{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:09:59Z","timestamp":1760238599781,"version":"build-2065373602"},"reference-count":36,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2020,8,20]],"date-time":"2020-08-20T00:00:00Z","timestamp":1597881600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004663","name":"Ministry of Science and Technology of Taiwan","doi-asserted-by":"publisher","award":["MOST 108-2321-B-010-008-MY2, 108-2314-B-303-010, 108-2636-E-006-010, 109-2636-E-006-010 (Young Scholar Fellowship Program), 107-2221-E-010-021-MY2, and 107-2221-E-010-011"],"award-info":[{"award-number":["MOST 108-2321-B-010-008-MY2, 108-2314-B-303-010, 108-2636-E-006-010, 109-2636-E-006-010 (Young Scholar Fellowship Program), 107-2221-E-010-021-MY2, and 107-2221-E-010-011"]}],"id":[{"id":"10.13039\/501100004663","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>Electroencephalography (EEG)-based brain computer interfaces (BCIs) translate motor imagery commands into the movements of an external device (e.g., a robotic arm). The automatic design of spectral and spatial filters is a challenging task, as the frequency bands of the spectral filters must be predefined by previously published studies and given that they may be affected during trials by artifacts and improper motor imagery (MI). This study aimed to eliminate the contaminated trials automatically during classifier training, and to simultaneously learn the spectral and spatial patterns without the need for predefined frequency bands. Compared with previous studies that measured the discriminative power of a frequency band based on mutual information, this study determined the difference of the class conditional probability density function between two MI classes. This information was further shared to measure the contamination level of the trial that simplified the computation. A particle-based approximation technique iteratively constructed a filter bank that extracted discriminative features, and simultaneously removed potentially contaminated trials. The particle weight was estimated by an analysis of variance F-test instead of mutual information as commonly used in previous studies. The experimental results of a publicly available dataset revealed that the proposed method outperformed the other BCI in terms of the classification accuracy. Asymmetrical spatial patterns were found on left- versus right-hand MI classifications. The learnt spectral and spatial patterns were consistent with prior neurophysiological knowledge.<\/jats:p>","DOI":"10.3390\/sym12091387","type":"journal-article","created":{"date-parts":[[2020,8,20]],"date-time":"2020-08-20T21:13:42Z","timestamp":1597958022000},"page":"1387","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Simultaneously Spatiospectral Pattern Learning and Contaminated Trial Pruning for Electroencephalography-Based Brain Computer Interface"],"prefix":"10.3390","volume":"12","author":[{"given":"Chun-Ping","family":"Shieh","sequence":"first","affiliation":[{"name":"Department of Biomedical Engineering, National Yang Ming University, No.155, Section 2, Linong St., Taipei 11221, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5893-6299","authenticated-orcid":false,"given":"Shih-Hung","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, National Cheng Kung University, No. 1 University Road, Tainan 70101, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yu-Shun","family":"Liu","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, National Cheng Kung University, No. 1 University Road, Tainan 70101, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yun-Ting","family":"Kuo","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, National Yang Ming University, No.155, Section 2, Linong St., Taipei 11221, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yu-Chun","family":"Lo","sequence":"additional","affiliation":[{"name":"PhD Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chao-Hung","family":"Kuo","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, National Yang Ming University, No.155, Section 2, Linong St., Taipei 11221, Taiwan"},{"name":"Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei 11217, Taiwan"},{"name":"Department of Neurological Surgery, University of Washington, Seattle, WA 98195-6470, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"You-Yin","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, National Yang Ming University, No.155, Section 2, Linong St., Taipei 11221, Taiwan"},{"name":"PhD Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,8,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1123","DOI":"10.1109\/5.939829","article-title":"Motor imagery and direct brain-computer communication","volume":"89","author":"Pfurtscheller","year":"2001","journal-title":"Proc. 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