Differential Motor System Activation in Chemistry Problem Solving: Gesture‐Based Versus Model‐Based Instruction

ABSTRACT Gesture‐based instruction enhances spatial problem‐solving accuracy, yet the underlying neurocognitive mechanisms remain unclear. This study examines whether gesture enhances spatial problem‐solving in organic chemistry through activation patterns more consistent with offloading cognitive effort or coupling motor and working memory systems. Using functional near‐infrared spectroscopy (fNIRS), we compared students (68 recruited; n = 64 with usable fNIRS data) trained to translate between molecular diagrams using gesture‐based or model‐based instruction. Behavioral data revealed higher accuracy in the gesture‐based compared to the model‐based condition. In the fNIRS data, although channel‐level condition effects did not survive FDR correction, exploratory ROI‐level analyses showed increased activation in premotor and motor planning regions (BA 6) for the gesture group, whereas the model‐based learners exhibited greater dorsolateral prefrontal cortex (BA 46) activation to suggest higher executive control demands. These findings provide preliminary neurocognitive evidence consistent with offloading and show that gesture and physical models promote different problem‐solving strategies after embodied STEM instruction.