college-age individuals with the DRM, the second children with the DRM, and the third experiment tested categorized material with college-age individuals. The difference in the three experiments was to tease apart the effect of age and see if false memories could also be made using the categorized list, a material that was not created with the intent to elicit a false memory, like the DRM was. The categorized list is similar to the DRM list, and all of the words still converge on a word not listed. If curious, I have added a picture below of the DRM and categorized lists used in this study below. The DRM list is the first and the categorized list is the second. The participants were asked to rate how relevant each word on their list was to the condition they were placed in, this was the studies’ independent variable. The three conditions were survival, moving (as in, fitness or location,) and pleasantness. Conditions are different settings the participants are placed in to give the experiment variations and test different aspects of the situation. In this study the conditions were the mindset the participant took while making connections between the word lists and their condition. The researchers hypothesized “that participants in the survival condition would correctly recall more words” and that children in the survival condition would also remember better, and be less susceptible to false memories than in the other conditions (Otgaar & Smeets 2010.)
Otgaar and Smeets found that their hypothesis was only half right. While memory in the survival condition proved to be more accurate for the words, the participants also falsely remembered non-presented information more easily in the survival context (Otgaar & Smeets 2010.) This is true for all three experiments the experimenters performed. The researchers propose an explanation to why the survival condition had both the highest true and false recall, true meaning accurate recall, over both the pleasantness and moving conditions. They say that this false memory may not be maladaptive, but adaptive to survival, because it can be beneficial in certain situations (Sutton 2009.) An example of this would be if you were walking in a section of the woods and came across bear tracks. If you do not see a bear, you may go back to the woods again. But if you do see a bear, then it is more likely you will not, because the bear is a threat to your survival. So, if you create a false memory of seeing a bear, even if you did not, it may make it easier for you to survive.
This research shows that when our memory is the best, it can also be at its worst. But don’t let that get to your head, as it looks like false memories can make for the best survival advantage! Don’t fret too much over the idea that you are misremembering events either, for while it may be the best for your survival, memory is also still usually quite good. If you are curious about more research about memory in survival processing, here is a great article that can also be found of the CogBlog! It describes some research on the advantage of survival processing on memory.
Works Cited
Nairne, J. S., & Pandeirada, J. N. S. (2008). Adaptive memory: Is survival processing special? Journal of Memory and Language, 59, 377–385. doi:10.1016/j.jml.2008.06.001
Otgaar, H., & Smeets, T. (2010). Adaptive memory: Survival processing increases both true and false memory in adults and children. Journal of Experimental Psychology: Learning, Memory, and Cognition, 36(4), 1010-1016. doi:10.1037/a0019402
Sutton, J. (2009). Adaptive misbeliefs and false memories [Commentary on the article “The evolution of misbelief” by R. T. McKay & D. C. Dennet]. Behavioral and Brain Sciences, 32, 535–536. doi:10.1017/ S0140525X09991488
I thought that this was a great article and blog! The whole idea of survival memories is very interesting and reminds me a lot of what we learned about flashbulb memories. A flashbulb memory is a very clear and detailed memory for a very salient, public event. For example, many people would have flashbulb memories for 9/11. When we learned about flashbulb memories we learned that although they are very vivid, they can very easily be influence and are often incorrect, very much like the survival memory that is discussed in this paper. As these are both very salient events that happen in ones life, although they are slightly different in their salience, it makes sense that they both have some very similar characteristics. I also thought it was very interesting to look at it from a survival aspect in order to remember what to avoid, which is very similar to one of the seven sins of memory, persistence. Persistence is when one repeatedly remembers a event, even if they are actively trying not to remember it. I think in this case, survival memories could be thought of as persistence.
The relation between memory and survival is one that certainly goes back as far as humans can remember! Knowledge of past events that one experience, especially those that were threatening means the difference between calculated caution and blatant stupidity while approaching situations.
The prevalence of false memories is where this instinct seems to falter; but Emily brings up a good point about the useful potential of a false memory. A memory for survival does not necessarily have to be ‘fact-checked speech’ accurate, but can instead take on a form that gets the story across, like a boastful story told by Beowulf after an intense battle. Basically, it gets the point across, maybe in an exaggerated manner-but hey, this will make for a more powerful use of the experience.
I think this is really shown in the DRM test, especially because the falsely remembered word is called the “critical lure”. The word (in this example ‘cold’) represents the critical idea of the list! Humans are programmed for survival and efficiency (we use memory systems like the Hierarchical network model to minimize redundancy), so we automatically sum up lists or information into a meaningful conclusion. In survival cases, as mentioned, this means remembering “there is a bear in the woods” instead of “I saw bear tracks”.
Leah, its great that you mentioned persistence-I think this is a strong example of that ‘sin’.
As we learned, memory is a reconstruction of events that is influenced by all other memories. Survival situations definitely have potential to interfere with each other (either proactively or retroactively) and mesh into more unified memories that provide a simple idea of what to do or how to act in a dangerous situation. This gives more potential to falsely remembering an event because when it happened it was integrated into other memories for most efficient and useful recall.
Overall, despite memory’s shortcomings, memory is seeming to do its job of helping us stay alive. As you mentioned, it seems the faults are often developments we utilize to improve downright survival.