Melody Processing Characterizes Functional Neuroanatomy in the Aging Brain

The underlying roles and neurobiological mechanisms of music-based intervention in Alzheimer's disease: A comprehensive review

Non-pharmacological therapy has gained popularity in the intervention of Alzheimer's disease (AD) due to its apparent therapeutic effectiveness and the limitation of biological drug. A wealth of research indicates that music interventions can enhance cognition, mood and behavior in individuals with AD. Nonetheless, the underlying mechanisms behind these improvements have yet to be fully and systematically delineated. This review aims to holistically review how music-based intervention (MBI) ameliorates abnormal emotion, cognition decline, and behavioral changes in AD patients. We cover several key dimensions: the regulation of MBIs on cerebral blood flow (CBF), their impact on neurotransmission (including GABAergic and monoaminergic transmissions), modulation of synaptic plasticity, and hormonal release. Additionally, we summarize the clinical applications and limitations of active music-based intervention (AMBI), passive music-based intervention (PMBI), and hybrid music-based intervention (HMBI). This thorough analysis enhances our understanding of the role of MBI in AD and supports the development of non-pharmacological therapeutic strategies.

Neural correlates of musical familiarity: a functional magnetic resonance study

Existing neuroimaging studies on neural correlates of musical familiarity often employ a familiar vs. unfamiliar contrast analysis. This singular analytical approach reveals associations between explicit musical memory and musical familiarity. However, is the neural activity associated with musical familiarity solely related to explicit musical memory, or could it also be related to implicit musical memory? To address this, we presented 130 song excerpts of varying familiarity to 21 participants. While acquiring their brain activity using functional magnetic resonance imaging (fMRI), we asked the participants to rate the familiarity of each song on a five-point scale. To comprehensively analyze the neural correlates of musical familiarity, we examined it from four perspectives: the intensity of local neural activity, patterns of local neural activity, global neural activity patterns, and functional connectivity. The results from these four approaches were consistent and revealed that musical familiarity is related to the activity of both explicit and implicit musical memory networks. Our findings suggest that: (1) musical familiarity is also associated with implicit musical memory, and (2) there is a cooperative and competitive interaction between the two types of musical memory in the perception of music.

Rhythmic musical activities may strengthen connectivity between brain networks associated with aging-related deficits in timing and executive functions

Brain aging and common conditions of aging (e.g., hypertension) affect networks important in organizing information, processing speed and action programming (i.e., executive functions). Declines in these networks may affect timing and could have an impact on the ability to perceive and perform musical rhythms. There is evidence that participation in rhythmic musical activities may help to maintain and even improve executive functioning (near transfer), perhaps due to similarities in brain regions underlying timing, musical rhythm perception and production, and executive functioning. Rhythmic musical activities may present as a novel and fun activity for older adults to stimulate interacting brain regions that deteriorate with aging. However, relatively little is known about neurobehavioral interactions between aging, timing, rhythm perception and production, and executive functioning. In this review, we account for these brain-behavior interactions to suggest that deeper knowledge of overlapping brain regions associated with timing, rhythm, and cognition may assist in designing more targeted preventive and rehabilitative interventions to reduce age-related cognitive decline and improve quality of life in populations with neurodegenerative disease. Further research is needed to elucidate the functional relationships between brain regions associated with aging, timing, rhythm perception and production, and executive functioning to direct design of targeted interventions.

The neural bases of familiar music listening in healthy individuals: An activation likelihood estimation meta-analysis

Accumulating evidence suggests that the neural activations during music listening differs as a function of familiarity with the excerpts. However, the implicated brain areas are unclear. After an extensive literature search, we conducted an Activation Likelihood Estimation analysis on 23 neuroimaging studies (232 foci, 364 participants) to identify consistently activated brain regions when healthy adults listen to familiar music, compared to unfamiliar music or an equivalent condition. The results revealed a left cortical-subcortical co-activation pattern comprising three significant clusters localized to the supplementary motor areas (BA 6), inferior frontal gyrus (IFG, BA 44), and the claustrum/insula. Our results are discussed in a predictive coding framework, whereby temporal expectancies and familiarity may drive motor activations, despite any overt movement. Though conventionally associated with syntactic violation, our observed activation in the IFG may support a recent proposal of its involvement in a network that subserves both violation and prediction. Finally, the claustrum/insula plays an integral role in auditory processing, functioning as a hub that integrates sensory and limbic information to (sub)cortical structures.

The effect of repetition on intersubject synchrony assessed with fMRI

We investigated how repeated exposure to a stimulus affects intersubject synchrony in the brains of young and older adults. We used functional magnetic resonance imaging (fMRI) to measure brain responses to familiar and novel stimuli. Young adults participated in a familiarization paradigm designed to mimic 'natural' exposure while older adults were presented with stimuli they had known for more than 50 years. Intersubject synchrony was calculated to detect common stimulus-driven brain activity across young and older adults as they listened to the novel and familiar stimuli. Contrary to our hypotheses, synchrony was not related to the amount of stimulus exposure; both young and older adults showed more synchrony to novel than to familiar stimuli regardless of whether the stimuli had been heard once, known for a few weeks, or known for more than 50 years. In young adults these synchrony differences were found across the brain in the bilateral temporal lobes, and in the frontal orbital cortex. In older adults the synchrony differences were found only in the bilateral temporal lobes. This reduction may be related to an increase in idiosyncratic responses after exposure to a stimulus but does not seem to be related to how well the stimuli are learned or to differences in attention. Until the effects of repeated exposure on synchrony are fully understood, future studies using intersubject synchrony, where the novelty of the stimuli cannot be guaranteed, may consider exposing all of their participants to the stimuli once before data are collected to mitigate the effects of any systematic differences in stimulus exposure.

Decoding expectation and surprise in dementia: the paradigm of music

Making predictions about the world and responding appropriately to unexpected events are essential functions of the healthy brain. In neurodegenerative disorders, such as frontotemporal dementia and Alzheimer's disease, impaired processing of 'surprise' may underpin a diverse array of symptoms, particularly abnormalities of social and emotional behaviour, but is challenging to characterize. Here, we addressed this issue using a novel paradigm: music. We studied 62 patients (24 female; aged 53-88) representing major syndromes of frontotemporal dementia (behavioural variant, semantic variant primary progressive aphasia, non-fluent-agrammatic variant primary progressive aphasia) and typical amnestic Alzheimer's disease, in relation to 33 healthy controls (18 female; aged 54-78). Participants heard famous melodies containing no deviants or one of three types of deviant note-acoustic (white-noise burst), syntactic (key-violating pitch change) or semantic (key-preserving pitch change). Using a regression model that took elementary perceptual, executive and musical competence into account, we assessed accuracy detecting melodic deviants and simultaneously recorded pupillary responses and related these to deviant surprise value (information-content) and carrier melody predictability (entropy), calculated using an unsupervised machine learning model of music. Neuroanatomical associations of deviant detection accuracy and coupling of detection to deviant surprise value were assessed using voxel-based morphometry of patients' brain MRI. Whereas Alzheimer's disease was associated with normal deviant detection accuracy, behavioural and semantic variant frontotemporal dementia syndromes were associated with strikingly similar profiles of impaired syntactic and semantic deviant detection accuracy and impaired behavioural and autonomic sensitivity to deviant information-content (all P < 0.05). On the other hand, non-fluent-agrammatic primary progressive aphasia was associated with generalized impairment of deviant discriminability (P < 0.05) due to excessive false-alarms, despite retained behavioural and autonomic sensitivity to deviant information-content and melody predictability. Across the patient cohort, grey matter correlates of acoustic deviant detection accuracy were identified in precuneus, mid and mesial temporal regions; correlates of syntactic deviant detection accuracy and information-content processing, in inferior frontal and anterior temporal cortices, putamen and nucleus accumbens; and a common correlate of musical salience coding in supplementary motor area (all P < 0.05, corrected for multiple comparisons in pre-specified regions of interest). Our findings suggest that major dementias have distinct profiles of sensory 'surprise' processing, as instantiated in music. Music may be a useful and informative paradigm for probing the predictive decoding of complex sensory environments in neurodegenerative proteinopathies, with implications for understanding and measuring the core pathophysiology of these diseases.

Chinese and Western Musical Training Impacts the Circuit in Auditory and Reward Systems

Previous studies have provided evidence about the brain plasticity effects of musical training, however, the issue of how expertise in music styles induced by Chinese or Western musical training affects neuroplasticity and reward responses has been less considered, especially for subjects of Chinese origin. In this work, 16 musicians who trained in the Western music style (Western-trained musicians) and 18 musicians who trained in the Chinese music style (Chinese-trained musicians) were recruited as the musician group for the experiment, while 15 non-musicians were recruited as the control group. Using a paradigm that consisted of listening to Chinese and Western music and measurements using functional magnetic resonance imaging (fMRI) technology, we found that Chinese-trained musicians activated the bilateral superior temporal gyrus (STG) when listening to music, while Western-trained musicians activated the left STG. In addition, under the condition of listening to music with Chinese style, Chinese-trained musicians have a stronger functional connection in the circuit of the auditory and reward system than Western-trained musicians. The finding is opposite under the condition of listening to music with Western style. Interestingly, it seems that the circuit of Chinese-trained musicians is partial to the right STG, while Western-trained musicians show the opposite, i.e., a tendency toward the left STG. The influence of different music styles on experienced musicians is reflected by the functional activities and connections between the auditory system and the reward system. This outcome indicates that training in Chinese music style or Western music style affects the strategies of musicians when listening to music. Musical characteristics such as rhythm, melody and cultural attributes play an important role in this process. These findings, which provide evidence for functional neuroplasticity based on musical training, can enrich our insights into the musical brain.

Mapping magnetization transfer saturation (MTsat ) in human brain at 7T: Protocol optimization under specific absorption rate constraints

PURPOSE

To optimize a whole-brain magnetization transfer saturation (MT_sat ) protocol at 7T, focusing on maximizing obtainable MT_sat under the constraints of specific absorption rate (SAR) and transmit field inhomogeneity, while avoiding bias and keeping scan time short.

THEORY AND METHODS

MT_sat is a semi-quantitative metric, obtained by spoiled gradient-echo MRI in the imaging steady-state. Optimization was based on an established 7T dual flip angle protocol, and focused on MT pulse, readout flip angle, repetition time (TR), offset frequency (Δ), and correction of residual effects from transmit field inhomogeneities by separate flip angle mapping.

RESULTS

A 100% SAR level was reached at a 180° MT pulse flip angle, using a compact sinc main lobe (4 ms duration) and minimum TR = 26.5 ms. The use of Δ = +2.0 kHz caused no discernible direct saturation, while Δ = -2.0 kHz resulted in 45% higher MT_sat in white matter (WM) compared to Δ = +2.0 kHz. A 4° readout flip angle eliminated bias while yielding a good signal-to-noise ratio. Increased TR yielded only a little increase in MT_sat , and TR = 26.5 ms (scan time 04:58 min) was thus selected. Post hoc transmit field correction clearly improved homogeneity, especially in WM.

CONCLUSIONS

The range of MT_sat is limited at 7T, and this can partly be overcome by the exploitation of the asymmetry of the macromolecular lineshape through the sign of Δ. To reduce scan time, a compact MT pulse with a sufficiently narrow frequency response should be used. TR and readout flip angle should be kept short/small. Transmit field correction through separate flip angle mapping is required.

A specially designed medical screen for children suffering from burns: A randomized trial of a distraction-type therapy

•

The current study is the first to explore the medical screen as a treatment to control the pain and its related psychological symptoms on children suffering from burns;.

•

Compared with conventional dressing methods, the medical screen can be used as a novel way to decrease the negative experience of burn patients -ages 1–3 who require dressing changes.

;•

The medical screen is likely a feasible, acceptable and potentially efficacious treatment option for burns medical workers.

Objective

To evaluate the impact of the specially designed medical dressing screen during wound dressing changes of children who suffered burns to their hand or foot.

Design

Randomized controlled trial.

Setting

Burns and Plastic Reconstruction Unit.

Participants

Children (NN = 120) with burns on up to 1%-–5% of the total body surface area.

Interventions

The patients were selected and randomly allocated to 3 equal-sized groups as follows:control group (N control group (N = 40): the children received only regular dressing changes; computer group (NN = 40): a touch-screen computer was used for children during dressing changes; medical screen group (NN = 40): a medical screen combined with the touch-screen computer were used for children during dressing changes. All patients underwent a dressing change once per day for four days. Data were distributed four times: immediately after the initial dressing change (T1); and immediately after each times at next three consecutive days (T2-T4).Main Outcome M–T4).

Main outcome measures

The Pain level of the children evaluated by medical staffs was the primary outcome, the Pain level of the children evaluated by children's parents and the satisfaction of wound therapist were used as second outcomes.

Results

The mean scores related to pain level at the medical screen group displayed significantly better results than those of control group and those of the computer group. Additionally, the results of the pain evaluated by parents and satisfaction score of the wound therapist at the medical screen group was also better than other groups.

Conclusions

This study demonstrated “that the” application of the medical screen for burns can relieve the pain of 1-–3 years old children suffering from a burns during dressing changes. Additionally, the application of the medical screen also increased the satisfaction of the parents and the wound therapist performing the dressing changes.