Brain abilities peak at different ages finds new study

NEW DELHI: A new study of fluid intelligence, that is, our ability to think quickly and recall information, has upended conventional theory that it peaks at around age 20 and starts declining after that.

The study, based on test scores of over 50,000 online participants in a survey showed that different aspects of fluid intelligence peak at different ages, some as late as age 40.

The study was done by neuroscientists at MIT and Massachusetts General Hospital and appears in the journal Psychological Science.

“At any given age, you’re getting better at some things, you’re getting worse at some other things, and you’re at a plateau at some other things. There’s probably not one age at which you’re peak on most things, much less all of them,” says Joshua Hartshorne, a postdoc in MIT’s Department of Brain and Cognitive Sciences and one of the paper’s authors.

“It paints a different picture of the way we change over the lifespan than psychology and neuroscience have traditionally painted,” adds Laura Germine, a postdoc in psychiatric and neuro-developmental genetics at MGH and the paper’s other author.

Until now, it has been difficult to study how cognitive skills change over time because of the challenge of getting large numbers of people older than college students and younger than 65 to come to a psychology laboratory to participate in experiments. Hartshorne and Germine were able to take a broader look at aging and cognition because they have been running large-scale experiments on the Internet, where people of any age can become research subjects.

Their web sites, gameswithwords.org and testmybrain.org, feature cognitive tests designed to be completed in just a few minutes. Through these sites, the researchers have accumulated data from nearly 3 million people in the past several years.

For the Internet study, the researchers chose four tasks that peaked at different ages, based on data from earlier studies. Data from nearly 50,000 subjects showed that each cognitive skill they were testing peaked at a different age. For example, raw speed in processing information appears to peak around age 18 or 19, then starts to decline.

Meanwhile, short-term memory continues to improve until around age 25, when it levels off and then begins to drop around age 35. For the ability to evaluate other people’s emotional states, the peak occurred much later, in the 40s or 50s.

The researchers also included a vocabulary test, which serves as a measure of what is known as crystallized intelligence-the accumulation of facts and knowledge.

These results confirmed that crystallized intelligence peaks later in life, as previously believed, but the researchers also found something unexpected: while data from the Weschler IQ tests suggested that vocabulary peaks in the late 40s, the new data showed a later peak, in the late 60s or early 70s.

This aricle first appeared on the Times of India