Task-related influences on neurophysiological assessment of auditory rhyme: implications for clinical studies.

ABSTRACT

OBJECTIVE: The present study investigated whether implicit rhyme detection, as an implicit measure of phonological processing, can be assessed using a passive ERP paradigm. METHODS: Pseudoword pairs were presented to healthy adults while their EEG was recorded. Participants were either instructed to (a) indicate by a button press after each pseudoword pair whether the words rhymed or not (active paradigm) or (b) ignore the speech stimuli (passive paradigm). RESULTS: In the active rhyme paradigm, a typical phonological N400 effect was elicited with non-rhyming targets showing more negative ERPs at posterior sites during 400-600 ms compared to rhyming targets. In the passive paradigm, an anterior positive effect was elicited for non-rhyming targets during 350-750 ms compared to rhyming targets. CONCLUSIONS: Auditory rhyme processing can be studied at the group level by a passive neurophysiological measurement. In such a test, one should focus on the anterior positivity, which seems to reflect automatic rhyme detection. Future research is needed to make this task more reliable for studying rhyme detection at the individual level. SIGNIFICANCE: A passive ERP measurement of implicit phonological processing could possibly function as an indicator of future success in learning to read in children from clinical populations.