Poster #: 113
Topic: Speech and language (incl. deficits)
Thursday, Sep 10, 2015
Brain responses to foreign-language words are diminished in dyslexic children
1Cognitive Brain Research Unit, Institute of Behavioral Sciences, University of Helsinki, Helsinki, Finland
2Institute of Behavioural Sciences, University of Helsinki, Helsinki, Finland
Dyslexia is manifested as reading impairment, which is thought to result from compromised processing of phonological units. The impairment is not restricted to reading, however: dyslexic readers often have difficulties also in second-language (L2) learning. By comparing MMN responses to familiar and unfamiliar spoken L2 items between Finnish 9-11-year-old dyslexic readers and typically-reading control children, we aimed to determine whether the processing of spoken L2 words is compromised in dyslexia and whether this is due to sublexical or lexical processing. We also determined, how the activation of brain representations is linked with cognitive measures that are typically impaired in dyslexia, such as reading and rapid naming. The L2 deviant stimuli were 'she', 'shy', and pseudoword 'shoy'. Corresponding native-language equivalents used as controls were pseudoword 'sii' and words 'sai', and 'soi'. The results showed that as compared with typical readers, dyslexic readers' MMN responses were diminished for the most frequent L2 word 'she'. In contrast, no differences between the groups were found in MMNs for the other items, ruling out the possibility that dyslexic readers processing difficulty was sublexical in nature. Rather, the diminished responses for the familiar L2 word are interpreted to reflect dyslexic readers' compromised lexical representations. The MMN amplitudes for the L2 word 'she' were also found to negatively correlate with reading scores, implying that compromised activation of L2 lexical representations is closely linked with literacy skills.