“When the feeling’s gone”: a selective loss of musical emotion: Figure 1

Music perception in acquired prosopagnosia

BACKGROUND

Acquired prosopagnosia is often associated with other deficits such as dyschromatopsia and topographagnosia, from damage to adjacent perceptual networks. A recent study showed that some subjects with developmental prosopagnosia also have congenital amusia, but problems with music perception have not been described with the acquired variant.

OBJECTIVE

Our goal was to determine if music perception was also impaired in subjects with acquired prosopagnosia, and if so, its anatomic correlate.

METHOD

We studied eight subjects with acquired prosopagnosia, all of whom had extensive neuropsychological and neuroimaging testing. They performed a battery of tests evaluating pitch and rhythm processing, including the Montréal Battery for the Evaluation of Amusia.

RESULTS

At the group level, subjects with anterior temporal lesions were impaired in pitch perception relative to the control group, but not those with occipitotemporal lesions. Three of eight subjects with acquired prosopagnosia had impaired musical pitch perception while rhythm perception was spared. Two of the three also showed reduced musical memory. These three reported alterations in their emotional experience of music: one reported music anhedonia and aversion, while the remaining two had changes consistent with musicophilia. The lesions of these three subjects affected the right or bilateral temporal poles as well as the right amygdala and insula. None of the three prosopagnosic subjects with lesions limited to the inferior occipitotemporal cortex exhibited impaired pitch perception or musical memory, or reported changes in music appreciation.

CONCLUSION

Together with the results of our previous studies of voice recognition, these findings indicate an anterior ventral syndrome that can include the amnestic variant of prosopagnosia, phonagnosia, and various alterations in music perception, including acquired amusia, reduced musical memory, and subjective reports of altered emotional experience of music.

Music enhances structural maturation of emotional processing neural pathways in very preterm infants

Prematurity disrupts brain maturation by exposing the developing brain to different noxious stimuli present in the neonatal intensive care unit (NICU) and depriving it from meaningful sensory inputs during a critical period of brain development, leading to later neurodevelopmental impairments. Musicotherapy in the NICU environment has been proposed to promote sensory stimulation, relevant for activity-dependent brain plasticity, but its impact on brain structural maturation is unknown. Neuroimaging studies have demonstrated that music listening triggers neural substrates implied in socio-emotional processing and, thus, it might influence networks formed early in development and known to be affected by prematurity. Using multi-modal MRI, we aimed to evaluate the impact of a specially composed music intervention during NICU stay on preterm infant's brain structure maturation. 30 preterm newborns (out of which 15 were exposed to music during NICU stay and 15 without music intervention) and 15 full-term newborns underwent an MRI examination at term-equivalent age, comprising diffusion tensor imaging (DTI), used to evaluate white matter maturation using both region-of-interest and seed-based tractography approaches, as well as a T2-weighted image, used to perform amygdala volumetric analysis. Overall, WM microstructural maturity measured through DTI metrics was reduced in preterm infants receiving the standard-of-care in comparison to full-term newborns, whereas preterm infants exposed to the music intervention demonstrated significantly improved white matter maturation in acoustic radiations, external capsule/claustrum/extreme capsule and uncinate fasciculus, as well as larger amygdala volumes, in comparison to preterm infants with standard-of-care. These results suggest a structural maturational effect of the proposed music intervention on premature infants' auditory and emotional processing neural pathways during a key period of brain development.

Musical anhedonia and rewards of music listening: current advances and a proposed model

Music frequently elicits intense emotional responses, a phenomenon that has been scrutinized from multiple disciplines that span the sciences and arts. While most people enjoy music and find it rewarding, there is substantial individual variability in the experience and degree of music-induced reward. Here, we review current work on the neural substrates of hedonic responses to music. In particular, we focus the present review on specific musical anhedonia, a selective lack of pleasure from music. Based on evidence from neuroimaging, neuropsychology, and brain stimulation studies, we derive a neuroanatomical model of the experience of pleasure during music listening. Our model posits that hedonic responses to music are the result of connectivity between structures involved in auditory perception as a predictive process, and those involved in the brain's dopaminergic reward system. We conclude with open questions and implications of this model for future research on why humans appreciate music.

Neural architectures of music - Insights from acquired amusia

The ability to perceive and produce music is a quintessential element of human life, present in all known cultures. Modern functional neuroimaging has revealed that music listening activates a large-scale bilateral network of cortical and subcortical regions in the healthy brain. Even the most accurate structural studies do not reveal which brain areas are critical and causally linked to music processing. Such questions may be answered by analysing the effects of focal brain lesions in patients´ ability to perceive music. In this sense, acquired amusia after stroke provides a unique opportunity to investigate the neural architectures crucial for normal music processing. Based on the first large-scale longitudinal studies on stroke-induced amusia using modern multi-modal magnetic resonance imaging (MRI) techniques, such as advanced lesion-symptom mapping, grey and white matter morphometry, tractography and functional connectivity, we discuss neural structures critical for music processing, consider music processing in light of the dual-stream model in the right hemisphere, and propose a neural model for acquired amusia.

Insula stroke: the weird and the worrisome

Infarction of the insula is a common scenario with large tissue-volume strokes in the middle cerebral artery territory. Considered to be part of the central autonomic network, infarction of this region is associated with autonomic disturbances, in particular cardiovascular dysregulation. Risk of aspiration following stroke is also associated with involvement of the insula, consistent with its purported participation in complex functions of the mouth and pharynx. Strokes restricted to the insula are rare and present with a broad range of symptoms that offer a window of insight into the diverse functionality of the insular cortex. Chemosensory, autonomic, vestibular, auditory, somatosensory, language and oropharyngeal functional deficits are all recognised, among others. Long-term sequelae are unknown but profound symptoms, such as hemiparesis, are usually transient. Understanding the patterns of dysfunction highlighted provides the basis for future strategies to optimise stroke management on the discovery of insula involvement.

Not Cure But Heal: Music and Medicine

Do you know that our soul is composed of harmony? Leonardo Da Vinci Despite evidence for music-specific mechanisms at the level of pitch-pattern representations, the most fascinating aspect of music is its transmodality. Recent psychological and neuroscientific evidence suggest that music is unique in the coupling of perception, cognition, action and emotion. This potentially explains why music has been since time immemorial almost inextricably linked to healing processes and should continue to be.

The parietal opercular auditory-sensorimotor network in musicians: A resting-state fMRI study

Auditory-sensorimotor coupling is critical for musical performance, during which auditory and somatosensory feedback signals are used to ensure desired outputs. Previous studies reported opercular activation in subjects performing or listening to music. A functional connectivity analysis suggested the parietal operculum (PO) as a connector hub that links auditory, somatosensory, and motor cortical areas. We therefore examined whether this PO network differs between musicians and non-musicians. We analyzed resting-state PO functional connectivity with Heschl's gyrus (HG), the planum temporale (PT), the precentral gyrus (preCG), and the postcentral gyrus (postCG) in 35 musicians and 35 non-musicians. In musicians, the left PO exhibited increased functional connectivity with the ipsilateral HG, PT, preCG, and postCG, whereas the right PO exhibited enhanced functional connectivity with the contralateral HG, preCG, and postCG and the ipsilateral postCG. Direct functional connectivity between an auditory area (the HG or PT) and a sensorimotor area (the preCG or postCG) did not significantly differ between the groups. The PO's functional connectivity with auditory and sensorimotor areas is enhanced in musicians relative to non-musicians. We propose that the PO network facilitates musical performance by mediating multimodal integration for modulating auditory-sensorimotor control.

A case of musical anhedonia due to right putaminal hemorrhage: a disconnection syndrome between the auditory cortex and insula

A 63-year-old, right-handed professional chorus conductor developed right putaminal hemorrhage, and became unable to experience emotion while listening to music. Two years later, neurological examination revealed slight left hemiparesis. Neuromusicological assessments revealed impaired judgment of "musical sense," and the inability to discriminate the sound of chords in pure intervals from those in equal temperament. Brain MRI and tractography identified the old hemorrhagic lesion in the right putamen and impaired fiber connectivity between the right insula and superior temporal lobe. These findings suggest that musical anhedonia might be caused by a disconnection between the insula and auditory cortex.

Functional Connectivity of the Precuneus in Female University Students with Long-Term Musical Training

Conceiving concrete mental imagery is critical for skillful musical expression and performance. The precuneus, a core component of the default mode network (DMN), is a hub of mental image processing that participates in functions such as episodic memory retrieval and imagining future events. The precuneus connects with many brain regions in the frontal, parietal, temporal, and occipital cortices. The aim of this study was to examine the effects of long-term musical training on the resting-state functional connectivity of the precuneus. Our hypothesis was that the functional connectivity of the precuneus is altered in musicians. We analyzed the functional connectivity of the precuneus using resting-state functional magnetic resonance imaging (fMRI) data recorded in female university students majoring in music and nonmusic disciplines. The results show that the music students had higher functional connectivity of the precuneus with opercular/insular regions, which are associated with interoceptive and emotional processing; Heschl’s gyrus (HG) and the planum temporale (PT), which process complex tonal information; and the lateral occipital cortex (LOC), which processes visual information. Connectivity of the precuneus within the DMN did not differ between the two groups. Our finding suggests that functional connections between the precuneus and the regions outside of the DMN play an important role in musical performance. We propose that a neural network linking the precuneus with these regions contributes to translate mental imagery into information relevant to musical performance.