Integrating Time-Frequency and Performance Analysis to Explore Neurocognitive Differences in Solving Redox Reaction Problems Across Academic Levels

Abstract

Redox reactions represent a core yet challenging topic in high school chemistry, imposing significant cognitive demands on students. However, traditional behavioral measures are limited in their ability to uncover the cognitive processes underlying these learning difficulties. This study employed electroencephalography (EEG) alongside subjective cognitive load assessments to investigate the neurocognitive mechanisms differentiating high- and low-achieving students as they solved redox problems of varying difficulty. Thirty tenth-grade students participated in a mixed-design experiment. EEG signals and NASA-TLX subjective load ratings were recorded as participants solved simple and difficult redox problems. Time-frequency analysis was used to extract neural oscillatory features within the theta (4–8 Hz) and alpha (8–13 Hz) bands. Neurophysiological data revealed that low achievers exhibited stronger theta-band event-related synchronization (ERS), suggesting higher cognitive load during early working memory and control processes. In contrast, high achievers demonstrated stronger alpha-band event-related desynchronization (ERD), suggesting more efficient attentional allocation and information processing. These neural activation patterns differed significantly both between groups and across difficulty levels, a finding consistent with subjective load ratings from the NASA-TLX scale. This study provides neurocognitive evidence elucidating the sources of learning difficulties in chemistry. The findings offer implications for the design of targeted cognitive supports and differentiated instruction.