Percorrer por autor "Araújo, Susana"
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- A aprendizagem implícita em crianças disléxicasPublication . Inácio, Filomena; Faísca, Luís; Forkstam, Christian; Araújo, Susana; Bramão, Inês; Reis, Alexandra; Petersson, Karl MagnusThis study investigates the implicit sequence learning abilities of dyslexic children using an artificial grammar learning task and an extended exposure period. Twenty children with developmental dyslexia participated in the study and were matched with two control groups—one matched for age and the second for reading skills. During 3 days, all participants performed an acquisition task in which they were exposed to sequences of colored geometrical forms with an underlying grammatical structure. On the last day, after the acquisition task, participants were tested in a grammaticality classification task. Sequence learning was present in dyslexic children, as well as in both control groups, and no differences between groups were observed. These results suggest that implicit learning deficits cannot explain the characteristic reading difficulties of the dyslexics.
- Cognitive processes underlying reading and naming deficits in dyslexic readersPublication . Araújo, Susana; Reis, Alexandra; Petersson, Karl MagnusIn addition to phonological deficits, difficulties at the level of the visual recognition system (i. e. , the mechanisms that could affect the induction of orthographic representations or the connection of visual to lexical codes) constitute potential sources of the poor reading and visual naming that characterize dyslexia.
- Cognitive profiles in portuguese children with dyslexiaPublication . Pacheco, Andreia; Araújo, Susana; Faísca, Luís; Castro, S. L.; Petersson, Karl Magnus; Reis, AlexandraIndividuals with reading disorders like dyslexia seem not be a homogeneous group, neither with respect to the underlying causes nor the resulting cognitive profile. Our purpose was to analyze the cognitive profile, using a hierarchical cluster analysis, in an attempt to isolate the main cognitive profiles present in a sample of dyslexic Portuguese children.
- Cognitive subtyping of university students with dyslexia in a semi-transparent orthography: what can weaknesses and strengths tell us about compensation?Publication . Faisca, Luis; Reis, Alexandra; Araújo, SusanaDevelopmental dyslexia is characterized by a profile of reading- and writing-related difficulties which stands out as a core deficit in phonological processing. Although these difficulties seem to persist into adulthood, it is still an open question to what extent they are immune, or not, to the extensive training resulting from extended schooling. The main objective of this study was to explore the heterogeneity of the cognitive profile of European Portuguese highly literate adults with dyslexia. Thirty-one university students diagnosed with dyslexia during childhood and their matched skilled adult control readers were assessed through a battery of reading and cognitive tests. A cluster analysis of data obtained from participants with dyslexia identified two profile groups. While Cluster 1 grouped participants with clear phonological deficits and concomitant reading difficulties, Cluster 2 showed better performance on most of the core skills associated with reading and also better general cognitive abilities, suggesting that these dyslexic readers have partially resolved their phonological constraints along the development, probably due to the systematic exposure to reading and writing. As Cluster 2 matched typical readers in general cognitive abilities, it might also be the case that cognitive strengths associated with general intelligence worked as protective factors, helping students to strategically compensate for their reading difficulties. Overall, these results suggest that both mechanisms-partial remediation of the core phonological deficit and adoption of compensatory strategies supported by general cognitive skills-might contribute together to improving the reading performance of highly literate adults with dyslexia.
- Component processes subserving rapid automatized naming in dyslexic and non-dyslexic readersPublication . Araújo, Susana; Inácio, Filomena; Francisco, Ana; Faísca, Luís; Petersson, Karl Magnus; Reis, AlexandraThe current study investigated which time components of rapid automatized naming (RAN) predict group differences between dyslexic and non-dyslexic readers (matched for age and reading level), and how these components relate to different reading measures. Subjects performed two RAN tasks (letters and objects), and data were analyzed through a response time analysis. Our results demonstrated that impaired RAN performance in dyslexic readers mainly stem from enhanced inter-item pause times and not from difficulties at the level of post-access motor production (expressed as articulation rates). Moreover, inter-item pause times account for a significant proportion of variance in reading ability in addition to the effect of phonological awareness in the dyslexic group. This suggests that non-phonological factors may lie at the root of the association between RAN inter-item pauses and reading ability. In normal readers, RAN performance was associated with reading ability only at early ages (i.e. in the reading-matched controls), and again it was the RAN inter-item pause times that explain the association.
- A comprehensive assessment of the transcriptome of cork oak (Quercus suber) through EST sequencingPublication . Pereira-Leal, José B.; Abreu, Isabel A.; Alabaça, Cláudia S.; Almeida, Maria H.; Almeida, Paulo; Almeida, Tânia; Amorim, Maria I.; Araújo, Susana; Azevedo, Herlânder; Badia, Aleix; Batista, Dora; Bohn, Andreas; Capote, Tiago; Carrasquinho, Isabel; Chaves, Inês; Coelho, A. C.; Costa, Maria M. R.; Costa, Rita; Cravador, A.; Egas, Conceição; Faro, Carlos; Fortes, Ana M.; Fortunato, Ana S.; Gaspar, Maria J.; Gonçalves, Sónia; Graça, José; Horta, Marília; Inácio, Vera; Leitão, J. M.; Lino-Neto, Teresa; Marum, Liliana; Matos, José; Mendonça, Diogo; Miguel, Andreia; Miguel, Célia M.; Morais-Cecílio, Leonor; Neves, Isabel; Nóbrega, Filomena; Oliveira, Maria M.; Oliveira, Rute; Pais, Maria S.; Paiva, Jorge A.; Paulo, O. S.; Pinheiro, Miguel; Raimundo, João A. P.; Ramalho, J. C.; Ribeiro, Ana I.; Ribeiro, Teresa; Rocheta, Margarida; Rodrigues, Ana I.; Rodrigues, José C.; Saibo, Nelson J. M.; Santo, Tatiana; Santos, Ana M.; Sá-Pereira, Paula; Sebastiana, Mónica; Simões, Fernanda; Sobral, Rómulo S.; Tavares, Rui; Teixeira, Rita; Varela, Carolina; Veloso, Maria M.; Ricardo, Cândido P. P.Background: Cork oak (Quercus suber) is one of the rare trees with the ability to produce cork, a material widely used to make wine bottle stoppers, flooring and insulation materials, among many other uses. The molecular mechanisms of cork formation are still poorly understood, in great part due to the difficulty in studying a species with a long life-cycle and for which there is scarce molecular/genomic information. Cork oak forests are of great ecological importance and represent a major economic and social resource in Southern Europe and Northern Africa. However, global warming is threatening the cork oak forests by imposing thermal, hydric and many types of novel biotic stresses. Despite the economic and social value of the Q. suber species, few genomic resources have been developed, useful for biotechnological applications and improved forest management. Results: We generated in excess of 7 million sequence reads, by pyrosequencing 21 normalized cDNA libraries derived from multiple Q. suber tissues and organs, developmental stages and physiological conditions. We deployed a stringent sequence processing and assembly pipeline that resulted in the identification of ~159,000 unigenes. These were annotated according to their similarity to known plant genes, to known Interpro domains, GO classes and E.C. numbers. The phylogenetic extent of this ESTs set was investigated, and we found that cork oak revealed a significant new gene space that is not covered by other model species or EST sequencing projects. The raw data, as well as the full annotated assembly, are now available to the community in a dedicated web portal at http://www.corkoakdb.org. Conclusions: This genomic resource represents the first trancriptome study in a cork producing species. It can be explored to develop new tools and approaches to understand stress responses and developmental processes in forest trees, as well as the molecular cascades underlying cork differentiation and disease response.
- Early brain sensitivity to word frequency and lexicality during reading aloud and implicit readingPublication . Faisca, Luis; Reis, Alexandra; Araújo, SusanaThe present study investigated the influence of lexical word properties on the early stages of visual word processing (<250 ms) and how the dynamics of lexical access interact with task-driven top-down processes. We compared the brain's electrical response (event-related potentials, ERPs) of 39 proficient adult readers for the effects of word frequency and word lexicality during an explicit reading task versus a visual immediate-repetition detection task where no linguistic intention is required. In general, we observed that left-lateralized processes linked to perceptual expertise for reading are task independent. Moreover, there was no hint of a word frequency effect in early ERPs, while there was a lexicality effect which was modulated by task demands: during implicit reading, we observed larger N1 negativity in the ERP to real words compared to pseudowords, but in contrast, this modulation by stimulus type was absent for the explicit reading aloud task (where words yielded the same activation as pseudowords). Thus, data indicate that the brain's response to lexical properties of a word is open to influences from top-down processes according to the representations that are relevant for the task, and this occurs from the earliest stages of visual recognition (within ~200 ms). We conjectured that the loci of these early top-down influences identified for implicit reading are probably restricted to lower levels of processing (such as whole word orthography) rather than the process of lexical access itself.
- Electrophysiological correlates of impaired reading in dyslexic pre-adolescent childrenPublication . Araújo, Susana; Bramão, Inês; Faísca, Luís; Petersson, Karl Magnus; Reis, AlexandraIn this study, event related potentials (ERPs) were used to investigate the extent to which dyslexics (aged 9–13 years) differ from normally reading controls in early ERPs, which reflect prelexical orthographic processing, and in late ERPs, which reflect implicit phonological processing. The participants performed an implicit reading task, which was manipulated in terms of letter-specific processing, orthographic familiarity, and phonological structure. Comparing consonant- and symbol sequences, the results showed significant differences in the P1 and N1 waveforms in the control but not in the dyslexic group. The reduced P1 and N1 effects in pre-adolescent children with dyslexia suggest a lack of visual specialization for letter-processing. The P1 and N1 components were not sensitive to the familiar vs. less familiar orthographic sequence contrast. The amplitude of the later N320 component was larger for phonologically legal (pseudowords) compared to illegal (consonant sequences) items in both controls and dyslexics. However, the topographic differences showed that the controls were more left-lateralized than the dyslexics. We suggest that the development of the mechanisms that support literacy skills in dyslexics is both delayed and follows a non-normal developmental path. This contributes to the hemispheric differences observed and might reflect a compensatory mechanism in dyslexics.
- Implicit sequence learning is preserved in dyslexic childrenPublication . Inácio, Filomena; Faísca, Luís; Forkstam, Christian; Araújo, Susana; Bramão, Inês; Reis, Alexandra; Petersson, Karl MagnusThis study investigates the implicit sequence learning abilities of dyslexic children using an artificial grammar learning task with an extended exposure period. Twenty children with developmental dyslexia participated in the study and were matched with two control groups-one matched for age and other for reading skills. During 3 days, all participants performed an acquisition task, where they were exposed to colored geometrical forms sequences with an underlying grammatical structure. On the last day, after the acquisition task, participants were tested in a grammaticality classification task. Implicit sequence learning was present in dyslexic children, as well as in both control groups, and no differences between groups were observed. These results suggest that implicit learning deficits per se cannot explain the characteristic reading difficulties of the dyslexics.
- Lexical and phonological processes in dyslexic readers: evidence from a visual lexical decision taskPublication . Araújo, Susana; Faísca, Luís; Bramão, Inês; Petersson, Karl Magnus; Reis, AlexandraThe aim of the present study was to investigate whether reading failure in the context of an orthography of intermediate consistency is linked to inefficient use of the lexical orthographic reading procedure. The performance of typically developing and dyslexic Portuguese-speaking children was examined in a lexical decision task, where the stimulus lexicality, word frequency and length were manipulated. Both lexicality and length effects were larger in the dyslexic group than in controls, although the interaction between group and frequency disappeared when the data were transformed to control for general performance factors.