A phase-calibrated combined electrical-sensory neuromodulation platform for short-Term frontoparietal network modulation and cognitive fatigue resistance

Non-invasive multimodal neuromodulation is often limited by cross-modal temporal misalignment caused by modality-specific conduction delays. To address this challenge, we developed a microcontroller-based multiphysics stimulation platform integrating transcranial alternating current stimulation (tACS) with visual and auditory rhythmic inputs. A feedforward delaycompensation strategy using individualized ERP latencies (visual P1 and auditory N1) was implemented to reduce intermodal timing discrepancies.The system was evaluated in a randomized, sham-controlled crossover study with 15 participants providing complete EEG datasets. Compared with sensory-only stimulation, the phase-coordinated multiphysics condition increased resting-state frontoparietal theta power and enhanced functional connectivity (wPLI). During a subsequent high-load cognitive task, it was also associated with reduced accumulation of fatigue-related parietal alpha power.Exploratory analysis revealed a moderate association between parietal alpha stability and behavioral performance (r = 0.577, p = 0.024). These findings suggest that temporally coordinated cross-modal stimulation may support more stable large-scale neural dynamics and improved cognitive performance under sustained load, providing a technical framework for precision multimodal neuromodulation.