Haptic guidance lowers cognitive demand during the learning of unfamiliar handwriting tasks

Handwriting is a cognitively demanding task requiring complex sensorimotor coordination, traditionally learned through visual guidance. Recent studies suggest that haptic guidance can provide an alternative learning pathway by physically assisting movement execution. However, neuroscientific validation is still lacking. This study investigates the neural and behavioral differences between haptic and visual guidance in learning unfamiliar handwriting tasks of varying difficulty levels (easy, medium, and hard). Thirty-two participants were enrolled in this study. We analyzed brain activity in the prefrontal cortex, a key area associated with cognitive load and learning, using electroencephalography (EEG). Our results indicate that haptic guidance leads to lower cognitive demand compared to visual guidance, as evidenced by reduced theta and alpha band activity for easy tasks and reduced gamma band activity for the medium difficulty level of tasks (Wilcoxon Rank Sum test, p $<$ 0.05) without degrading the learning outcomes. Behavioral analysis showed that both haptic and visual guidance improved handwriting performance. Specifically, visual cues were more effective for medium difficulty tasks, while haptic cues showed a greater benefit for difficult tasks. These findings inform the design of haptic-assisted handwriting training systems, particularly for learners who may benefit from reduced cognitive load.