Comparison of Cervical and Ocular Vestibular Evoked Myogenic Potentials in Dancers and Non-Dancers

Evaluation of auditory working memory in Bharatanatyam dancers

Background

Neuroplasticity is a phenomenon exhibited by our nervous system as an indicator of overall development and in response to training, injury/loss of particular function, treatment/drugs and as a result of stimulation from the surrounding environment.

Objective

The aim of the current study was to assess the auditory working memory capacities in Bharatanatyam dancers.

Method

The participants comprised fifty-four females with normal hearing sensitivity who belonged to two groups. Group-I consisted of 27 individuals who underwent formal training in Bharatanatyam for a minimum period of three years. Group-II consisted of the age-matched control group, consisting of 27 individuals who were non-dancers. The auditory working memory tasks included arranging the English digits presented binaurally in forward, backward, ascending, and descending spans. The maximum values (for the length of sequence arranged), midpoint values (average score), and response time for each task were noted down and compared among groups.

Results

The scores were compared using the Mann-Whitney U test, which revealed enhanced working memory exhibited by dancers for maximum values and midpoint scores for all three tasks except ascending span. It was also noted that the dancers exhibited a shorter response time compared to non-dancers for all the tasks except ascending span.

Conclusion

The current study highlights an enhanced auditory working memory capacity in Bharatanatyam dancers, which could be perceived as evidence of neuroplastic changes induced in the auditory and motor cortex as a consequence of extensive stimulation for auditory processing abilities and motor planning resulting from long-term dance training and regular practice.

Vestibular System Eletrophysiology: An Analysis of the Relationship between Hearing and Movement

Introduction  Knowledge about the positive effects that music and dance bring, in its various forms, to the healthy human brain, is important not only in the context of basic neuroscience but may also strongly affect practices in neurorehabilitation.

Objective  To verify the relationship between hearing and movement and, specifically, to analyze the interference of professional dance practice and formal musical training in the magnitude of the vestibule-cervical and vestibular reflexes.

Method  The sample consisted of 92 subjects, aged between 18 and 35 years old, 31 professional musicians, 31 ballet dancers, and 30 control subjects. Only subjects with normal hearing sensitivity were included. Cervical vestibular evoked myogenic potential (cVEMP) was recorded in the sternocleidomastoid muscle, and ocular vestibular evoked myogenic potential (oVEMP) was recorded in the lower oblique muscle of the eye, using tone-bursts (500Hz). Analysis of variance (ANOVA) or Kruskall-Wallis tests were performed.

Results  The cVEMP presented earlier and higher amplitude waves when recorded in the group of dancers, with a significant difference between all tested groups for latency and amplitude of the N23 wave; the comparison was restricted between dancers and control groups, with no difference between ballet dancers and musicians. The N1 wave of the oVEMP presented lower latencies in dancers than in musicians and controls ( p  = 0.001). No significant differences were found between the groups for the P1 wave.

Conclusion  Greater magnitudes of vestibule-cervical reflex responses and faster vestibule-ocular reflex responses were observed in dancers. Dance practice provides greater development of the vestibular system, but musical training also contributes to the magnitude of these responses.

Effect of practicing yoga on cervical vestibular evoked myogenic potential

The present study attempted to determine the effect of practicing yoga on functioning of sacculo-collic pathway using cervical vestibular evoked myogenic potential (cVEMP). cVEMP was recorded from 40 participants (20 who practice yoga regularly and 20 who do not practice yoga regularly). The differences in amplitude of P1, N1, P1-N1 complex, asymmetry ratio and latencies of P1 and N1 of cVEMP were compared between both the groups. The results of the study showed that there was a significant increase (p < 0.05) in the amplitude of P1, N1 and P1-N1 complex and a significant reduction in latency (p < 0.05) for experimental group. The asymmetry ratio in individuals who practice yoga was significantly lower (Mean = 6.73) compared to the control group (Mean = 19.13). Multivariate regression analyses suggested that the number of years of yoga practice significantly predicted the amplitude of P1-N1 complex (β = 0.70, p < 0.01) and amplitude ratio (β = 0.72, p < 0.01). Thus, practicing yoga improves postural control and strengthens the muscles and vestibular system leading to enhanced cVEMP responses. The plastic changes in the vestibular system and increased muscular strength because of constant practicing of yoga could have led to changes in cVEMP responses. However, further studies on a larger group of individuals are essential for better clinical applicability of the results.

Enhanced auditory evoked potentials in musicians: A review of recent findings

Auditory evoked potentials serve as an objective mode for assessment to check the functioning of the auditory system and neuroplasticity. Literature has reported enhanced electrophysiological responses in musicians, which shows neuroplasticity in musicians. Various databases including PubMed, Google, Google Scholar and Medline were searched for references related to auditory evoked potentials in musicians from 1994 till date. Different auditory evoked potentials in musicians have been summarized in the present article. The findings of various studies may support as evidences for music-induced neuroplasticity which can be used for the treatment of various clinical disorders. The search results showed enhanced auditory evoked potentials in musicians compared to non-musicians from brainstem to cortical levels. Also, the present review showed enhanced attentive and pre-attentive skills in musicians compared to non-musicians.