Modeling cyclic variations in sustained human performance as measured by reaction time and the flash visual evoked...

Area of Science:

• Cognitive Neuroscience
• Psychology
• Neurobiology

Background:

• Sustained attention exhibits cyclic variations, with performance fluctuating approximately every 1.5 and 5.2 minutes.
• Norepinephrine-based arousal systems are hypothesized to underlie these performance cycles.
• The role of cholinergic pathways, alongside noradrenergic ones, in attention and these cycles remains unclear.

Purpose of the Study:

• To validate the existence of 1.5 and 5.2-minute cycles in sustained human performance.
• To investigate the involvement of cholinergic activity in these performance cycles.
• To differentiate the neural underpinnings of the identified performance cycles.

Main Methods:

• Twenty-seven participants completed a 15-minute continuous performance task.
• Reaction time was measured to assess performance fluctuations.
• Flash visual evoked potential P2 (FVEP-P2) amplitudes served as a cortical marker for cholinergic activity.

Main Results:

• Spectral analysis confirmed the presence of both 1.5 and 5.2-minute cycles in sustained performance.
• Model fitting revealed the 5.2-minute cycle, but not the 1.5-minute cycle, in cortical activity (FVEP-P2 amplitudes).
• These findings support the validity of both performance cycles and implicate acetylcholine in the longer cycle.

Conclusions:

• The 1.5 and 5.2-minute cycles are valid phenomena in sustained human performance.
• Cholinergic system activity is specifically linked to the 5.2-minute performance cycle.
• This research advances understanding of the neurobiological basis of attention fluctuations.