Surprise-related activation in the nucleus accumbens interacts with music-induced pleasantness.

Ofir Shany,Talma Hendler,Neomi Singer,Nori Jacoby,Roni Granot,Ricardo Tarrasch,Benjamin Paul Gold

doi:10.1093/scan/nsz019

Abstract

How can music—merely a stream of sounds—be enjoyable for so many people? Recent accounts of this phenomenon are inspired by predictive coding models, hypothesizing that both confirmation and violations of musical expectations associate with the hedonic response to music via recruitment of the mesolimbic system and its connections with the auditory cortex. Here we provide support for this model, by revealing associations of music-induced pleasantness with musical surprises in the activity and connectivity patterns of the nucleus accumbens (NAcc)—a central component of the mesolimbic system. We examined neurobehavioral responses to surprises in three naturalistic musical pieces using fMRI and subjective ratings of valence and arousal. Surprises were associated with changes in reported valence and arousal, as well as with enhanced activations in the auditory cortex, insula and ventral striatum, relative to unsurprising events. Importantly, we found that surprise-related activation in the NAcc was more pronounced among individuals who experienced greater music-induced pleasantness. These participants also exhibited stronger surprise-related NAcc–auditory cortex connectivity during the most pleasant piece, relative to participants who found the music less pleasant. These findings provide a novel demonstration of a direct link between musical surprises, NAcc activation and music-induced pleasantness.

Highlights

For many people, music is a source of highly pleasing emotional experiences
The current paper presents a novel analysis of a data set (Singer et al, 2016) which was previously used to develop a method for highlighting large-scale networks that track the ongoing music-induced emotional experience and to explain how such shared representation is related to a wide set of musical features
In accordance with theories stressing the role of musical expectations in emotion elicitation (Meyer, 1956; Huron, 2006; Juslin and Västfjäll, 2008), we found that musical surprises related to transient enhancements in arousal and to both positive and negative shifts in valence (Figure 1)

Summary

Introduction

One neuropsychological mechanism by which music is believed to achieve this impact is musical expectancy—namely the constant establishment of predictions regarding the ‘what’ and ‘when’ of future auditory events and their subsequent fulfillment or violation (Meyer, 1956; Huron, 2006). Learning about new perceptual features of an unexpected stimulus and determining whether the surprise was better or worse than expected are essential for directing future actions (den Ouden et al, 2012) This process of signaling reward prediction error—the degree to which an incoming stimulus matches the expected level of reward—is supported by the mesolimbic system in the brain (Bromberg-Martin et al, 2010; Schultz, 2010; Berridge and Kringelbach, 2013). The functional interactions of this region with cortical areas involved in the processing of acoustic and structural features of music, such as the superior temporal gyrus (STG) and inferior frontal gyrus (IFG), are assumed to underlie the integration of musical expectations with reward sensation (Salimpoor et al, 2013, 2015)

Methods

Results

Discussion

Conclusion