Theory Behind the Emotional Effects of Music on the Brain
There seems to be some consensus that music derives its emotional power from dynamic aspects of brain systems that are normally used for control of more regular emotional responses, though it is difficult to even differentiate between a ‘regular’ emotional response and something different. Some argue that ‘regular' emotional responses are those responses that have evolutionary value, though even this can be an ambiguous claim.
As music is an integral part of our human experience, one might infer that our passion for music reflects, as Panksepp eloquently states, “the ancestral ability of our mammalian brain to transmit and receive basic emotional sounds.” We are aware that through evolution, our nervous system is reactive to musical stimuli.
There seem to be many different aspects of how emotional changes are caused by music. On the objective end lies the specific musical attributes of the song or piece: the pitch, rhythm, timbre, etc that compose the various sounds that compose a piece of music. On the subjective end, however, lie the personal memories and cultural values associated with the music, generated through multiple exposures, experience, and a variety of other factors. These factors, as well as many others, have a strong influence on the emotional impact of music.
Obviously, the subjective aspect of the emotional effects of music are huge, and learning and experience play significant roles. Some have suggested that personality may be an integral component of how individuals respond to music.
This ability to respond so powerfully to musical stimuli raises an important question: Has our brain developed in order to respond to music, or has music reflected the manner in which our brains work? Though it is unlikely that various regions of our brain are developed specifically for the processing of music and the emotions associated with it, it is much more likely that music is able to trigger specific regions of the brain in a unique manner, reflecting the development of the nervous system.
It is not unreasonable to hypothesize that we are so reactive to music because it reflects many aspects of the prosodic elements of speech (rhythm, stress, intonation, etc), as well as other functions of the brain.