**1. Introduction**

Going to concerts, listening to music in your living room, singing together or even playing an instrument is part of most people's everyday life. Recent research indicates that apart from just changing the current mood this may have long-lasting influences on the brain. This contribution, therefore, describes how music shapes the brain as the outcome of

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

interactions with the sounds. These interactions can be multifarious, as in the case of performing, listening or mentally imaging music, but they all show complex and widespread activity in many areas of the brain. This activity, moreover, is related to training, previous exposure, personal preference, emotional involvement and many other modulating factors related to the cultural background and biological repertoire of each individual [1–7]. Musical training, moreover, is related to structural changes within auditory and motor areas of the brain and reinforces functional coupling of these regions during musical tasks as evidenced by many neuroimaging studies [8–10]. These changes have been observed also in white-matter tracts, such as the corpus callosum, the corticospinal tract and the arcuate fasciculus [11–13]. Studies (particularly those with a longitudinal design) showing the causal relation between the brain changes and the duration of musical training have convinced some researchers to consider musical training as a model for investigating practice-related brain plasticity in humans [14].

Music is a powerful stimulator of the brain. Acoustically, it consists of time-varying sound events that are characterised by a large number of features—more than hundred features can be computationally extracted that are tracked by several regions of the brain [15]. Many low-level features, such as timbre and pitch, are partly processed in Heschl's gyrus and the right anterior part of the superior temporal gyrus, in which the primary and non-primary auditory cortices are located [16, 17]. Besides auditory cortices, also motor regions, such as the supplementary motor area and the cerebellum, are involved during musical activities, including both playing and listening. Due to audio-motor coupling that is necessary for playing an instrument, listening is influenced by the motor demands intrinsic to musical practice, even to the extent that this would become manifest also in the brain responses to music listening alone [18, 19]. Moreover, practising and performing music is a complex, multimodal behaviour that requires extensive motor and cognitive abilities. It relies on immediate and accurate associations between motor sequences and auditory events leading to multimodal predictions [10, 20, 21], which engage broad networks of the brain [16, 22, 23]. Music training has thus been associated with changes in the brain, and some of these changes have been causally linked to the duration of the training, which makes the musician's brain a most interesting model for the study of neuroplasticity [9, 24]. This holds in particular for performing musicians, who provide a unique pool of subjects for investigating both the features of the expert brain and, when considering the length of the training, also the neural correlates of skill acquisition. Musicians' training and practice require the simultaneous integration of multimodal sensory and motor information in sensory and cognitive domains, combining skills in auditory perception, kinaesthetic control, visual perception and pattern recognition [25, 26]. In addition, musicians have the ability to memorise long and complex bimanual finger sequences and to translate musical symbols into motor sequences (see **Figure 1**). Some musicians are even able to perceive and identify tones in the absence of a reference tone, a rare ability termed absolute pitch [27, 28].

for an overview). While some of these changes might be what characterise individuals that decide to undertake a musical profession, and hence might exist at birth, others could be a direct result of training, as suggested by the significant relations between years of training and brain measures (e.g., [36]), as well as by longitudinal designs recording brain responses

**Figure 1.** Illustration of several perceptual, motor, interoceptive and emotional skills that are acquired during musical

Music and Brain Plasticity: How Sounds Trigger Neurogenerative Adaptations

http://dx.doi.org/10.5772/intechopen.74318

87

Here, we propose that the differences observed between the brains of musicians and non-musicians can be attributed to neuroplastic adaptations responding to the challenging demands of musical practice. Alternative explanations are also possible, such as that the differences exist even before training in those individuals that choose music as their profession, but accumulating evidence points at a causal relation between music training and brain changes. The behavioural correlates of these differences are multiple and can be seen especially in childhood (e.g., [38]). Besides, it has been shown that music may be beneficial in relation to a number of symptoms in several kinds of impairment, such as epilepsy, Alzheimer's disease, Parkinson's disease and senile dementia (see [39] for an overview). Hence, it is possible to

In this contribution, we first expose the concept of adaptation, both from the phylogenetic and ontogenetic points of view. We then narrow down this concept by putting forward the hypothesis of music-induced neuroplasticity, with a first distinction between macrostructural and microstructural adaptations. Thereafter, we consider the reorganisation of the brain as the outcome of learning and skill acquisition, both at a structural and functional level of description with a major focus on the adult musician or listener as a model for the interaction between ontogeny and phylogeny. This latter, further, is considered from the point of view of network science with a major focus on the role of resting-state networks. Clinical and thera-

conceive of dealing with music in educational, clinical and therapeutic terms.

before and after music training (e.g., [29, 37]).

training.

peutic applications, finally, are envisioned also.

The brain changes that musical training entails are numerous and well-documented [2, 3, 5, 9, 24, 26–34]: they involve brain regions important for auditory processing, coordination of fast movements and cognitive control, as well as sensory-to-motor coupling mechanisms (see [35], Music and Brain Plasticity: How Sounds Trigger Neurogenerative Adaptations http://dx.doi.org/10.5772/intechopen.74318 87

interactions with the sounds. These interactions can be multifarious, as in the case of performing, listening or mentally imaging music, but they all show complex and widespread activity in many areas of the brain. This activity, moreover, is related to training, previous exposure, personal preference, emotional involvement and many other modulating factors related to the cultural background and biological repertoire of each individual [1–7]. Musical training, moreover, is related to structural changes within auditory and motor areas of the brain and reinforces functional coupling of these regions during musical tasks as evidenced by many neuroimaging studies [8–10]. These changes have been observed also in white-matter tracts, such as the corpus callosum, the corticospinal tract and the arcuate fasciculus [11–13]. Studies (particularly those with a longitudinal design) showing the causal relation between the brain changes and the duration of musical training have convinced some researchers to consider musical training as a model for investigating

Music is a powerful stimulator of the brain. Acoustically, it consists of time-varying sound events that are characterised by a large number of features—more than hundred features can be computationally extracted that are tracked by several regions of the brain [15]. Many low-level features, such as timbre and pitch, are partly processed in Heschl's gyrus and the right anterior part of the superior temporal gyrus, in which the primary and non-primary auditory cortices are located [16, 17]. Besides auditory cortices, also motor regions, such as the supplementary motor area and the cerebellum, are involved during musical activities, including both playing and listening. Due to audio-motor coupling that is necessary for playing an instrument, listening is influenced by the motor demands intrinsic to musical practice, even to the extent that this would become manifest also in the brain responses to music listening alone [18, 19]. Moreover, practising and performing music is a complex, multimodal behaviour that requires extensive motor and cognitive abilities. It relies on immediate and accurate associations between motor sequences and auditory events leading to multimodal predictions [10, 20, 21], which engage broad networks of the brain [16, 22, 23]. Music training has thus been associated with changes in the brain, and some of these changes have been causally linked to the duration of the training, which makes the musician's brain a most interesting model for the study of neuroplasticity [9, 24]. This holds in particular for performing musicians, who provide a unique pool of subjects for investigating both the features of the expert brain and, when considering the length of the training, also the neural correlates of skill acquisition. Musicians' training and practice require the simultaneous integration of multimodal sensory and motor information in sensory and cognitive domains, combining skills in auditory perception, kinaesthetic control, visual perception and pattern recognition [25, 26]. In addition, musicians have the ability to memorise long and complex bimanual finger sequences and to translate musical symbols into motor sequences (see **Figure 1**). Some musicians are even able to perceive and identify tones in the absence of a reference tone, a rare ability termed absolute

The brain changes that musical training entails are numerous and well-documented [2, 3, 5, 9, 24, 26–34]: they involve brain regions important for auditory processing, coordination of fast movements and cognitive control, as well as sensory-to-motor coupling mechanisms (see [35],

practice-related brain plasticity in humans [14].

86 Neuroplasticity - Insights of Neural Reorganization

pitch [27, 28].

**Figure 1.** Illustration of several perceptual, motor, interoceptive and emotional skills that are acquired during musical training.

for an overview). While some of these changes might be what characterise individuals that decide to undertake a musical profession, and hence might exist at birth, others could be a direct result of training, as suggested by the significant relations between years of training and brain measures (e.g., [36]), as well as by longitudinal designs recording brain responses before and after music training (e.g., [29, 37]).

Here, we propose that the differences observed between the brains of musicians and non-musicians can be attributed to neuroplastic adaptations responding to the challenging demands of musical practice. Alternative explanations are also possible, such as that the differences exist even before training in those individuals that choose music as their profession, but accumulating evidence points at a causal relation between music training and brain changes. The behavioural correlates of these differences are multiple and can be seen especially in childhood (e.g., [38]). Besides, it has been shown that music may be beneficial in relation to a number of symptoms in several kinds of impairment, such as epilepsy, Alzheimer's disease, Parkinson's disease and senile dementia (see [39] for an overview). Hence, it is possible to conceive of dealing with music in educational, clinical and therapeutic terms.

In this contribution, we first expose the concept of adaptation, both from the phylogenetic and ontogenetic points of view. We then narrow down this concept by putting forward the hypothesis of music-induced neuroplasticity, with a first distinction between macrostructural and microstructural adaptations. Thereafter, we consider the reorganisation of the brain as the outcome of learning and skill acquisition, both at a structural and functional level of description with a major focus on the adult musician or listener as a model for the interaction between ontogeny and phylogeny. This latter, further, is considered from the point of view of network science with a major focus on the role of resting-state networks. Clinical and therapeutic applications, finally, are envisioned also.
