Browsing by Author "Araujo, Susana"
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- A meta-analytic review of naming-speed deficits in developmental dyslexiaPublication . Araujo, Susana; Faisca, LuisThis study presents a meta-analytic review of serial rapid automatized naming (RAN) deficits in individuals with dyslexia relative to typical readers (based on 216 effect sizes comprising 8335 dyslexic readers, 14,083 age-matched controls, and 921 reading-matched controls). A random-effects model analysis indicated a large impairment in speeded RAN in individuals with dyslexia compared with age-matched controls (d = 1.19) but a similar performance when compared with reading-matched controls (d = 0.13). In addition, dyslexic readers presented a deficit in discrete-naming formats (d = 0.74), although the deficit in serial RAN was notably larger; hence, adding seriality is particularly detrimental for these readers. The deficit appears to span all stimulus types (alphanumeric and nonalphanumeric), indicating that processes beyond letter processing are responsible for the delays and are independent of set size. Poor RAN is a long-term and universal symptom of dyslexia, and the transparency of the writing system does not influence its severit
- Disentangling stimulus plausibility and contextual congruency: Electrophysiological evidence for differential cognitive dynamicsPublication . Coco, Moreno I.; Araujo, Susana; Petersson, Karl MagnusExpectancy mechanisms are routinely used by the cognitive system in stimulus processing and in anticipation of appropriate responses. Electrophysiology research has documented negative shifts of brain activity when expectancies are violated within a local stimulus context (e.g., reading an implausible word in a sentence) or more globally between consecutive stimuli (e.g., a narrative of images with an incongruent end). In this EEG study, we examine the interaction between expectancies operating at the level of stimulus plausibility and at more global level of contextual congruency to provide evidence for, or against, a disassociation of the underlying processing mechanisms. We asked participants to verify the congruency of pairs of cross-modal stimuli (a sentence and a scene), which varied in plausibility. ANOVAs on ERP amplitudes in selected windows of interest show that congruency violation has longer-lasting (from 100 to 500 ms) and more widespread effects than plausibility violation (from 200 to 400 ms). We also observed critical interactions between these factors, whereby incongruent and implausible pairs elicited stronger negative shifts than their congruent counterpart, both early on (100-200 ms) and between 400-500 ms. Our results suggest that the integration mechanisms are sensitive to both global and local effects of expectancy in a modality independent manner. Overall, we provide novel insights into the interdependence of expectancy during meaning integration of cross-modal stimuli in a verification task.
- Reading and reading-related skills in adults with dyslexia from different orthographic systems: a review and meta-analysisPublication . Reis, Alexandra; Araujo, Susana; Morais, Inês Salomé; Faisca, LuisAn individual diagnosed with dyslexia in childhood typically remains dyslexic throughout his/her life. However, the cognitive profile of adults with dyslexia has been less explored than that of children. This meta-analytic study is intended to clarify three questions: (1) To what extent, and in what manner, do adults with reading difficulties (dyslexia) differ from typical adult readers in measures of reading and writing competence and related cognitive skills?; (2) To what extent do speed measures pose a greater challenge than accuracy measures in an adult population that has already had years of print exposure?; and (3) To what extent does orthographic transparency modulate the reading profile of adults with dyslexia? A total of 178 studies comparing adults with dyslexia and matched controls were reviewed. The results showed that adults with dyslexia exhibited poor performance on almost all reading and writing tasks expressed by very large effect sizes (range 1.735 <= d <= 2.034), except for reading comprehension (d = 0.729). Deficits in reading- and writing-related variables are also present but with a lower expression (range 0.591 <= d <= 1.295). These difficulties are exacerbated for speed measures, especially for word and pseudoword reading, phonological awareness and orthographic knowledge. Orthographic transparency proved to be a significant moderator of dyslexic deficits in word and pseudoword reading, reading comprehension, spelling and phonological awareness, with the expression of the deficits being weaker on transparent-as opposed to intermediate and opaque-orthographies. Overall, the meta-analysis shows that reading and writing difficulties persist in adulthood and are more pronounced in speed measures. Moreover, symptoms are more severe for reading and writing than they are for measures tapping into the cognitive processes underlying reading skills. Orthographic transparency has a significant effect on the manifestation of dyslexia, with dyslexia symptoms being less marked on transparent orthographies. In addition, phonological awareness seems to be a minor problem in adulthood, especially for transparent orthographies.