[1] Univ Hlth Network, Dept Anesthesia & Pain Management, Toronto, ON, Canada
[2] Univ Hlth Network, Toronto Gen Hosp, Res Inst, Toronto, ON, Canada
[3] Univ Hlth Network, Joint Dept Med Imaging, Toronto, ON, Canada
[4] Univ Hlth Network, Funct Neuroimaging Lab, Toronto, ON, Canada
[5] Univ Toronto, Dept Anesthesiol, Toronto, ON, Canada
[6] Univ Toronto, Inst Med Sci, Toronto, ON, Canada
[7] Univ Toronto, Dept Physiol, Toronto, ON, Canada