O processamento de sentenças ambíguas por bons e maus leitores: um estudo de ressonância magnética funcional

Abstract

Many studies have investigated the processing difficulties of children with reading difficulties at the word level (BUCHWEITZ et al., 2017; FROST et al., 2009; HANCOCK et al., 2017; KEARNS et al., 2019; PRESTON et al., 2015; PUGH et al., 2008, 2013; SHAYWITZ et al., 2000). As an extension of these studies, the present work has two goals: (i) to investigate poor reader’s processing of language beyond the word, at the sentence level; and (ii) describe, through behavioral measures and neural correlates, the processing of syntactically ambiguous sentences of typical and dyslexic Brazilian Portuguese-speaking children. We conducted two studies, a behavioral one and a functional magnetic resonance imaging study with 9 to 12 years old children. In the behavioral study, were carried out reading and speech comprehension experiments about syntactically ambiguous sentences. Before the experiments, five reading and writing tasks were applied with the children to divide them into groups of good and poor readers. 57.37% of the children were poor readers, 42.62% typical readers. Therefore, more than half of the children (57.37%) in the 5th grade of public the public tested school are not reading properly for their age. Readers with typical development identified the structural ambiguity of the ambiguous sentences in our experiments, whereas the children with reading difficulties did not. In addition, there was a statistical correlation between fluency and the understanding the structural ambiguity of sentences: the more words per minute a child read, the faster and more accurate was the processing of both reading and speech ambiguous sentences. The fMRI study on the processing of structurally ambiguous sentences in Brazilian Portuguese was done with five dyslexic children and sixteen children with typical reading development. The activation in the left inferior frontal gyrus (BA 44, 45, 47) and in the middle and superior temporal gyrus (Wernicke's area) in the reading of the syntactic ambiguity sentences replicated data from previous studies (FIEBACH; VOS; FRIEDERICI, 2004; MASON et al., 2003; MASON; JUST, 2007; RODD et al., 2010; RODD; DAVIS; JOHNSRUDE, 2005). The direct comparison between structurally ambiguous sentences and unambiguous sentences activated the Brodmann area 47, only for participants who identify the structural ambiguity of the ambiguous sentences. The correlation between fluency and identifying the structural ambiguity of the ambiguous sentences was found in all the experiments carried out in this research. Children with greater reading proficiency showed faster and more accurate speech comprehension of structurally ambiguous sentences, indicating the bidirectional correlation between reading and speech comprehension. Children with better reading fluency were better in processing sentences.