Abstract:In recent years, functional nearinfrared spectroscopy (fNIRS) and electroencephalography (EEG) have been extensively employed to measure and analyze neurocognitive responses and mental states during natural and social interactions. While fNIRS-EEG bimodal fusion has shown promise, challenges remain, including limited channel counts, low sensitivity, and poor data synchronization. To address these issues and enable more effective investigation of neurophysiological dynamics in everyday scenarios, we developed a lightweight fNIRS-EEG imaging system capable of synchronized acquisition, real-time data transmission, and visualization. The system integrates 80-channel fNIRS and 32-channel EEG coverage across the whole brain. System performance was first validated through a series of benchmark tests. For fNIRS, the signal fluctuation under fully parallel measurement remained below 1%, with linearity exceeding 0.99, successfully detecting 20% signal variation at a 10 mm depth in a two-layer brain-mimicking phantom. For EEG, the system achieved a signal-to-noise ratio of 52 dB (with a 1 μV reference noise level) at an input of 100 μV, and a common-mode rejection ratio of up to 112 dB. In integrated mode, the system supports simultaneous sampling at 20 Hz (fNIRS) and 500 Hz (EEG), with timestamping based on the terminal clock to enable synchronous hyperscanning. To further demonstrate in-vivo capability, a canonical steady-state visual stimulation experiment was conducted, confirming the system′s ability to monitor neural activation. In summary, this integrated system provides a novel, real-time platform for simultaneous monitoring of brain electrical activity and hemodynamic responses, facilitating research on perception and cognition in real-world contexts.