On the perception of stress position by French listeners: An EEG investigation

In this EEG study, we examined the ability of French listeners to perceive and use the position of stress in a discrimination task. Event-Related-Potentials (ERPs) were recorded while participants performed a same-different task. Different stimuli diverged either in one phoneme (e.g., /3y'(sic)i/-/3y'(sic)(sic)/) or in stress position (e.g., /3y'(sic)i/-/'3y(sic)i/). Although participants reached 93% of correct responses, ERP results indicated that a change in stress position was not detected while a change in one phoneme elicited a MisMatchNegativity (MMN) response. It results that in the early moments of speech processing, stimuli that are phonemically identical but that differ in stress position are perceived as being strictly similar. We concluded that the good performance observed in behavioral responses on stress position contrasts are due to attentional/decisional processes linked to discrimination tasks, and not to automatic and unconscious processes involved in stress position processing.