ng to a questionnaire completed by the parents, belonged to families of SES A No performance differences were found on the cognitive tasks evaluated in this study in children aged 6—7 years old, 8—9 years old and 10, 11 and 12 years old.
We then decided to split the sample in these three age ranges. According to a study of Brito , the cutoff point suggested for the Brazilian population is a performance above the 90 th percentile. We only evaluate children who fit the inclusion criteria. No child was excluded after cognitive assessment.
The schools were selected by convenience sampling and the names of the students from each grade were randomly selected draw. The following memory tasks were used for this study: digit span forward and backward maximum score: 28 points , pseudoword span maximum score: 20 points , visuospatial working memory similar to Corsi Blocks, but on 2 D, maximum score: 28 points , immediate recall of a list of nine words, immediate recall of nine figures showed to children visuoverbal episodic memory and semantic memory 4 general knowledge questions — 1 point each.
For assessment of language: rhyme task children had to say which words rhyme, total score of 4 points , phonemic subtraction take off one phoneme of a composite three-letter syllable, total score of 6 points , listening comprehension 5 points , inferential processing total score of 8 points , reading aloud 17 points , reading comprehension total score of 5 points , spelling total score of 19 points , spontaneous writing and written copies of words.
First, the construction of measurement models will be described, and finally, the structural model. The indexes of adjustments of models are presented according to Byrne The following tasks were used: rhyme, phonemic subtraction, reading words and pseudowords, spontaneous writing and reading comprehension as indicators of the latent variable oral and written language.
The tasks digit span forward and backward , pseudoword span and visuospatial working memory composed the latent variable working memory. The go-no go task and the orthographic and semantic verbal fluency tasks were used as indicators of the latent variable executive functions inhibitory control component. The latent variable verbal memory was composed of the following tasks: semantic memory, episodic memory immediate recall and visuoverbal episodic memory.
Once the literature has affirmed that there are differences in the contribution of SES to the different ages, we made the structural models by age range 6—7, 8—9, 10— The estimated coefficients are reported in Fig. The estimated coefficients are reported in Figs. The results show a moderate effect of SES and specifically parental education mainly maternal education on the performance in memory working memory , language and executive functions, especially for younger children from 6 to 12 years old.
The children with lower SES had lower performance regarding IQ, verbal episodic and semantic memory, working memory, written language, visuoverbal memory and inhibitory control tasks than those with higher SES. The findings of the present study are consistent with those from other studies that have demonstrated the contribution of SES to cognitive performance at different age ranges, especially in younger children Blair et al.
In fact, the magnitude of the relationship between SES and the identified factors were similar to other studies conducted in other contexts, like US and Canada Lupien et al. In the early years of childhood until school age, the socioeconomic status is a major factor since it may limit the conditions of the environment, what impacts on stimulation, access to materials and activities that favor cognitive development, presence of parents or caregivers and willingness to engage in activities with the child Forns et al.
Cognition, in general, and more specifically, memory, language and executive functions, seem to be more affected by the socioeconomic environment, due to its prolonged development — at a neuroanatomical level —, which may lead to increased susceptibilit