SAN FRANCISCO, Sept. 4 (UPI) -- U.S. scientists say they've determined memory loss in older adults results from impaired suppression of extraneous information and slowed processing speed.
Researchers at the University of California-San Francisco and the University of California-Berkeley used electroencephalography to measure how quickly neurons processed information in study participants ages 19-33 and 60-72.
The subjects were shown sets of images consisting of two faces and two scenes, and then instructed to remember images of a specific category. Nine seconds later, they were asked to identify an image from that category.
The findings revealed the capacity to ignore irrelevant information and the ability to process information quickly diminished with age. Significantly, neural processing speed decline among older participants occurred only during the very early stages of visual processing -- within 200 milliseconds.
"The study showed that the brains of older adults have a deficit in suppressing irrelevant information during visual working memory encoding, but only in the first tenth to two tenths of a second of visual processing," said Assistant Professor Adam Gazzaley of UCSF, the study's lead author.
The researchers' findings are detailed in the online edition of the Proceedings of the National Academy of Sciences.
