Weighed Down By Wisdom: Older Brains Are Slow But Not Why You Think
Last week, while waiting for the tank to fill at the gas station, I saw something that made my heart ache a little. In the spot behind mine, an elderly gentleman was trying to purchase gas, but was obviously perplexed by the digital pump and all its questions about discount cards, etc.
He kept looking back and forth between the pump and his car, lips slowly moving as he read the prompts silently to himself. Part of me wanted to rush over and say, “Here, let me help you with that!” but I didn’t. I didn’t want to insinuate that he wasn’t capable of pumping his own gas. While I drove away, I couldn’t help but feel sad. Old age will come for all of us, and some day it will very likely be me, moving slowly through some task that takes a teenager mere seconds. I was momentarily depressed at the prospect, but something I read a few days later changed my perspective.
A study spearheaded by Dr. Michael Ramscar of the University of Tuebingen found that the slow-down we see in older brains isn’t because of some kind of cognitive decay–like a car rusting in a junk yard–but rather the weight of decades of life experience. The research claims that scientists have assumed cognitive decline is the result of the brain shutting down in advanced year, but that may actually be due to faulty cognitive measures.
During the study, computers programmed as though they were humans were tasked with reading a certain amount each day and learning new things along the way. “When the researchers let a computer ‘read’ only so much, its performance on cognitive tests resembled that of a young adult. But if the same computer was exposed to the experiences we might encounter over a lifetime—with reading simulated over decades—its performance now looked like that of an older adult,” explains Ramscar in a press release. “Often it was slower, but not because its processing capacity had declined. Rather, just as it takes longer to find a missing sock as a drawer gets bigger, increased ‘experience’ had caused the computer’s database to grow, giving it more data to process—and that processing takes time.”
Essentially, it took the computers longer to search for a certain word or fact the bigger their databases became, a fairly intuitive fact that has important implications for our understanding of age-related slowdowns and decline.
Better healthcare and a shift away from manual labor careers means the planet is home to more elderly people than ever before, and it’s completely possible that younger generations will live even longer (climate change and environmental pollution notwithstanding). Ramscar and his fellow Tuebingen researchers hope that their discovery will change beliefs the cause of declining cognitive abilities, which often mean that older adults are seen as a burden on society.
Commenting on these findings in an editorial in the Journal Topics in Cognitive Science, editors Wayne Gray and Thomas Hills suggest, “It is time we rethink what we mean by the aging mind before our false assumptions result in decisions and policies that marginalize the old or waste precious public resources to remediate problems that do not exist.”
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