Event Abstract Back to Event A region-based two-step P300-BMI in patients with spinocerebellar ataxia Kouji Takano1, Shiro Ikegami1, 2, Toshihiro Kawase1, Masahiro Nagao3, Tetsuo Komori4 and Kenji Kansaku1, 5* 1 Research Institute of National Rehabilitation Center for Persons with Disabilities, Department of Rehabilitation for Brain Function, Japan 2 Chiba University, Graduate School of Medicine, Japan 3 Tokyo Metropolitan Neurological Hospital, Department of Neurology, Japan 4 National Hakone Hospital, Japan 5 University of Electro-Communications, Japan Brain-machine interface (BMI) or brain-computer interface (BCI) is an interface technology that utilizes neurophysiological signals from the brain to control external machines or computers. We have developed a P300-based BMI system to support daily activities of persons with disabilities (Komatsu et al., 2008; Kansaku, 2011), and found that green/blue chromatic and luminance flicker matrices improved the BMI performance for able-bodied subjects and spinal cord injury patients (Takano et al, 2009; Ikegami et al., 2011). We also created a region-based 2-step speller, which has a larger flashing area than the conventional visual array. The first step used 2 × 3 regions (six choices), and the second step used 3 × 3 regions (nine choices). The bottom row was empty in the first step. We reported that the two-step procedure provided significantly increased accuracy compared with a conventional row/column speller for the amyotrophic lateral sclerosis patients (Ikegami et al., 2014). In this study, we investigated the performance of the region-based 2-step P300 BMI speller for spinocerebellar ataxia (SCA) patients and also for age- and sex-matched able-bodied control subjects. Eight SCA patients and 8 age- and sex-matched control subjects who had not trained in BMI operation before (52-72 years old; 2 men) participated in this study. They were required to input Japanese hiragana characters using the in-house P300-based BMI system. Eight channel EEG data was recorded, and a linear discriminant analysis distinguished a region that the subject gazed at from other regions of the matrix. Online accuracy was evaluated. The mean online accuracy was 70.6% for the SCA patients, and 69.5% for the able-bodied control subjects (the first step: 87.5% and 87.2%, the second step: 79.0% and 67.2%, respectively). The accuracy exceeded 70% in 5 out of 8 SCA patients and 6 out of 8 control subjects without significant training. In the 7 SCA patients whose accuracies exceeded 70% in the first step, the accuracy was significantly different between the first step and the second step (p = 0.0036). Such difference was not observed in the control subjects (p = 0.44). These results suggest that the region-based 2-step speller for P300-based BMI may be beneficial for SCA patients. Keywords: P300-BMI, spinocerebellar ataxia, brain-computer interface (BCI), Brain-machine interface (BMI), Amyotrophic lateral sclerosis (ALS) Conference: 2015 International Workshop on Clinical Brain-Machine Interfaces (CBMI2015), Tokyo, Japan, 13 Mar - 15 Mar, 2015. Presentation Type: Poster 1-4 Topic: Clinical Brain-Machine Interfaces Citation: Takano K, Ikegami S, Kawase T, Nagao M, Komori T and Kansaku K (2015). A region-based two-step P300-BMI in patients with spinocerebellar ataxia. Conference Abstract: 2015 International Workshop on Clinical Brain-Machine Interfaces (CBMI2015). doi: 10.3389/conf.fnhum.2015.218.00032 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 23 Apr 2015; Published Online: 29 Apr 2015. * Correspondence: Dr. Kenji Kansaku, Research Institute of National Rehabilitation Center for Persons with Disabilities, Department of Rehabilitation for Brain Function, Tokorozawa, Saitama, Japan, kansakuk@dokkyomed.ac.jp Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Kouji Takano Shiro Ikegami Toshihiro Kawase Masahiro Nagao Tetsuo Komori Kenji Kansaku Google Kouji Takano Shiro Ikegami Toshihiro Kawase Masahiro Nagao Tetsuo Komori Kenji Kansaku Google Scholar Kouji Takano Shiro Ikegami Toshihiro Kawase Masahiro Nagao Tetsuo Komori Kenji Kansaku PubMed Kouji Takano Shiro Ikegami Toshihiro Kawase Masahiro Nagao Tetsuo Komori Kenji Kansaku Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.