Think You're Immune to False Memory? You're Not.
The most disconcerting aspect of human memory is not that we forget things; it's that we falsely remember them. Each and every day, thousands of individuals recall details that never existed or events that did not take place. Most of the time these mistakes are trivial. What does it really matter if you're absolutely certain you washed the dishes on Friday when in fact you were actually playing video games? But in some instances, the impacts of false memories are grave. We know for a fact that at least 225 men and women have been convicted of serious crimes because witnesses convincingly, yet mistakenly, named them as the culprits.
Is anybody immune to false memories? Psychologists have theorized that people with hyperthymesia (HSAM) -- a condition that grants uncanny autobiographical memory -- might be impervious to such mistakes. But a new study just published to the Proceedings of the National Academy of Sciences thoroughly dispels that idea. Though people with HSAM are able to remember "the day of the week a date fell on and details of what happened that day from every day of their life since mid-childhood," they can still be easily fooled into unknowingly constructing false memories.
Researchers at the University of California - Irvine put 20 subjects with HSAM as well as 38 age and gender matched controls through three different memory distortion experiments. In the first, HSAM subjects and controls were presented with 20 lists of 15 associated words. Later they were presented with a selection of words and asked to pick which were in the original list. Included were unrelated words that never appeared the first time as well as twenty related words that also didn't appear. Both HSAM individuals and controls falsely recalled seeing 70% of the related words.
In the second experiment, subjects and controls watched slideshows depicting two simple crimes. Forty minutes later, they were presented with two short narratives describing the events, each with three subtle pieces of misinformation. Twenty minutes later, they were questioned on their memory of each slideshow. HSAM subjects produced an average of 2.6 false memories about the events, more than controls.
The final experiment was simple. Researchers told subjects and controls that there was a video of the plane United 93 crashing in Pennsylvania on 9/11 (there never was such a video) and asked if they had seen it. 20% of HSAM individuals and 29% of controls said that they had.
Through the amount of memory distortions by subjects and controls mirrored previous studies, the study's small sample size could still limit the results. Moreover, the researchers professed to the possibility that subjects may not have produced genuinely false memories; they may have just been guessing incorrectly.
Overall, the results of the study further substantiate the idea that human memory is not recorded but constructed. We recall events and details by association, using basic emotional, tactile, and visual cues to piece together a memory. Sometimes, that process manufactures jumbled falsehoods.
Source: Lawrence Patihis et. al. "False memories in highly superior autobiographical memory individuals." Proc. Nat. Acad. Sci. 2013.