German and U.S. researchers have decoded natural continuously spoken speech from brain waves and transformed it into text, a step toward communication with computers or humans by thought alone. Brain activity recorded by electrodes. Spoken words are then decoded from neural activity patterns.
Their “Brain-to-Text” system recorded signals from an electrocorticographic (ECoG)* electrode array located on relevant surfaces of the frontal and temporal lobes of the cerebral cortex of seven epileptic patients, who participated voluntarily in the study during their clinical treatment.
The patients read sample text (from a limited set of words) aloud during the study. Machine learning algorithms were then used to extract the most likely word sequence from the signals, and automatic speech-to-text methods created the text output. The system achieved word error rates as low as 25% and phone (instances of phonemes in utterances) error rates below 50%.
The researchers suggest that the Brain-to-Text system might lead to a speech-communication method for locked-in (unable to communicate) patients in the future.