Music As A Bridge To Consciousness

There are striking anecdotes of how music can bring previously here are striking anecdotes of how music can bring previously unresponsive individuals “back to life.”  Could this activating function of music also be helpful in other disorders that disconnect individuals from their loved ones? Recently, interesting findings have been made on how music could be used to stimulate individuals with disturbances of consciousness, and how brain responses to sound could be used to trace the progress of recovery from conditions as severe as coma.

Disorders of consciousness are grave conditions typically resulting from severe brain trauma. These disorders are most often divided into two categories: unresponsive wakefulness syndrome (UWS), previously called vegetative state, and minimally conscious state (MCS). Individuals with UWS are unable to respond to requests and commands by others, but their eyes are open and they exhibit reflexes. Individuals with MCS are more responsive, and sometimes show signs of consciousness, but are still unable to communicate. These two states of consciousness are different from coma, which is more severe, and where reflexes may be retained but do not involve eye opening.1

In addition to being serious disruptions of health, disturbances of consciousness cause great personal distress to the families and loved ones of patients. Finding new ways to make contact with and activate individuals in these states would thereby not only improve the status of patients but also potentially alleviate the suffering of those close to the patient.

Why and how might music offer relief to patients suffering from disorders of consciousness and their families?

Results showed increased brain activation at certain bandwidths in a number of patients while they were listening to preferred music

The effects that music listening has on the brain are well documented. Research has shown that exposure to music activates the brain very widely. In addition to activity in the auditory areas, motor areas, areas related to learning, memory, attention, as well as areas related to emotions are stimulated.2 This widespread stimulation might be especially welcome in hospital settings that typically offer very few activating impulses to the brain. For example, important research by Teppo Särkämö and his colleagues has shown that enriching the recovery environment with music, for even just one hour per day, can accelerate cognitive and emotional recovery after stroke.2 Perhaps this kind of enrichment could be beneficial for patients with disturbances of consciousness as well.

An article published earlier this year3 provides tentative support for this idea. In the study, researchers investigated the responses of 20 healthy subjects and 21 individuals with disturbances of consciousness to preferred music, disliked music (selected based on the accounts of family members), white noise, silence as well as live improvised music that was played in a way that the tempo matched the breathing rhythm of the patient. During the presentation of music, electroencephalogram (EEG), heart rate variability, and breathing were recorded.

The results of the study show mixed, but encouraging results. More specifically, there was increased brain activation at certain bandwidths in a number of patients while they were listening to preferred music. Additionally, patients with the most severe disturbances of consciousness showed increased blink rate to preferred music. Some patients even exhibited increases in heart rate and heart rate variability as well as eye and body movements. These types of results seem promising, but, as noted in a recent review paper on the use of music in treatment of disorders of consciousness,4 a lot more research is needed until reliable conclusions can be drawn. In any case, including favorite music of a patient into the recovery environment can be a way to support the relationship between the patient and their loved ones.

Emerging brain imaging techniques, for which music is a perfect stimulus, could change the way we assess and understand disorders of consciousness like coma

A more thoroughly studied way of using sound to support treatment of patients with disturbances of consciousness is in tracing recovery by evaluating brain responses to sound. The brain continuously forms memory of regularities in the auditory scene. When these regularities are violated, meaning when there is an unpredicted change in the sound, a brain response called the Mismatch Negativity (MMN) appears.

Typically the MMN is recorded with something called an oddball paradigm, where the listener is presented with a series of repeating tones and infrequent oddballs that differ in the pitch or timbre from the repeating tone. In real life settings, you might therefore produce an MMN response to a modulation of key in a piece of music, or a mistuned note played by a violinist. In studies such as the recent paper by Elsa Huan and colleagues5, the MMN response has been successfully used to gauge the likelihood of patients in coma regaining consciousness. It has also recently been suggested 6 that the MMN response holds promise of becoming a valuable clinical tool for assessing patients with disturbances of consciousness or other cognitive functions.

Music is one of the most activating stimuli for the brain. Hopefully in the future, well-conducted studies will corroborate the accumulating anecdotal evidence on the positive effects of music for enriching the recovery setting, for prediction of clinical outcomes, as well as for strengthening the feeling of connection between the patient and their caretakers and loved ones.

Written by Ketki Karanam

References

1. Bodart, O., Laureys, S., & Gosseries, O. (2013, April). Coma and disorders of consciousness: scientific advances and practical considerations for clinicians. In Seminars in neurology (Vol. 33, No. 02, pp. 083-090). Thieme Medical Publishers. doi: 10.1055/s-0033-1348965

2. Särkämö, T., Tervaniemi, M., Laitinen, S., Forsblom, A., Soinila, S., Mikkonen, M., et al. (2008). Music listening enhances cognitive recovery and mood after middle cerebral artery stroke. Brain 131, 866–876.  doi: 10.1093/brain/awn013

3. O'Kelly, J., James, L., Palaniappan, R., Fachner, J., Taborin, J., & Magee, W. L. (2013). Neurophysiological and behavioral responses to music therapy in vegetative and minimally conscious states. Frontiers in human neuroscience, 7, 884.  doi: 10.3389/fnhum.2013.00884

 4. Rollnik, J. D., & Altenmüller, E. (2014). Music in disorders of consciousness. Frontiers in neuroscience, 8. doi: 10.3389/fnins.2014.00190

5. Juan, E., De Lucia, M., Tzovara, A., Beaud, V., Oddo, M., Clarke, S., & Rossetti, A. O. (2016). Prediction of cognitive outcome based on the progression of auditory discrimination during coma. Resuscitation, 106, 89-95. doi: 10.1016/j.resuscitation.2016.06.032.

6. Schall, U. (2016). Is it time to move mismatch negativity into the clinic?. Biological psychology,116, 41-46. doi: 10.1016/j.biopsycho.2015.09.001.