Mental fatigue and temporal preparation in simple reaction-time performance

Area of Science:

• Cognitive Psychology
• Neuroscience
• Human Factors

Background:

• Mental fatigue, often from prolonged time on task (TOT), significantly impairs performance, particularly in tasks requiring voluntary attention control.
• Temporal preparation, a process enhancing reaction time (RT) through warning signals, is crucial for speeded actions.
• The mechanisms of temporal preparation, whether voluntary attentional processes or automatic trace conditioning, are debated, especially concerning their susceptibility to fatigue.

Purpose of the Study:

• To investigate if mental fatigue induced by prolonged time on task (TOT) affects temporal preparation in a simple reaction-time (RT) task.
• To differentiate between attentional orienting and trace conditioning accounts of temporal preparation under conditions of mental fatigue.

Main Methods:

• Participants completed a simple reaction-time task over a 51-minute work period to induce mental fatigue (TOT).
• The foreperiod (FP) duration between warning and imperative stimuli varied across trials.
• Reaction times (RTs) were analyzed for overall effects of fatigue and selective effects based on FP length.

Main Results:

• A typical increase in overall reaction time (RT) was observed, indicating general cognitive efficiency decrements due to mental fatigue.
• No selective increase in RT was found for trials with longer foreperiods (FPs) despite fatigue.
• The pattern of results suggests that mental fatigue did not impair temporal preparation under time uncertainty.

Conclusions:

• Prolonged time on task (TOT)-induced mental fatigue generally reduces cognitive efficiency.
• Temporal preparation for speeded actions under time uncertainty remains unaffected by mental fatigue.
• These findings support the trace conditioning account of temporal preparation over the voluntary attentional orienting account.