Poster B62, Tuesday, August 20, 2019, 3:15 – 5:00 pm, Restaurant Hall
Text-induced shifts in speech perception in children with and without developmental dyslexia: Distinct cortical activation patterns underlie similar behavioural findings
Linda Romanovska1, Roef Janssen1, Milene Bonte1;1Dept. Cognitive Neuroscience, Maastricht University
While most children successfully learn to read within the first few years of schooling, around 10% of children struggle with reading acquisition due to developmental dyslexia. A proposed core deficit of the reading problems observed in adults and children with dyslexia is altered letter-speech sound coupling. In our study we investigate the associations between speech and text in 8-10 year-old children using MRI and text-based recalibration. In this paradigm, an ambiguous speech sound midway between /aba/ and /ada/ is combined with disambiguating ‘aba’ or ‘ada’ text to bias the perception of the ambiguous speech in the direction of text. While this shift (recalibration) has been shown not to be significant in adult dyslexic readers, we have recently demonstrated that behaviourally, children with and without dyslexia show comparable recalibration effects. Preliminary fMRI findings employing this paradigm in the same children groups, reveal different activation patterns between highly fluent typical readers and dyslexic readers in key reading and language-related brain areas including the auditory cortex, prefrontal areas and visual fusiform areas. Activation in these areas also appears to be linked to reading skills, with higher reading fluency and better letter-speech sound substitution associated with higher activation levels. These findings suggest fine-tuned differences in the neurocognitive mechanisms underlying recalibration in children with and without dyslexia despite the comparable observed behavioural effect.
Themes: Perception: Speech Perception and Audiovisual Integration, Reading
Method: Functional Imaging