In short: the malfunction was a retraction of the device “threads”/interface to the brain surface. The remedy was an update to the sensitivity of the device, and normal behavior resumed with the patient.

> “a number of threads retracted from [Arbaugh’s] brain, resulting in a net decrease in the number of effective electrodes,”

> “In response to this change, we modified the recording algorithm to be more sensitive to neural population signals, improved the techniques to translate these signals into cursor movements, and enhanced the user interface,”

> “These refinements produced a rapid and sustained improvement in BPS, that has now superseded Noland’s initial performance,”