Translating scalp EEG directly into free-form text has long been seen as one of the most ambitious goals for non-invasive brain-computer interfaces. But when researchers fed random noise instead of real EEG into several published decoders, some models still produced fluent sentences and scored about as well as they did on real brain data, suggesting the language model was doing most of the work. The field has since made noise-baseline tests and decoding without teacher forcing standard validation practice, and has used magnetoencephalography (MEG) as a comparison to quantify how far EEG trails cleaner signals.
