Electrophysiological evidence of sustained attention to music among conscious participants and unresponsive hospice patients at the end of life

Abstract

ObjectiveTo characterize electrophysiological activity, and likely neural sources of that activity, associated with listening to music in both healthy participants and in a small group of hospice patients both when responsive and when unresponsive hours before death. MethodsYoung, healthy participants (N = 22) were asked to attend to (Active condition) and to ignore (Passive condition) brief (6 s) music excerpts. A smaller group (N = 13) of hospice patients was asked to attend to the same musical excerpts (Active condition only), both when they were responsive (N = 8) and again when they became unresponsive (N = 4) only hours before death. EEG-derived event-related spectral perturbations (ERSPs) to music stimuli, and their approximate neural sources, were computed for each individual in both groups. ResultsIn the healthy participants, alpha-band ERSP during the music excerpts in a group-level analysis was significantly lower in posterio-parietal brain areas in the Active condition than in the Passive condition (event-related desynchronization, ERD). Moreover, in an analysis of individual ERSP data, most (18 of 22 or 84%) healthy participants showed meaningful sustained (4 or more seconds) alpha-band suppression in one or more posterio-parietal brain areas when they were asked to attend to the music, whereas far fewer healthy participants (only 7 of 19 or 37%) generated the same response when asked to ignore the music, indicating that posterio-parietal alpha-band ERD could be a useful marker of music listening. Similarly, 75% of eight responsive hospice patients, and 100% of four unresponsive hospice patients showed sustained posterio-parietal alpha-band suppression when asked to attend to the music, indicating that they could be listening to the music covertly even when overtly unresponsive. ConclusionsSome (but likely not all, as other patients will vary from those we studied) unresponsive patients at the end of life might be able to listen to music, despite being unable to overtly indicate their awareness. SignificanceMusic stimulation may be a promising way to engage unresponsive patients.