Perception and production of music
Encyclopedia
Perception and production of music is a relatively new area of neuroscience
investigating the neural mechanisms that underlie the musical processes in humans. It includes neuromotor mechanisms and auditory processing streams in the brain involved with the performance
of music
, especially those implicated in the regulation of timing
, pitch
, sequence, and rhythm
.
The cognitive process
of performing music requires the interaction of neural mechanisms in both motor and auditory systems. Since every action expressed in a performance produces a sound that influences subsequent expression, this leads to impressive sensorimotor interplay
models of auditory cortex. One current model is a hierarchical system in which several pathways emerge from the primary auditory cortex (A1), projecting towards different targets.
There is a ventrally projecting auditory stream from A1 within the neocortex and possibly a second stream projecting anteriorly along the superior temporal gyrus (STG). A distinct stream projects and follows a more dorsal/posterior course to reach a parietal target, but the functional differentiation of these pathways are unclear.
, though the dependence could be indirectly mediated by the presence of harmonic overtones corresponding to that fundamental frequency (despite the absence of the fundamental frequency itself). Neurons lateral to A1 in marmoset monkeys were found to be sensitive specifically to the fundamental frequency of a complex tone, suggesting that pitch constancy may be enabled by such a neural mechanism. Pitch constancy refers to the ability to perceive pitch identity across changes in acoustical properties, such as loudness, temporal envelope, or timbre
. The importance of cortical regions lateral to A1 for pitch coding is also supported by studies of human cortical lesions and functional magnetic resonance imaging (fMRI) of the brain. These data suggest a hierarchical system for pitch processing, with more abstract properties of sound stimulus processed further along the processing pathways.
Even in studies where subjects only listen to rhythms, the basal ganglia, cerebellum, dPMC and SMA are often implicated. The analysis of rhythm may depend on interactions between the auditory and motor systems.
.
These functions and their neural mechanisms have been investigated separately in many studies, but little is known about their combined interaction in producing a complex musical performance. The study of music requires examining them together.
or clock mechanism where time is represented through oscillations or pulses. An opposing view to this metronome mechanism has also been hypothesized stating that it is an emergent property of the kinematics of movement itself. Kinematics is defined as parameters of movement through space without reference to forces (for example, direction, velocity and acceleration).
Functional neuroimaging
studies, as well as studies of brain-damaged patients, have linked movement timing to several cortical and sub-cortical regions, including the cerebellum
, basal ganglia
and supplementary motor area
(SMA). Specifically the basal ganglia and possibly the SMA have been implicated in interval timing at longer timescales (1 second and above), while the cerebellum may be more important for controlling motor timing at shorter timescales (milliseconds). Furthermore, these results indicate that motor timing is not controlled by a single brain region, but by a network of regions that control specific parameters of movement and that depend on the relevant timescale of the rhythmic sequence.
The cerebellum is arguably important for sequence learning and for the integration of individual movements into unified sequences, while the pre-SMA and SMA have been shown to be involved in organizing or chunking of more complex movement sequences.
Chunking, defined as the re-organization or re-grouping of movement sequences into smaller sub-sequences during performance, is thought to facilitate the smooth performance of complex movements and to improve motor memory.
Lastly, the premotor cortex has been shown to be involved in tasks that require the production of relatively complex sequences, and it may contribute to motor prediction.
, sensory–motor and premotor cortices in the control of movements, when the integration of spatial, sensory and motor information is required. Few studies so far have explicitly examined the role of spatial processing in the context of musical tasks.
patients.
Feedback interactions are particularly relevant in playing an instrument such as a violin, or in singing, where pitch is variable and must be continuously controlled. If auditory feedback is blocked, musicians can still execute well-rehearsed pieces, but expressive aspects of performance are affected. When auditory feedback is experimentally manipulated by delays or distortions, motor performance is significantly altered: asynchronous feedback disrupts the timing of events, whereas alteration of pitch information disrupts the selection of appropriate actions, but not their timing. This suggests that disruptions occur because both actions and percepts depend on a single underlying mental representation.
system has an important role in neural models of sensory–motor integration. There is considerable evidence that neurons respond to both actions and the accumulated observation of actions. A system proposed to explain this understanding of actions is that visual representations of actions are mapped onto our own motor system.
Some mirror neurons are activated both by the observation of goal-directed actions, and by the associated sounds produced during the action. This suggests that the auditory modality can access the motor system. While these auditory–motor interactions have mainly been studied for speech processes, and have focused on Broca’s area and the vPMC, as of 2011, experiments have begun to shed light on how these interactions are needed for musical performance. Results point to a broader involvement of the dPMC and other motor areas.
Recruitment of the SMA and premotor areas is also reported when musicians are asked to imagine performing
Neuroscience
Neuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...
investigating the neural mechanisms that underlie the musical processes in humans. It includes neuromotor mechanisms and auditory processing streams in the brain involved with the performance
Performance
A performance, in performing arts, generally comprises an event in which a performer or group of performers behave in a particular way for another group of people, the audience. Choral music and ballet are examples. Usually the performers participate in rehearsals beforehand. Afterwards audience...
of music
Music
Music is an art form whose medium is sound and silence. Its common elements are pitch , rhythm , dynamics, and the sonic qualities of timbre and texture...
, especially those implicated in the regulation of timing
Timing
Timing is the time when something happens or the spacing of events in time. Some typical uses are:* The act of measuring the elapsed time of something or someone, often at athletic events such as swimming or running, where participants are timed with a device such as a stopwatch...
, pitch
Pitch
Pitch may refer to:* Pitch , a viscous substance produced by plants or formed from petroleum* Pitch * sales pitch** elevator pitch, a very short sales pitch such as that made during an elevator ride* Pitch accent-Music and acoustics:...
, sequence, and rhythm
Rhythm
Rhythm may be generally defined as a "movement marked by the regulated succession of strong and weak elements, or of opposite or different conditions." This general meaning of regular recurrence or pattern in time may be applied to a wide variety of cyclical natural phenomena having a periodicity or...
.
The cognitive process
Cognition
In science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...
of performing music requires the interaction of neural mechanisms in both motor and auditory systems. Since every action expressed in a performance produces a sound that influences subsequent expression, this leads to impressive sensorimotor interplay
Music perception: auditory processing streams
Considerable progress has been made in anatomicAnatomy
Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...
models of auditory cortex. One current model is a hierarchical system in which several pathways emerge from the primary auditory cortex (A1), projecting towards different targets.
There is a ventrally projecting auditory stream from A1 within the neocortex and possibly a second stream projecting anteriorly along the superior temporal gyrus (STG). A distinct stream projects and follows a more dorsal/posterior course to reach a parietal target, but the functional differentiation of these pathways are unclear.
Pitch
A feature of sound relevant for music is its musical pitch. Pitch has complex properties related to scales, and perceived pitch typically depends on the fundamental frequencyFundamental frequency
The fundamental frequency, often referred to simply as the fundamental and abbreviated f0, is defined as the lowest frequency of a periodic waveform. In terms of a superposition of sinusoids The fundamental frequency, often referred to simply as the fundamental and abbreviated f0, is defined as the...
, though the dependence could be indirectly mediated by the presence of harmonic overtones corresponding to that fundamental frequency (despite the absence of the fundamental frequency itself). Neurons lateral to A1 in marmoset monkeys were found to be sensitive specifically to the fundamental frequency of a complex tone, suggesting that pitch constancy may be enabled by such a neural mechanism. Pitch constancy refers to the ability to perceive pitch identity across changes in acoustical properties, such as loudness, temporal envelope, or timbre
Timbre
In music, timbre is the quality of a musical note or sound or tone that distinguishes different types of sound production, such as voices and musical instruments, such as string instruments, wind instruments, and percussion instruments. The physical characteristics of sound that determine the...
. The importance of cortical regions lateral to A1 for pitch coding is also supported by studies of human cortical lesions and functional magnetic resonance imaging (fMRI) of the brain. These data suggest a hierarchical system for pitch processing, with more abstract properties of sound stimulus processed further along the processing pathways.
Hemispheric asymmetries
Lateralization of cortical responses is an important aspect of tonal processing, with empirical data favoring a right-hemisphere advantage for tonal functions. An explanation for this hemispheric difference may be related to abstract knowledge domains, such as language. However, details of the stage of sound processing where such differences appear are poorly understood.Rhythm
Music also relies on rhythm. Behavioural studies demonstrate that rhythm and pitch can be perceived separately, but that they also interact in creating a musical perception. Studies of auditory rhythm discrimination and reproduction in patients with brain injury have linked these functions to the auditory regions of the temporal lobe, but have shown no consistent localization or lateralization. Neuropsychological and neuroimaging studies have shown that the motor regions of the brain contribute to both perception and production of rhythms.Even in studies where subjects only listen to rhythms, the basal ganglia, cerebellum, dPMC and SMA are often implicated. The analysis of rhythm may depend on interactions between the auditory and motor systems.
Music production: motor control systems
Musical performance usually involves at least three elementary motor control functions: timing, sequencing, and spatial organization of motor movements. Accuracy in timing of movements is related to musical rhythm. Rhythm, the pattern of temporal intervals within a musical measure or phrase, in turn creates the perception of stronger and weaker beats. Sequencing and spatial organization relate to the expression of individual notes on a musical instrumentMusical instrument
A musical instrument is a device created or adapted for the purpose of making musical sounds. In principle, any object that produces sound can serve as a musical instrument—it is through purpose that the object becomes a musical instrument. The history of musical instruments dates back to the...
.
These functions and their neural mechanisms have been investigated separately in many studies, but little is known about their combined interaction in producing a complex musical performance. The study of music requires examining them together.
Timing
Although neural mechanisms involved in timing movement have been studied rigorously over the past 20 years, much remains controversial. The ability to phrase movements in precise time has been accredited to a neural metronomeMetronome
A metronome is any device that produces regular, metrical ticks — settable in beats per minute. These ticks represent a fixed, regular aural pulse; some metronomes also include synchronized visual motion...
or clock mechanism where time is represented through oscillations or pulses. An opposing view to this metronome mechanism has also been hypothesized stating that it is an emergent property of the kinematics of movement itself. Kinematics is defined as parameters of movement through space without reference to forces (for example, direction, velocity and acceleration).
Functional neuroimaging
Functional neuroimaging
Functional neuroimaging is the use of neuroimaging technology to measure an aspect of brain function, often with a view to understanding the relationship between activity in certain brain areas and specific mental functions...
studies, as well as studies of brain-damaged patients, have linked movement timing to several cortical and sub-cortical regions, including the cerebellum
Cerebellum
The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
, basal ganglia
Basal ganglia
The basal ganglia are a group of nuclei of varied origin in the brains of vertebrates that act as a cohesive functional unit. They are situated at the base of the forebrain and are strongly connected with the cerebral cortex, thalamus and other brain areas...
and supplementary motor area
Supplementary motor area
The supplementary motor area is a part of the sensorimotor cerebral cortex . It was included, on purely cytoarchitectonic arguments, in area 6 of Brodmann and the Vogts...
(SMA). Specifically the basal ganglia and possibly the SMA have been implicated in interval timing at longer timescales (1 second and above), while the cerebellum may be more important for controlling motor timing at shorter timescales (milliseconds). Furthermore, these results indicate that motor timing is not controlled by a single brain region, but by a network of regions that control specific parameters of movement and that depend on the relevant timescale of the rhythmic sequence.
Sequencing
Motor sequencing has been explored in terms of either the ordering of individual movements, such as finger sequences for key presses, or the coordination of subcomponents of complex multi-joint movements. Implicated in this process are various cortical and sub-cortical regions, including the basal ganglia, the SMA and the pre-SMA, the cerebellum, and the premotor and prefrontal cortices, all involved in the production and learning of motor sequences but without explicit evidence of their specific contributions or interactions amongst one another. In animals, neurophysiological studies have demonstrated an interaction between the frontal cortex and the basal ganglia during the learning of movement sequences. Human neuroimaging studies have also emphasized the contribution of the basal ganglia for well-learned sequences.The cerebellum is arguably important for sequence learning and for the integration of individual movements into unified sequences, while the pre-SMA and SMA have been shown to be involved in organizing or chunking of more complex movement sequences.
Chunking, defined as the re-organization or re-grouping of movement sequences into smaller sub-sequences during performance, is thought to facilitate the smooth performance of complex movements and to improve motor memory.
Lastly, the premotor cortex has been shown to be involved in tasks that require the production of relatively complex sequences, and it may contribute to motor prediction.
Spatial organization
Few studies of complex motor control have distinguished between sequential and spatial organization, yet expert musical performances demand not only precise sequencing but also spatial organization of movements. Studies in animals and humans have established the involvement of parietalParietal lobe
The parietal lobe is a part of the Brain positioned above the occipital lobe and behind the frontal lobe.The parietal lobe integrates sensory information from different modalities, particularly determining spatial sense and navigation. For example, it comprises somatosensory cortex and the...
, sensory–motor and premotor cortices in the control of movements, when the integration of spatial, sensory and motor information is required. Few studies so far have explicitly examined the role of spatial processing in the context of musical tasks.
Music performance: auditory–motor interactions
There are a few interactions that may bridge the gap between auditory and motor processes.Feedforward and feedback interactions
An auditory–motor interaction may be loosely defined as any engagement of or communication between the two systems. Two classes of auditory-motor interaction are "feedforward" and "feedback". In feedforward interactions, it is the auditory system that predominately influences the motor output, often in a predictive way. An example is the phenomenon of tapping to the beat, where the listener anticipates the rhythmic accents in a piece of music. Another example is the effect of music on movement disorders: rhythmic auditory stimuli have been shown to improve walking ability in Parkinson’s disease and strokeStroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
patients.
Feedback interactions are particularly relevant in playing an instrument such as a violin, or in singing, where pitch is variable and must be continuously controlled. If auditory feedback is blocked, musicians can still execute well-rehearsed pieces, but expressive aspects of performance are affected. When auditory feedback is experimentally manipulated by delays or distortions, motor performance is significantly altered: asynchronous feedback disrupts the timing of events, whereas alteration of pitch information disrupts the selection of appropriate actions, but not their timing. This suggests that disruptions occur because both actions and percepts depend on a single underlying mental representation.
Models of auditory–motor interactions
Several models of auditory–motor interactions have been advanced. The model of Hickok and Poeppel, which is specific for speech processing, proposes that a ventral auditory stream maps sounds onto meaning, whereas a dorsal stream maps sounds onto articulatory representations. They and others suggest that posterior auditory regions at the parieto-temporal boundary are crucial parts of the auditory–motor interface, mapping auditory representations onto motor representations of speech, and onto melodies.Mirror/echo neurons and auditory–motor interactions
The mirror neuronMirror neuron
A mirror neuron is a neuron that fires both when an animal acts and when the animal observes the same action performed by another. Thus, the neuron "mirrors" the behaviour of the other, as though the observer were itself acting. Such neurons have been directly observed in primate and other...
system has an important role in neural models of sensory–motor integration. There is considerable evidence that neurons respond to both actions and the accumulated observation of actions. A system proposed to explain this understanding of actions is that visual representations of actions are mapped onto our own motor system.
Some mirror neurons are activated both by the observation of goal-directed actions, and by the associated sounds produced during the action. This suggests that the auditory modality can access the motor system. While these auditory–motor interactions have mainly been studied for speech processes, and have focused on Broca’s area and the vPMC, as of 2011, experiments have begun to shed light on how these interactions are needed for musical performance. Results point to a broader involvement of the dPMC and other motor areas.
Musical training
Although auditory–motor interactions can be observed in people without formal musical training, musicians are an excellent population to study because of their long-established and rich associations between auditory and motor systems. Musicians have been shown to have anatomical adaptations that correlate with their training. Some neuroimaging studies have observed that musicians show lower levels of activity in motor regions than non-musicians during the performance of simple motor tasks, which may suggest a more efficient pattern of neural recruitment.Motor imagery
Previous neuroimaging studies have consistently reported activity in the SMA and premotor areas, as well as in auditory cortices, when non-musicians imagine hearing musical excerpts.Recruitment of the SMA and premotor areas is also reported when musicians are asked to imagine performing
See also
- Cognitive neuroscience of musicCognitive neuroscience of musicThe cognitive neuroscience of music is the scientific study of brain-based mechanisms involved in the cognitive processes underlying music. Methods include functional magnetic resonance imaging , transcranial magnetic stimulation , magnetoencephalography , electroencephalography , and positron...
- Music and the brainMusic and the brainMusic and the brain is the science that studies the neural mechanisms that underlie musical behaviours in humans and animals. These behaviours include music listening, performing, composing, reading, writing, and ancillary activities. It also is increasingly concerned with the brain basis for...
- Cognitive musicologyCognitive musicologyCognitive musicology is a branch of Cognitive Science concerned with computationally modeling musical knowledge with the goal of understanding both music and cognition. More broadly, it can be considered the set of all phenomena surrounding computational modeling of musical thought and action...
- Music cognitionMusic cognitionMusic cognition is an interdisciplinary approach to understanding the mental processes that support musical behaviors, including perception, comprehension, memory, attention, and performance...
- Music psychologyMusic psychologyMusic psychology,or the psychology of music, may be regarded as a branch of psychology or a branch of musicology. It aims to explain and understand musical behavior and musical experience...
External links
- Rhythm Perception and Production, Tecumseh Fitch