Effects of early childhood music training: a randomized clinical trial

Abstract

The effects of music on the brain and, consequently, on the development of different skills, have been described, with results that highlight music learning, as it activates both cerebral hemispheres, simultaneously, and stimulates the brain, globally. Additionally, the similarities in the hierarchical structure of the learning process of music and language lead to a belief in the existing connection between both in higher cognitive functions and subsystems such as memory, attention, and categorization. Studies carried out with children using cochlear implants have shown that musical training can improve rhythmic and pitch perception, in addition to helping in the development of prosody perception. However, the high heterogeneity of the final result, justified by the methodological diversity of the studies associated with different degrees of bias, limits the ability to generalize the data. Thus, it is necessary to carry out studies with objective measures and control of variables such as auditory acuity and the quality of the information that is arriving in the auditory cortex, in order to isolate the effect of music on the child's global development. This methodological rigor cannot be achieved in individuals presented with hearing loss because, in addition to the interference of the electronic device, there is a variability of factors inherent in the etiology and environmental factors in which the child is inserted that imply a risk of bias. Thus, the present study aims at verifying the effects of musical training with the Music Learning Theory-acculturation-carried out in early childhood in normally hearing children with reference to global developmental milestones and the maturation of the auditory cortex. This is a controlled, longitudinal, randomized, and blind clinical study. A total of 60 children aged six months are estimated as an initial sample, randomly subdivided into the simple type of three groups: the negative control group (Group 1), which will have only social exposure to music, a common condition for all groups. The group with a controlled musical intervention (Group 2), considered a positive control group, will have a musical intervention without a defined methodology, but that will provide musical experience. The experimental group (Group 3) will have an additional musical intervention based on MLT, that is, in a structured way with sequenced learning activities. Musical training and controlled musical exposure will be carried out in a collective format, once a week for 50 minutes over a period of five months, totaling 20 classes. The pre- and post-intervention assessment will be carried out through the application of the Bayley-III Child Development Scale, in order to verify the markers of the development of language, motor, socioemotional, cognitive, and adaptive behavior skills, in addition to the potential cortical auditory evoked responses P1, N1, P2, N2. Statistical analysis will be performed using the Statistical Software Package for the Social Sciences (SPSS), version 24, for all analyzed variables. Data normality will be analyzed using the Shapiro-Wilk test. Assuming that the variables of interest have a normal distribution, for intragroup comparative analysis pre- and post-intervention, the paired Student's t test will be used, and the comparison between groups will be performed by Analysis of Variance (ANOVA) of repeated measures. If the variables of interest do not have a normal distribution, the corresponding non-parametric tests will be applied. In order to investigate which set of predictor variables (independent variables) provides a better explanation for the outcome variable (dependent variable) and to understand the relationship between an outcome variable and a predictor one, controlling for the effect of other predictor variables, a multiple regression analysis will be carried out. The significance level adopted will be 5%. (AU)