Benefits of dance for Parkinson's: The music, the moves, and the company

Dance classes designed for people with Parkinson's are very popular and associated not only with increasing individuals' motor control abilities but also their mood; not least by providing a social network and the enjoyment of the music. However, quantitative evidence of the benefits is inconsistent and often lacks in power. For a better understanding of the contradictory findings between participants' felt experiences and existing quantitative findings in response to dance classes, we employed a mixed method approach that focussed on the effects of music. Participant experience of the dance class was explored by means of semi-structured interviews and gait changes were measured in a within-subjects design through the Timed Up and Go (TUG) test before and after class, with and without music. We chose the TUG test for its ecological validity, as it is a simple test that resembles movements done in class. We hypothesised that the music and the dance class would have a facilitating effect on the TUG performance. In line with existing research, we found that before class, the gait of 26 participants was significantly improved when accompanied by a soundtrack. However, after class, music did not have a significantly facilitating effect, yet gait without music significantly improved after class compared to before. We suggest that whilst the music acts as an external stimulator for movement before the dance class, after the dance class, participants have an internalised music or rhythm that supports their motor control. Thus, externally played music is of less relevance. The importance of music was further emphasised in the qualitative data alongside social themes. A better understanding of how music and dance affects Parkinson's symptoms and what aspects make individuals 'feel better' will help in the design of future interventions.

"I'm Never Going to Be in Phantom of the Opera": Relational and Emotional Wellbeing of Parkinson's Carers and Their Partners in and Beyond Dancing

The caregiving of people who suffer from Parkinson's predominantly falls on their life partners. Living with and caring for somebody with Parkinson's can cause a range of emotional, psychological, and financial pressures. Whilst an increasing number of alternative treatments for Parkinson's is available, such as dancing, the focus is predominantly on the motor and emotional improvements of the person suffering from Parkinson's. For caregivers, however, dancing can be a double-edged sword: Although dancing can offer an opportunity to enjoy a social event with their partner; attending dance classes puts additional responsibilities on the carer. The present study thus aimed at exploring the experiences of participants with Parkinson's who attended dance classes as well as the experiences of their care-partners in and around these classes along with their view on everyday life changes experienced since dancing. Six couples were interviewed individually where one partner had Parkinson's. The interviews were also analyzed separately using inductive thematic analysis. In line with existing programmes that offer dance for people with Parkinson's, the classes used a mixture of ballroom, ballet, contemporary, and creative dance styles; supported and influenced by an instructors' extensive knowledge of the abilities and needs of those with Parkinson's. A recurring challenge for Parkinson's sufferers relates to "who is in control?" based on the many unknown changes of Parkinson's; as well as seeing/being seen. Yet frustrations were oftentimes counteracted with humour. Also, when dancing, participants with Parkinson's reported enjoying playful interactions. Caregivers' themes focussed on theirs and their partners' wellbeing regarding social contacts and openness, as well as issues surrounding their responsibilities as carers. Whilst some identified dance movements that help them in everyday tasks, they and their care-partners question the impact of dance on their motor control. Yet, participants unanimously agree that dance provides relevant opportunities for social contact and comparison. Nevertheless, the care-partners' concerns remain about the burden of increasing responsibility for the wellbeing of both partners but they also reported enjoying dancing with their partner. Experiencing their loved ones as more cheerful after starting dance classes is recognised an important positive and impactful outcome of dancing together.

Feeling for the Other With Ease: Prospective Actors Show High Levels of Emotion Recognition and Report Above Average Empathic Concern, but Do Not Experience Strong Distress

Differences in empathic abilities between acting, dance, and psychology students were explored, in addition to the appropriateness of existing empathy measures in the context of these cohorts. Students (N = 176) across Higher Education Institutions in the United Kingdom and Europe were included in the online survey analysis, consisting of the Reading the Mind in the Eyes (RME) test, the Interpersonal Reactivity Index (IRI), the Empathy Quotient (EQ), and the E-drawing test (EDT), each measuring particular facets of empathy. Based on existing evidence and our understanding of the discipline practices, we predicted that acting students would perform the best at identifying people’s emotional expressions but might lack other cognitive or affective empathy skills, particularly those related to emotional reactions. This cohort thus provides an opportunity to evaluate different empathy measures. While actors showed significantly higher RME scores than dancers, the difference between actors and psychologists was marginal. Moreover, actors’ scores did not differ significantly on other empathy measures, such as their concern for others’ emotional wellbeing or fantasy, both measured by IRI subscales. Psychology students scored highest in the IRI perspective taking subscale and the data supported anecdotal evidence that psychologists were more concerned for others’ emotional wellbeing than dancers or actors. Dancers seemed the least concerned with others’ perspectives and emotional states, which we explained through a somatosensory ‘inward’ focus required by their art form. Nevertheless, compared to the general population, our groups reported higher empathic abilities on all IRI subscales except for personal distress. Altogether, our study shows that the RME, the IRI, and the EDT vary in their susceptibility to different facets of empathic abilities in acting, dance, and psychology students whereas the EQ does not. Emotions can be expressed and perceived through language, facial expressions, or behavior. As many empathy tests focus on one type of signal they might miss other strategies. Where empathy tests are applied to individuals that have a predominance to read or respond to others in a particular way, as we showed through these three disciplines, they might not capture these empathic strategies. We thus propose that empathy tests must evolve by means of integrating varied forms of communication.

Neuronal bases of structural coherence in contemporary dance observation

The neuronal processes underlying dance observation have been the focus of an increasing number of brain imaging studies over the past decade. However, the existing literature mainly dealt with effects of motor and visual expertise, whereas the neural and cognitive mechanisms that underlie the interpretation of dance choreographies remained unexplored. Hence, much attention has been given to the action observation network (AON) whereas the role of other potentially relevant neuro-cognitive mechanisms such as mentalizing (theory of mind) or language (narrative comprehension) in dance understanding is yet to be elucidated. We report the results of an fMRI study where the structural coherence of short contemporary dance choreographies was manipulated parametrically using the same taped movement material. Our participants were all trained dancers. The whole-brain analysis argues that the interpretation of structurally coherent dance phrases involves a subpart (superior parietal) of the AON as well as mentalizing regions in the dorsomedial prefrontal cortex. An ROI analysis based on a similar study using linguistic materials (Pallier et al., 2011) suggests that structural processing in language and dance might share certain neural mechanisms.

Differences in fMRI intersubject correlation while viewing unedited and edited videos of dance performance

Intersubject correlation (ISC) analysis of functional magnetic resonance imaging (fMRI) data provides insight into how continuous streams of sensory stimulation are processed by groups of observers. Although edited movies are frequently used as stimuli in ISC studies, there has been little direct examination of the effect of edits on the resulting ISC maps. In this study we showed 16 observers two audiovisual movie versions of the same dance. In one experimental condition there was a continuous view from a single camera (Unedited condition) and in the other condition there were views from different cameras (Edited condition) that provided close up views of the feet or face and upper body. We computed ISC maps for each condition, as well as created a map that showed the difference between the conditions. The results from the Unedited and Edited maps largely overlapped in the occipital and temporal cortices, although more voxels were found for the Edited map. The difference map revealed greater ISC for the Edited condition in the Postcentral Gyrus, Lingual Gyrus, Precentral Gyrus and Medial Frontal Gyrus, while the Unedited condition showed greater ISC in only the Superior Temporal Gyrus. These findings suggest that the visual changes associated with editing provide a source of correlation in maps obtained from edited film, and highlight the utility of using maps to evaluate the difference in ISC between conditions.

"Some like it hot": spectators who score high on the personality trait openness enjoy the excitement of hearing dancers breathing without music

Music is an integral part of dance. Over the last 10 years, however, dance stimuli (without music) have been repeatedly used to study action observation processes, increasing our understanding of the influence of observer’s physical abilities on action perception. Moreover, beyond trained skills and empathy traits, very little has been investigated on how other observer or spectators’ properties modulate action observation and action preference. Since strong correlations have been shown between music and personality traits, here we aim to investigate how personality traits shape the appreciation of dance when this is presented with three different music/sounds. Therefore, we investigated the relationship between personality traits and the subjective esthetic experience of 52 spectators watching a 24 min lasting contemporary dance performance projected on a big screen containing three movement phrases performed to three different sound scores: classical music (i.e., Bach), an electronic sound-score, and a section without music but where the breathing of the performers was audible. We found that first, spectators rated the experience of watching dance without music significantly different from with music. Second, we found that the higher spectators scored on the Big Five personality factor openness, the more they liked the no-music section. Third, spectators’ physical experience with dance was not linked to their appreciation but was significantly related to high average extravert scores. For the first time, we showed that spectators’ reported entrainment to watching dance movements without music is strongly related to their personality and thus may need to be considered when using dance as a means to investigate action observation processes and esthetic preferences.

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.

Motor simulation without motor expertise: enhanced corticospinal excitability in visually experienced dance spectators

The human “mirror-system” is suggested to play a crucial role in action observation and execution, and is characterized by activity in the premotor and parietal cortices during the passive observation of movements. The previous motor experience of the observer has been shown to enhance the activity in this network. Yet visual experience could also have a determinant influence when watching more complex actions, as in dance performances. Here we tested the impact visual experience has on motor simulation when watching dance, by measuring changes in corticospinal excitability. We also tested the effects of empathic abilities. To fully match the participants' long-term visual experience with the present experimental setting, we used three live solo dance performances: ballet, Indian dance, and non-dance. Participants were either frequent dance spectators of ballet or Indian dance, or “novices” who never watched dance. None of the spectators had been physically trained in these dance styles. Transcranial magnetic stimulation was used to measure corticospinal excitability by means of motor-evoked potentials (MEPs) in both the hand and the arm, because the hand is specifically used in Indian dance and the arm is frequently engaged in ballet dance movements. We observed that frequent ballet spectators showed larger MEP amplitudes in the arm muscles when watching ballet compared to when they watched other performances. We also found that the higher Indian dance spectators scored on the fantasy subscale of the Interpersonal Reactivity Index, the larger their MEPs were in the arms when watching Indian dance. Our results show that even without physical training, corticospinal excitability can be enhanced as a function of either visual experience or the tendency to imaginatively transpose oneself into fictional characters. We suggest that spectators covertly simulate the movements for which they have acquired visual experience, and that empathic abilities heighten motor resonance during dance observation.

Injury, imagery, and self-esteem in dance healthy minds in injured bodies?

The purpose of this study was to investigate a selection of psychological variables (help-seeking behaviors, mental imagery, self-esteem) in relation to injury among UK dancers. We recruited 216 participants from eight dance styles and six levels of involvement. It was found that 83.5% of the participants had experienced at least one injury in the past year. The most common response to injury was to inform someone, and most continued to dance when injured, albeit carefully. Physical therapy was the most common treatment sought when an injury occurred (38.1%), and dancers seemed to follow recommendations offered. Injured and non-injured dancers did not differ in their imagery frequencies (facilitative, debilitative, or injury-related) and scored similarly (and relatively high) in self-esteem. Neither facilitative nor debilitative imagery was correlated with self-esteem, but dancers who engaged in more facilitative imagery in general also reported doing so when injured. Altogether, it appears that injury is not related to dancers' self-esteem or imagery, at least not when injuries are mild or moderate. Even so, such conclusions should be made with caution, given that most dancers do sustain at least one injury each year.

Segmenting the Body into Parts: Evidence from Biases in Tactile Perception

How do we individuate body parts? Here, we investigated the effect of body segmentation between hand and arm in tactile and visual perception. In a first experiment, we showed that two tactile stimuli felt farther away when they were applied across the wrist than when they were applied within a single body part (palm or forearm), indicating a “category boundary effect”. In the following experiments, we excluded two hypotheses, which attributed tactile segmentation to other, nontactile factors. In Experiment 2, we showed that the boundary effect does not arise from motor cues. The effect was reduced during a motor task involving flexion and extension movements of the wrist joint. Action brings body parts together into functional units, instead of pulling them apart. In Experiments 3 and 4, we showed that the effect does not arise from perceptual cues of visual discontinuities. We did not find any segmentation effect for the visual percept of the body in Experiment 3, nor for a neutral shape in Experiment 4. We suggest that the mental representation of the body is structured in categorical body parts delineated by joints, and that this categorical representation modulates tactile spatial perception.

Towards a sensorimotor aesthetics of performing art

The field of neuroaesthetics attempts to identify the brain processes underlying aesthetic experience, including but not limited to beauty. Previous neuroaesthetic studies have focussed largely on paintings and music, while performing arts such as dance have been less studied. Nevertheless, increasing knowledge of the neural mechanisms that represent the bodies and actions of others, and which contribute to empathy, make a neuroaesthetics of dance timely. Here, we present the first neuroscientific study of aesthetic perception in the context of the performing arts. We investigated brain areas whose activity during passive viewing of dance stimuli was related to later, independent aesthetic evaluation of the same stimuli. Brain activity of six naïve male subjects was measured using fMRI, while they watched 24 dance movements, and performed an irrelevant task. In a later session, participants rated each movement along a set of established aesthetic dimensions. The ratings were used to identify brain regions that were more active when viewing moves that received high average ratings than moves that received low average ratings. This contrast revealed bilateral activity in the occipital cortices and in right premotor cortex. Our results suggest a possible role of visual and sensorimotor brain areas in an automatic aesthetic response to dance. This sensorimotor response may explain why dance is widely appreciated in so many human cultures.