title: Complexity and familiarity enhance single-trial detectability of imagined movements with electroencephalography.
abstract: OBJECTIVE
  We sought to determine whether the sensorimotor rhythms (SMR) elicited during motor imagery (MI) of complex and familiar actions could be more reliably detected with electroencephalography (EEG), and subsequently classified on a single-trial basis, than those elicited during relatively simpler imagined actions.
  
  
  METHODS
  Groups of healthy volunteers, including experienced pianists and ice hockey players, performed MI of varying complexity and familiarity. Their electroencephalograms were recorded and compared using brain-computer interface (BCI) approaches and spectral analyses.
  
  
  RESULTS
  Relative to simple MI, significantly more participants produced classifiable SMR for complex MI. During MI of performance of a complex musical piece, the EEG of the experienced pianists was classified significantly more accurately than during MI of performance of a simpler musical piece. The accuracy of EEG classification was also significantly more sustained during complex MI.
  
  
  CONCLUSIONS
  MI of complex actions results in EEG responses that are more reliably classified for more individuals than MI of relatively simpler actions, and familiarity with actions enhances these responses in some cases.
  
  
  CONCLUSIONS
  The accuracy of SMR-based BCIs in non-communicative patients may be improved by employing familiar and complex actions. Increased sensitivity to MI may also improve diagnostic accuracy for severely brain-injured patients in a vegetative state.
authors.affiliation: The Brain and Mind Institute, Department of Psychology, Western University, London, Ont., Canada. Electronic address: rgibso5@uwo.ca.
authors.forename: Raechelle M
authors.initials: RM
authors.lastname: Gibson
authors.affiliation: Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.
authors.forename: Srivas
authors.initials: S
authors.lastname: Chennu
authors.affiliation: The Brain and Mind Institute, Department of Psychology, Western University, London, Ont., Canada.
authors.forename: Adrian M
authors.initials: AM
authors.lastname: Owen
authors.affiliation: The Brain and Mind Institute, Department of Psychology, Western University, London, Ont., Canada.
authors.forename: Damian
authors.initials: D
authors.lastname: Cruse
mesh_terms: D000328:Adult; D062207:Brain-Computer Interfaces; D004569:Electroencephalography / Q000145:classification* / Q000379:methods; D005260:Female; D006801:Humans; D019018:Imagery, Psychotherapy / Q000145:classification*; D007092:Imagination / Q000145:classification / Q000502:physiology; D008297:Male; D009068:Movement / Q000502:physiology; D009146:Music; D021641:Recognition, Psychology / Q000145:classification / Q000502:physiology; D013177:Sports / Q000502:physiology; D055815:Young Adult
keywords: Electroencephalography; Motor imagery; Movement complexity; Sensorimotor rhythm; Vegetative state