Sustained vs. Selective Attention
Sustained attention (vigilance) is the ability to maintain focus over extended periods - critical for monitoring tasks and long test sessions. Selective attention involves filtering relevant information from distractors. Both decline with time on task, a phenomenon called the vigilance decrement. After 15-20 minutes of continuous monitoring, detection rates typically drop by 10-15%, and reaction times increase measurably.
Factors Affecting Attention Span
Sleep quality is the strongest modifiable predictor of attention span - even mild sleep restriction (6 hours vs. 8) produces measurable deficits. Physical exercise, particularly aerobic activity, enhances sustained attention for several hours post-exercise. Digital media consumption patterns, caffeine timing, hydration, and ambient noise levels all influence attentional capacity. Meditation practice has been shown to extend sustained attention duration.
Attention in Cognitive Benchmarking
Benchmark tests measure attention through tasks like the Continuous Performance Test (CPT) and Psychomotor Vigilance Task (PVT). Lapses - unusually slow responses indicating momentary attention failures - are more informative than average reaction time for assessing attentional stability. Keeping test sessions under 5 minutes minimizes fatigue effects and produces more reliable measurements of peak attentional capacity.