The rewards of music listening: Response and physiological connectivity of the mesolimbic system V. Menon (a,b,c) and D.J. Levitin (d) NeuroImage 28 (2005), 175-184 a) Department of Psychiatry and Behavioral Sciences, Stanford University
School of Medicine, Stanford, CA 94305, USA Abstract: Although the neural underpinnings of music cognition have been widely
studied in the last 5 years, relatively little is known about the neuroscience
underlying emotional reactions that music induces in listeners. Many people
spend a significant amount of time listening to music, and its emotional
power is assumed but not well understood. Here, we use functional and
effective connectivity analyses to show for the first time that
listening to music strongly modulates activity in a network of mesolimbic
structures involved in reward processing including the nucleus
accumbens (NAc) and the ventral tegmental area (VTA), as well
as the hypothalamus and insula, which are thought to be involved in regulating
autonomic and physiological responses to rewarding and emotional stimuli.
Responses in the NAc and the VTA were strongly correlated pointing to
an association between dopamine release and NAc response to music.
Responses in the NAc and the hypothalamus were also strongly correlated
across subjects, suggesting a mechanism by which listening to pleasant
music evokes physiological reactions. Effective connectivity confirmed
these findings, and showed significant VTA-mediated interaction of
the NAc with the hypothalamus, insula, and orbitofrontal cortex. The
enhanced functional and effective connectivity between brain regions mediating
reward, autonomic, and cognitive processing provides insight into understanding
why listening to music is one of the most rewarding and pleasurable human
experiences. Comment: In 2004, Sutoo and Akiyama showed for the first
time that music raises dopamine levels in the brain of rats.
Because their experiments cannot be carried out on humans, it remained
unknown if music raises dopamine levels also in humans. Menon and
Levitin have now for the first time shown strong indications from connectivity
analyses based on brain imaging data that this indeed is the case. Why
the dopaminergic neurons in the upper part of the brain stem (ventral
tegmental area, VTA) should respond to an increased order in the activity
of auditory neurons, as occurs during music exposure, remains to be
explored. When investigating this question it may be useful to remember
the so-called frequency following response (FFR) that can be recorded
from the human skull during exposure to harmonic complex tones. The neuron
potentials that cause the FFR are generated in the auditory midbrain,
and thus in close proximity to the dopaminergic neurons in the VTA. So,
there would be good reasons to bear in mind the possibility of an electrotonic
influence of the auditory midbrain upon the dopaminergic neurons in
the VTA. |