New implant may help speech-impaired persons to communicate

New implant may help speech-impaired persons to communicate
Researchers at the University of California, United States, have successfully tested an experimental brain implant that translates brain signals into words on a computer screen. The study was published in the New England Journal of Medicine.
The implant was tested on a 36-year-old man, who successfully used it to communicate words and sentences in English, 15 years after he had suffered a stroke that caused his speech to be impaired. The study was carried out in 50 sessions over 81 weeks.
The researchers created speech detection and word classification models and used deep learning techniques to make predictions from his neural activity. The deep-learning technique is machine learning, based on artificial neural networks.“The speech-detection model processed each time point of neural activity during a task and detected onsets and offsets of word-production attempts in real-time,” the study explained.
For each attempt that was detected, the word-classification model predicted a set of word probabilities by processing the neural activity spanning from one second before to three seconds after the detected onset of attempted speech. The predicted probability associated with each word in the 50-word set quantified how likely it was that the participant was attempting to say that word during the detected attempt.”
The researchers successfully decoded sentences made by the participant at the rate of 15.2 words per minute, with a median error rate of 26.6 per cent. 98% of the participant’s attempts to form individual words were successfully detected and researchers decoded them with a 47.1% accuracy.