Funciones ejecutivas entre músicos y no músicos: un metaanálisis / Executive functions between musicians and non-musicians: a metanalysis

RESUMEN

Resumen Se ha sugerido que la práctica profesional de un instrumento musical esta relacionada con mejores puntajes en tareas de funciones ejecutivas. Con el fin de examinar sistemáticamente esta hipótesis se realizó un metaanálisis para identificar el efecto de la interpretación de un instrumento en las funciones ejecutivas, así como las variables que podrían moderar dicho efecto. El metaanálisis incluyó estudios empíricos que: (1) compararon los puntajes en medidas de funciones ejecutivas entre músicos y no músicos; (2) reportaron las medias y desviaciones estándar; (3) el grupo de comparación no recibió entrenamiento musical; y (4) los participantes no presentaron discapacidad motora o cognitiva. Se identificó que los músicos, en comparación con los no músicos, muestran mejores puntajes en tareas de funciones ejecutivas (d = .712). Los resultados apoyan la hipótesis de que la práctica de un instrumento musical está relacionada con mejores puntuaciones en tareas de funciones ejecutivas.

ABSTRACT

Abstract Nowadays, it is widely accepted that experience can modify multiple aspects of the functioning and structure of the brain; however, there is still a long way to go to understand the mechanisms behind these modifications. In order to understand the relationship between experience and brain plasticity, models and paradigms have been adapted from cognitive neurosciences; one of them has been music training. In the last decades, this paradigm has strengthened because it allows us to understand the structural and functional modifications produced by training. It has been demonstrated that musicians compared to non-musicians present larger sizes of specific brain regions, in particular, the prefrontal cortex, which is associated with a better performance in executive functions tasks. In addition, long-term neurophysiological changes have been identified in people who play an instrument. A relationship between playing an instrument and better performance in executive functions has been identified. However, the evidence of this effect is contradictory. Executive functions are a series of general control processes that help regulate thinking and behavior. Some research indicates that learning an instrument is associated with better performance in working memory, but not regarding tasks related to inhibitory control and cognitive flexibility. However, other studies have revealed significant differences between musicians and non-musicians, both in working memory and tasks of cognitive flexibility as well as in inhibitory control. It is possible that the contradictory results are due to the methodological diversity through which this topic has been addressed, since some studies have carried out experimental and quasi-experimental designs, and others have developed correlational approaches. In addition, different theoretical models have been used to evaluate executive functions. For this study, we work with the theoretical model of Miyake et al. (2000), which is a solid theoretical-empirical proposal about three clearly differentiable executive functions: inhibitory control, cognitive flexibility, and working memory. A meta-analysis was performed with the purpose of identifying the effect of playing an instrument on executive functions as well as identifying the moderator variables. By doing this, we wanted to clarify the problem in question and the controversial results; therefore, empirical studies comparing musicians against non-musicians were included. The comparison group should not have been exposed to musical training, the participants should not present motor or cognitive disabilities, and finally, studies should report means and standard deviations for the scores on executive functions tasks. We included papers published between January 2000 and July 2017. The moderator variables studied were: age in months at the time of evaluation, age at which training began, and total years of training. The coding strategy allowed us to identify a total of 42 294 articles. The titles and abstracts were analyzed and those that did not meet the inclusion criteria were eliminated. This procedure allowed the detection of 24 articles for future analysis, and 12 out of them were finally selected. These 12 articles contributed to 60 effect sizes and 513 participants. The results showed that musicians have a better performance in executive functions tasks when they are compared to non-musicians, d = .712, n = 60, IC95% = (.57; .85), p < .0001. Additionally, the analysis of moderating variables revealed that the practice of an instrument equally benefits all executive functions, and the most important benefit occurs in older adults and children. Results support the hypothesis that the high level of difficulty involved with learning to play an instrument can influence a better performance in executive functions tasks. Our study points out the need of designing research that allows the scientific community to investigate the effect of prolonged musical training over time.