Brain-to-Text Decoding: A Non-invasive Approach via Typing
This study addresses the need for non-invasive neural decoding in individuals with aphasia or motor impairments. We propose a novel sentence-level brain signal decoding paradigm—“covert rehearsal–tapping”—and introduce Brain2Qwerty, an end-to-end deep learning architecture that jointly processes MEG and EEG signals to directly predict character sequences. Our contributions are threefold: (1) we establish the first non-invasive sentence decoding paradigm anchored on typing behavior; (2) we demonstrate that decoding performance is synergistically driven by both motor execution and high-level language cognition; and (3) we infer underlying cognitive mechanisms via systematic error pattern analysis. Evaluation on healthy participants shows a mean character error rate (CER) of 32% for MEG (best individual: 19%), substantially outperforming EEG (67% CER) and significantly narrowing the performance gap with invasive approaches.