Neuroscientists from Duke Medical Center have discovered that older people use their brains differently than younger people when it comes to storing memories, particularly those associated with negative emotions.
The study, appearing online in the January issue of Psychological Science, is a novel look at how brain connections change with age.
Older adults, age seventy on average, and younger adults, age twenty-four on average, were shown a series of thirty photographs while their brains were imaged in a functional MRI (fMRI) machine. Some of the photos were neutral in nature while others had strong negative content such as attacking snakes, mutilated bodies, and violent acts. In the fMRI machine, the subjects looked at the photos and ranked them on a pleasantness scale. Following the scan they were asked, unexpectedly, to recall memories in order to help determine whether the brain activity that occurred while looking at the pictures could predict later memory.
The researchers found that older adults have less connectivity between an area of the brain that generates emotions and a region involved in memory and learning. But they also found that older adults have stronger connections with the frontal cortex, the higher-thinking area of the brain that controls these lower-order parts of the brain. On the other hand, young adults used more of the brain regions typically involved in emotion and recalling memories.
Roberto Cabeza, professor in the Center for Cognitive Neuroscience and senior author of the study, speculates that at different ages, brain strategies also differ. "Younger adults might need to keep an accurate memory for both positive and negative information in the world. Older people dwell in a world with a lot of negatives, so perhaps they have learned to reduce the impact of negative information and remember in a different way."
Upside of Aging
April 1, 2009