Brain responses to changes in speech sound durations differ between infants with and without familial risk for dyslexia.
A specific learning disability, developmental dyslexia, is a language-based disorder that is shown to be strongly familial. Therefore, infants born to families with a history of the disorder are at an elevated risk for the disorder. However, little is known of the potential early markers of dyslexia. Here we report differences between 6-month-old infants with and without high risk of familial dyslexia in brain electrical activation generated by changes in the temporal structure of speech sounds, a critical cueing feature in speech. We measured event-related brain responses to consonant duration changes embedded in ata pseudowords applying an oddball paradigm, in which pseudoword tokens with varying /t/ duration were presented as frequent standard (80%) or as rare deviant stimuli (each 10%) with an interval of 610 msec between the stimuli. The infants at risk differ from control infants in both their initial responsiveness to sounds per se and in their change-detection responses dependent on the stimulus context. These results show that infants at risk due to a familial background of reading problems process auditory temporal cues of speech sounds differently from infants without such a risk even before they learn to speak.
Leppänen
Paavo H T
PH
Department of Psychology, University of Jyväskylä, Finland. paavo.leppanen@psyka.jyu.fi
Richardson
Ulla
U
Pihko
Elina
E
Eklund
Kenneth M
KM
Guttorm
Tomi K
TK
Aro
Mikko
M
Lyytinen
Heikki
H
D000161:Acoustic Stimulation; D001921:Brain / Q000502:physiology* / Q000503:physiopathology; D004410:Dyslexia / Q000235:genetics* / Q000503:physiopathology; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007223:Infant; D008297:Male; D013067:Speech Perception / Q000502:physiology*