A new study shows that age-related memory decline may begin sooner than was previously thought. But 40-somethings take note: countering it may be a matter of minimizing distractions.
Many researchers wonder if changes in memory involve multiple mechanisms. To investigate, Cheryl Grady and colleagues at the Rotman Research Institute at Baycrest, University of Toronto, used functional magnetic resonance imaging (fMRI) to measure brain activity in adults performing memory tasks. The findings were reported in the February issue of the Journal of Cognitive Neuroscience.
The groups-people in their 20s, 40s, and over 65-answered questions about words and pictures, such as whether they were of living or nonliving things or appeared in upper- or lower-case letters. Next, in the memory phase, participants selected from a list the words and pictures they had seen.
Ideally, brain activity increases in areas involved in the task itself and decreases in those devoted to unrelated things, such as monitoring one's internal state or planning dinner. Those in their 20s showed this pattern-probably explaining young people's ability to study, watch TV, and chat with friends all at once, Grady says.
But an imbalance appeared in the middle-age group, with activity continuing in the "non-task-related" parts of the brain. Such activity was more pronounced in participants over 65.
"Our study shows that the brain changes seen in older adults begin gradually, in the 40s and 50s, and has implications not just for memory but for focus," Grady concludes. "Once we're past that magic age where multitasking is no problem, we might want to step back, turn off the distractions, and concentrate on what we're doing."