Background:
Large language models (LLMs), such as ChatGPT, have demonstrated impressive performance on general medical examinations; however, their effectiveness significantly declines in specialized board examinations due to limited domain-specific training data and computational constraints inherent to their self-attention mechanisms. This study investigates a novel token-splitting strategy informed by Cognitive Load Theory (CLT), aimed at overcoming these limitations by optimizing cognitive processing and enhancing knowledge retention in specialized educational contexts.

Methods:
We implemented a token-splitting approach by segmenting Taiwan plastic surgery board examination materials and associated textbook content into cognitively manageable segments ranging from 4,000 to 20,000 tokens. These segmented inputs were provided to GPT-4.1 via its standard ChatGPT web interface. Model performance was rigorously evaluated, comparing accuracy and efficiency across various token lengths and question complexities classified according to Bloom's Taxonomy.

Results:
The GPT-4.1 model utilizing the token-splitting strategy significantly outperformed the baseline (unmodified) model, achieving notably higher accuracy across both single-choice and multiple-choice questions. The optimal segmentation length was determined to be 6,000 tokens, effectively balancing cognitive coherence with information retention and model attention. Errors observed at this optimal length primarily resulted from content absent from textual materials or requiring multimodal interpretation (e.g., image-based reasoning). Provided relevant textual content was adequately segmented, GPT-4.1 consistently demonstrated high accuracy (From74.77% to 92.49%).

Conclusion:
The findings highlight that a token-splitting approach, grounded in Cognitive Load Theory, significantly enhances LLM performance on specialized medical board examinations. This accessible, user-friendly strategy provides educators and clinicians with a practical means to improve AI-assisted education outcomes without requiring complex technical skills or infrastructure. Future research and development integrating multimodal capabilities and adaptive segmentation strategies promise to further optimize educational applications and clinical decision-making support.