Does Concentration Change With Age? The Purpose of the SART Experiment
Do we sometimes take it for granted that “concentration declines with age”? When we spend long hours studying or working, we may find ourselves thinking, “I feel like I could focus better when I was younger.” Especially when preparing for qualification exams or working on tasks that require careful attention to detail, it is natural to worry that the duration of our focus may be influenced by age.
It is well known that physical strength tends to decline over time. Because of this, it is easy to assume that concentration must fade in the same way. But is the equation “age = reduced focus” really supported by scientific evidence? Is concentration simply a matter of stamina? Or might it be shaped by more complex factors such as fatigue, strategy, motivation, or one’s momentary state?
A recent study examined a wide range of adults—from 18 years old to people in their 80s—using an online experiment designed to measure sustained attention. Age was treated as a continuous variable, and researchers carefully analyzed accuracy during the task, reaction time, and even changes in subjective fatigue. The results were somewhat different from what many people might expect. The relationship between age and concentration may not be explained by a simple narrative of “decline.”
In this article, we will walk step by step through the findings of this Sustained Attention to Response Task (SART) experiment and explore the relationships among age, fatigue, and performance. Let us set aside assumptions for a moment and calmly examine what the data actually reveal about the true nature of concentration.
What Is the SART Experiment? An Overview of a Psychological Test Measuring Attention and Fatigue
This study, published in 2024, involved 115 adults ranging in age from 18 to 81. One notable feature is that the experiment was conducted online rather than in a laboratory setting. This approach made it possible to recruit a relatively balanced sample across a wide age range.
Participants first completed a questionnaire measuring trait fatigue, or their long-term tendency to feel fatigued. This assessment captures a relatively stable personal characteristic—essentially, “How easily do you tend to feel tired in everyday life?” They also reported their state fatigue, meaning how fatigued they felt at that specific moment just before beginning the task.
The main task that followed was the Sustained Attention to Response Task (SART), a widely used measure of sustained attention. In this task, numbers appear rapidly on a screen, and participants must respond quickly to each one—except for a specific target number, to which they must withhold their response. Although the task appears simple, it is designed to test the ability to maintain attention consistently over time.
The researchers carefully analyzed accuracy during the task—particularly performance on trials requiring response inhibition—as well as changes in reaction time. After completing the task, participants again reported their state fatigue, allowing the researchers to examine how much fatigue had changed as a result of the task itself.
In other words, this study simultaneously examined:
- Age
- Long-term fatigue tendencies (trait fatigue)
- Momentary subjective fatigue (state fatigue)
- Actual task performance
By analyzing these factors together, the study provides a more nuanced answer to the question: Is concentration determined by age alone?
Are Older Adults at a Disadvantage in Focus? Results from the SART Experiment
The analysis revealed a surprising pattern: higher age was associated with better accuracy on the SART task. Particularly important was performance on so-called no-go trials, where participants were required to withhold their response. In these trials, responding impulsively leads to an error. In other words, this part of the task specifically measures the ability to maintain attention while exercising appropriate inhibition.
Many people tend to assume that “younger individuals must have better concentration.” However, the data from this study showed a tendency for accuracy to improve with increasing age. This finding challenges the common assumption that aging automatically leads to a simple decline in focus.
Why might this pattern have emerged? The researchers suggest several possible explanations. One is that older participants may adopt a more cautious, accuracy-oriented strategy. While younger individuals might prioritize speed, older adults may consciously choose to avoid mistakes, even if that means responding more slowly.
Another possibility involves differences in motivation or task engagement. Even when performing the same task, individuals of different ages may approach it differently. Concentration is not merely a fixed ability—it can also be shaped by strategy, mindset, and the way a person chooses to engage with the task.
These results quietly challenge the intuitive belief that “focus is a privilege of youth.” At least in this dataset, performance could not be explained by age alone.
How Much Does Fatigue Reduce Focus? The Relationship Between State Fatigue and Performance
The next key issue to examine is the relationship between fatigue and performance.
Participants rated their momentary fatigue (state fatigue) and energy levels both before and after completing the SART task. The results showed that subjective fatigue increased significantly after the task, while perceived energy levels declined. In other words, this sustained attention task genuinely induced fatigue.
Even more importantly, increases in fatigue were linked to decreases in accuracy. When comparing the first block of the task with the final block, participants who experienced greater increases in fatigue also tended to show larger declines in accuracy. This suggests that the effect was not merely a shift in mood; subjective fatigue was directly associated with measurable changes in objective performance.
Interestingly, long-term fatigue tendencies (trait fatigue) were less predictive of performance changes than the degree of fatigue experienced during the task itself. In other words, whether someone is generally prone to feeling tired mattered less than how much their fatigue increased in that specific situation.
These findings offer important insight into how we think about concentration. Declines in focus may not simply reflect a lack of willpower, but rather the influence of fatigue as a temporary state.
Concentration is not a fixed ability. It fluctuates depending on one’s condition in the moment.
Do People Who Tire Easily Experience Greater Declines in Focus? The Surprising Findings on Trait Fatigue
At this point, another intriguing result emerges.
The researchers compared participants’ long-term fatigue tendencies (trait fatigue) with the amount of fatigue increase induced by the task. Intuitively, one might expect that individuals who are generally more prone to fatigue would experience even greater increases in fatigue during the task. However, the data pointed in a different direction.
In fact, participants with higher levels of trait fatigue tended to show smaller increases in fatigue during the task. In other words, those who typically report feeling more fatigued did not experience a dramatic worsening of fatigue as a result of the task.
The researchers suggest the possibility of a “ceiling effect.” If someone’s baseline fatigue level is already high, there may simply be less room for it to increase further. Another possibility is that individuals who live with chronic fatigue may have developed adaptive strategies for handling monotonous tasks like the SART.
These findings carry important implications. The simple assumption that “people who tire easily will inevitably deteriorate further” does not appear to hold. Fatigue does not accumulate in a purely one-directional way; the degree of change may depend on an individual’s baseline condition and reference point.
When discussing concentration and fatigue, we often fall into binary thinking—strong or weak, high or low. In reality, fatigue is a dynamic and relative phenomenon.
Is Concentration Determined by Age? What Matters Most Is Your Current State
One clear finding from the study is that age itself does not automatically reduce concentration. In fact, in this experiment, older participants tended to perform the task more accurately. This challenges the intuitive assumption that “youth equals better focus” and invites a reconsideration of that common belief.
What was more strongly linked to concentration was momentary fatigue—state fatigue. Participants who experienced larger increases in fatigue during the task also showed greater declines in performance. This suggests that concentration is not a fixed ability, but rather a dynamic capacity that is heavily influenced by one’s immediate condition.
Furthermore, the study produced a somewhat paradoxical result: individuals with a long-term tendency toward fatigue did not necessarily show greater deterioration. Fatigue does not appear to follow a simple linear rule in which “more fatigue always means worse outcomes.” Instead, the way fatigue changes seems to depend on baseline levels and individual characteristics.
Overall, the study suggests that when discussing concentration, what matters more than chronological age is one’s present state. Focus is not something permanently determined at birth; it shifts according to strategy, mindset, and current condition.
There is no need to limit one’s potential because of age. Rather, managing and optimizing one’s state may be the true key to maintaining concentration.
Reference
Hanzal, S., Learmonth, G., Thut, G., & Harvey, M. (2024). Probing sustained attention and fatigue across the lifespan. PLOS ONE, 19(7), e0292695.
https://doi.org/10.1371/journal.pone.0292695