The march of time is not as strong on the human mind as conventional wisdom would suggest. Some parts get even better with age, just like fine wine.
Some of our mental abilities, such as spatial visualization and processing speed, will inevitably diminish as our brains age. Research has shown that other mental abilities, such as vocabulary or verbal comprehension, can be improved with time.
Two fundamental brain functions have been identified by new research involving 702 participants aged between 58 and 98. These functions seem to grow stronger with age.
Participants were asked to complete an Attention Network test (ANT) in which they are shown a central arrow with two flanking arrows and then asked to press a button that corresponds to the orientation of the central arrow as quickly as possible.
Before each arrow was displayed, a variety of cues were shown on the screen. There were three options: a cue to indicate where the oncoming arrow should go, or no cue.
Researchers found that older volunteers did not respond as well to the task, despite being able to compare their responses and adjust for various confounding factors. They were less prepared for next arrow because they didn't respond to the time cue as well.
However, it was found that older people were better at directing their attention towards a specific point on the screen when they used cues to shift the brain's focus. This held true up to a very old age.
Individuals who were older had a tendency to cancel out distracting and conflicting cues on the screen. This skill was improved at least up until the mid-to-late 70s.
Researchers tested participants' brain functions related to alerting (being ready to adapt to new info), orienting and executive inhibition.
Joo Verssimo, a psycholinguist from the University of Lisbon in Portugal, says that "all three processes are used constantly."
For example, alerting means being more prepared when approaching an intersection when you drive a car. When you shift your attention from a predictable movement such as a pedestrian, it is called orientation. Executive function is a way to block distractions like birds and billboards, so that you can focus on driving.
Research suggests that older drivers may be less responsive to new situations, but are more adept at staying focused and orienting themselves on the road.
The ability to manage one's attention is a higher-order brain function. While the authors don't suggest that all executive functions will remain intact or improve in one's 70s, it does seem that at least some do.
These forms of attention can also be useful in the car. Research shows that executive control and orienting are critical components of memory, decision-making, navigation, math, language, reading, and self-control.
According to Michael Ullman, a neuroscientist at Georgetown University, "These results are remarkable and have important implications for how we should see aging."
"People believe that executive functions and attention decline with age. This is despite some intriguing clues from smaller studies. Our large study shows that these essential abilities actually increase with age, probably because we continue to practice them throughout our lives.
These findings are contrary to the results of a dozen other tests which have shown that aging affects all three aspects attention.
The current study's authors point out that previous studies had small sample sizes and did not control for other factors like education and sex.
They also compared older and younger adults to one another, rather than focusing on their age ranges.
This is an argument that some researchers believe is wrong. It could mean we are overlooking the variability in the age group of interest.
These limitations are addressed by the new research. Although the findings of this research will require further investigation, it indicates that attention does not diminish with age.
It makes sense that orienting and inhibiting attention, which are skills that can be improved with practice over time, will become stronger as we get older.
However, it's important to remain vigilant as this state is not easily improved by practice and is more likely that it will decline over time.
It is not as easy as we thought. This study also showed that the same group of participants had a strong decline in working memory in another study. This, according to the authors, underscores the complexity of the aging brain.
Ullman says that the findings will not only alter our understanding of how aging affects the brain, but could also lead to clinical improvements for patients with aging disorders like Alzheimer's.
The study was published by Nature Human Behavior.
