Focal Brain Lesions Causing Acquired Amusia Map to a Common Brain Network.

Music is a universal human attribute. The study of amusia, a neurologic music processing deficit, has increasingly elaborated our view on the neural organization of the musical brain. However, lesions causing amusia occur in multiple brain locations and often also cause aphasia, leaving the distinct neural networks for amusia unclear. Here, we utilized lesion network mapping to identify these networks. A systematic literature search was carried out to identify all published case reports of lesion-induced amusia. The reproducibility and specificity of the identified amusia network were then tested in an independent prospective cohort of 97 stroke patients (46 female and 51 male) with repeated structural brain imaging, specifically assessed for both music perception and language abilities. Lesion locations in the case reports were heterogeneous but connected to common brain regions, including bilateral temporoparietal and insular cortices, precentral gyrus, and cingulum. In the prospective cohort, lesions causing amusia mapped to a common brain network, centering on the right superior temporal cortex and clearly distinct from the network causally associated with aphasia. Lesion-induced longitudinal structural effects in the amusia circuit were confirmed as reduction of both gray and white matter volume, which correlated with the severity of amusia. We demonstrate that despite the heterogeneity of lesion locations disrupting music processing, there is a common brain network that is distinct from the language network. These results provide evidence for the distinct neural substrate of music processing, differentiating music-related functions from language, providing a testable target for noninvasive brain stimulation to treat amusia.

Choir singing is associated with enhanced structural connectivity across the adult lifespan.

The global ageing of populations calls for effective, ecologically valid methods to support brain health across adult life. Previous evidence suggests that music can promote white matter (WM) microstructure and grey matter (GM) volume while supporting auditory and cognitive functioning and emotional well-being as well as counteracting age-related cognitive decline. Adding a social component to music training, choir singing is a popular leisure activity among older adults, but a systematic account of its potential to support healthy brain structure, especially with regard to ageing, is currently missing. The present study used quantitative anisotropy (QA)-based diffusion MRI connectometry and voxel-based morphometry to explore the relationship of lifetime choir singing experience and brain structure at the whole-brain level. Cross-sectional multiple regression analyses were carried out in a large, balanced sample (N = 95; age range 21-88) of healthy adults with varying levels of choir singing experience across the whole age range and within subgroups defined by age (young, middle-aged, and older adults). Independent of age, choir singing experience was associated with extensive increases in WM QA in commissural, association, and projection tracts across the brain. Corroborating previous work, these overlapped with language and limbic networks. Enhanced corpus callosum microstructure was associated with choir singing experience across all subgroups. In addition, choir singing experience was selectively associated with enhanced QA in the fornix in older participants. No associations between GM volume and choir singing were found. The present study offers the first systematic account of amateur-level choir singing on brain structure. While no evidence for counteracting GM atrophy was found, the present evidence of enhanced structural connectivity coheres well with age-typical structural changes. Corroborating previous behavioural studies, the present results suggest that regular choir singing holds great promise for supporting brain health across the adult life span.

Right ventral stream damage underlies both poststroke aprosodia and amusia.

BACKGROUND AND PURPOSE: This study was undertaken to determine and compare lesion patterns and structural dysconnectivity underlying poststroke aprosodia and amusia, using a data-driven multimodal neuroimaging approach. METHODS: Thirty-nine patients with right or left hemisphere stroke were enrolled in a cohort study and tested for linguistic and affective prosody perception and musical pitch and rhythm perception at subacute and 3-month poststroke stages. Participants listened to words spoken with different prosodic stress that changed their meaning, and to words spoken with six different emotions, and chose which meaning or emotion was expressed. In the music tasks, participants judged pairs of short melodies as the same or different in terms of pitch or rhythm. Structural magnetic resonance imaging data were acquired at both stages, and machine learning-based lesion-symptom mapping and deterministic tractography were used to identify lesion patterns and damaged white matter pathways giving rise to aprosodia and amusia. RESULTS: Both aprosodia and amusia were behaviorally strongly correlated and associated with similar lesion patterns in right frontoinsular and striatal areas. In multiple regression models, reduced fractional anisotropy and lower tract volume of the right inferior fronto-occipital fasciculus were the strongest predictors for both disorders, over time. CONCLUSIONS: These results highlight a common origin of aprosodia and amusia, both arising from damage and disconnection of the right ventral auditory stream integrating rhythmic-melodic acoustic information in prosody and music. Comorbidity of these disabilities may worsen the prognosis and affect rehabilitation success.

Effects of neurological music therapy on behavioural and emotional recovery after traumatic brain injury: A randomized controlled cross-over trial.

Traumatic brain injury (TBI) causes deficits in executive function (EF), as well as problems in behavioural and emotional self-regulation. Neurological music therapy may aid these aspects of recovery. We performed a cross-over randomized controlled trial where 40 persons with moderate-severe TBI received a 3-month neurological music therapy intervention (2 times/week, 60 min/session), either during the first (AB, n = 20) or second (BA, n = 20) half of a 6-month follow-up period. The evidence from this RCT previously demonstrated that music therapy enhanced general EF and set shifting. In the current study, outcome was assessed with self-report and caregiver-report questionnaires performed at baseline, 3-month, 6-month, and 18-month stages. The results showed that the self-reported Behavioural Regulation Index of the Behaviour Rating Inventory of Executive Function (BRIEF-A) improved more in the AB than BA group from baseline to 3-month stage and the effect was maintained in the 6-month follow-up. No changes in mood or quality of life questionnaires were observed. However, a qualitative content analysis of the feedback revealed that many participants experienced the intervention as helpful in terms of emotional well-being and activity. Our results suggest that music therapy has a positive effect on everyday behavioural regulation skills after TBI.

Resting-state language network neuroplasticity in post-stroke music listening: A randomized controlled trial.

Recent evidence suggests that post-stroke vocal music listening can aid language recovery, but the network-level functional neuroplasticity mechanisms of this effect are unknown. Here, we sought to determine if improved language recovery observed after post-stroke listening to vocal music is driven by changes in longitudinal resting-state functional connectivity within the language network. Using data from a single-blind randomized controlled trial on stroke patients (N = 38), we compared the effects of daily listening to self-selected vocal music, instrumental music and audio books on changes of the resting-state functional connectivity within the language network and their correlation to improved language skills and verbal memory during the first 3 months post-stroke. From acute to 3-month stage, the vocal music and instrumental music groups increased functional connectivity between a cluster comprising the left inferior parietal areas and the language network more than the audio book group. However, the functional connectivity increase correlated with improved verbal memory only in the vocal music group cluster. This study shows that listening to vocal music post-stroke promotes recovery of verbal memory by inducing changes in longitudinal functional connectivity in the language network. Our results conform to the variable neurodisplacement theory underpinning aphasia recovery.

Enriched Music-supported Therapy for chronic stroke patients: a study protocol of a randomised controlled trial.

BACKGROUND: Residual motor deficits of the upper limb in patients with chronic stroke are common and have a negative impact on autonomy, participation and quality of life. Music-Supported Therapy (MST) is an effective intervention to enhance motor and cognitive function, emotional well-being and quality of life in chronic stroke patients. We have adapted the original MST training protocol to a home-based intervention, which incorporates increased training intensity and variability, group sessions, and optimisation of learning to promote autonomy and motivation. METHODS: A randomised controlled trial will be conducted to test the effectiveness of this enriched MST (eMST) protocol in improving motor functions, cognition, emotional well-being and quality of life of chronic stroke patients when compared to a program of home-based exercises utilizing the Graded Repetitive Arm Supplementary Program (GRASP). Sixty stroke patients will be recruited and randomly allocated to an eMST group (n = 30) or a control GRASP intervention group (n = 30). Patients will be evaluated before and after a 10-week intervention, as well as at 3-month follow-up. The primary outcome of the study is the functionality of the paretic upper limb measured with the Action Research Arm Test. Secondary outcomes include other motor and cognitive functions, emotional well-being and quality of life measures as well as self-regulation and self-efficacy outcomes. DISCUSSION: We hypothesize that patients treated with eMST will show larger improvements in their motor and cognitive functions, emotional well-being and quality of life than patients treated with a home-based GRASP intervention. TRIAL REGISTRATION: The trial has been registered at ClinicalTrials.gov and identified as NCT04507542 on 8 August 2020.

DARE to move: feasibility study of a novel dance-based rehabilitation method in severe traumatic brain injury.

Objective: Dance is a versatile and multimodal rehabilitation method, which may be useful also in traumatic brain injury (TBI) rehabilitation. Here, we assessed the feasibility and preliminary effects of a novel dance-based intervention called Dual-Assisted Dance Rehabilitation (DARE).Method: This is a feasibility study with a cross-over design where 11 persons with severe/extremely severe TBI received a 12-week (2 times/week) DARE program. Motor and neuropsychological tests and questionnaires measuring mood, executive functions, and quality of life were performed at baseline, 3-month, and 6-month stage. Self-perceived benefits were assessed with a post-intervention questionnaire.Results: Acceptability of and adherence to DARE were encouraging: 91% were fully consistent with protocol, and adherence to DARE sessions was 83-100%. Pre-post treatment effects sizes were medium-large for self-reported depression (BDI-II: d = 1.19-1.74) and executive deficits (BRIEF-A: d = 0.43-1.09) and for test-assessed trunk movement control (TIS: d = 0.47-0.76) and cognitive functioning (WAIS-IV subtests: d = 0.34-0.89). Other outcome measures did not show similar positive effect sizes. Self-perceived benefits were largest for mobility and cognition.Conclusion: Dance-based rehabilitation is a feasible and promising method in severe TBI and its efficacy should be assessed with a larger clinical trial.

Resting-State Network Plasticity Induced by Music Therapy after Traumatic Brain Injury.

Traumatic brain injury (TBI) is characterized by a complex pattern of abnormalities in resting-state functional connectivity (rsFC) and network dysfunction, which can potentially be ameliorated by rehabilitation. In our previous randomized controlled trial, we found that a 3-month neurological music therapy intervention enhanced executive function (EF) and increased grey matter volume in the right inferior frontal gyrus (IFG) in patients with moderate-to-severe TBI (N = 40). Extending this study, we performed longitudinal rsFC analyses of resting-state fMRI data using a ROI-to-ROI approach assessing within-network and between-network rsFC in the frontoparietal (FPN), dorsal attention (DAN), default mode (DMN), and salience (SAL) networks, which all have been associated with cognitive impairment after TBI. We also performed a seed-based connectivity analysis between the right IFG and whole-brain rsFC. The results showed that neurological music therapy increased the coupling between the FPN and DAN as well as between these networks and primary sensory networks. By contrast, the DMN was less connected with sensory networks after the intervention. Similarly, there was a shift towards a less connected state within the FPN and SAL networks, which are typically hyperconnected following TBI. Improvements in EF were correlated with rsFC within the FPN and between the DMN and sensorimotor networks. Finally, in the seed-based connectivity analysis, the right IFG showed increased rsFC with the right inferior parietal and left frontoparietal (Rolandic operculum) regions. Together, these results indicate that the rehabilitative effects of neurological music therapy after TBI are underpinned by a pattern of within- and between-network connectivity changes in cognitive networks as well as increased connectivity between frontal and parietal regions associated with music processing.

Neural Basis of Acquired Amusia and Its Recovery after Stroke.

UNLABELLED: Although acquired amusia is a relatively common disorder after stroke, its precise neuroanatomical basis is still unknown. To evaluate which brain regions form the neural substrate for acquired amusia and its recovery, we performed a voxel-based lesion-symptom mapping (VLSM) and morphometry (VBM) study with 77 human stroke subjects. Structural MRIs were acquired at acute and 6 month poststroke stages. Amusia and aphasia were behaviorally assessed at acute and 3 month poststroke stages using the Scale and Rhythm subtests of the Montreal Battery of Evaluation of Amusia (MBEA) and language tests. VLSM analyses indicated that amusia was associated with a lesion area comprising the superior temporal gyrus, Heschl's gyrus, insula, and striatum in the right hemisphere, clearly different from the lesion pattern associated with aphasia. Parametric analyses of MBEA Pitch and Rhythm scores showed extensive lesion overlap in the right striatum, as well as in the right Heschl's gyrus and superior temporal gyrus. Lesions associated with Rhythm scores extended more superiorly and posterolaterally. VBM analysis of volume changes from the acute to the 6 month stage showed a clear decrease in gray matter volume in the right superior and middle temporal gyri in nonrecovered amusic patients compared with nonamusic patients. This increased atrophy was more evident in anterior temporal areas in rhythm amusia and in posterior temporal and temporoparietal areas in pitch amusia. Overall, the results implicate right temporal and subcortical regions as the crucial neural substrate for acquired amusia and highlight the importance of different temporal lobe regions for the recovery of amusia after stroke. SIGNIFICANCE STATEMENT: Lesion studies are essential in uncovering the brain regions causally linked to a given behavior or skill. For music perception ability, previous lesion studies of amusia have been methodologically limited in both spatial accuracy and time domain as well as by small sample sizes, providing coarse and equivocal information about which brain areas underlie amusia. By using longitudinal MRI and behavioral data from a large sample of stroke patients coupled with modern voxel-based analyses methods, we were able provide the first systematic evidence for the causal role of right temporal and striatal areas in music perception. Clinically, these results have important implications for the diagnosis and prognosis of amusia after stroke and for rehabilitation planning.

The Nature and Nurture of Melody: A Twin Study of Musical Pitch and Rhythm Perception.

Both genetic and environmental factors are known to play a role in our ability to perceive music, but the degree to which they influence different aspects of music cognition is still unclear. We investigated the relative contribution of genetic and environmental effects on melody perception in 384 young adult twins [69 full monozygotic (MZ) twin pairs, 44 full dizygotic (DZ) twin pairs, 70 MZ twins without a co-twin, and 88 DZ twins without a co-twin]. The participants performed three online music tests requiring the detection of pitch changes in a two-melody comparison task (Scale) and key and rhythm incongruities in single-melody perception tasks (Out-of-key, Off-beat). The results showed predominantly additive genetic effects in the Scale task (58 %, 95 % CI 42-70 %), shared environmental effects in the Out-of-key task (61 %, 49-70 %), and non-shared environmental effects in the Off-beat task (82 %, 61-100 %). This highly different pattern of effects suggests that the contribution of genetic and environmental factors on music perception depends on the degree to which it calls for acquired knowledge of musical tonal and metric structures.

[Effectiveness of music in brain rehabilitation. A systematic review]. / Musiikin vaikuttavuus aivojen kuntoutuksessa.

There is no curative treatment for diseases causing brain injury. Music causes extensive activation of the brain, promoting the repair of neural systems. Addition of music listening to rehabilitation enhances the regulation or motor functions in Parkinson and stroke patients, accelerates the recovery of speech disorder and cognitive injuries after stroke, and decreases the behavioral disorders of dementia patients. Music enhances the ability to concentrate and decreases mental confusion. The effect of music can also be observed as structural and functional changes of the brain. The effect is based, among other things, on lessening of physiologic stress and depression and on activation of the dopaminergic mesolimbic system.

The effects of music combined to paired associative stimulation on motor-evoked potentials and alertness in spinal cord injury patients and healthy subjects.

Paired associative stimulation (PAS) consisting of high-intensity transcranial magnetic stimulation (TMS) and high-frequency peripheral nerve stimulation (known as high-PAS) induces plastic changes and improves motor performance in patients with incomplete spinal cord injury (SCI). Listening to music during PAS may potentially improve mood and arousal and facilitate PAS-induced neuroplasticity via auditory-motor coupling, but the effects have not been explored. This pilot study aimed to determine if the effect of high-PAS on motor-evoked potentials (MEPs) and subjective alertness can be augmented with music. Ten healthy subjects and nine SCI patients received three high-PAS sessions in randomized order (PAS only, PAS with music synchronized to TMS, PAS with self-selected music). MEPs were measured before (PRE), after (POST), 30 min (POST30), and 60 min (POST60) after stimulation. Alertness was evaluated with a questionnaire. In healthy subjects, MEPs increased at POST in all sessions and remained higher at POST60 in PAS with synchronized music compared with the other sessions. There was no difference in alertness. In SCI patients, MEPs increased at POST and POST30 in PAS only but not in other sessions, whereas alertness was higher in PAS with self-selected music. More research is needed to determine the potential clinical effects of using music during high-PAS.

Emotional and musical factors combined with song-specific age predict the subjective autobiographical saliency of music in older adults.

Music that evokes strong emotional responses is often experienced as autobiographically salient. Through emotional experience, the musical features of songs could also contribute to their subjective autobiographical saliency. Songs which have been popular during adolescence or young adulthood (ages 10-30) are more likely to evoke stronger memories, a phenomenon known as a reminiscence bump. In the present study, we sought to determine how song-specific age, emotional responsiveness to music, musical features, and subjective memory functioning contribute to the subjective autobiographical saliency of music in older adults. In a music listening study, 112 participants rated excerpts of popular songs from the 1950s to the 1980s for autobiographical saliency. Additionally, they filled out questionnaires about emotional responsiveness to music and subjective memory functioning. The song excerpts' musical features were extracted computationally using MIRtoolbox. Results showed that autobiographical saliency was best predicted by song-specific age and emotional responsiveness to music and musical features. Newer songs that were more similar in rhythm to older songs were also rated higher in autobiographical saliency. Overall, this study contributes to autobiographical memory research by uncovering a set of factors affecting the subjective autobiographical saliency of music.

The evolution of whole-brain turbulent dynamics during recovery from traumatic brain injury.

It has been previously shown that traumatic brain injury (TBI) is associated with reductions in metastability in large-scale networks in resting-state fMRI (rsfMRI). However, little is known about how TBI affects the local level of synchronization and how this evolves during the recovery trajectory. Here, we applied a novel turbulent dynamics framework to investigate whole-brain dynamics using an rsfMRI dataset from a cohort of moderate to severe TBI patients and healthy controls (HCs). We first examined how several measures related to turbulent dynamics differ between HCs and TBI patients at 3, 6, and 12 months post-injury. We found a significant reduction in these empirical measures after TBI, with the largest change at 6 months post-injury. Next, we built a Hopf whole-brain model with coupled oscillators and conducted in silico perturbations to investigate the mechanistic principles underlying the reduced turbulent dynamics found in the empirical data. A simulated attack was used to account for the effect of focal lesions. This revealed a shift to lower coupling parameters in the TBI dataset and, critically, decreased susceptibility and information-encoding capability. These findings confirm the potential of the turbulent framework to characterize longitudinal changes in whole-brain dynamics and in the reactivity to external perturbations after TBI.

Structural Neuroplasticity Effects of Singing in Chronic Aphasia.

Singing-based treatments of aphasia can improve language outcomes, but the neural benefits of group-based singing in aphasia are unknown. Here, we set out to determine the structural neuroplasticity changes underpinning group-based singing-induced treatment effects in chronic aphasia. Twenty-eight patients with at least mild nonfluent poststroke aphasia were randomized into two groups that received a 4-month multicomponent singing intervention (singing group) or standard care (control group). High-resolution T1 images and multishell diffusion-weighted MRI data were collected in two time points (baseline/5 months). Structural gray matter (GM) and white matter (WM) neuroplasticity changes were assessed using language network region of interest-based voxel-based morphometry (VBM) and quantitative anisotropy-based connectometry, and their associations to improved language outcomes (Western Aphasia Battery Naming and Repetition) were evaluated. Connectometry analyses showed that the singing group enhanced structural WM connectivity in the left arcuate fasciculus (AF) and corpus callosum as well as in the frontal aslant tract (FAT), superior longitudinal fasciculus, and corticostriatal tract bilaterally compared with the control group. Moreover, in VBM, the singing group showed GM volume increase in the left inferior frontal cortex (Brodmann area 44) compared with the control group. The neuroplasticity effects in the left BA44, AF, and FAT correlated with improved naming abilities after the intervention. These findings suggest that in the poststroke aphasia group, singing can bring about structural neuroplasticity changes in left frontal language areas and in bilateral language pathways, which underpin treatment-induced improvement in speech production.

Enriched music-supported therapy for individuals with chronic stroke: a randomized controlled trial.

OBJECTIVE: Many stroke survivors still present with upper-limb paresis six months post-stroke, impacting their autonomy and quality of life (QoL). We designed an enriched Music-supported Therapy (eMST) program to reduce disability in this population. We evaluated the eMST's effectiveness in improving functional abilities and QoL in chronic stroke individuals compared to the conventional motor program Graded Repetitive Arm Supplementary Program (GRASP). METHODS: We conducted a pragmatic two-arm parallel-group randomized controlled trial with a 3-month follow-up and masked assessment. The eMST involved playing instruments during individual self-administered and group music therapy sessions. The GRASP consisted of self-administered motor exercises using daily objects. Both interventions were completed at home with telemonitoring and involved four one-hour weekly sessions for 10 weeks. The primary outcome was upper-limb motor function measured with the Action Research Arm Test. Secondary outcomes included motor impairment, daily life motor performance, cognitive functions, emotional well-being, QoL, self-regulation, and self-efficacy. Intention-to-treat (ITT) and per-protocol (PP) analyses were conducted including participants who discontinued the intervention and those who completed it entirely, respectively. RESULTS: Fifty-eight chronic stroke patients were randomized to the eMST-group (n = 26; age: 64.2 ± 12.5; 6 [23.1%] females; 2.8 ± 2.9 years post-stroke), and the control group (n = 32; age: 62.2 ± 12; 8 [25%] females; 1.8 ± 6.2 years post-stroke). The eMST-group had more participants achieving a clinically relevant improvement in motor impairment post-intervention than the control group for the ITT (55% vs 21.6%; OR = 4.5 (95% CI 1.4-14); p = .019) and PP analyses (60% vs 20%; OR = 6 (95% CI 1.5-24.7); p = .024), sustained at follow-up. The eMST-group reported greater improvements in emotion (difference = 11.1 (95% CI 0.8-21.5; p = 0.36) and participation (difference = 10.3 (95% CI 0.6-25.9); p = 0.41) subscales of QoL, and higher enjoyment during the sessions (difference = 1 (95% CI 0.3-1.5); p = 0.12). No changes were found in other outcomes. CONCLUSION: eMST demonstrated superiority over conventional motor rehabilitation program in enhancing upper-limb functions and QoL in chronic stroke individuals. TRIAL REGISTRATION: ClinicalTrials.gov (ID: NCT04507542).

Longitudinal effects of choir singing on aging cognition and wellbeing: a two-year follow-up study.

Introduction: While increasing evidence points toward the benefits of musical activities in promoting cognitive and emotional well-being in older adults, more longitudinal studies are needed to establish their long-term effects and uncover the mechanisms through which musical activities affect well-being. Most previous research has focused on instrumental musical activities, but little is currently known about the long-term effects of singing, even though neuroimaging evidence suggests that it is a versatile activity for the brain, involving a multitude of neural processes that are potentially beneficial for well-being. Methods: We conducted a 2-year follow-up study to assess aging-related changes in cognitive functioning and emotional and social well-being with self-report questionnaires and standardized tests in 107 older adult choir singers and 62 demographically matched non-singers. Data were collected at baseline (T1), and at 1-year (T2) and 2-year (T3) follow-ups using questionnaires on subjective cognitive functioning, depression, social engagement, and quality of life (QOL) in all participants and neuropsychological tests in a subgroup of participants (45 choir singers and 41 non-singers). Results: The results of linear mixed model analysis showed that in verbal flexibility (phonemic fluency task), the choir singers had higher scores already at T1 and showed no change over time, whereas the non-singers showed enhancement from T1 to T3. Furthermore, active retrieval of word knowledge (WAIS-IV Vocabulary task) showed significantly different changes from T1 to T2 between the groups (enhancement in choir singers and decline in non-singers), however lacking significant change within groups. Similar opposite trajectories of QOL related to social inclusion and safety of the environment (WHOQOL-Bref Environmental subscale) were significant from T1 to T3, but these changes were not significant within groups or at each timepoint. Within the choir singers, shorter experience in choir singing was associated with greater improvement in the vocabulary task over the follow-up period, suggesting that initiation of choir singing at older age induces some verbal benefits. There were no group differences in any other questionnaire or neuropsychological measure over time. Discussion: In conclusion, our results suggest that choir singing at older age is associated with a sustained enhancement of phonemic fluency, while the effects on other verbal skills and quality of life are less clear.

Differential effects of ageing on the neural processing of speech and singing production.

Background: Understanding healthy brain ageing has become vital as populations are ageing rapidly and age-related brain diseases are becoming more common. In normal brain ageing, speech processing undergoes functional reorganisation involving reductions of hemispheric asymmetry and overactivation in the prefrontal regions. However, little is known about how these changes generalise to other vocal production, such as singing, and how they are affected by associated cognitive demands. Methods: The present cross-sectional fMRI study systematically maps the neural correlates of vocal production across adulthood (N=100, age 21-88 years) using a balanced 2x3 design where tasks varied in modality (speech: proverbs / singing: song phrases) and cognitive demand (repetition / completion from memory / improvisation). Results: In speech production, ageing was associated with decreased left pre- and postcentral activation across tasks and increased bilateral angular and right inferior temporal and fusiform activation in the improvisation task. In singing production, ageing was associated with increased activation in medial and bilateral prefrontal and parietal regions in the completion task, whereas other tasks showed no ageing effects. Direct comparisons between the modalities showed larger age-related activation changes in speech than singing across tasks, including a larger left-to-right shift in lateral prefrontal regions in the improvisation task. Conclusion: The present results suggest that the brains' singing network undergoes differential functional reorganisation in normal ageing compared to the speech network, particularly during a task with high executive demand. These findings are relevant for understanding the effects of ageing on vocal production as well as how singing can support communication in healthy ageing and neurological rehabilitation.

Hodological organization of spoken language production and singing in the human brain.

Theories expounding the neural relationship between speech and singing range from sharing neural circuitry, to relying on opposite hemispheres. Yet, hodological studies exploring their shared and distinct neural networks remain scarce. In this study, we combine a white matter connectometry approach together with comprehensive and naturalistic appraisal of verbal expression during spoken language production and singing in a sample of individuals with post-stroke aphasia. Our results reveal that both spoken language production and singing are mainly supported by the left hemisphere language network and projection pathways. However, while spoken language production mostly engaged dorsal and ventral streams of speech processing, singing was associated primarily with the left ventral stream. These findings provide evidence that speech and singing share core neuronal circuitry within the left hemisphere, while distinct ventral stream contributions explain frequently observed dissociations in aphasia. Moreover, the results suggest prerequisite biomarkers for successful singing-based therapeutic interventions.