The Inhibition of High Load Task on Individual Cognition：A Functional Near-Infrared Spectroscope Study

Zhou, Chengmao; Song, Xiaohui; Ye, Changqing · 2021 · Crossref

DOI: 10.21203/rs.3.rs-494113/v1

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 the neural mechanisms of cognitive load, specifically examining how varying levels of task difficulty affect prefrontal cortex (PFC) activation. Motivated by the limitations of subjective and behavioral measures in assessing cognitive load, the authors utilized functional near-infrared spectroscopy (fNIRS) to provide an objective, physiological measurement of brain activity. The research aims to determine whether PFC sensitivity to task difficulty influences individual cognitive load and to identify the neural signatures of cognitive overload. The experimental design involved 15 healthy adult participants who performed a variable N-back working memory task with three load levels (N=1, N=2, and N=3). Brain activity was recorded using a 52-channel fNIRS device focused on the prefrontal region. Data analysis employed a General Linear Model (GLM) to estimate brain activation parameters, with oxygenated hemoglobin levels serving as the primary indicator of neural activity. Behavioral data, including accuracy and reaction time, were analyzed using repeated-measures analysis of variance. The results demonstrated a non-linear relationship between task load and PFC activation. At low (N=1) and moderate (N=2) loads, the posterolateral prefrontal cortex and frontoorbital regions showed significant positive activation, correlating with high task accuracy and stable reaction times. However, at the high load level (N=3), which induced cognitive overload, the PFC exhibited negative activation, particularly in the left posterior dorsal cortex. Behaviorally, this shift corresponded with a significant drop in accuracy (M = 75.67%) and increased reaction time variability. The findings indicate that while moderate difficulty effectively engages the PFC for working memory processing, exceeding the brain’s processing capacity leads to inhibitory states in the prefrontal regions. The study concludes that effective learning and cognitive performance depend on maintaining task difficulty within the individual’s processing limits to maximize PFC activation. These findings have significant implications for educational practice, suggesting that instructional design should be tailored to avoid cognitive overload. Furthermore, the identification of negative PFC activation as a marker of overload provides a physiological basis for developing targeted interventions, such as rest periods or emotion regulation strategies, to restore optimal cognitive states and improve learning outcomes.

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-nvidia on 2026-08-10; verification: verified.

Topics

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

• neuro workload indices
• workload measurement