Brain activity during repetitive cognitive load in young adults: a pilot study

Understanding how brain activity evolves with repetitive cognitive load is critical for assessing neural adaptations related to learning, fatigue, and efficiency. This pilot study investigates electroencephalographic (EEG) changes over five days of cognitive training in young adults performing a memory task. The study included eight healthy participants, who completed EEG recordings during a cognitive load task. To assess brain activity, we computed absolute spectral power across theta, alpha, sub-alpha (lower, upper), beta, sub-beta (lower, mid, upper), and gamma frequency bands. Nonparametric statistical methods, including a cluster-based permutation test, were applied to assess differences between the first and fifth day. Results indicate a significant power increase in theta, particularly in the midline and parietal regions, suggesting enhanced cognitive control and memory retrieval. Alpha power also increased, reflecting improved processing efficiency with reduced cognitive effort. Furthermore, lower and mid-beta activity showed an increase over time, indicating sustained attentional engagement and optimized cognitive processing. A reduction in the beta/alpha ratio suggests a transition from effortful processing to more automatic retrieval. No significant changes were observed in gamma power, implying that cognitive load did not induce excessive strain. These findings highlight neuroplastic adaptations to cognitive training, supporting the role of EEG in tracking learning-related changes in brain activity.