Large-scale single-neuron recording in the human cortex using an ultra-flexible electrode array

Monitoring neural population activity at single-cell resolution is essential for fundamental research and clinical innovation. However, translating advanced recording techniques from animal models to humans remains a challenge. Flexible neural electrodes have emerged as powerful tools for large-scale single-unit recordings due to their biocompatibility and high recording density. Here, we demonstrate reliable, high-density single-unit recordings during intraoperative procedures in human patients using ultra-Flexible Implantable Neural Electrode (uFINE) arrays. The uFINE array exhibited sufficient mechanical robustness to maintain structural integrity throughout surgical operations. We successfully recorded 719 single units from 11 patients, with up to 135 single units simultaneously recorded. The flexibility of uFINE array minimized signal disturbances from brain pulsations, enabling stable and continuous single-unit detection. Stimulus and response tuning were observed at the level of individual neurons in awake patients.