[1] Harvard Med Sch, Dept Phys Med & Rehabil, Spaulding Rehabil Hosp, Boston, MA 02115 USA
[2] Massachusetts Gen Hosp, Lab Neuroimaging Coma & Consciousness, Boston, MA 02114 USA
[3] Univ Liege, Coma Sci Grp, GIGA, Consciousness & Neurol Dept, Liege, Belgium
[4] Univ Hosp Liege, Liege, Belgium