Alame Darine, Chandanathil Merin, Easton Brianna, Verma Shweta, Bennett N'Kozi, Moldovan Nicole R, Crowley Denise, Millis Richard M
Department of Physiology, American University of Antigua, St. John's, ATG.
Department of Occupational Therapy, Monmouth University, West Long Branch, USA.
Cureus. 2025 Jun 18;17(6):e86277. doi: 10.7759/cureus.86277. eCollection 2025 Jun.
Background Cognitive load theory postulates that effective learning depends on balancing a learner's cognitive capacity with cognitive load. Medical students are required to answer complex multiple-choice questions (MCQs) that involve complex vignettes and distractors, in 90 s per question. This demands the ability to rapidly process information, filter out irrelevant data, and suppress incorrect yet tempting answer choices. The Stroop color-conflict test represents a cognitive interference task that may simulate time-limited conditions for answering MCQs. This exploratory study tested whether selected quantitative electroencephalographic (qEEG) indices could behave as biomarkers that remain stable across sequential Stroop loads. Methods Thirteen healthy adults (11 retained after outlier removal) completed a midline (Fz, Cz, Pz) qEEG protocol comprising (i) 5 minutes of resting baseline, (ii) 5 minutes after a congruent low-load (LL) Stroop test and (iii) 5 minutes after an incongruent high-load (HL) Stroop test. Voltage amplitude (µV) and mode frequency (Hz) were extracted for theta (4-7 Hz), alpha (8-12 Hz), low-beta (12-20 Hz) and high-beta (20-30 Hz) bandwidths. Derived ratios, θ/β, α/β, θ/α and high-β/low-β, plus a frontal-posterior theta ratio (Fz/Pz), were analyzed with paired t-tests and repeated-measures ANOVA. Outliers were removed using a strict |z| > 2 threshold applied to every site-specific metric. Results Significant Baseline → LL load sensitivity was found for alpha-dominant (mode) frequency. The dominant frequencies, voltage amplitudes and voltage amplitude ratios for the other bandwidths (θ, low-β, high-β) were nonsignificant and therefore not load sensitive. None of the markers exhibited significant changes from LL → HL. Alpha voltage amplitudes were found to be higher at Pz than at Cz and Fz, exhibiting posterior dominant site sensitivity. High-β/low-β and θ/β ratios were found to be higher at Fz and Cz than at Pz, exhibiting frontal dominant site sensitivity. Conclusion These findings suggest significant Stroop testing-related qEEG changes in medical students trained to answer complex MCQs under time constraints. Alpha dominant frequency was found to be load sensitive but site insensitive. Load insensitivity of alpha voltage amplitude, θ/β ratio and high-β/low-β ratio at the Cz, Fz and Pz midline recording sites suggests site specificity of these variables. These findings appear to support the hypothesis that the site-specific topographic markers alpha voltage amplitude, θ/β and high-β/low-β ratio may be useful for characterizing responses to Stroop testing. However, the load sensitivity of alpha dominant frequency measured at the Cz, Fz and Pz midline recording sites may be useful for workload tracking to identify and remediate information-processing problems. These preliminary findings should be interpreted cautiously pending larger studies of cognitive loading in other populations of learners trained to take high-stakes, time-limited examinations.
背景 认知负荷理论假定，有效的学习取决于在学习者的认知能力与认知负荷之间取得平衡。医学生需要在每题90秒内回答涉及复杂病例摘要和干扰项的复杂多项选择题（MCQ）。这需要具备快速处理信息、过滤无关数据以及抑制错误但诱人的答案选项的能力。斯特鲁普颜色冲突测试是一项认知干扰任务，可能模拟回答MCQ的限时条件。本探索性研究测试了选定的定量脑电图（qEEG）指标是否可作为在连续的斯特鲁普负荷下保持稳定的生物标志物。方法 13名健康成年人（剔除离群值后保留11名）完成了一项中线（Fz、Cz、Pz）qEEG方案，包括：（i）5分钟静息基线，（ii）一致低负荷（LL）斯特鲁普测试后5分钟，以及（iii）不一致高负荷（HL）斯特鲁普测试后5分钟。提取了theta（4 - 7Hz）、alpha（8 - 12Hz）、低beta（12 - 20Hz）和高beta（20 - 30Hz）带宽的电压幅值（µV）和模式频率（Hz）。使用配对t检验和重复测量方差分析对导出的比率θ/β、α/β、θ/α和高β/低β，以及前后theta比率（Fz/Pz）进行分析。使用严格的|z|>2阈值对每个特定部位的指标去除离群值。结果 发现alpha主导（模式）频率在基线→LL负荷时有显著敏感性。其他带宽（θ、低β、高β）的主导频率、电压幅值和电压幅值比率无显著差异，因此对负荷不敏感。从LL→HL，没有标志物表现出显著变化。发现Pz处的alpha电压幅值高于Cz和Fz处，表现出后部主导部位敏感性。发现Fz和Cz处的高β/低β和θ/β比率高于Pz处，表现出前部主导部位敏感性。结论 这些发现表明，在接受过限时回答复杂MCQ训练的医学生中，与斯特鲁普测试相关的qEEG有显著变化。发现alpha主导频率对负荷敏感，但对部位不敏感。Cz、Fz和Pz中线记录部位的alpha电压幅值、θ/β比率和高β/低β比率对负荷不敏感，表明这些变量具有部位特异性。这些发现似乎支持以下假设，即部位特异性地形图标志物alpha电压幅值、θ/β和高β/低β比率可能有助于表征对斯特鲁普测试的反应。然而，在Cz、Fz和Pz中线记录部位测量的alpha主导频率的负荷敏感性可能有助于工作量跟踪，以识别和纠正信息处理问题。在对其他接受高风险、限时考试训练的学习者群体进行更大规模的认知负荷研究之前，这些初步发现应谨慎解读。
