Structural and functional plasticity specific to musical training with wind instruments

Involvement of the intrinsic functional network of the red nucleus in complex behavioral processing

Previous studies suggested the possibility that the red nucleus (RN) is involved in other cognitive functions than motion per se, even though such functions have yet to be clarified. We investigated the activation of RN during several tasks and its intrinsic functional network associated with social cognition and musical practice. The tasks included finger tapping, n-back, and memory recall tasks. Region of interest for RN was identified through those tasks, anatomical information of RN, and a brain atlas. The intrinsic functional network was identified for RN by an analysis of connectivity between RN and other regions typically involved in seven known resting state functional networks with RN used as the seed region. Association of the RN network with a psychological trait of the interpersonal reactivity index and musical training years revealed subnetworks that included empathy related regions or music practice related regions. These social or highly coordinated motor activity represent the most complex functions ever known to involve the RN, adding further evidence for the multifunctional roles of RN. These discoveries may lead to a new direction of investigations to clarify probable novel roles for RN in high-level human behavior.

Brain Plasticity Reflects Specialized Cognitive Development Induced by Musical Training

Learning a musical instrument requires a long period of training and might induce structural and functional changes in the brain. Previous studies have shown brain plasticity resulting from training with a musical instrument. However, these studies did not distinguish the effects on brain plasticity of specific musical instruments as they examined the brain of musicians who had learned a single musical instrument/genre and did not control for confounding factors, such as common or interactive effects involved in music training. To address this research gap, the present work investigated musicians who had experience with both a piano and a wind instrument, for example, flute, trumpet, clarinet etc. By examining the difference between the 2 musical instruments in the same subject, we avoided the effects common to all musical instruments and the confounding factors. Therefore, we identified several high-tier brain areas displaying a brain plasticity specific to each musical instrument. Our findings show that learning a musical instrument might result in the development of high cognitive functions reflecting the skills/abilities unique to the instrument played.

Tooth Position in Wind Instrument Players: Dentofacial Cephalometric Analysis

Background: Specific dentofacial characteristics in wind instrumentalists should be taken in consideration when analyzing physiological and anatomical issues regarding the musician’s embouchure, posture, and biomechanics during musical performance. Objectives: To compare tooth cephalometric characteristics between wind instrument players and string players (overjet, overbite, lower facial height, facial convexity, lower incisor inclination, and interincisal angle). Methods: In total, 48 wind instrumentalists (67%) and 24 string instrumentalists (33%). These musicians performed lateral tele-radiography and the correspondent linear and angular measurements of the dentofacial cephalometric analysis. Statistical comparison of wind and string instrumentalists was made by using an independent t-test. Results: Small variations on the analyzed parameters were found between the wind and string instrument groups. Based on the cephalometric analysis the variable interincisal angle was statistically significant (p < 0.05), when comparing the wind and string instrument group. Conclusions: Knowledge of the overjet and overbite value permits a substantial analysis on the tooth position of wind instrument players, where both of these parameters are increased and greater than the norm value. The cephalometry was an added value on the interpretation of possible factors that lead to the position of the central incisors of wind instruments. Till some extent in this group of musicians the applied forces during the embouchure mechanism on the anterior teeth and the existing perioral forces promote an equilibrium on the vector of forces. This study findings demonstrate that when evaluating the two samples, wind and string instruments there are different dentofacial configurations, however the only statistically significant differences that were found are related to the interincisal angle (p < 0.05).

Articulatory motor planning and timbral idiosyncrasies as underlying mechanisms of instrument-specific absolute pitch in expert musicians

The study of musical expertise illustrates how intense training in a specialized domain may instigate development of implicit skills. While absolute pitch, or the ability to identify musical pitches without external reference, is rare even in professional musicians and is understood to have a genetic component, anecdotal evidence and pilot data suggest that some musicians without traditional absolute pitch are nonetheless better able to name notes played on their musical instrument of expertise than notes played on less familiar instruments. We have previously termed this particular gain in absolute pitch identification ability "instrument-specific absolute pitch" (ISAP) and have proposed that this skill is related to learned instrument type-specific timbral and intonational idiosyncrasies and articulatory motor planning activated by the timbre of the instrument. In this Registered Report Protocol, we describe two experiments designed to investigate ISAP in professional oboists. Experiment 1 tests for ISAP ability by comparing oboists' pitch identification accuracies for notes played on the oboe and on the piano. A subset of the participants from Experiment 1 who demonstrate this ability will be recruited for Experiment 2; the purpose of Experiment 2 is to test hypotheses concerning a mechanistic explanation for ISAP. The outcome of these experiments may provide support for the theory that some individuals have ISAP and that the underlying mechanisms of this ability may rely on the perception of subtle timbral/intonational idiosyncrasies and on articulatory motor planning developed through intensive long-term training. In general, this work will contribute to the understanding of specialized expertise, specifically of implicit abilities and biases that are not addressed directly in training, but that may yet develop through practice of a related skill set.

A Theory of Instrument-Specific Absolute Pitch

While absolute pitch (AP)—the ability to name musical pitches globally and without reference—is rare in expert musicians, anecdotal evidence suggests that some musicians may better identify pitches played on their primary instrument than pitches played on other instruments. We call this phenomenon “instrument-specific absolute pitch” (ISAP). In this paper we present a theory of ISAP. Specifically, we offer the hypothesis that some expert musicians without global AP may be able to more accurately identify pitches played on their primary instrument(s), and we propose timbral cues and articulatory motor imagery as two underlying mechanisms. Depending on whether informative timbral cues arise from performer- or instrument-specific idiosyncrasies or from timbre-facilitated tonotopic representations, we predict that performance may be enhanced for notes played by oneself, notes played on one’s own personal instrument, and/or notes played on any exemplar of one’s own instrument type. Sounds of one’s primary instrument may moreover activate kinesthetic memory and motor imagery, aiding pitch identification. In order to demonstrate how our theory can be tested, we report the methodology and analysis of two exemplary experiments conducted on two case-study participants who are professional oboists. The aim of the first experiment was to determine whether the oboists demonstrated ISAP ability, while the purpose of the second experiment was to provide a preliminary investigation of the underlying mechanisms. The results of the first experiment revealed that only one of the two oboists showed an advantage for identifying oboe tones over piano tones. For this oboist demonstrating ISAP, the second experiment demonstrated that pitch-naming accuracy decreased and variance around the correct pitch value increased as an effect of transposition and motor interference, but not of instrument or performer. These preliminary data suggest that some musicians possess ISAP while others do not. Timbral cues and motor imagery may both play roles in the acquisition of this ability. Based on our case study findings, we provide methodological considerations and recommendations for future empirical testing of our theory of ISAP.

Functional and Structural Plasticity Co-express in a Left Premotor Region During Early Bimanual Skill Learning

Introduction: Motor skill learning already triggers the functional reorganization of regional brain activity after short periods of training. Recent studies suggest that microstructural change may emerge at similar timescales, but the spatiotemporal profiles of functional and structural plasticity have rarely been traced in parallel. Recently, we demonstrated that 5 days of endoscopic skill training induces changes in task-related brain activity in the ventral premotor cortex (PMv) and other areas of the frontoparietal grasping network. Here, we analyzed microstructural data, collected during the same experiment to investigate if microstructural plasticity overlaps temporally and spatially with the training-induced changes in task-related brain activity. Materials and Methods: Thirty-nine students were divided into a full-routine group (n = 20), that underwent three endoscopy training sessions in the MR-scanner as well as a 5-day virtual reality (VR)-endoscopy training and a brief-routine group (n = 19), that only performed the in-scanner endoscopy training sessions. Diffusion Tensor Imaging (DTI)-derived fractional anisotropy (FA) and resting-state functional magnetic resonance imaging (rs-fMRI) were collected at baseline, after the first and after the last VR-training session. Results: The full-routine group showed significant FA changes in a left-hemispheric subcortical cluster underlying the PMv region, for which we previously demonstrated functional plasticity during endoscopy training in the same sample. Functional (task-related fMRI) and structural (FA) changes showed the largest change from the first to the second scan, suggesting similar temporal dynamics. In the full-routine group, the FA change in the subcortical cluster underlying the left PMv scaled positively with the individual improvement in endoscopic surgery. Conclusion: Microstructural white-matter plasticity mirrors the spatiotemporal profile of task-dependent plasticity during a 5-day course of endoscopy skill training. The observed similarities motivate future research on the interplay between functional and structural plasticity during early skill acquisition.

The Effects of Bimanual Coordination in Music Interventions on Executive Functions in Aging Adults

Music training programs have been shown to enhance executive functions in aging adults; however, little is known regarding the extent to which different types of bimanual coordination (i.e., fine and gross motor) in music instruction contribute to these outcomes. The aim of this study was to examine the effects of bimanual coordination in music interventions on cognitive performance in healthy older adults (60-80 years). Participants (N = 135) completed motor measures and battery of standardized cognitive measures, before and after a 16-week music training program with a 3 h practice requirement. All participants were matched by age, education, and estimate of intelligence to one of three training programs: piano training (fine motor); percussion instruction (gross motor), and music listening instruction (MLI) (no motor control condition). Results of a Repeated Measures ANOVA revealed significant enhancements in bimanual synchronization and visual scanning/working memory abilities for fine and gross motor training groups as compared to MLI. Pairwise comparisons revealed that piano training significantly improved motor synchronization skills as compared to percussion instruction or music listening. Results suggest that active music performance may benefit working memory, the extent of these benefits may depend upon coordination demands.

The descending motor tracts are different in dancers and musicians

Long-term motor training, such as dance or gymnastics, has been associated with increased diffusivity and reduced fiber coherence in regions including the corticospinal tract. Comparisons between different types of motor experts suggest that experience might result in specific structural changes related to the trained effectors (e.g., hands or feet). However, previous studies have not segregated the descending motor pathways from different body-part representations in motor cortex (M1). Further, most previous diffusion tensor imaging studies used whole-brain analyses based on a single tensor, which provide poor information about regions where multiple white matter (WM) tracts cross. Here, we used multi-tensor probabilistic tractography to investigate the specific components of the descending motor pathways in well-matched groups of dancers, musicians and controls. To this aim, we developed a procedure to identify the WM regions below the motor representations of the head, hand, trunk and leg that served as seeds for tractography. Dancers showed increased radial diffusivity (RD) in comparison with musicians, in descending motor pathways from all the regions, particularly in the right hemisphere, whereas musicians had increased fractional anisotropy (FA) in the hand and the trunk/arm motor tracts. Further, dancers showed larger volumes compared to both other groups. Finally, we found negative correlations between RD and FA with the age of start of dance or music training, respectively, and between RD and performance on a melody task, and positive correlations between RD and volume with performance on a whole-body dance task. These findings suggest that different types of training might have different effects on brain structure, likely because dancers must coordinate movements of the entire body, whereas musicians focus on fewer effectors.

Abnormalities in grey matter structure in embouchure dystonia

INTRODUCTION

Embouchure dystonia (ED) is a debilitating movement disorder in professional brass players leading to involuntary muscle contractions/spasms during play. To date, activity changes in sensorimotor cortices during motor tasks and tactile processing, as well as connectivity changes at rest in sensorimotor and auditory brain networks have been described in the disease.

OBJECTIVE

To characterize differences in grey matter volume and asymmetry between brass musicians suffering from ED, healthy brass musicians and healthy nonmusicians.

METHODS

High-resolution structural magnetic resonance imaging was obtained from 24 brass musicians with ED, 23 healthy brass musicians and 24 healthy nonmusicians. Whole-brain voxel-wise morphometry and asymmetry analyses, as well as region-of-interest-based volumetry analysis were performed on the subjects' images and compared between groups. Further, correlations with clinical parameters were investigated.

RESULTS

ED patients showed increased grey matter volume in the primary sensorimotor cortex in relation to both healthy brass players and nonmusicians. Both healthy and diseased musicians showed increased thalamic symmetry in relation to nonmusicians; diseased brass musicians additionally showed increased basal ganglia symmetry compared to nonmusicians. There was an inverse correlation of disease duration with both mean putaminal volume and the extent of basal ganglia asymmetry.

CONCLUSION

This work provides first evidence for structural abnormalities in task-specific orofacial (musician's) dystonia. Somatotopy-related structural primary sensorimotor cortex changes underlying previously observed functional abnormalities underscore the role of maladaptive plasticity in the disease. The study further shows subcortical brain (a)symmetry changes in healthy brass players and hints at a possible role of such changes in focal dystonia.

Structural Covariance Analysis Reveals Differences Between Dancers and Untrained Controls

Dancers and musicians differ in brain structure from untrained individuals. Structural covariance (SC) analysis can provide further insight into training-associated brain plasticity by evaluating interregional relationships in gray matter (GM) structure. The objectives of the present study were to compare SC of cortical thickness (CT) between expert dancers, expert musicians and untrained controls, as well as to examine the relationship between SC and performance on dance- and music-related tasks. A reduced correlation between CT in the left dorsolateral prefrontal cortex (DLPFC) and mean CT across the whole brain was found in the dancers compared to the controls, and a reduced correlation between these two CT measures was associated with higher performance on a dance video game task. This suggests that the left DLPFC is structurally decoupled in dancers and may be more strongly affected by local training-related factors than global factors in this group. This work provides a better understanding of structural brain connectivity and training-induced brain plasticity, as well as their interaction with behavior in dance and music.

Estimation of vocational aptitudes using functional brain networks

The success of human life in modern society is highly dependent on occupation. Therefore, it is very important for people to identify and develop a career plan that best suits their aptitude. Traditional test batteries for vocational aptitudes are not oriented to measure developmental changes in job suitability because repeated measurements can introduce bias as the content of the test batteries is learned. In this study, we attempted to objectively assess vocational aptitudes by measuring functional brain networks and identified functional brain networks that intrinsically represented vocational aptitudes for 19 job divisions in a General Aptitude Test Battery. In addition, we derived classifiers based on these networks to predict the aptitudes of our test participants for each job division. Our results suggest that the measurement of brain function can indeed yield an objective evaluation of vocational aptitudes; this technique will enable a person to follow changes in one's job suitability with additional training or learning, paving a new way to advise people on career development.