Effects of Music on the Pain Response in the Central Nervous System Using Functional Magnetic Resonance Imaging
Dobek, Christine Elizabeth
The oldest procedure for pain relief has been music. There is abundant behavioural evidence to support music’s pain relieving properties, however, studies to date have yet to investigate music-induced analgesia via imaging. Our first imaging study used thermal stimulation just below pain threshold in combination with various music stimuli, to determine whether music can affect neural activity in response to heat stimuli within brainstem and spinal cord regions. Differential responses to music stimuli were found within regions known for descending modulation, and familiar classical music had a unique effect on neural activity in these regions compared to unpleasant music, reverse music, and no music. This study confirmed that the emotional valence of music affects neural activity in the brainstem and spinal cord. The second study used a well-defined pain paradigm applied with or without favorite music to study the neural activity responses in the brain, brainstem, and spinal cord using imaging. Subjective pain ratings were significantly lower when painful stimuli were administered with music than without music. The pain condition alone elicited neural activity in brain regions consistently activated during similar pain studies. Brain regions associated with pleasurable music listening were activated including limbic, frontal, and auditory regions when comparing music to non-music pain conditions. In addition, neural regions showed activity responses indicative of descending modulation when contrasting the two conditions. These regions include the spinothalamic tract, dorsolateral prefrontal cortex (DLPFC), periaqueductal grey (PAG), rostral ventromedial medulla (RVM), and the dorsal gray matter of the spinal cord. The data suggest that music seems to engage mesolimbic and mesocortical brain regions to activate the descending pain modulation pathway. Lower subjective pain ratings corresponded to a greater suppression in the dorsal gray matter when listening to music. This is the first imaging study to characterize the neural response of pain and how it is mitigated by music listening, and brain and spinal fMRI are appropriate means to study pain processing and its modulation in the central nervous system.