Silent Communication: Toward Using Brain Signals

This article summarizes the results of the authors´ collaborative efforts to date. These efforts are described in detail . In these studies, nine subjects were evaluated temporarily implanted with electrode grids for epilepsy monitoring. Auditory words were presented once at the beginning of each 4-s trial. Visual words were displayed on the screen for the complete duration of a trial. Subjects were asked to either speak aloud (i.e., overtly) or imagine speaking (i.e., covertly) each word. Thus, there were four experimental conditions: visual/actual, audio/actual, visual/imagined, and audio/imagined.audio/imagined.