A New Auditory Multi-Class Brain-Computer Interface Paradigm: Spatial Hearing as an Informative Cue

• Published in: PloS one Vol. 5; no. 4; p. e9813
• Main Authors: Schreuder, Martijn, Blankertz, Benjamin, Tangermann, Michael
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.04.2010; Public Library of Science (PLoS)
• Subjects: Acoustic Stimulation - methods; Adult; Amyotrophic lateral sclerosis; Amyotrophic Lateral Sclerosis - physiopathology; Artificial intelligence; Auditory evoked potentials; Brain; Brain - physiology; Brain research; Classification; Clinical trials; Computer applications; Cues; Ears & hearing; Event-related potentials; Feedback; Human-computer interface; Humans; Implants; Information transfer; Neurological Disorders/Neuromuscular Diseases; Neuroscience/Cognitive Neuroscience; Neuroscience/Sensory Systems; Physiology/Sensory Systems; Spatial distribution; Stimuli; Time Factors; User-Computer Interface; Visual perception; Visual stimuli; Germany
• DOI: 10.1371/journal.pone.0009813
• ISSN: 1932-6203

Most P300-based brain-computer interface (BCI) approaches use the visual modality for stimulation. For use with patients suffering from amyotrophic lateral sclerosis (ALS) this might not be the preferable choice because of sight deterioration. Moreover, using a modality different from the visual one minimizes interference with possible visual feedback. Therefore, a multi-class BCI paradigm is proposed that uses spatially distributed, auditory cues. Ten healthy subjects participated in an offline oddball task with the spatial location of the stimuli being a discriminating cue. Experiments were done in free field, with an individual speaker for each location. Different inter-stimulus intervals of 1000 ms, 300 ms and 175 ms were tested. With averaging over multiple repetitions, selection scores went over 90% for most conditions, i.e., in over 90% of the trials the correct location was selected. One subject reached a 100% correct score. Corresponding information transfer rates were high, up to an average score of 17.39 bits/minute for the 175 ms condition (best subject 25.20 bits/minute). When presenting the stimuli through a single speaker, thus effectively canceling the spatial properties of the cue, selection scores went down below 70% for most subjects. We conclude that the proposed spatial auditory paradigm is successful for healthy subjects and shows promising results that may lead to a fast BCI that solely relies on the auditory sense.