Musical Disorders

Nearly everyone is exposed to music on a daily basis and the human brain is equipped with the necessary neural architecture to naturally acquire musical abilities during early development. Despite the universality of music, a minority of individuals present with very specific musical deficits that cannot be attributed to a general auditory dysfunction, intellectual disability, or a lack of musical exposure. These musical deficiencies can either be present from birth (congenital amusia, beat finding disorder) or acquired following a neurological event (acquired amusia). The purpose of the present chapter is to provide an overview of these intriguing musical disorders, highlight their common and different underlying features, and to demonstrate how they represent a unique opportunity to study brain function and to isolate brain areas that play a specific role in musical processing.

Neurologic Music Therapy in Sensorimotor Rehabilitation

Since the 1990s, a strong body of research evidence has set the foundation for the use of rhythm and music as important tools in the development, rehabilitation, and maintenance of sensorimotor function, particularly in the treatment of neurologic disorders. This chapter examines the connection between music and sensorimotor function, and the underlying neurological principles and mechanisms behind music perception, production, and cognition as they relate to motor function. The role of neurologic music therapy to facilitate functional movement is discussed with a variety of populations and movement disorders including: Parkinson’s disease, stroke, traumatic brain injury, multiple sclerosis, cerebral palsy, autism and healthy elderly. The chapter is divided into sections related to acquired movement disorders, degenerative diseases, and developmental disorders.

Neural Basis of Music Perception: Melody, Harmony, and Timbre

During listening, acoustic features of sounds are extracted in the auditory system (in the auditory brainstem, thalamus, and auditory cortex). To establish auditory percepts of melodies and rhythms (i.e., to establish auditory “Gestalten” and auditory objects), sound information is buffered and processed in the auditory sensory memory. Musical structure is then processed based on acoustical similarities and rhythmical organization. In addition, musical structure is processed according to (implicit) knowledge about musical regularities underlying scales, melodic and harmonic progressions, and so on. These structures are based on both local and (hierarchically organized) nonlocal dependencies. This chapter reviews neural correlates of these processes, with regard to both brain-electric responses to sounds, and the neuroanatomical architecture of music perception.

Musical Expertise and Brain Structure: The Causes and Consequences of Training

Brain imaging studies have demonstrated that music training can change brain structure, predominantly in the auditor-motor network that underlies music performance. The chapter argues that the observed differences in brain structure between experts and novices, and the changes that occur with training derive from at least four sources: first, pre-existing individual differences that promote certain skills; second, lengthy and consistent training which likely produces structural changes in the brain networks tapped by performance; third, practice during specific periods of development which may result in changes that do not occur at other periods of time; fourth, the rewarding nature of music itself, as well as the reward value of practice which may make music training a particularly effective driver of brain plasticity.

The Neuroscientific Study of Music: A Burgeoning Discipline

Numerous pioneers laid the groundwork for current neuromusical research. Beginning with Franz Joseph Gall in the eighteenth century, and continuing with John Hughlings Jackson, August Knoblauch, Richard Wallaschek, and others, these early forerunners were interested in localizing musicality in the brain and learning more about how music is processed in both healthy individuals and those with dysfunctions of various kinds. Since then, research literature has mushroomed, especially in the latter part of the twentieth and early twenty-first centuries. The current volume features the work of fifty-four authors who have contributed over 350,000 words in thirty-three chapters. These chapters are organized into sections on music, the brain, and cultural contexts; music processing in the human brain; neural responses to music; musicianship and brain function; developmental issues in music and the brain; music, the brain, and health; and the future.

Music and Memory

Music is encoded and stored in different memory systems. These memory systems overlap with “classical” non-musical memory systems to a large extent. However, there are also some specific features that are associated with music memory. This chapter describes the memory processes and their neural underpinnings which are involved during music listening and remembering of music. One specific feature of music memory is that music encoding, storing, and retrieval are associated with neurophysiological activations controlled by a widely distributed network, indicating that lots of information is activated by the musical content. This distributed network activation could be the key to understanding the often reported and suggested beneficial influences of music on non-music memory information.

Neural Correlates of Music and Emotion

This chapter presents a theoretical and empirical review of studies of the neural correlates of emotional responses to music. First, it outlines basic definitions and distinctions of the field of music and affect. Second, it describes an extensive theoretical framework that may serve to organize the domain. Third, the authors review seventy-eight empirical studies (e.g., PET/fMRI, EEG, lesion studies) conducted between 1982 and 2016. They distinguish different empirical approaches to music and emotion in brain research and draw some general conclusions based on the results so far. The review reveals that some brain areas have been more or less consistently reported across studies, with partly distinct patterns for perception and induction of emotions, but that we still do not know what role each brain region plays in the emotion process. This is largely due to a lack of studies that attempt to manipulate underlying psychological mechanisms in a systematic manner. The chapter concludes by discussing the implications of the results and by making methodological recommendations for future research.

New Horizons for Brain Research in Music

This final chapter of The Oxford Handbook of Music and Neuroscience tries to appraise potential new horizons for future brain-based research in music, including new trajectories in the neuroscience of music perception and production, clinical applications, music learning, musician health, and intersections of biology, culture, and aesthetics. The study of music as a science and an object of scientific inquiry has actually a long and rich history in human culture and the more prevalent belief that music should, as one of its primary functions, express and induce emotions, is a relatively recent one—firmly implanted only since the early nineteenth-century Romantic period (Berlyne, 1971). The evidence presented in the previous chapters has provided a comprehensive basis to shape a future architecture of basic and applied neuroscience research in music, whose outlines are sketched out here. Therefore, as a draft for future possibilities, this chapter contains few new references. The references for this chapter are the previous chapters.

Neural Mechanisms of Musical Imagery

Findings regarding the neural mechanisms of musical imagery are summarized, and both auditory and motor components of musical imagery are considered. Similarities of musical imagery and music perception (involving results from studies using behavioral and psychophysical methods, clinical data from brain-damaged patients, electrophysiology, and brain imaging), examples of involuntary musical imagery (involving anticipatory musical imagery, musical hallucinations, schizophrenia, earworms, and synesthesia), and aspects of embodied aspects of musical imagery (involving spatial and force metaphors, mimicry, the inner ear/inner voice distinction, effects of mental practice and performance, dance and other motor acts, and musical affect) are considered. It is concluded that many neural mechanisms involved in musical imagery are similar to neural mechanisms involved in music perception, cognition, and production. The importance of motor activation to musical imagery is highlighted, and the importance of an embodied approach to musical imagery is discussed.

Neural Basis of Rhythm Perception

To understand and enjoy music, it is important to be able to hear the beat and move your body to the rhythm. However, impaired rhythm processing has a broader impact on perception and cognition beyond music-specific tasks. We also experience rhythms in our everyday interactions, through the lip and jaw movements of watching someone speak, the syllabic structure of words on the radio, and in the movements of our limbs when we walk. Impairments in the ability to perceive and produce rhythms are related to poor language outcomes, such as dyslexia, and they can provide an index of a primary symptom in movement disorders, such as Parkinson’s disease. The chapter summarizes a growing body of literature examining the neural underpinnings of rhythm perception and production. It highlights the importance of auditory-motor relationships in finding and producing a beat in music by reviewing evidence from a number of methodologies. These approaches illustrate how rhythmic auditory information capitalizes on auditory-motor interactions to influence motor excitability, and how beat perception emerges as a function of nonlinear oscillatory dynamics of the brain. Together these studies highlight the important role of rhythm in human development, evolutionary comparisons, multi-modal perception, mirror neurons, language processing, and music.