Real-time neuroimaging and cognitive monitoring using wearable dry EEG

TLDR

The study addresses the need for robust real‑time measurement and interpretation of complex brain activity in wearable settings, with potential broad impact on research, medicine, and brain‑computer interfaces. The authors present and evaluate a wearable high‑density dry‑electrode EEG system and an open‑source software framework for online neuroimaging and cognitive state classification. The system employs a real‑time software framework featuring adaptive artifact rejection, cortical source localization, effective connectivity inference, and constrained logistic regression (ProxConn) for state classification, evaluated on simulated 64‑channel EEG and nine subjects, achieving high accuracy (AUC ≈ 0.97) for connectivity estimation. The system achieved significant response‑error classification above chance (AUC ≈ 0.74–0.82) using effective connectivity and ERP features, demonstrating feasibility of real‑time cortical connectivity analysis and cognitive state classification from high‑density wearable dry EEG, with pipelines released in open‑source.

Abstract

We present and evaluate a wearable high-density dry-electrode EEG system and an open-source software framework for online neuroimaging and state classification.The system integrates a 64-channel dry EEG form factor with wireless data streaming for online analysis. A real-time software framework is applied, including adaptive artifact rejection, cortical source localization, multivariate effective connectivity inference, data visualization, and cognitive state classification from connectivity features using a constrained logistic regression approach (ProxConn). We evaluate the system identification methods on simulated 64-channel EEG data. Then, we evaluate system performance, using ProxConn and a benchmark ERP method, in classifying response errors in nine subjects using the dry EEG system.Simulations yielded high accuracy (AUC = 0.97 ± 0.021) for real-time cortical connectivity estimation. Response error classification using cortical effective connectivity [short-time direct-directed transfer function (sdDTF)] was significantly above chance with similar performance (AUC) for cLORETA (0.74 ±0.09) and LCMV (0.72 ±0.08) source localization. Cortical ERP-based classification was equivalent to ProxConn for cLORETA (0.74 ±0.16) but significantly better for LCMV (0.82 ±0.12) .We demonstrated the feasibility for real-time cortical connectivity analysis and cognitive state classification from high-density wearable dry EEG.This paper is the first validated application of these methods to 64-channel dry EEG. This study addresses a need for robust real-time measurement and interpretation of complex brain activity in the dynamic environment of the wearable setting. Such advances can have broad impact in research, medicine, and brain-computer interfaces. The pipelines are made freely available in the open-source SIFT and BCILAB toolboxes.