title: Questioning the dichotomy between vegetative state and minimally conscious state: a review of the statistical evidence.
abstract: Given the enormous consequences that the diagnosis of vegetative state (VS) vs. minimally conscious state (MCS) may have for the treatment of patients with disorders of consciousness, it is particularly important to empirically legitimate the distinction between these two discrete levels of consciousness. Therefore, the aim of this contribution is to review all the articles reporting statistical evidence concerning the performance of patients in VS vs. patients in MCS, on behavioral or neurophysiological measures. Twenty-three articles matched these inclusion criteria, and comprised behavioral, electroencephalographic (EEG), positron emission tomography (PET) and magnetic resonance imaging (MRI) measures. The analysis of these articles yielded 47 different statistical findings. More than half of these findings (n = 24) did not reveal any statistically significant difference between VS and MCS. Overall, there was no combination of variables that allowed reliably discriminating between VS and MCS. This pattern of results casts doubt on the empirical validity of the distinction between VS and MCS.
authors.affiliation: Institute of Neuroscience, Université Catholique de Louvain Brussels, Belgium.
authors.forename: Giulia
authors.initials: G
authors.lastname: Liberati
authors.affiliation: ECONA - Interuniversity Centre for Research on Cognitive Processing in Natural and Artificial Systems, "Sapienza" University of Rome Rome, Italy ; Department of Philosophy, Catholic University of Eichstätt-Ingolstadt Eichstätt, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hünefeldt
authors.affiliation: ECONA - Interuniversity Centre for Research on Cognitive Processing in Natural and Artificial Systems, "Sapienza" University of Rome Rome, Italy ; Department of Psychology, Sapienza, University of Rome Rome, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Olivetti Belardinelli
keywords: brain injury; consciousness; minimally conscious state; unresponsive wakefulness syndrome; vegetative state