EEG-Based Auditory BCI for Communication in a Completely Locked-In Patient Using Volitional Frequency Band Modulation

TL;DR

This study demonstrates that a completely locked-in ALS patient can use an EEG-based BCI to communicate by volitionally modulating brain activity, showing potential for restoring communication in severe paralysis.

Contribution

First evidence that non-invasive EEG BCIs enable communication in CLIS patients through voluntary frequency band modulation guided by auditory feedback.

Findings

Patient successfully responded to questions with above-chance accuracy

Volitional modulation of alpha and beta bands was consistent over sessions

Communication was achieved across multiple online sessions

Abstract

Patients with amyotrophic lateral sclerosis (ALS) in the completely locked-in state (CLIS) can lose all reliable motor control and are left without any means of communication. It remains unknown whether non-invasive electroencephalogram (EEG) based brain-computer interfaces (BCIs) can support volitional communication in CLIS. Here, we show that a CLIS patient was able to operate an EEG-based BCI across multiple online sessions to respond to both general knowledge and personally relevant assistive questions. The patient delivered "Yes"/"No" responses by volitionally modulating alpha and beta band power at different channels, guided by real-time auditory feedback from the BCI. The patient communicated assistive needs above chance in all sessions, achieving a perfect score in the final session. Performance on general knowledge questions varied across sessions, with two sessions showing accurate and above-chance responses, while the first and last sessions remained at chance level. The patient also showed consistent modulation patterns over time. These findings suggest that non-invasive BCIs may offer a potential pathway for restoring basic communication in CLIS.