During patient monitoring, a depth of consciousness (DOC) measure, such as a bispectral index, may be used in conjunction with additional information obtained from an awareness metric derived from one or more physiological signals, such as a photoplethysmograph signal. In an embodiment, a DOC measure may be combined with information from an awareness metric to produce a combined DOC measure. In an embodiment, information from an awareness metric derived from one or more physiological signals may be used to provide an indication of confidence in a DOC measure. In an embodiment, a DOC measure may be used to provide an indication of confidence in a depth of consciousness assessment based on an awareness metric. In an embodiment, one or the other of a DOC measure and an awareness metric may be used to provide an indication of a patient's depth of consciousness (e.g., by one “overriding” the other).