Predictive processing, cognitive control, and tonality stability of music: An fMRI study of chromatic harmony

Music reward sensitivity is associated with greater information transfer capacity within dorsal and motor white matter networks in musicians

There are pronounced differences in the degree to which individuals experience music-induced pleasure which are linked to variations in structural connectivity between auditory and reward areas. However, previous studies exploring the link between white matter structure and music reward sensitivity (MRS) have relied on standard diffusion tensor imaging methods, which present challenges in terms of anatomical accuracy and interpretability. Further, the link between MRS and connectivity in regions outside of auditory-reward networks, as well as the role of musical training, have yet to be investigated. Therefore, we investigated the relation between MRS and structural connectivity in a large number of directly segmented and anatomically verified white matter tracts in musicians (n = 24) and non-musicians (n = 23) using state-of-the-art tract reconstruction and fixel-based analysis. Using a manual tract-of-interest approach, we additionally tested MRS-white matter associations in auditory-reward networks seen in previous studies. Within the musician group, there was a significant positive relation between MRS and fiber density and cross section in the right middle longitudinal fascicle connecting auditory and inferior parietal cortices. There were also positive relations between MRS and fiber-bundle cross-section in tracts connecting the left thalamus to the ventral precentral gyrus and connecting the right thalamus to the right supplementary motor area, however, these did not survive FDR correction. These results suggest that, within musicians, dorsal auditory and motor networks are crucial to MRS, possibly via their roles in top-down predictive processing and auditory-motor transformations.

Effects of personalized music listening on post-stroke cognitive impairment: A randomized controlled trial

BACKGROUND AND PURPOSE

Previous studies have suggested that music listening has the potential to positively affect cognitive functions and mood in individuals with post-stroke cognitive impairment (PSCI), with a preference for self-selected music likely to yield better outcomes. However, there is insufficient clinical evidence to suggest the use of music listening in routine rehabilitation care to treat PSCI. This randomized control trial (RCT) aims to investigate the effects of personalized music listening on mood improvement, activities of daily living (ADLs), and cognitive functions in individuals with PSCI.

MATERIALS AND METHODS

A total of 34 patients with PSCI were randomly assigned to either the music group or the control group. Patients in the music group underwent a three-month personalized music-listening intervention. The intervention involved listening to a personalized playlist tailored to each individual's cultural, ethnic, and social background, life experiences, and personal music preferences. In contrast, the control group patients listened to white noise as a placebo. Cognitive function, neurological function, mood, and ADLs were assessed.

RESULTS

After three months of treatment, the music group showed significantly higher Montreal Cognitive Assessment (MoCA) scores compared to the control group (p=0.027), particularly in the domains of delayed recall (p=0.019) and orientation (p=0.023). Moreover, the music group demonstrated significantly better scores in National Institutes of Health Stroke Scale (NIHSS) (p=0.008), Barthel Index (BI) (p=0.019), and Zarit Caregiver Burden Interview (ZBI) (p=0.008) compared to the control group. No effects were found on mood as measured by the Hamilton Anxiety Rating Scale (HAMA) and the Hamilton Depression Rating Scale (HAMD).

CONCLUSION

Personalized music listening promotes the recovery of cognitive and neurological functions, improves ADLs, and reduces caregiver burden in patients with PSCI.

Metaphors or mechanism? Predictive coding and a (brief) history of empirical study of the arts

Predictive processing (PP) offers an intriguing approach to perception, cognition, but also to appreciation of the arts. It does this by positing both a theoretical basis-one might say a 'metaphor'-for how we engage and respond, placing emphasis on mismatches rather than fluent overlap between schema and environment. Even more, it holds the promise for translating metaphor into neurobiological bases, suggesting a means for considering mechanisms-from basic perceptions to possibly even our complex, aesthetic experiences. However, while we share the excitement of this promise, the history of empirical or psychological aesthetics is also permeated by metaphors that have progressed our understanding but which also tend to elude translation into concrete, mechanistic operationalization-a challenge that can also be made to PP. We briefly consider this difficulty of convincing implementation of PP via a brief historical outline of some developments in the psychological study of aesthetics and art in order to show how these ideas have often anticipated PP but also how they have remained at the level of rather metaphorical and difficult-to-measure concepts. Although theoretical in scope, we hope that this commentary will spur researchers to reflect on PP with the aim of translating metaphorical explanations into well-defined mechanisms in future empirical study. This article is part of the theme issue 'Art, aesthetics and predictive processing: theoretical and empirical perspectives'.

Prediction errors arising from switches between major and minor modes in music: An fMRI study

The major and minor modes in Western music have positive and negative connotations, respectively. The present fMRI study examined listeners' neural responses to switches between major and minor modes. We manipulated the final chords of J. S. Bach's keyboard pieces so that each major-mode passage ended with either the major (Major-Major) or minor (Major-Minor) tonic chord, and each minor-mode passage ended with either the minor (Minor-Minor) or major (Minor-Major) tonic chord. If the final major and minor chords have positive and negative reward values respectively, the Major-Minor and Minor-Major stimuli would cause negative and positive reward prediction errors (RPEs) respectively in a listener's brain. We found that activity in a frontoparietal network was significantly higher for Major-Minor than for Major-Major. Based on previous research, these results support the idea that a major-to-minor switch causes negative RPE. The contrast of Minor-Major minus Minor-Minor yielded activation in the ventral insula and visual cortex, speaking against the idea that a minor-to-major switch causes positive RPE. We discuss our results in relation to executive functions and the emotional connotations of major versus minor modes.