title: Motor imagery learning across a sequence of trials in stroke patients.
abstract: In brain-computer interfaces (BCIs), electrical brain signals during motor imagery are utilized as commands connecting the brain to a computer. To use BCI in patients with stroke, unique brain signal changes should be characterized during motor imagery process. This study aimed to examine the trial-dependent motor-imagery-related activities in stroke patients.
  
  
  
  During the recording of electroencephalography (EEG) signals, 12 chronic stroke patients and 11 age-matched healthy controls performed motor imagery finger tapping at 1.3 sec intervals. Trial-dependent brain signal changes were assessed by analysis of the mu and beta bands.
  
  
  
  Neuronal activity in healthy controls was observed over bilateral hemispheres at the mu and beta bands regardless of changes in the trials, whereas neuronal activity in stroke patients was mainly seen over the ipsilesional hemisphere at the beta band. With progression to repeated trials, healthy controls displayed a decrease in cortical activity in the contralateral hemisphere at the mu band and in bilateral hemispheres at the beta band. In contrast, stroke patients showed a decreasing trend in cortical activity only over the ipsilesional hemisphere at the beta band.
  
  
  
  Trial-dependent changes during motor imagery learning presented in a different manner in stroke patients. Understanding motor imagery learning in stroke patients is crucial for enhancing the effectiveness of motor-imagery-based BCIs.
authors.affiliation: Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Irwon-dong, Gangnam-gu, Seoul, Republic of Korea.
authors.forename: Minji
authors.initials: M
authors.lastname: Lee
authors.affiliation: Department of Physical and Rehabilitation Medicine, Center for Prevention & Rehabilitation, Heart Vascular and Stroke, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-dong, Gangnam-gu, Seoul, Republic of Korea.
authors.forename: Chang-Hyun
authors.initials: CH
authors.lastname: Park
authors.affiliation: Department of Biomedical Engineering, Hanyang University, Haengdang 1-dong, Seongdong-gu, Seoul, Republic of Korea.
authors.forename: Chang-Hwan
authors.initials: CH
authors.lastname: Im
authors.affiliation: Department of Biomedical Engineering, Hanyang University, Haengdang 1-dong, Seongdong-gu, Seoul, Republic of Korea.
authors.forename: Jung-Hoon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Center for Bionics, Korea Institute of Science and Technology (KIST), Wolgok 2-dong, Seongbuk-gu, Seoul, Republic of Korea.
authors.forename: Gyu-Hyun
authors.initials: GH
authors.lastname: Kwon
authors.affiliation: Center for Bionics, Korea Institute of Science and Technology (KIST), Wolgok 2-dong, Seongbuk-gu, Seoul, Republic of Korea.
authors.forename: Laehyun
authors.initials: L
authors.lastname: Kim
authors.affiliation: Department of Physical and Rehabilitation Medicine, Center for Prevention & Rehabilitation, Heart Vascular and Stroke, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-dong, Gangnam-gu, Seoul, Republic of Korea.
authors.forename: Won Hyuk
authors.initials: WH
authors.lastname: Chang
authors.affiliation: Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Irwon-dong, Gangnam-gu, Seoul, Republic of Korea.|Department of Physical and Rehabilitation Medicine, Center for Prevention & Rehabilitation, Heart Vascular and Stroke, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-dong, Gangnam-gu, Seoul, Republic of Korea.
authors.forename: Yun-Hee
authors.initials: YH
authors.lastname: Kim
mesh_terms: D000368:Aged; D058256:Brain Waves / Q000502:physiology*; D062207:Brain-Computer Interfaces / Q000592:standards*; D005260:Female; D006801:Humans; D007092:Imagination / Q000502:physiology*; D007858:Learning / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D020521:Stroke / Q000503:physiopathology*; D000071939:Stroke Rehabilitation / Q000592:standards*
keywords: Motor imagery; SPM; brain-computer interfaces; electroencephalography; stroke