My mother had an incredible autobiographical memory. She could remember with remarkable clarity the details of everyday events and people from her childhood between the two world wars on the Channel Island of Jersey and the Isle of Wight off England’s southern coast. Her siblings frequently expressed amazement at her ability to resurrect long-forgotten minutiae from their past.
My sisters and I had similar experiences with her. Once, while we were reminiscing about a long summer camping trip we had taken together through Europe more than three decades earlier, I was stunned by her remembrance of places and people that I had long since forgotten, down to what we ate and where.
My mother wouldn’t have qualified as a hyperthymesiac — someone with an exceptionally superior autobiographical memory — for you couldn’t give her a random date and have her recite what she did that day. But if she had taken an autobiographical memory test, I’m confident she would have scored well above average.
I have always wished I had inherited that type of memory. But after reading a paper published recently in the journal Neuropsychologia, I’m feeling much more content with my rather modest autobiographical-memory skills. For in the paper, a team of Canadian cognitive scientists from the Rotman Research Institute in Toronto report on three otherwise perfectly healthy middle-aged adults (two from the United States, one from the United Kingdom) who are unable to re-live their past.
“Many of us can relate to the idea that people have different abilities when remembering events. What is unique about these individuals is that they have no personal recollection,” said Brian Levine, a neuropsychologist and the paper’s senior author, in a statement released with the paper. “Even though they can learn and recall information normally and hold down professional careers, they cannot re-experience the past with a vivid sense of personal reliving. It’s as if their past was experienced in the third person.”
Levine and his colleagues have named this unusual condition “severely deficient autobiographical memory” (SDAM).
‘Normal’ in all other respects
Writing on the British Psychological Society’s website, psychologist and journalist Christian Jarrett offers a great summary of what Levine and his colleagues discovered from testing the three people in the paper:
AA is a 52-year-old married woman; BB is a 40-year-old single man; and CC is a 49-year-old man living with his partner. All three are high functioning in their everyday lives, they have jobs, yet they also claim a life-long inability to recollect and relive past events from a first-person perspective (a condition they became fully aware of in their late teens or early adulthood). Their memory for facts and skills is completely normal. Two of the individuals had experienced depression many years earlier, but there was no evidence of this persisting.
Through intense neuropsychological testing for intelligence, memory and mental performance, the three individuals mostly scored normally or higher than normal. One key exception was poor performance on the ability to draw a complex figure from memory. The researchers think this visual memory deficit could be key to understanding their lack of autobiographical memories.
To test their memories of their lives, the researchers interviewed AA, BB and CC about various incidents from their pasts — a mixture of questions about generic life events and also personal incidents the participants proposed themselves after looking at their calendars or consulting loved ones.
Compared to fifteen comparison participants (matched with the target participants for age and educational background), the impaired participants were able to provide significantly fewer autobiographical, first-person details from their teen and youth years. For more recent events, the impaired participants’ recall appeared more normal, but the researchers think this is due to a combination of conservative scoring (when in doubt the researchers scored reminisces as autobiographical in nature), and the participants having learned compensation strategies such as studying diaries and photos and substituting their lack of autobiographical memory for memory of facts and semantic detail.
From a subjective perspective, the impaired participants described their own memories of past events from both distant and more recent times as almost completely lacking a first-person perspective or involving any sense of “re-experiencing”. They also struggled to imagine future events, consistent with the idea that memory and future imagination involve shared mental processes.
Brain scans revealed that the three participants had less “activity” in those areas of the brain believed involved in the processing of autobiographical memory. That finding may explain, said Levine, the participants’ “inability to mentally project the self through time and their reduced visualization abilities, compared to the matched controls.”
Limitations and implications
Given that only three people were involved in this research, Levine and his co-authors caution against overinterpreting their findings. They emphasize that many questions remain.
“A crucial question for future research,” they write in their paper, “pertains to whether these findings reflect an extreme on a continuum of ability in episodic autobiographical recollection,” or a condition (perhaps caused by some as-yet-unidentified neurological factor) that does not fall within the normal distribution of autobiographical-memory abilities.
No matter what SDAM turns out to be, however, it is worth further study, say Levine and his colleagues, because such research may “provide valuable information concerning memory disorders and dementia and the relationship of real-life memory capacities to other traits (such as personality traits) and susceptibility to psychiatric disorders, such as depression and post-traumatic stress disorder which are associated with altered [autobiographical memory] processing and may even mediate the development and maintenance of these disorders, particularly in PTSD.”
You can read the study on Neuropsychologia’s website.