Younger People Retrieve Memories in High-Def
Young peoples' memories are retrieved in higher definition than older individuals, according to a new study published in the journal Attention, Perception & Psychophysics.
The researchers, led by Philip Ko of Vanderbilt University, had 11 adults around 67 years old and 13 individuals roughly 23 years old perform a task in which they were asked to memorize the appearance of two, three or four colored dots.
During the exercise, the dots disappeared and were followed a few seconds later by a single dot that appeared in either one of the memorized colors or a new one altogether. The participants were then asked to determine whether the color was the same or different while researchers took a neural measure of their memory capacity using electroencephalography, or EEG.
The results revealed that while neural measurements were similar in both groups, the younger group answered correctly more often. According to the researchers, this suggests that both groups stored the same number of items, but the older group stored those items at a lower resolution.
Unlike older people, younger individuals may be able to use another type of of visual memory, known as perceptual implicit memory, to give them a leg up when trying to retrieve stored information, the researchers speculate.
"We don't know why older adults perform poorly when their neural activity suggests their memory capacity is intact, but we have two leads," Ko said.
First, based on further analysis of the information gathered both in this and other studies from the researchers' lab, the scientists suggest that the way older individuals go about retrieving memories differs from younger adults.
"Second, there is emerging evidence from other labs suggesting that the quality of older adults' memories is poorer than younger adults," Ko said. "In other words, while older adults might store the same number of items, their memory of each item is 'fuzzier' than that of younger adults."