Eficiência cerebral e velocidade de processamento de alunos dos Ensino Básico de Belo Horizonte, MG

Abstract

Brain efficiency predicts individual differences in cognitive performance, which can be determined by neuronal activity and consequent brain energy consumption during tasks. One of the important parameters of measurement of this efficiency is the processing speed, a basic component in the study of the individual differences of intelligence. Considering the accomplishment of simple cognitive tasks, faster individuals present less neuronal activation and, therefore, better brain efficiency. In this way, it is possible to establish a positive relation between the speed at which simple cognitive tasks are performed and intelligence. The main objective of this study was to verify the occurrence of a better cerebral efficiency in Brazilian children, at two different periods, through measures of reaction time. Therefore, the data obtained in an earlier study, carried out in 2005 by the Laboratory for Evaluation of Individual Differences - LADI / UFMG, were used to compare the performance of schoolchildren in 2017/2018. In order to match the current sample with that of 2005, 198 students aged between 10 and 15 years, enrolled in the public education system of Belo Horizonte, were tested with the Raven’s Progressive Matrices Test - General Scale. The sample finally compared was composed of 48 children evaluated in 2005 and 48 children evaluated in 2017/2018. Reaction Time measurement was obtained by performing a Computerized Perceptual Discrimination task. Subjects also underwent an Out-of-Network Disruptive Behavior Assessment using the Attention Deficit and Hyperactivity Disorder Scale, the same measure used in 2005. Despite the matching effort in age and socioeconomic level, the gender and hyperactivity genders had a greater influence on the sample than in the 2005 sample. The final results indicated that the samples did not differ significantly in cognitive performance over a 12-year interval. Similarly, there were no statistically significant differences between the samples at the time spent for decision-making. This is probably due to the significant correlation between reaction time and cognitive performance (-0.33 in 2005 and -0.38 in 2017/2018). We conclude that there is an intimate relationship between cognitive performance and processing speed, as there is a need to control behavioral aspects of the samples in studies that intend to identify cognitive gains over time.