The effect of dance on mental health and quality of life of people with Parkinson's disease: A systematic review and three-level meta-analysis.

OBJECTIVES: Parkinson's disease (PD) is a neurodegenerative disease that affects millions of individuals worldwide. Dance has emerged as a comprehensive intervention for enhancing well-being in this population. This meta-analysis aimed to assess the effectiveness of dance on mental health and quality of life among individuals with PD. METHODS: Three databases were searched in December 2022. Research papers comparing the effects of dance with a non-dance control on the quality of life or mental health of individuals with PD were included. Two authors independently screened the studies, extracted data, and assessed methodological quality of eligible studies. To address the interdependence of effect sizes within studies, the three-level meta-analysis approach was employed to analyze the data. RESULTS: Thirteen trials involving a total of 496 participants were included, with 11 being subjected to statistical analysis. The results indicated that dance had a positive impact on mental health (g = 0.43, 95 % CI = [0.11, 0.75]) and quality of life (g = 0.46, 95 % CI = [-0.04, 0.95]) when compared to passive control groups. Moderator analyses revealed that non-partnered dance and dance interventions with lower total dosages were particularly beneficial for mental health. CONCLUSION: Dance interventions are an effective lifestyle activity for enhancing mental health and quality of life in individuals with PD. A theoretical framework is proposed to explain the impact of dance on well-being from neurological, social, physical, and psychological perspectives.

Why is music therapeutic for neurological disorders? The Therapeutic Music Capacities Model.

Music has cognitive, psychosocial, behavioral and motor benefits for people with neurological disorders such as dementia, stroke, Parkinson's disease (PD) and Autism Spectrum Disorder (ASD). Here we discuss seven properties or 'capacities' of music that interact with brain function and contribute to its therapeutic value. Specifically, in its various forms, music can be engaging, emotional, physical, personal, social and persuasive, and it promotes synchronization of movement. We propose the Therapeutic Music Capacities Model (TMCM), which links individual properties of music to therapeutic mechanisms, leading to cognitive, psychosocial, behavioral and motor benefits. We review evidence that these capacities have reliable benefits for people with dementia, stroke, PD and ASD when employed separately or in combination. The model accounts for the profound value that music affords human health and well-being and provides a framework for the development of non-pharmaceutical treatments for neurological disorders.

Syntactic and non-syntactic sources of interference by music on language processing.

Music and language are complex hierarchical systems in which individual elements are systematically combined to form larger, syntactic structures. Suggestions that music and language share syntactic processing resources have relied on evidence that syntactic violations in music interfere with syntactic processing in language. However, syntactic violations may affect auditory processing in non-syntactic ways, accounting for reported interference effects. To investigate the factors contributing to interference effects, we assessed recall of visually presented sentences and word-lists when accompanied by background auditory stimuli differing in syntactic structure and auditory distraction: melodies without violations, scrambled melodies, melodies that alternate in timbre, and environmental sounds. In Experiment 1, one-timbre melodies interfered with sentence recall, and increasing both syntactic complexity and distraction by scrambling melodies increased this interference. In contrast, three-timbre melodies reduced interference on sentence recall, presumably because alternating instruments interrupted auditory streaming, reducing pressure on long-distance syntactic structure building. Experiment 2 confirmed that participants were better at discriminating syntactically coherent one-timbre melodies than three-timbre melodies. Together, these results illustrate that syntactic processing and auditory streaming interact to influence sentence recall, providing implications for theories of shared syntactic processing and auditory distraction.

Syntactic processing in music and language: Parallel abnormalities observed in congenital amusia.

Evidence is accumulating that similar cognitive resources are engaged to process syntactic structure in music and language. Congenital amusia - a neurodevelopmental disorder that primarily affects music perception, including musical syntax - provides a special opportunity to understand the nature of this overlap. Using electroencephalography (EEG), we investigated whether individuals with congenital amusia have parallel deficits in processing language syntax in comparison to control participants. Twelve amusic participants (eight females) and 12 control participants (eight females) were presented melodies in one session, and spoken sentences in another session, both of which had syntactic-congruent and -incongruent stimuli. They were asked to complete a music-related and a language-related task that were irrelevant to the syntactic incongruities. Our results show that amusic participants exhibit impairments in the early stages of both music- and language-syntactic processing. Specifically, we found that two event-related potential (ERP) components - namely Early Right Anterior Negativity (ERAN) and Left Anterior Negativity (LAN), associated with music- and language-syntactic processing respectively, were absent in the amusia group. However, at later processing stages, amusics showed similar brain responses as controls to syntactic incongruities in both music and language. This was reflected in a normal N5 in response to melodies and a normal P600 to spoken sentences. Notably, amusics' parallel music- and language-syntactic impairments were not accompanied by deficits in semantic processing (indexed by normal N400 in response to semantic incongruities). Together, our findings provide further evidence for shared music and language syntactic processing, particularly at early stages of processing.

The Impact of Music on the Self in Dementia.

In this review, we consider how the onset and progression of dementia can disrupt one's sense of self, and propose that music is an ideal tool for alleviating this distressing symptom. Various aspects of the self can be impaired in people with dementia, depending on how the self is defined. There are anecdotal reports that music can 'bring people back to themselves' in the face of dementia, but there have been scarce empirical investigations of this topic. Motivated by a consideration of the existing literature, we outline a novel theoretical framework that accounts for the relationship between music and the self in people with dementia. We propose that music has a number of 'design features' that make it uniquely equipped to engage multiple aspects of the self. We suggest that each design feature interacts with different aspects of the self to varying degrees, promoting overall wellbeing. We discuss how existing research on music and dementia fits within this framework, and describe two case studies in which music was an ideal stimulus for reaffirming their sense of self. Our framework may be useful for the diagnosis and treatment of impairments of self in people with dementia, and highlights how music, given its ability to engage all aspects of the self simultaneously, can result in an overall enhanced sense of self.

Pitch discrimination associated with phonological awareness: Evidence from congenital amusia.

Research suggests that musical skills are associated with phonological abilities. To further investigate this association, we examined whether phonological impairments are evident in individuals with poor music abilities. Twenty individuals with congenital amusia and 20 matched controls were assessed on a pure-tone pitch discrimination task, a rhythm discrimination task, and four phonological tests. Amusic participants showed deficits in discriminating pitch and discriminating rhythmic patterns that involve a regular beat. At a group level, these individuals performed similarly to controls on all phonological tests. However, eight amusics with severe pitch impairment, as identified by the pitch discrimination task, exhibited significantly worse performance than all other participants in phonological awareness. A hierarchical regression analysis indicated that pitch discrimination thresholds predicted phonological awareness beyond that predicted by phonological short-term memory and rhythm discrimination. In contrast, our rhythm discrimination task did not predict phonological awareness beyond that predicted by pitch discrimination thresholds. These findings suggest that accurate pitch discrimination is critical for phonological processing. We propose that deficits in early-stage pitch discrimination may be associated with impaired phonological awareness and we discuss the shared role of pitch discrimination for processing music and speech.

Affective evaluation of simultaneous tone combinations in congenital amusia.

Congenital amusia is a neurodevelopmental disorder characterized by impaired pitch processing. Although pitch simultaneities are among the fundamental building blocks of Western tonal music, affective responses to simultaneities such as isolated dyads varying in consonance/dissonance or chords varying in major/minor quality have rarely been studied in amusic individuals. Thirteen amusics and thirteen matched controls enculturated to Western tonal music provided pleasantness ratings of sine-tone dyads and complex-tone dyads in piano timbre as well as perceived happiness/sadness ratings of sine-tone triads and complex-tone triads in piano timbre. Acoustical analyses of roughness and harmonicity were conducted to determine whether similar acoustic information contributed to these evaluations in amusics and controls. Amusic individuals' pleasantness ratings indicated sensitivity to consonance and dissonance for complex-tone (piano timbre) dyads and, to a lesser degree, sine-tone dyads, whereas controls showed sensitivity when listening to both tone types. Furthermore, amusic individuals showed some sensitivity to the happiness-major association in the complex-tone condition, but not in the sine-tone condition. Controls rated major chords as happier than minor chords in both tone types. Linear regression analyses revealed that affective ratings of dyads and triads by amusic individuals were predicted by roughness but not harmonicity, whereas affective ratings by controls were predicted by both roughness and harmonicity. We discuss affective sensitivity in congenital amusia in view of theories of affective responses to isolated chords in Western listeners.

The Pitch Imagery Arrow Task: effects of musical training, vividness, and mental control.

Musical imagery is a relatively unexplored area, partly because of deficiencies in existing experimental paradigms, which are often difficult, unreliable, or do not provide objective measures of performance. Here we describe a novel protocol, the Pitch Imagery Arrow Task (PIAT), which induces and trains pitch imagery in both musicians and non-musicians. Given a tonal context and an initial pitch sequence, arrows are displayed to elicit a scale-step sequence of imagined pitches, and participants indicate whether the final imagined tone matches an audible probe. It is a staircase design that accommodates individual differences in musical experience and imagery ability. This new protocol was used to investigate the roles that musical expertise, self-reported auditory vividness and mental control play in imagery performance. Performance on the task was significantly better for participants who employed a musical imagery strategy compared to participants who used an alternative cognitive strategy and positively correlated with scores on the Control subscale from the Bucknell Auditory Imagery Scale (BAIS). Multiple regression analysis revealed that Imagery performance accuracy was best predicted by a combination of strategy use and scores on the Vividness subscale of BAIS. These results confirm that competent performance on the PIAT requires active musical imagery and is very difficult to achieve using alternative cognitive strategies. Auditory vividness and mental control were more important than musical experience in the ability to perform manipulation of pitch imagery.

Discrimination of stress in speech and music: a mismatch negativity (MMN) study.

The aim of this study was to determine if duration-related stress in speech and music is processed in a similar way in the brain. To this end, we tested 20 adults for their abstract mismatch negativity (MMN) event-related potentials to two duration-related stress patterns: stress on the first syllable or note (long-short), and stress on the second syllable or note (short-long). A significant MMN was elicited for both speech and music except for the short-long speech stimulus. The long-short stimuli elicited larger MMN amplitudes for speech and music compared to short-long stimuli. An extra negativity-the late discriminative negativity (LDN)-was observed only for music. The larger MMN amplitude for long-short stimuli might be due to the familiarity of the stress pattern in speech and music. The presence of LDN for music may reflect greater long-term memory transfer for music stimuli.

The effect of intensity on relative pitch.

In two experiments, we examined the effect of intensity and intensity change on judgements of pitch differences or interval size. In Experiment 1, 39 musically untrained participants rated the size of the interval spanned by two pitches within individual gliding tones. Tones were presented at high intensity, low intensity, looming intensity (up-ramp), and fading intensity (down-ramp) and glided between two pitches spanning either 6 or 7 semitones (a tritone or a perfect fifth interval). The pitch shift occurred in either ascending or descending directions. Experiment 2 repeated the conditions of Experiment 1 but the shifts in pitch and intensity occurred across two discrete tones (i.e., a melodic interval). Results indicated that participants were sensitive to the differences in interval size presented: Ratings were significantly higher when two pitches differed by 7 semitones than when they differed by 6 semitones. However, ratings were also dependent on whether the interval was high or low in intensity, whether it increased or decreased in intensity across the two pitches, and whether the interval was ascending or descending in pitch. Such influences illustrate that the perception of pitch relations does not always adhere to a logarithmic function as implied by their musical labels, but that identical intervals are perceived as substantially different in size depending on other attributes of the sound source.

Effect of deviance direction and calculation method on duration and frequency mismatch negativity (MMN).

The mismatch negativity (MMN) component of the auditory event-related potential (ERP) reflects the process of change detection in the auditory system. The present study investigated the effect of deviance direction (increment vs. decrement) and calculation method (traditional vs. same-stimulus) on the amplitude of MMN. MMN was recorded for increments and decrements in frequency and duration in 20 adults. The stimuli (standard/deviant) were 250 Hz/350 Hz (frequency MMN) and 200 ms/300 ms (duration MMN) for increment MMN and vice versa for decrement MMN. Amplitude of MMN was calculated in two ways: the traditional method (subtracting ERP to the standard from the deviant presented in the same block) and the same-stimulus method (subtracting ERP to identical stimuli presented as standard in one block and deviant in another block). We found that increments in frequency produced higher MMN amplitudes compared to decrements for both methods of calculation. For duration deviance, the decrement MMN was absent in the traditional method, while the decrement and increment MMN did not differ for the same-stimulus method. These findings suggest that the brain processes frequency increments and decrements in different ways. The results also suggest the use of same-stimulus method for the calculation of duration MMN when long duration stimuli are used.