An Electromyographic Analysis of the Effects of Cognitive Fatigue on Online and Anticipatory Action Control

Salomone, Mick; Burle, Borı́s; Fabre, Ludovic; Berberian, Bruno · 2021 · OpenAlex-citations

DOI: 10.3389/fnhum.2020.615046

archive: archived pipeline: cataloged verified

Get this paper ↗ (DOI — opens at the source; we link to it, we don't host it)

Summary

This study investigates how cognitive fatigue disrupts adaptive capabilities, specifically focusing on online and anticipatory action control. Cognitive fatigue poses significant safety risks in critical systems, such as aviation, by impairing the ability to handle unexpected events. While previous research has established that fatigue degrades performance, the specific mechanisms—whether fatigue increases the capture of incorrect automatic responses or impairs their suppression—remain unclear. To address this, the authors utilized electromyography (EMG) and distribution analysis to dissociate the strength of automatic response activation from the capacity to suppress it, providing a more granular view than traditional behavioral metrics alone. The experimental design involved 24 participants divided into two groups: High Cognitive Load (HCL) and Low Cognitive Load (LCL). To induce varying levels of fatigue, participants first performed the Time Load Dual Back (TLDB) task, a dual-task designed to create distinct fatigue states based on cognitive load intensity. Following this, all participants completed a 45-minute Simon task, a classic conflict paradigm that elicits automatic, incorrect responses. The study measured performance evolution over time (beginning, middle, and end) and assessed subjective states, including fatigue, effort, sleepiness, and alertness, using visual analog scales and the NASA RTLX. EMG recordings of the flexor pollicis brevis muscles allowed for the identification of "partial errors"—subliminal muscle activations of the incorrect hand—enabling the calculation of correction ratios and the strength of automatic activation. The results demonstrated that time on task impaired online control by disrupting the capacity to suppress incorrect responses, as evidenced by a decreased correction ratio, while leaving the strength of the automatic response activation unaffected. Additionally, participants increasingly prioritized speed over accuracy as the task progressed, resulting in more fast guesses. This shift suggests a strategic move toward less effortful responses rather than a total incapacity to exert effort. The study also found that subjective fatigue and perceived effort increased over time and correlated with the EMG measures of impaired suppression, whereas sleepiness and alertness did not show such correlations. The HCL group exhibited these deficits more prominently, confirming the induction of higher fatigue levels. The significance of these findings lies in clarifying the mechanism of cognitive fatigue: it primarily causes a disengagement of effort, leading to a failure in the active suppression of automatic responses, rather than an inability to inhibit them due to resource depletion. This distinction implies that fatigue-related errors stem from a strategic choice to reduce cognitive effort when costs outweigh perceived benefits. For fields relying on sustained attention and rapid adaptation, such as aviation or nuclear plant operation, these results highlight the importance of monitoring subjective effort and implementing interventions that maintain engagement, rather than solely focusing on metabolic resources or alertness levels.

Provenance

The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed.

Summary generated by qwen3.6-27b-prismaquant on 2026-06-25; verification: verified.

Topics

Ranked by relevance to this paper. Hover a topic for its definition.

• time on task