title: An alternative perspective.
abstract: The need for a revised definition is discussed and a more simplified alternative is suggested.
authors.affiliation: Department of Rehabilitation Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: Wolf
mesh_terms: D006801:Humans; D011603:Psychophysiology; D012660:Semantics