This post is based on a section with the same subtitle in “The Cognitive Upside of Aging” is an article by Alexandra Michel in the February 2017 Observer, and publication of the Association for Psychological Science (APS). This study used data collected from TestMyBrain.org and was published in “Psychological Science.” It found another unexpected boom for aging brains: Sustained attention tends to improve over time, peaking in the mid-40s.
This study was led by Francesca C. Fortenbaugh, Joseph DeGutis, and Michael S. Esterman of the Boston Attention and Learning Laboratory at the VA Boston Healthcare System. This study tested sustained attention across 10,430 adults using a specialized task for identifying individual differences in people’s ability to focus on a single task over 4 minutes. DeGutis said in a statement, “While younger adults may excel in the speed and flexibility of information processing, adults approaching their middle-years may have the greatest capacity to remain focused. One current hypothesis is that compared to younger adults, adults in their mid-years mind-wander less, leading to better sustained attention performance. This sample was larger than all previous efforts to model changes in sustained-attention performance during development, aging, or across the life span combined, which allows us to more precisely model transition periods in performance across the life span using segmented linear regression”
Sustained attention underlies several important cognitive processes, including learning, perception, and memory. Lapses in attention can lead to serious problems ranging from difficulty at work to an increased risk of car accidents. Measuring attention across individuals is itself a challenge; attention fluctuates, sometimes dramatically, from moment to moment.
The researchers used a new tool they developed: the gradual-onset continuos performance task (gradCPT). Participants were shown serious of grayscale photographs go 10 city scenes and 10 mountain scenes. One photograph gradually transitioned into the next every 800 milliseconds, so that as one image faded, a new image steadily took its place.
There were 5,027 male and 5,403 female participants between 10 and 70 years old who completed the gradCPT on TestMyBrain.org between March and September of 2014. The participants were told to press the space bar whenever they saw a city scene, but to withhold a response when the image was a mountain scene. Here the goal was to create a task that required frequent responses from participants while having a relatively low cognitive demand. Identifying the differences between the two scenes was easy, but carefully attending to the transitions repeatedly became challenging over time.
By analyzing mean reaction time, reaction time variability, hits, misses, discrimination ability, and criterion (a measure of strategy or willingness to respond in the case of uncertainty), the researchers were able to tease apart the changes in unsustained attention across the lifespan. From the ages 10 through 16, gains in both reaction times and discrimination ability were extremely large. After age 16, gains in these skills were much smaller until they peaked around age 43.
A factor analysis of the results suggests than people also begin to use different cognitive strategies as they age. Younger individuals demonstrated faster reaction times (due to either super information-processing speed or more liberal response strategy), whereas older individuals showed a slower, more cautious strategy and evidence they made more adjustments after a mistake.