Neurological research: a paralyzed patient can communicate again

Experimental process and successes

BCI insertion surgery was performed in March 2019. “The patient had two arrays of microelectrodes implanted in the left dominant motor cortex under general anesthesia,” the study says. However, there was still a long way to go after the operation before concrete statements were made like those on day 247 or 253. Because use of the device was initially trained with the patient – the device must learn to read the patient’s thoughts. To do this, the user must imagine certain eye movements, which in turn activate certain brain waves that the program can assign to an audio signal. The goal was for the patient to be able to answer yes or no in a targeted manner when the so-called speller suggested messages to the patient with the help of artificial intelligence.

During the first 135 days of the trial, the investigators made 107 attempts to elicit a comprehensible statement from the patient using this method—until they were finally able to do so on day 107 after transplantation. According to the study, “First of all I would like to thank Niels and Berbaumer” is one of his first understood phrases. From now on, there are always days when a patient can form sentences. For example, on day 251, he asked for more eye gel and on day 461 he asked to raise the headboard if he had visitors in his room.

Despite these successes, research into how paralyzed patients communicate using brain-computer interfaces is still in its infancy. Study results show: Of the more than 460-day trial, the technology was used only intermittently. Especially at the end of the period, unsuccessful attempts to use prevailed. In addition, it takes an average of 1-2 minutes for a patient to form a letter, and the period during which a patient can use the device at once per day varies: “Some days form less than 100 letters, and on others more than 400” . Fluent conversation is not possible at any point in the experiment.