These findings are reported in a Canadian study to be published in the December 2002 issue of Psychology and Aging, a scientific journal published by the American Psychological Association (APA). The study was led by neuropsychologist Brian Levine and doctoral student Eva Svoboda, both of The Rotman Research Institute at Baycrest Centre for Geriatric Care and University of Toronto.
In the study, 15 healthy younger adults (aged 19-34) and 15 healthy older adults (aged 66-89) recalled personally-experienced events from different periods in their life. These periods included early childhood (to age 11), adolescent-teenage, early adulthood, middle age, and the previous year. The recollections were then transcribed and the content analyzed word-for-word using a new scoring method that distinguished among different types of information.
The analysis showed two main kinds of information about the recalled events: specific facts and details about the event (favored by younger adults), AND general facts cutting across multiple events (for which older adults excelled). So when recalling their first kiss, younger adults might describe the color of their sweetheart's sweater, what the weather was like, or where they were standing. Older adults might also provide some specific details, but they are more likely to speak at length about the broader context: "It was just after the war, the borders were reopened and I was anxious to begin a new life, settle down and start a family." This difference held even as younger and older adults were talking about events of a similar age and when the examiner asked probing questions about the time, place, perceptual and emotional details related to the event.
Now that their technique has been validated in younger and older adults, Levine and his colleagues are using it to study people with brain damage that might affect the way they re-experience events from their own past. They are focusing their attention on the frontal lobes of the brain, which are involved in strategic operations necessary for retrieving specific details in memory. Their ongoing research in patients with dementia, strokes, tumors and traumatic injuries suggests that frontal lobe brain damage causes an exaggerated version of the pattern seen in aging. In some cases, patients' memories are stripped of event-specific details altogether; all that remains are the general circumstances surrounding the event.
Levine speculates that changes in older adults' frontal lobes may explain the 'age effect' found in this study, although the age-related changes are very subtle in comparison to the patients' damage.
However, the news for seniors isn't all bad. "Younger adults excel at rote memory, but it's up for debate as to whether a detail-oriented approach to remembering is better or just different than a more holistic and contextual slant to explaining or remembering specific life events," says Svoboda.
According to Levine, which kind of memory is best may depend on the person and their goals. "If you think about the roles that younger and older adults play in society, especially in a hunter-gatherer situation where we evolved, it's more important for the younger ones to remember specific details related to activities where their physical ability is necessary, such as which way the bison went," he explains. "Older adults may not be as fleet of foot, so they have less need for these details. But they have the accumulated knowledge -- call it wisdom -- that the younger adults need to guide their decisions, such as knowing where bison are most likely to congregate at a certain time of year."
The following is a summary of the Rotman study's key findings:
- Older adults produced fewer specific details, but more general factual information than younger adults in autobiographical recall;
- This pattern held even when memories were matched for age and when participants were prompted with questions designed to bring out specific details;
- The findings may relate to subtle brain differences associated with aging; and
- Older and younger adults have different memory abilities that might correspond to their values and roles in society.
Funding for the study was provided by the Canadian Institutes of Health Research and Baycrest's Rotman Research Institute. Baycrest Centre for Geriatric Care is an academic centre fully affiliated with the University of Toronto.
Journal
Psychology and Aging