A 2012 research paper conducted by researchers from the Centre for Research in Epidemiology and Population Health in France and University College London in the UK found that “cognitive decline can begin as early as age 45”. The study observed approximately 7,000 participants over a 10-year period.
According to an article in BMJ Best Practice the, “participants’ cognitive functions were assessed three times over the study period. Individuals were tested for memory, vocabulary and aural and visual comprehension skills. The latter include recalling in writing as many words beginning with “S” (phonemic fluency) and as many animal names (semantic fluency) as possible. The results show that cognitive scores declined in all categories (memory, reasoning, phonemic and semantic fluency) and there was faster decline in older people.”
The National Geographic News reports that when Michael Ramscar, a linguistics researcher at the University of Tübingen in Germany read the paper at age 45 he thought, “That doesn’t make sense to me; 99 percent of the people I look up to intellectually, who keep me on my mettle, are older than I am.”
Ramscar was compelled to create his own study under the premise that previous research studies on aging and cognition asked the wrong questions. The resulting study entitled, The Myth of Cognitive Decline: Non-Linear Dynamics of Lifelong Learning contends that an older adult’s slower memory recall is a reflection of “memory search demands, which escalate as experience grows.” Or as the National Geographic article explains, “It could be that older, wiser heads are so chock full of knowledge that it simply takes longer to retrieve the right bits.”
“I could see precious little evidence of decline in [the models of] healthy, older people,” Ramscar says. “Their slowness and slight forgetfulness were exactly what I’d expect”.
The National Geographic News article also offers the perspective of Denise Park, co-director of the Center for Vital Longevity at the University of Texas at Dallas. “She sees the value of Ramscar’s research but also believes there’s no denying that the brain deteriorates with age just as every other body part does.” Park explains that imaging studies show signs of ‘shrinkage’ as the brain ages.
“It may be true that knowledge slows down the system, but that doesn’t mean that the system, as it ages, doesn’t also operate more slowly,” says Park. “I would argue that the amount of knowledge allows us to compensate for the slowdown. I strongly believe that our everyday performance does not decline with age.”
For more information on this topic check out Ramscar’s blog The Importance of Being Wrong.