Edited by Dale Purves, Duke University, Durham, NC, and approved January 3, 2019 (received for review June 8, 2018)
Prediction errors are crucial for perception, learning, and adaptability. Can they also explain the abstract pleasures we derive from seemingly nonadaptive behaviors? We present evidence of musically elicited reward prediction errors (RPEs), illustrating that an abstract stimulus without apparent biological value can engage the reward system simply by manipulating expectations. Our results demonstrate that musical events can elicit formally modeled RPEs like those observed for concrete rewards, such as food or money, and that these signals support learning. This extension of the RPE model to music implies that predictive processing might play a much wider role in reward and pleasure than previously realized, and inspires new perspectives on aesthetics as well as potential therapeutic and educational applications.
Enjoying music reliably ranks among life’s greatest pleasures. Like many hedonic experiences, it engages several reward-related brain areas, with activity in the nucleus accumbens (NAc) most consistently reflecting the listener’s subjective response. Converging evidence suggests that this activity arises from musical “reward prediction errors” (RPEs) that signal the difference between expected and perceived musical events, but this hypothesis has not been directly tested. In the present fMRI experiment, we assessed whether music could elicit formally modeled RPEs in the NAc by applying a well-established decision-making protocol designed and validated for studying RPEs. In the scanner, participants chose between arbitrary cues that probabilistically led to dissonant or consonant music, and learned to make choices associated with the consonance, which they preferred. We modeled regressors of trial-by-trial RPEs, finding that NAc activity tracked musically elicited RPEs, to an extent that explained variance in the individual learning rates. These results demonstrate that music can act as a reward, driving learning and eliciting RPEs in the NAc, a hub of reward- and music enjoyment-related activity.
Author contributions: B.P.G., M.B., A.D., and R.J.Z. designed research; B.P.G. performed research; B.P.G., E.M.-H., Y.Z., and M.B. analyzed data; and B.P.G. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
Data deposition: The data reported in this paper have been deposited in NeuroVault, https://neurovault.org/collections/4778/.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1809855116/-/DCSupplemental.
Published under the PNAS license.
