Brain-controlled typing finally becomes reality

Aclinical research publication led by Stanford University investigators has demonstrated that a brain-to-computer hookup can enable people with paralysis to type via direct brain control at the highest speeds and accuracy levels reported to date. The report involved study participants with severe limb weakness — amyotrophic lateral sclerosis, also called Lou Gehrig’s disease, and from a spinal cord injury. They each had one or two babyaspirin-sized electrode arrays placed in their brains to record signals from the motor cortex, a region controlling muscle movement. These signals were transmitted to a computer via a cable and translated by algorithms into point-and-click commands guiding a cursor to characters on an onscreen keyboard. Each participant, after minimal training, mastered the technique sufficiently to outperform the results of any previous test of brain-computer interfaces, or BCIs, for enhancing communication by people with similarly impaired movement. Notably, the study participants achieved these typing rates without the use of automatic word-completion assistance common in electronic keyboarding applications nowadays, which likely would have boosted their performance. One participant, Dennis Degray of Menlo Park, California, was able to type 39 correct characters per minute, equivalent to about eight words per minute. This point-and-click approach could be applied to a variety of computing devices, including smartphones and tablets, without substantial modifications, the Stanford researchers said.

Millions of people with paralysis reside in the United States. Sometimes their paralysis comes gradually, as occurs in ALS. In several ensuing research sessions, study participants, who underwent implant surgeries, were encouraged to attempt or visualize patterns of desired arm, hand and finger movements. Resulting neural signals from the motor cortex were electronically extracted by the embedded recording devices, transmitted to a computer and translated by Shenoy’s algorithms into commands directing a cursor on an onscreen keyboard to participant-specified characters. The researchers gauged the speeds at which the patients were able to correctly copy phrases and sentences. An intracortical BCI uses a silicon chip, with 100 electrodes that penetrate the brain and tap into the electrical activity of individual nerve cells.