MIND：A Multimodal fNIRS-EEG Dataset for Unilateral Limb Motor Imagery

This dataset provides a multimodal brain signal collection acquired during a unilateral, four-direction motor imagery (MI) paradigm. It includes simultaneously recorded electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) signals from 30 healthy participants (12 females and 18 males, aged 19--25 years) performing right upper-limb directional MI tasks, including horizontal left-to-right, vertical top-to-bottom, diagonal upper-left to lower-right, and diagonal upper-right to lower-left movements. Each participant completed six recording sessions organized into three modules, yielding 120 MI trials per subject (30 trials per direction), together with resting-state recordings; all trials were visually cued and annotated with precise onset and offset times. The dataset is designed to support research on fine-grained motor intention decoding and multimodal brain--computer interfaces.