The present study investigated Stroop interference effects in young adult and older deaf American Sign Language (ASL) and English bilinguals with ASL and English stimuli.

Deaf ASL-English bilinguals (n = 108; aged 21–88) signed their responses in two computerized Stroop tasks, one with ASL videos of color signs and one with printed English color words. Participants saw 120 trials in each language with 84 congruent and 36 incongruent trials.

Even though participants responded in ASL in both tasks, Stroop effects were larger with English than with ASL stimuli in both response times (RTs) and errors, a pattern of results not typically seen in spoken-language bilinguals (in which Stroop effects are often smaller between-languages than within-languages). Older participants showed larger Stroop effects than younger participants, especially in English RTs. Aging effects in error rates were not significant in either language.

The finding of larger Stroop effects in deaf signers with English rather than ASL stimuli suggests a possibly critical role for modality of presentation in eliciting Stroop effects. Additional work is needed to determine why English is more sensitive to aging effects in deaf signers, and which language will be most sensitive for detecting cognitive impairment in this population.