versión On-line ISSN 1668-7027
LIPINA, Sebastián Javier et al. Pobreza y desempeño ejecutivo en alumnos preescolares de la Ciudad de Buenos Aires (República Argentina). Interdisciplinaria [online]. 2004, vol.21, n.2, pp. 153-193. ISSN 1668-7027.
In general, the effects of poverty on early cognitive performance have been studied using a definition of poverty based on terms of income, and within the context of paradigms of cognitive evaluation based on the hypothesis of a general intelligence factor. Conversely, in the present report the concept of Unsatisfied Basic Needs (UBN) was used as poverty criterion, and a cognitive paradigm of executive functions based on neurobiological concepts was applied. This paradigm outlines the existence of discrete and interactive components of cognitive functioning guided toward objectives, and associated to the activation of cerebral circuits that involves the prefrontal cortex. The performance of 247 preschoolers (3 to 5 year-olds) from schools in District 4 of the City of Buenos Aires (Boca-Barracas), and in the districts of Vicente López and San Isidro of Gran Buenos Aires, was compared. Sample groups included children from poor (UBN) and non-poor homes or with Satisfied Basic Needs (SBN). They were studied with a battery of executive tests [A-not-B, Spatial Reversal, and Color Reversal (Espy, Kaufmann, McDiarmid, & Glisky, 1999); Three and Four Colors (Balamore & Wozniak, 1984); Strooplike Day-Night (Gerstadt, Hong, & Diamond (1994); and Tower of London (Shallice, 1982)] to evaluate the components of cognitive flexibility (working memory, attentional shifting, self-monitoring, and conceptual transfer), goal-setting (initiating, planning, problem solving, and strategic behavior), and attentional control. A selection procedure was applied to all cases, taking into account: prematurity, weight at the time of birth, medical record of neurological and developmental disorders, actual weight, height and their relationship at the time of testing, intellectual quotient of execution (WPPSI), and official certification of child abuse in their homes. Poor homes were identified by applying a scale of socio-economic level (NES) based on conceptual and operational definitions used by the Instituto Nacional de Estadísticas y Censos (INDEC) of Argentina. Bivariate and multivariate tests were applied to analyze the effects of the independent variables (socio-economic group, age, sex and difficulty level) on the dependents and their interactions. Correlations and simple regressions were applied to analyze the associations between cognitive performance and socio-economic level. In A-not-B, Spatial Reversal and Color Reversal tests the UBN group made less previous correct trials before reaching the efficiency criteria (difficulty to find the hidden rule) and consecutive correct trials (difficulty to maintain outstanding information). They also made more reiterative errors (failure in the control of interferences). In the Three and Four Colors Test, the UBN group had lower scores in all the analyzed variables. Children within this group also needed more demonstrations and verbalizations from the experimenters. In the Tower of London Test, UBN children showed an increased delay to begin and to organize the task, and were less efficient in achieving the objectives. Planning time decreased when cognitive demands were increased. The SBN group showed an inverse profile. Both groups had similar performance in the Stroop-like Day-Night Test. When performance variations were analyzed in terms of age and difficulty level, the tendencies were similar to those reported in previous studies. Gender differences were registered in A-not-B and Tower of London tests, with girls showing a better perform-ance. Finally, there were positive associations between performance success and socio-economic total score, and negative associations between errors and socio-economic total score. Present results confirm that poverty has a negative impact on cognitive performance in terms of the executive function paradigm used. The advantages of a cognitive paradigm based on a neurobiological theoretical framework in the context of social and school intervention programs for children from a socially risky population, are also discussed.
Palabras clave : Poverty; Cognitive development; Executive functions; Preschoolers.