Brain Activation during Sentence Comprehension among Good and Poor Readers

Abstract

This study sought to increase current understanding of the neuropsychological basis of poor reading ability by using fMRI to examine brain activation during a visual sentence comprehension task among good and poor readers in the third (n = 32) and fifth (n = 35) grades. Reading ability, age, and the combination of both factors made unique contributions to cortical activation. The main finding was of parietotemporal underactivation (less activation than controls) among poor readers at the 2 grade levels. A positive linear relationship (spanning both the poor and good readers) was found between reading ability and activation in the left posterior middle temporal and postcentral gyri and in the right inferior parietal lobule such that activation increased with reading ability. Different developmental trajectories characterized good and poor readers in the left angular gyrus: activation increased with age among good readers, a change that failed to occur among poor readers. The parietotemporal cortex is discussed in terms of its role in reading acquisition, with the left angular gyrus playing a key role. It is proposed that the functioning of the cortical network underlying reading is dependent on a combination of interacting factors, including physiological maturation, neural integrity, skill level, and the nature of the task.

Fact learning in complex arithmetic and figural‐spatial tasks: The role of the angular gyrus and its relation to mathematical competence

“…Extensive training of problem-solution pairs (e.g., arithmetic facts such as ''3 3 3 5 9'') may finally result in an automatic activation and/or retrieval of the solution upon recognition of the problem. Evidence in favour of this assumption comes from several language studies demonstrating that the angular gyrus is also involved in the mapping between phonological and orthographic units at both, the letter and word level, and in their integration with semantic representations [Booth et al, 2002;Callan et al, 2005;Joubert et al, 2004;Meyler et al, 2007]. Callan et al [2005], for instance, showed that the acquisition of new orthographic-phonological mappings results in increasing angular gyrus activation.…”

Modifying the brain activation of poor readers during sentence comprehension with extended remedial instruction: A longitudinal study of neuroplasticity

“…The question of continuity of function in the brain-behavior relationship remains to be further explored, although initial evidence supports this view (e.g. Hampson et al, 2006;Meyler et al, 2007;Shaywitz et al, 2002). The answer could have relevance for our understanding of the nature of reading problems, and for public policy regarding their identification and treatment.…”

“…While only a few studies have examined cortical function among poor readers in higher-level reading tasks, evidence is beginning to emerge indicating that underactivation in the parietotemporal and occipito-temporal regions may likewise characterize poor readers when they are reading sentences for comprehension (e.g. Kronbichler et al, 2006;Meyler et al, 2007;Seki et al, 2001). Together, the findings from word-level and sentence-level studies support the view that underfunctioning of these regions represents 0028-3932/$ -see front matter © 2008 Elsevier Ltd. All rights reserved.…”

Right-hemispheric cortical contributions to language ability in healthy adults

“…A study adapting a semantic discrimination task showed that children with good reading skills express increased activation in the left BA 22 (Meyler et al, 2007). In another study on children and adults, high word generation performance is predominantly characterized by activation in the right frontal cortex and in medial cortical areas (Brown et al, 2005).…”

“…The review suggests that there is a mainly left-lateralized network, involving frontoparietal regions, activated by tasks tapping intelligence and reasoning. The functional correlates of this model may be explained by the neural efficiency hypothesis of intelligence, which states that less activation in involved neural networks is correlated with increased cognitive performance (Haier et al, 1988;Neubauer & Fink, 2009;Brown et al, 2005;Meyler et al, 2007).…”