Accurately assessing age

In spite of what the song says, age isn’t just a number, so determining the number of birthdays someone has celebrated can be difficult. From a purely physical perspective, various medical and cosmetic procedures and the number of jars and tubes from companies tagged as “anti-aging” can make it difficult to figure out someone’s age. Also, similar to the myth that there are several dozen Eskimo words for “snow,” people might employ a variety of approaches to discuss the number of years someone’s been alive. For example, they might couch references to age in terms of being either old enough or else young enough to do something or act in a certain way.

Recently, a team of American researchers described a novel way to determine a person’s age—with the aid of brain scans. Apparently, like the rings on a tree, a combination of brain scanning techniques can allow researchers to conduct a series of measurements on the structures of the brain, using that information to accurately determine a person’s age.

“We have uncovered a ‘developmental clock’ of sorts within the brain—a biological signature of maturation that captures age differences quite well, regardless of other kinds of differences that exist across individuals,” said study first author Timothy Brown of the University of California, San Diego School of Medicine in a statement.

To gauge the accuracy of this technique, the team worked with nearly 1,000 study participants between the ages of 3 years and 20 years. They scanned the brains of the volunteers and then came up with a model of brain development based on more than 200 markers known to change over time.

In much the same way that there are height and weight charts doctors can reference to assess a child’s physical development, there are markers in the brain that can be used to chart its development from childhood onward. Brown and his colleagues found that despite physical or emotional appearances, the structures in one’s brain can pinpoint age with more than 90 percent accuracy, suggesting there is a timeline involved and it cannot be altered.

These measurements and brain structures can play a role in maintaining brain activity later in life. A study released by British researchers back in May showed that the tissue structure in the brain that allowed nerves to connect to various parts of the brain plays a role in maintaining a sharp mind over the years.

Several researchers working on brain functions have shown that exercises such as solving puzzles or meditation can help people stave off conditions such as Alzheimer’s disease in which their brain cells degrade and memories are lost. One such study was presented in early August during the annual gathering of the American Psychological Association and showed that a computerized memory-online game had improved motor and language skills of participants compared to the members of a control group.

“The fact that we found a collection of brain measures that so accurately captures a person’s chronological age means that brain development, or at least certain anatomical aspects of it, is more tightly controlled than we knew previously,” said Brown.

The study by Brown and his colleagues was published August 16 in the journal Current Biology.

E-mail the author at [email protected].