Action representation of sound: audiomotor recognition network while listening to newly acquired actions

Inter-individual differences in audio-motor learning of piano melodies and white matter fiber tract architecture

Humans vary substantially in their ability to learn new motor skills. Here, we examined inter-individual differences in learning to play the piano, with the goal of identifying relations to structural properties of white matter fiber tracts relevant to audio-motor learning. Non-musicians (n = 18) learned to perform three short melodies on a piano keyboard in a pure audio-motor training condition (vision of their own fingers was occluded). Initial learning times ranged from 17 to 120 min (mean ± SD: 62 ± 29 min). Diffusion-weighted magnetic resonance imaging was used to derive the fractional anisotropy (FA), an index of white matter microstructural arrangement. A correlation analysis revealed that higher FA values were associated with faster learning of piano melodies. These effects were observed in the bilateral corticospinal tracts, bundles of axons relevant for the execution of voluntary movements, and the right superior longitudinal fasciculus, a tract important for audio-motor transformations. These results suggest that the speed with which novel complex audio-motor skills can be acquired may be determined by variability in structural properties of white matter fiber tracts connecting brain areas functionally relevant for audio-motor learning.

Action-perception coupling in violinists

The current study investigates auditory-motor coupling in musically trained participants using a Stroop-type task that required the execution of simple finger sequences according to aurally presented number sequences (e.g., "2," "4," "5," "3," "1"). Digital remastering was used to manipulate the pitch contour of the number sequences such that they were either congruent or incongruent with respect to the resulting action sequence. Conservatoire-level violinists showed a strong effect of congruency manipulation (increased response time for incongruent vs. congruent trials), in comparison to a control group of non-musicians. In Experiment 2, this paradigm was used to determine whether pedagogical background would influence this effect in a group of young violinists. Suzuki trained violinists differed significantly from those with no musical background, while traditionally trained violinists did not. The findings extend previous research in this area by demonstrating that obligatory audio-motor coupling is directly related to a musicians' expertise on their instrument of study and is influenced by pedagogy.

Flexibility of movement organization in piano performance

Piano performance involves a large repertoire of highly skilled movements. The acquisition of these exceptional skills despite innate neural and biomechanical constraints requires a sophisticated interaction between plasticity of the neural system and organization of a redundant number of degrees of freedom (DOF) in the motor system. Neuroplasticity subserving virtuosity of pianists has been documented in neuroimaging studies investigating effects of long-term piano training on structure and function of the cortical and subcortical regions. By contrast, recent behavioral studies have advanced the understanding of neuromuscular strategies and biomechanical principles behind the movement organization that enables skilled piano performance. Here we review the motor control and biomechanics literature, introducing the importance of describing motor behaviors not only for understanding mechanisms responsible for skillful motor actions in piano playing, but also for advancing diagnosis and rehabilitation of movement disorders caused by extensive piano practice.

Monitoring Individual and Joint Action Outcomes in Duet Music Performance

We investigated whether people monitor the outcomes of their own and their partners' individual actions as well as the outcome of their combined actions when performing joint actions together. Pairs of pianists memorized both parts of a piano duet. Each pianist then performed one part while their partner performed the other; EEG was recorded from both. Auditory outcomes (pitches) associated with keystrokes produced by the pianists were occasionally altered in a way that either did or did not affect the joint auditory outcome (i.e., the harmony of a chord produced by the two pianists' combined pitches). Altered auditory outcomes elicited a feedback-related negativity whether they occurred in the pianist's own part or the partner's part, and whether they affected individual or joint action outcomes. Altered auditory outcomes also elicited a P300 whose amplitude was larger when the alteration affected the joint outcome compared with individual outcomes and when the alteration affected the pianist's own part compared with the partner's part. Thus, musicians engaged in joint actions monitor their own and their partner's actions as well as their combined action outcomes, while at the same time maintaining a distinction between their own and others' actions and between individual and joint outcomes.

Knowing too little or too much: the effects of familiarity with a co-performer's part on interpersonal coordination in musical ensembles

Expert ensemble musicians produce exquisitely coordinated sounds, but rehearsal is typically required to do so. Ensemble coordination may thus be influenced by the degree to which individuals are familiar with each other's parts. Such familiarity may affect the ability to predict and synchronize with co-performers' actions. Internal models related to action simulation and anticipatory musical imagery may be affected by knowledge of (1) the musical structure of a co-performer's part (e.g., in terms of its rhythm and phrase structure) and/or (2) the co-performer's idiosyncratic playing style (e.g., expressive micro-timing variations). The current study investigated the effects of familiarity on interpersonal coordination in piano duos. Skilled pianists were required to play several duets with different partners. One condition included duets for which co-performers had previously practiced both parts, while another condition included duets for which each performer had practiced only their own part. Each piece was recorded six times without joint rehearsal or visual contact to examine the effects of increasing familiarity. Interpersonal coordination was quantified by measuring asynchronies between pianists' keystroke timing and the correlation of their body (head and torso) movements, which were recorded with a motion capture system. The results suggest that familiarity with a co-performer's part, in the absence of familiarity with their playing style, engenders predictions about micro-timing variations that are based instead upon one's own playing style, leading to a mismatch between predictions and actual events at short timescales. Predictions at longer timescales—that is, those related to musical measures and phrases, and reflected in head movements and body sway—are, however, facilitated by familiarity with the structure of a co-performer's part. These findings point to a dissociation between interpersonal coordination at the level of keystrokes and body movements.

Rhythmic and melodic deviations in musical sequences recruit different cortical areas for mismatch detection

The mismatch negativity (MMN), an event-related potential (ERP) representing the violation of an acoustic regularity, is considered as a pre-attentive change detection mechanism at the sensory level on the one hand and as a prediction error signal on the other hand, suggesting that bottom-up as well as top-down processes are involved in its generation. Rhythmic and melodic deviations within a musical sequence elicit a MMN in musically trained subjects, indicating that acquired musical expertise leads to better discrimination accuracy of musical material and better predictions about upcoming musical events. Expectation violations to musical material could therefore recruit neural generators that reflect top-down processes that are based on musical knowledge. We describe the neural generators of the musical MMN for rhythmic and melodic material after a short-term sensorimotor-auditory (SA) training. We compare the localization of musical MMN data from two previous MEG studies by applying beamformer analysis. One study focused on the melodic harmonic progression whereas the other study focused on rhythmic progression. The MMN to melodic deviations revealed significant right hemispheric neural activation in the superior temporal gyrus (STG), inferior frontal cortex (IFC), and the superior frontal (SFG) and orbitofrontal (OFG) gyri. IFC and SFG activation was also observed in the left hemisphere. In contrast, beamformer analysis of the data from the rhythm study revealed bilateral activation within the vicinity of auditory cortices and in the inferior parietal lobule (IPL), an area that has recently been implied in temporal processing. We conclude that different cortical networks are activated in the analysis of the temporal and the melodic content of musical material, and discuss these networks in the context of the dual-pathway model of auditory processing.

Musical expertise and second language learning

Increasing evidence suggests that musical expertise influences brain organization and brain functions. Moreover, results at the behavioral and neurophysiological levels reveal that musical expertise positively influences several aspects of speech processing, from auditory perception to speech production. In this review, we focus on the main results of the literature that led to the idea that musical expertise may benefit second language acquisition. We discuss several interpretations that may account for the influence of musical expertise on speech processing in native and foreign languages, and we propose new directions for future research.

Uni- and multisensory brain areas are synchronised across spectators when watching unedited dance recordings

The superior temporal sulcus (STS) and gyrus (STG) are commonly identified to be functionally relevant for multisensory integration of audiovisual (AV) stimuli. However, most neuroimaging studies on AV integration used stimuli of short duration in explicit evaluative tasks. Importantly though, many of our AV experiences are of a long duration and ambiguous. It is unclear if the enhanced activity in audio, visual, and AV brain areas would also be synchronised over time across subjects when they are exposed to such multisensory stimuli. We used intersubject correlation to investigate which brain areas are synchronised across novices for uni- and multisensory versions of a 6-min 26-s recording of an unfamiliar, unedited Indian dance recording (Bharatanatyam). In Bharatanatyam, music and dance are choreographed together in a highly intermodal-dependent manner. Activity in the middle and posterior STG was significantly correlated between subjects and showed also significant enhancement for AV integration when the functional magnetic resonance signals were contrasted against each other using a general linear model conjunction analysis. These results extend previous studies by showing an intermediate step of synchronisation for novices: while there was a consensus across subjects' brain activity in areas relevant for unisensory processing and AV integration of related audio and visual stimuli, we found no evidence for synchronisation of higher level cognitive processes, suggesting these were idiosyncratic.

The neural control of singing

Singing provides a unique opportunity to examine music performance—the musical instrument is contained wholly within the body, thus eliminating the need for creating artificial instruments or tasks in neuroimaging experiments. Here, more than two decades of voice and singing research will be reviewed to give an overview of the sensory-motor control of the singing voice, starting from the vocal tract and leading up to the brain regions involved in singing. Additionally, to demonstrate how sensory feedback is integrated with vocal motor control, recent functional magnetic resonance imaging (fMRI) research on somatosensory and auditory feedback processing during singing will be presented. The relationship between the brain and singing behavior will be explored also by examining: (1) neuroplasticity as a function of various lengths and types of training, (2) vocal amusia due to a compromised singing network, and (3) singing performance in individuals with congenital amusia. Finally, the auditory-motor control network for singing will be considered alongside dual-stream models of auditory processing in music and speech to refine both these theoretical models and the singing network itself.

Motor simulation and the coordination of self and other in real-time joint action

Joint actions require the integration of simultaneous self- and other-related behaviour. Here, we investigated whether this function is underpinned by motor simulation, that is the capacity to represent a perceived action in terms of the neural resources required to execute it. This was tested in a music performance experiment wherein on-line brain stimulation (double-pulse transcranial magnetic stimulation, dTMS) was employed to interfere with motor simulation. Pianists played the right-hand part of piano pieces in synchrony with a recording of the left-hand part, which had (Trained) or had not (Untrained) been practiced beforehand. Training was assumed to enhance motor simulation. The task required adaptation to tempo changes in the left-hand part that, in critical conditions, were preceded by dTMS delivered over the right primary motor cortex. Accuracy of tempo adaptation following dTMS or sham stimulations was compared across Trained and Untrained conditions. Results indicate that dTMS impaired tempo adaptation accuracy only during the perception of trained actions. The magnitude of this interference was greater in empathic individuals possessing a strong tendency to adopt others' perspectives. These findings suggest that motor simulation provides a functional resource for the temporal coordination of one's own behaviour with others in dynamic social contexts.

Toward a neural chronometry for the aesthetic experience of music

Music is often studied as a cognitive domain alongside language. The emotional aspects of music have also been shown to be important, but views on their nature diverge. For instance, the specific emotions that music induces and how they relate to emotional expression are still under debate. Here we propose a mental and neural chronometry of the aesthetic experience of music initiated and mediated by external and internal contexts such as intentionality, background mood, attention, and expertise. The initial stages necessary for an aesthetic experience of music are feature analysis, integration across modalities, and cognitive processing on the basis of long-term knowledge. These stages are common to individuals belonging to the same musical culture. The initial emotional reactions to music include the startle reflex, core "liking," and arousal. Subsequently, discrete emotions are perceived and induced. Presumably somatomotor processes synchronizing the body with the music also come into play here. The subsequent stages, in which cognitive, affective, and decisional processes intermingle, require controlled cross-modal neural processes to result in aesthetic emotions, aesthetic judgments, and conscious liking. These latter aesthetic stages often require attention, intentionality, and expertise for their full actualization.

Hippocampal volume predicts fluid intelligence in musically trained people

Recently, age-related hippocampal (HP) volume loss could be associated with a decrease in general fluid intelligence (gF). In the present study we investigated whether and how extensive musical training modulates human HP volume and gF performance. Previously, some studies demonstrated positive effects of musical training on higher cognitive functions such as learning and memory, associated with neural adaptations beyond the auditory domain. In order to detect possible associations between musical training and gF, we bilaterally segmented the HP formation and assessed the individual gF performance of people with different levels of musical expertise. Multiple regression analyses revealed that HP volume predicts gF in musicians but not in nonmusicians; in particular, bilaterally enhanced HP volume is associated with increased gF exclusively in musically trained people (amateurs and experts). This result suggests that musical training facilitates the recruitment of cognitive resources, which are essential for gF and linked to HP functioning. Musical training, even at a moderate level of intensity, can thus be considered as a potential strategy to decelerate age-related effects of cognitive decline.

Motor development and motor resonance difficulties in autism: relevance to early intervention for language and communication skills

Research suggests that a sub-set of children with autism experience notable difficulties and delays in motor skills development, and that a large percentage of children with autism experience deficits in motor resonance. These motor-related deficiencies, which evidence suggests are present from a very early age, are likely to negatively affect social-communicative and language development in this population. Here, we review evidence for delayed, impaired, and atypical motor development in infants and children with autism. We then carefully review and examine the current language and communication-based intervention research that is relevant to motor and motor resonance (i.e., neural "mirroring" mechanisms activated when we observe the actions of others) deficits in children with autism. Finally, we describe research needs and future directions and developments for early interventions aimed at addressing the speech/language and social-communication development difficulties in autism from a motor-related perspective.

A beamformer analysis of MEG data reveals frontal generators of the musically elicited mismatch negativity

To localize the neural generators of the musically elicited mismatch negativity with high temporal resolution we conducted a beamformer analysis (Synthetic Aperture Magnetometry, SAM) on magnetoencephalography (MEG) data from a previous musical mismatch study. The stimuli consisted of a six-tone melodic sequence comprising broken chords in C- and G-major. The musical sequence was presented within an oddball paradigm in which the last tone was lowered occasionally (20%) by a minor third. The beamforming analysis revealed significant right hemispheric neural activation in the superior temporal (STC), inferior frontal (IFC), superior frontal (SFC) and orbitofrontal (OFC) cortices within a time window of 100-200 ms after the occurrence of a deviant tone. IFC and SFC activation was also observed in the left hemisphere. The pronounced early right inferior frontal activation of the auditory mismatch negativity has not been shown in MEG studies so far. The activation in STC and IFC is consistent with earlier electroencephalography (EEG), optical imaging and functional magnetic resonance imaging (fMRI) studies that reveal the auditory and inferior frontal cortices as main generators of the auditory MMN. The observed right hemispheric IFC is also in line with some previous music studies showing similar activation patterns after harmonic syntactic violations. The results demonstrate that a deviant tone within a musical sequence recruits immediately a distributed neural network in frontal and prefrontal areas suggesting that top-down processes are involved when expectation violation occurs within well-known stimuli.

A review of "music and movement" therapies for children with autism: embodied interventions for multisystem development

The rising incidence of Autism Spectrum Disorders (ASDs) has led to a surge in the number of children needing autism interventions. This paper is a call to clinicians to diversify autism interventions and to promote the use of embodied music-based approaches to facilitate multisystem development. Approximately 12% of all autism interventions and 45% of all alternative treatment strategies in schools involve music-based activities. Musical training impacts various forms of development including communication, social-emotional, and motor development in children with ASDs and other developmental disorders as well as typically developing children. In this review, we will highlight the multisystem impairments of ASDs, explain why music and movement therapies are a powerful clinical tool, as well as describe mechanisms and offer evidence in support of music therapies for children with ASDs. We will support our claims by reviewing results from brain imaging studies reporting on music therapy effects in children with autism. We will also discuss the critical elements and the different types of music therapy approaches commonly used in pediatric neurological populations including autism. We provide strong arguments for the use of music and movement interventions as a multisystem treatment tool for children with ASDs. Finally, we also make recommendations for assessment and treatment of children with ASDs, and provide directions for future research.

Rhythm, movement, and autism: using rhythmic rehabilitation research as a model for autism

Recently, there has been increased focus on movement and sensory abnormalities in autism spectrum disorders (ASD). This has come from research demonstrating cortical and cerebellar differences in autism, with suggestion of early cerebellar dysfunction. As evidence for an extended profile of ASD grows, there are vast implications for treatment and therapy for individuals with autism. Persons with autism are often provided behavioral or cognitive strategies for navigating their environment; however, these strategies do not consider differences in motor functioning. One accommodation that has not yet been explored in the literature is the use of auditory rhythmic cueing to improve motor functioning in ASD. The purpose of this paper is to illustrate the potential impact of auditory rhythmic cueing for motor functioning in persons with ASD. To this effect, we review research on rhythm in motor rehabilitation, draw parallels to motor dysfunction in ASD, and propose a rationale for how rhythmic input can improve sensorimotor functioning, thereby allowing individuals with autism to demonstrate their full cognitive, behavioral, social, and communicative potential.

Interacting Cortical and Basal Ganglia Networks Underlying Finding and Tapping to the Musical Beat

Humans are able to find and tap to the beat of musical rhythms varying in complexity from children's songs to modern jazz. Musical beat has no one-to-one relationship with auditory features—it is an abstract perceptual representation that emerges from the interaction between sensory cues and higher-level cognitive organization. Previous investigations have examined the neural basis of beat processing but have not tested the core phenomenon of finding and tapping to the musical beat. To test this, we used fMRI and had musicians find and tap to the beat of rhythms that varied from metrically simple to metrically complex—thus from a strong to a weak beat. Unlike most previous studies, we measured beat tapping performance during scanning and controlled for possible effects of scanner noise on beat perception. Results showed that beat finding and tapping recruited largely overlapping brain regions, including the superior temporal gyrus (STG), premotor cortex, and ventrolateral PFC (VLPFC). Beat tapping activity in STG and VLPFC was correlated with both perception and performance, suggesting that they are important for retrieving, selecting, and maintaining the musical beat. In contrast BG activity was similar in all conditions and was not correlated with either perception or production, suggesting that it may be involved in detecting auditory temporal regularity or in associating auditory stimuli with a motor response. Importantly, functional connectivity analyses showed that these systems interact, indicating that more basic sensorimotor mechanisms instantiated in the BG work in tandem with higher-order cognitive mechanisms in PFC.

Differential activation of brain regions involved with error-feedback and imitation based motor simulation when observing self and an expert's actions in pilots and non-pilots on a complex glider landing task

In this fMRI study we investigate neural processes related to the action observation network using a complex perceptual-motor task in pilots and non-pilots. The task involved landing a glider (using aileron, elevator, rudder, and dive brake) as close to a target as possible, passively observing a replay of one's own previous trial, passively observing a replay of an expert's trial, and a baseline do nothing condition. The objective of this study is to investigate two types of motor simulation processes used during observation of action: imitation based motor simulation and error-feedback based motor simulation. It has been proposed that the computational neurocircuitry of the cortex is well suited for unsupervised imitation based learning, whereas, the cerebellum is well suited for error-feedback based learning. Consistent with predictions, pilots (to a greater extent than non-pilots) showed significant differential activity when observing an expert landing the glider in brain regions involved with imitation based motor simulation (including premotor cortex PMC, inferior frontal gyrus IFG, anterior insula, parietal cortex, superior temporal gyrus, and middle temporal MT area) than when observing one's own previous trial which showed significant differential activity in the cerebellum (only for pilots) thought to be concerned with error-feedback based motor simulation. While there was some differential brain activity for pilots in regions involved with both Execution and Observation of the flying task (potential Mirror System sites including IFG, PMC, superior parietal lobule) the majority was adjacent to these areas (Observation Only Sites) (predominantly in PMC, IFG, and inferior parietal loblule). These regions showing greater activity for observation than for action may be involved with processes related to motor-based representational transforms that are not necessary when actually carrying out the task.

The influence of body movements on children's perception of music with an ambiguous expressive character

The theory of embodied music cognition states that the perception and cognition of music is firmly, although not exclusively, linked to action patterns associated with that music. In this regard, the focus lies mostly on how music promotes certain action tendencies (i.e., dance, entrainment, etc.). Only recently, studies have started to devote attention to the reciprocal effects that people’s body movements may exert on how people perceive certain aspects of music and sound (e.g., pitch, meter, musical preference, etc.). The present study positions itself in this line of research. The central research question is whether expressive body movements, which are systematically paired with music, can modulate children’s perception of musical expressiveness. We present a behavioral experiment in which different groups of children (7–8 years, N = 46) either repetitively performed a happy or a sad choreography in response to expressively ambiguous music or merely listened to that music. The results of our study show indeed that children’s perception of musical expressiveness is modulated in accordance with the expressive character of the dance choreography performed to the music. This finding supports theories that claim a strong connection between action and perception, although further research is needed to uncover the details of this connection.

Music Making and the Aging Brain

The chapter reviews the evidence in support of the idea that cognitive functions can benefit from listening to music or making music and how this evidence might be used to stabilize cognitive aging and prevent or diminish cognitive decline. The beneficial effects are more or less direct (e. g., for auditory perception) or indirect (e. g., for arousal and motivation). The core functions engaged during music listening or music making are executive functions that include attention, working memory, planning, and motor control. These functions are mainly controlled by neural networks located in the frontal cortex, the brain area that undergoes strongest decline in volume with increasing age. In this paper it is argued that this shrinkage of the frontal cortex or the natural course of the decline in frontal brain volume can be counteracted by engaging frontal executive functions through music listening and making. However, current experimental data supporting beneficial effects of music listening and music making is scarce. Therefore, well controlled randomized control group experiments are urgently needed.

Auditory coding of human movement kinematics

Although visual perception is dominant on motor perception, control and learning, auditory information can enhance and modulate perceptual as well as motor processes in a multifaceted manner. During last decades new methods of auditory augmentation had been developed with movement sonification as one of the most recent approaches expanding auditory movement information also to usually mute phases of movement. Despite general evidence on the effectiveness of movement sonification in different fields of applied research there is nearly no empirical proof on how sonification of gross motor human movement should be configured to achieve information rich sound sequences. Such lack of empirical proof is given for (a) the selection of suitable movement features as well as for (b) effective kinetic-acoustical mapping patterns and for (c) the number of regarded dimensions of sonification. In this study we explore the informational content of artificial acoustical kinematics in terms of a kinematic movement sonification using an intermodal discrimination paradigm. In a repeated measure design we analysed discrimination rates of six everyday upper limb actions to evaluate the effectiveness of seven different kinds of kinematic-acoustical mappings as well as short-term learning effects. The kinematics of the upper limb actions were calculated based on inertial motion sensor data and transformed into seven different sonifications. Sound sequences were randomly presented to participants and discrimination rates as well as confidence of choice were analysed. Data indicate an instantaneous comprehensibility of the artificial movement acoustics as well as short-term learning effects. No differences between different dimensional encodings became evident thus indicating a high efficiency for intermodal pattern discrimination for the acoustically coded velocity distribution of the actions. Taken together movement information related to continuous kinematic parameters can be transformed into the auditory domain. Additionally, pattern based action discrimination is obviously not restricted to the visual modality. Artificial acoustical kinematics might be used to supplement and/or substitute visual motion perception in sports and motor rehabilitation.

Neural correlates of music recognition in Down syndrome

The brain mechanisms that subserve music recognition remain unclear despite increasing interest in this process. Here we report the results of a magnetoencephalography experiment to determine the temporal dynamics and spatial distribution of brain regions activated during listening to a familiar and unfamiliar instrumental melody in control adults and adults with Down syndrome (DS). In the control group, listening to the familiar melody relative to the unfamiliar melody, revealed early and significant activations in the left primary auditory cortex, followed by activity in the limbic and sensory-motor regions and finally, activation in the motor related areas. In the DS group, listening to the familiar melody relative to the unfamiliar melody revealed increased significant activations in only three regions. Activity began in the left primary auditory cortex and the superior temporal gyrus and was followed by enhanced activity in the right precentral gyrus. These data suggest that familiar music is associated with auditory-motor coupling but does not activate brain areas involved in emotional processing in DS. These findings reveal new insights on the neural basis of music perception in DS as well as the temporal course of neural activity in control adults.

Multisensory integration and neuroplasticity in the human cerebral cortex

There is a strong interaction between multisensory processing and the neuroplasticity of the human brain. On one hand, recent research demonstrates that experience and training in various domains modifies how information from the different senses is integrated; and, on the other hand multisensory training paradigms seem to be particularly effective in driving functional and structural plasticity. Multisensory training affects early sensory processing within separate sensory domains, as well as the functional and structural connectivity between uni- and multisensory brain regions. In this review, we discuss the evidence for interactions of multisensory processes and brain plasticity and give an outlook on promising clinical applications and open questions.

Repetition suppression in auditory-motor regions to pitch and temporal structure in music

Music performance requires control of two sequential structures: the ordering of pitches and the temporal intervals between successive pitches. Whether pitch and temporal structures are processed as separate or integrated features remains unclear. A repetition suppression paradigm compared neural and behavioral correlates of mapping pitch sequences and temporal sequences to motor movements in music performance. Fourteen pianists listened to and performed novel melodies on an MR-compatible piano keyboard during fMRI scanning. The pitch or temporal patterns in the melodies either changed or repeated (remained the same) across consecutive trials. We expected decreased neural response to the patterns (pitch or temporal) that repeated across trials relative to patterns that changed. Pitch and temporal accuracy were high, and pitch accuracy improved when either pitch or temporal sequences repeated over trials. Repetition of either pitch or temporal sequences was associated with linear BOLD decrease in frontal-parietal brain regions including dorsal and ventral premotor cortex, pre-SMA, and superior parietal cortex. Pitch sequence repetition (in contrast to temporal sequence repetition) was associated with linear BOLD decrease in the intraparietal sulcus (IPS) while pianists listened to melodies they were about to perform. Decreased BOLD response in IPS also predicted increase in pitch accuracy only when pitch sequences repeated. Thus, behavioral performance and neural response in sensorimotor mapping networks were sensitive to both pitch and temporal structure, suggesting that pitch and temporal structure are largely integrated in auditory-motor transformations. IPS may be involved in transforming pitch sequences into spatial coordinates for accurate piano performance.

Perspective-taking in blindness: electrophysiological evidence of altered action representations

It is well established that the mental simulation of actions involves visual and/or somatomotor representations of those imagined actions. To investigate whether the total absence of vision affects the brain activity associated with the retrieval of motor representations, we recorded the readiness potential (RP), a marker of motor preparation preceding the execution, as well as the motor imagery of the right middle-finger extension in the first-person (1P; imagining oneself performing the movement) and in the third-person (3P; imagining the experimenter performing the movement) modes in 19 sighted and 10 congenitally blind subjects. Our main result was found for the single RP slope values at the Cz channel (likely corresponding to the supplementary motor area). No difference in RP slope was found between 1P and 3P in the sighted group, suggesting that similar motor preparation networks are recruited to simulate our own and other people's actions in spite of explicit instructions to perform the task in 1P or 3P. Conversely, reduced RP slopes in 3P compared with 1P found in the blind group indicated that they might have used an alternative, nonmotor strategy to perform the task in 3P. Moreover, movement imagery ability, assessed both by means of mental chronometry and a modified version of the Movement Imagery Questionnaire-Revised, indicated that blind and sighted individuals had similar motor imagery performance. Taken together, these results suggest that complete visual loss early in life modifies the brain networks that associate with others' action representations.

Auditory-motor learning influences auditory memory for music

In two experiments, we investigated how auditory-motor learning influences performers' memory for music. Skilled pianists learned novel melodies in four conditions: auditory only (listening), motor only (performing without sound), strongly coupled auditory-motor (normal performance), and weakly coupled auditory-motor (performing along with auditory recordings). Pianists' recognition of the learned melodies was better following auditory-only or auditory-motor (weakly coupled and strongly coupled) learning than following motor-only learning, and better following strongly coupled auditory-motor learning than following auditory-only learning. Auditory and motor imagery abilities modulated the learning effects: Pianists with high auditory imagery scores had better recognition following motor-only learning, suggesting that auditory imagery compensated for missing auditory feedback at the learning stage. Experiment 2 replicated the findings of Experiment 1 with melodies that contained greater variation in acoustic features. Melodies that were slower and less variable in tempo and intensity were remembered better following weakly coupled auditory-motor learning. These findings suggest that motor learning can aid performers' auditory recognition of music beyond auditory learning alone, and that motor learning is influenced by individual abilities in mental imagery and by variation in acoustic features.

A gray matter of taste: sound perception, music cognition, and Baumgarten's aesthetics

Music is an ancient and ubiquitous form of human expression. One important component for which music is sought after is its aesthetic value, whose appreciation has typically been associated with largely learned, culturally determined factors, such as education, exposure, and social pressure. However, neuroscientific evidence shows that the aesthetic response to music is often associated with automatic, physically- and biologically-grounded events, such as shivers, chills, increased heart rate, and motor synchronization, suggesting the existence of an underlying biological platform upon which contextual factors may act. Drawing on philosophical notions and neuroscientific evidence, I argue that, although there is no denying that social and cultural context play a substantial role in shaping the aesthetic response to music, these act upon largely universal, biological mechanisms involved with neural processing. I propose that the simultaneous presence of culturally-influenced and biologically-determined contributions to the aesthetic response to music epitomizes Baumgarten's equation of sensory perception with taste. Taking the argument one step further, I suggest that the heavily embodied aesthetic response to music bridges the cleavage between the two discrepant meanings-the one referring to sensory perception, the other referring to judgments of taste-traditionally attributed to the word "aesthetics" in the sciences and the humanities.

Tractography-based parcellation of the human left inferior parietal lobule

The inferior parietal lobule (IPL) is a functionally and anatomically heterogeneous region. Much of the information about the anatomical connectivity and parcellation of this region was obtained from histological studies on non-human primates. However, whether these findings from non-human primates can be applied to the human inferior parietal lobule, especially the left inferior parietal lobule, which shows evidence of considerable evolution from primates to humans, remains unclear. In this study, diffusion MRI was employed to investigate the anatomical connectivities of the human left inferior parietal lobule. Using a new algorithm, spectral clustering with edge-weighted centroidal voronoi tessellations, to search for regional variations in the probabilistic connectivity profiles of all left inferior parietal lobule voxels with all the rest of the brain identified six subregions with distinctive connectivity properties in the left inferior parietal lobule. Consistent with cytoarchitectonic findings, four subregions were found in the left supramarginal gyrus and two subregions in the left angular gyrus. The specific connectivity patterns of each subregion of the left inferior parietal lobule were supported by both the anatomical and functional connectivity properties for each subregion, as calculated by a meta-analysis-based target method and by voxel-based whole brain anatomical and functional connectivity analyses. The proposed parcellation scheme for the human left inferior parietal lobule and the maximum probability map for each subregion may facilitate more detailed future studies of this brain area.

Degree of musical expertise modulates higher order brain functioning

Using functional magnetic resonance imaging, we show for the first time that levels of musical expertise stepwise modulate higher order brain functioning. This suggests that degree of training intensity drives such cerebral plasticity. Participants (non-musicians, amateurs, and expert musicians) listened to a comprehensive set of specifically composed string quartets with hierarchically manipulated endings. In particular, we implemented 2 irregularities at musical closure that differed in salience but were both within the tonality of the piece (in-key). Behavioral sensitivity scores (d') of both transgressions perfectly separated participants according to their level of musical expertise. By contrasting brain responses to harmonic transgressions against regular endings, functional brain imaging data showed compelling evidence for stepwise modulation of brain responses by both violation strength and expertise level in a fronto-temporal network hosting universal functions of working memory and attention. Additional independent testing evidenced an advantage in visual working memory for the professionals, which could be predicted by musical training intensity. The here introduced findings of brain plasticity demonstrate the progressive impact of musical training on cognitive brain functions that may manifest well beyond the field of music processing.

The body knows what it should do: automatic motor compensation for illusory heaviness contagion

We can share various feelings with others just through observation, as if it were an automatic resonance. This connective function between the self and others could promote the facilitation of our social communication; however, it is still unclear as to how it works in terms of self-other representation. In this study, we showed participants a picture of a model holding a ball, which was weighted with sand. We instructed participants to move one of their arms to a horizontal position and hold it immobile. Those participants who knew the actual weight of the ball (1 kg) tended to raise this arm above the horizontal, in response to their expectation of the need to resist the weight of the ball. This compensatory reaction to the illusion of heaviness suggests that our bodily resonance could be mandatory and predictive. We discuss this new behavioral phenomenon in terms of motor simulation or the mirror-neuron system.

Self-recognition of highly skilled actions: a study of orchestral conductors

The influence of movement skill on action representations and identification of agency was investigated. Point-light displays were created of highly skilled gestures of thirteen orchestral conductors in visual, auditory, and audiovisual versions and compared to two control conditions (static images and gait cycles of the same participants). In subsequent experimental sessions, participants indicated whether displays presented them or other conductors, whether the soundtrack contained their or others' musical interpretations, and rated the quality and emotional content of the gestures. Self-recognition was more accurate in conditions presenting highly skilled conducting movements as compared to other displays. Participants judged the quality of their own movements to be better than those of others, independently of whether or not they recognized movement agency. Emotional content was perceived accurately across conditions both for own and others' actions. These results point to the influence of dynamical characteristics of motor skill, rather than merely type of movement or emotional content, on action representations and self-other identification.

Changes in neuromagnetic beta-band oscillation after music-supported stroke rehabilitation

Precise timing of sound is crucial in music for both performing and listening. Indeed, listening to rhythmic sound sequences activates not only the auditory system but also the sensorimotor system. Previously, we showed the significance of neural beta-band oscillations (15-30 Hz) for the timing processing that involves such auditory-motor coordination. Thus, we hypothesized that motor rehabilitation training incorporating music playing will stimulate and enhance auditory-motor interaction in stroke patients. We examined three chronic patients who received Music-Supported Therapy following the protocols practiced by Schneider. Neuromagnetic beta-band activity was remarkably alike during passive listening to a metronome and during finger tapping, with or without the metronome, for either the paretic or nonparetic hand, suggesting a shared mechanism of the beta modulation. In the listening task, the magnitude of the beta decrease after the tone onset was more pronounced at the posttraining time point and was accompanied by improved arm and hand skills. The present case data give insight into the neural underpinnings of rehabilitation with music making and rhythmic auditory stimulation.

The involvement of audio-motor coupling in the music-supported therapy applied to stroke patients

Music-supported therapy (MST) has been developed recently to improve the use of the affected upper extremity after stroke. MST uses musical instruments, an electronic piano and an electronic drum set emitting piano sounds, to retrain fine and gross movements of the paretic upper extremity. In this paper, we first describe the rationale underlying MST, and we review the previous studies conducted on acute and chronic stroke patients using this new neurorehabilitation approach. Second, we address the neural mechanisms involved in the motor movement improvements observed in acute and chronic stroke patients. Third, we provide some recent studies on the involvement of auditory-motor coupling in the MST in chronic stroke patients using functional neuroimaging. Finally, these ideas are discussed and focused on understanding the dynamics involved in the neural circuit underlying audio-motor coupling and how functional connectivity could help to explain the neuroplastic changes observed after therapy in stroke patients.

When right is all that is left: plasticity of right-hemisphere tracts in a young aphasic patient

Using an adapted version of Melodic Intonation Therapy (MIT), we treated an adolescent girl with a very large left-hemisphere lesion and severe nonfluent aphasia secondary to an ischemic stroke. At the time of her initial assessment 15 months after her stroke, she had reached a plateau in her recovery despite intense and long-term traditional speech-language therapy (approximately five times per week for more than one year). Following an intensive course of treatment with our adapted form of MIT, her performance improved on both trained and untrained phrases, as well as on speech and language tasks. These behavioral improvements were accompanied by functional MRI changes in the right frontal lobe as well as by an increased volume of white matter pathways in the right hemisphere. No increase in white matter volume was seen in her healthy twin sister, who was scanned twice over the same time period. This case study not only provides further evidence for MIT's effectiveness, but also indicates that intensive treatment can induce functional and structural changes in a right-hemisphere fronto-temporal network.

Mental imagery in music performance: underlying mechanisms and potential benefits

This paper examines the role of mental imagery in music performance. Self-reports by musicians, and various other sources of anecdotal evidence, suggest that covert auditory, motor, and/or visual imagery facilitate multiple aspects of music performance. The cognitive and motor mechanisms that underlie such imagery include working memory, action simulation, and internal models. Together these mechanisms support the generation of anticipatory images that enable thorough action planning and movement execution that is characterized by efficiency, temporal precision, and biomechanical economy. In ensemble performance, anticipatory imagery may facilitate interpersonal coordination by enhancing online predictions about others' action timing. Overlap in brain regions subserving auditory imagery and temporal prediction is consistent with this view. It is concluded that individual differences in anticipatory imagery may be a source of variation in expressive performance excellence and the quality of ensemble cohesion. Engaging in effortful musical imagery is therefore justified when artistic perfection is the goal.

The multisensory brain and its ability to learn music

Playing a musical instrument requires a complex skill set that depends on the brain's ability to quickly integrate information from multiple senses. It has been well documented that intensive musical training alters brain structure and function within and across multisensory brain regions, supporting the experience-dependent plasticity model. Here, we argue that this experience-dependent plasticity occurs because of the multisensory nature of the brain and may be an important contributing factor to musical learning. This review highlights key multisensory regions within the brain and discusses their role in the context of music learning and rehabilitation.

Cued memory reactivation during sleep influences skill learning

Information acquired during waking can be reactivated during sleep, promoting memory stabilization. After people learned to produce two melodies in time with moving visual symbols, we produced a relative improvement in performance by presenting one melody during an afternoon nap. Electrophysiological signs of memory processing during sleep corroborated the notion that appropriate auditory stimulation that does not disrupt sleep can nevertheless bias memory consolidation in relevant brain circuitry.

Specialization of the posterior temporal lobes for audio-motor processing - evidence from a functional magnetic resonance imaging study of skilled drummers

Sounds of hammering or clapping can evoke simulation of the arm movements that have been previously associated with those sounds. This audio-motor transformation also occurs at the sequential level and plays a role in speech and music processing. The present study aimed to demonstrate how the activation pattern of the sensorimotor network was modulated by the sequential nature of the auditory input and effector. Fifteen skilled drum set players participated in our functional magnetic resonance imaging study. Prior to the scan, these drummers practiced six drumming grooves. During the scan, there were four rehearsal conditions: covertly playing the drum set under the guidance of its randomly-presented isolated stroke sounds, covertly playing the drum set along with the sounds of learned percussion music, covertly reciting the syllable representation along with this music, and covertly reciting along with the syllable representation of this music. We found greater activity in the bilateral posterior middle temporal gyri for active listening to isolated drum strokes than for active listening to learned drum music. These regions might mediate the one-to-one mappings from sounds to limb movements. Compared with subvocal rehearsals along with learned drum music, covert rehearsals of limb movements along with the same music additionally activated a lateral subregion of the left posterior planum temporale. Our results illustrate a functional specialization of the posterior temporal lobes for audio-motor processing.

Neuronal Correlates of Perception, Imagery, and Memory for Familiar Tunes

We used fMRI to investigate the neuronal correlates of encoding and recognizing heard and imagined melodies. Ten participants were shown lyrics of familiar verbal tunes; they either heard the tune along with the lyrics, or they had to imagine it. In a subsequent surprise recognition test, they had to identify the titles of tunes that they had heard or imagined earlier. The functional data showed substantial overlap during melody perception and imagery, including secondary auditory areas. During imagery compared with perception, an extended network including pFC, SMA, intraparietal sulcus, and cerebellum showed increased activity, in line with the increased processing demands of imagery. Functional connectivity of anterior right temporal cortex with frontal areas was increased during imagery compared with perception, indicating that these areas form an imagery-related network. Activity in right superior temporal gyrus and pFC was correlated with the subjective rating of imagery vividness. Similar to the encoding phase, the recognition task recruited overlapping areas, including inferior frontal cortex associated with memory retrieval, as well as left middle temporal gyrus. The results present new evidence for the cortical network underlying goal-directed auditory imagery, with a prominent role of the right pFC both for the subjective impression of imagery vividness and for on-line mental monitoring of imagery-related activity in auditory areas.

Effects of humanness and gender in voice processing

When we observe a producible human movement, the brain performs a specific perception-action matching process, which possibly facilitates perceptual processing. In this work, we wanted to study whether the producibility of a sound affects the speed at which it is categorized. Participants were presented with isolated sounds, either sung by a natural male or female voice ('producible') or distorted by saturation ('non-producible'), and had to categorize them as produced by a voice or by a machine. We analyzed reaction time variations as a function of the gender and humanness of the voice. Results corroborate the existence of a 'human bias' in auditory perception, and suggest a processing speed asymmetry between natural female and male voices.