title: Autonomic responses to correct outcomes and interaction errors during single-switch scanning among children with severe spastic quadriplegic cerebral palsy.
abstract: BACKGROUND
  The combination of single-switch access technology and scanning is the most promising means of augmentative and alternative communication for many children with severe physical disabilities. However, the physical impairment of the child and the technology's limited ability to interpret the child's intentions often lead to false positives and negatives (corresponding to accidental and missed selections, respectively) occurring at rates that frustrate the user and preclude functional communication. Multiple psychophysiological studies have associated cardiac deceleration and increased phasic electrodermal activity with self-realization of errors among able-bodied individuals. Thus, physiological measurements have potential utility at enhancing single-switch access, provided that such prototypical autonomic responses exist in persons with profound disabilities.
  
  
  METHODS
  The present case series investigated the autonomic responses of three pediatric single-switch users with severe spastic quadriplegic cerebral palsy, in the context of a single-switch letter matching activity. Each participant exhibited distinct autonomic responses to activity engagement.
  
  
  RESULTS
  Our analysis confirmed the presence of the autonomic response pattern of cardiac deceleration and increased phasic electrodermal activity following true positives, false positives and false negatives errors, but not subsequent to true negative outcomes.
  
  
  CONCLUSIONS
  These findings suggest that there may be merit in complementing single-switch input with autonomic measurements to improve augmentative and alternative communications for pediatric access technology users.
authors.forename: Brian
authors.initials: B
authors.lastname: Leung
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Rosebrugh Building, 164 College Street, Room 407, Toronto M5S 3G9, Canada. tom.chau@utoronto.ca.
authors.forename: Tom
authors.initials: T
authors.lastname: Chau
mesh_terms: D001341:Autonomic Nervous System / Q000502:physiology*; D002547:Cerebral Palsy / Q000150:complications / Q000534:rehabilitation*; D002648:Child; D006801:Humans; D008297:Male; D011782:Quadriplegia / Q000209:etiology / Q000534:rehabilitation; D016896:Treatment Outcome; D014584:User-Computer Interface