A carregar...
Projeto de investigação
Looking into N170: Exploring how the brain adapts to reading acquisition and expertise
Financiador
Autores
Publicações
Early Brain Sensitivity to Word Frequency and Lexicality During Reading Aloud and Implicit Reading
Publication . Faísca, Luís; Reis, Alexandra; Araújo, Susana
The 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 immediaterepetition 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.
Cognitive subtyping of university students with dyslexia in a semi-transparent orthography: what can weaknesses and strengths tell us about compensation?
Publication . Faísca, Luís; Reis, Alexandra; Araújo, Susana
Developmental 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.
Unidades organizacionais
Descrição
Palavras-chave
Contribuidores
Financiadores
Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
3599-PPCDT
Número da atribuição
PTDC/PSI-GER/32602/2017