Brain Activity During Performance of Naming Tasks: Comparison Between Dyslexic and Regular Readers

Abstract

This research was aimed at contributing to the current understanding of the underlying factors of naming speed and the causes of naming speed deficits. Forty regular readers and 40 dyslexic university students participated in the study. Electrophysiological (Event-Related Potentials [ERPs]) and behavioral measures were employed. Behavioral baseline tasks assessed general ability, reading skills, reading-related cognitive abilities, and standard Rapid Automatized Naming (RAN) and Rapid Alternating Stimulus tests. ERP tasks included letter and object naming tasks adapted for electrophysiological research presentation. The dyslexics were significantly slower and less accurate than the controls on most of the baseline measures. On all the naming tasks, the peak ERP latencies were elicited later, reaction times were longer, and the P300 latency width was wider among the dyslexics as compared to the regular readers. On the choice reaction time naming tasks, accuracy for both groups was almost perfect. When naming presentation time was controlled by the experiment, the dyslexics were significantly less accurate than the controls. Our data indicated that effective naming speed was related to an earlier P200 latency peak among regular readers and to an earlier P300 latency peak and narrower area component activation in the dyslexic group. The results from this study suggest that effective RAN speed among regular readers might be a result of efficient processing of RAN information at the input stage of stimulis perception and evaluation as well as of updating and processing the information in short-term memory among dyslexics.

An examination of the rapid automatized naming–reading relationship using functional magnetic resonance imaging

“…For example, working with preschool children with and without familial risk of reading difficulties, Raschle and colleagues (2011) reported a significant relationship of the left temporoparietal and occipitotemporal regions with RAN such that, as grey matter volume increased, RAN performance improved (see also Eckert, 2004, for a review of structural findings in individuals with dyslexia). Overall, the shared RAN-reading brain regions identified here are in line with previous hypotheses regarding the neural correlates of RAN and our findings are consistent with the current reading literature (see Breznitz, 2005;Guenther & Vladusich, 2012;Indefrey & Levelt, 2004;Misra et al, 2004;Price, 2012).…”

“…RAN has been found to be highly predictive of reading ability in multiple populations and across age groups (Breznitz, 2005;Kirby et al, 2003;Misra et al, 2004;Moll et al, 2009;Powell et al, 2007;Wile & Borowsky, 2004). We provided direct evidence that RAN and reading rely on highly similar neural regions.…”

“…have used neuroimaging techniques to study the neural activation during RAN (e.g., Breznitz, 2005;Christodoulou, 2010;Gonzalez-Garriod, Gomez-Velazquez, Zarabozo, Ruiz-Villeda, & de la Serna Tuya, 2011;Misra, Katzir, Wolf, & Poldrack, 2004;Wiig et al, 2002) and the neural relationship between RAN and reading (e.g., He et al, 2013;Norton et al, 2014;Turkeltaub, Gareau, Flowers, Zeffiro, & Eden, 2003). To our knowledge, only one study has investigated the neural circuitry of RAN using fMRI (Misra et al, 2004).…”

Visual naming deficits in dyslexia: An ERP investigation of different processing domains

“…Electrophysiological recording has a high temporal precision that these measures lack, thereby providing very useful in any attempt to decompose the distinct cognitive processing stages required for production. Somewhat surprisingly, however, very few studies have taken advantage of these measures in the study of impaired visual naming in dyslexia (for an exception see Breznitz (2005) and ). As an example, using a silent object-and letter-naming task, Breznitz (2005) observed that dyslexics' slowness in naming is manifested already at the early stage of stimulus identification and classification (N1-P2-N2 complex), which persists when processing the information in memory (P300) and into the output stage.…”

“…Somewhat surprisingly, however, very few studies have taken advantage of these measures in the study of impaired visual naming in dyslexia (for an exception see Breznitz (2005) and ). As an example, using a silent object-and letter-naming task, Breznitz (2005) observed that dyslexics' slowness in naming is manifested already at the early stage of stimulus identification and classification (N1-P2-N2 complex), which persists when processing the information in memory (P300) and into the output stage. Maylseless and Breznitz (2011), in turn, found differences between groups when viewing objects and pseudo-objects in an object decision task, corresponding to the P1 and N1 components, i.e., shorter peak latencies were exhibited by the dyslexics, which is interpreted as due to the greater cognitive demands of the task on this group.…”