A N400 event-related potential elicitation paradigm for Canadian French speakers

The N400 event-related brain potential (ERP) can be used to evaluate language comprehension, and may be a particularly powerful tool for the assessment of individuals who are behaviourally unresponsive. This study presents a set of semantic violation sentences developed in Canadian French and characterizes their ability to elicit an N400 effect in healthy adults. A novel set of 100 French sentences were created and normed through two surveys that assessed sentence cloze probability (n = 98) and semantic plausibility (n = 99). The best 80 sentences (40 congruent; 40 incongruent) were selected for the final stimulus set and tested for their ability to elicit N400 effects in 33 French-speaking individuals. The final stimulus set successfully generated an N400 effect in the grand-average across all individuals, and in the grand-average within age groups (young, middle-age, and older adults). On a single-subject level, the final stimulus set elicited N400 effects in 76% of the participants. The feasibility of using this stimulus set to assess semantic processing in behaviourally unresponsive individuals was demonstrated in a case example of a French individual in a disorder of consciousness. These sentences enable the inclusion of Canadian French speakers in this simple assessment of language comprehension abilities.