Roessler, A. & Sebastián, N.
Brain and Cognition Unit, University Pompeu Fabra, Barcelona
The auditory speech signal is highly variable and mechanisms to extract meaningful information are complex and not yet fully explained by speech perception models. Indexical information (speaker’s accent, emotional state) presents a source of information as well as variability. Recent literature has shown that fine-grained details of the auditory signal are retained in memory. In bilingual societies as in Barcelona, people are constantly exposed to two languages and importantly to slight (foreign-accented) mispronunciations. Furthermore, in bilingual contexts, speaker information correlates with language of communication. Therefore, comparing monolinguals with bilinguals might help to gather valuable insights into the role of variability in speech perception by investigating possible strategy-differences between mono-and bilinguals.
We conducted an auditory recognition memory experiment testing monolinguals (Madrid) and bilinguals (Barcelona). Subjects were presented with a list of words of which half were repeated by either the same speaker or a second speaker. In a continuous design subjects had to make an “old”-“new” judgement, while ignoring the speaker dimension. On repeated trials subjects´ reaction times should be faster (repetition priming), but a speaker change between presentations could block (attenuate) this effect. Accordingly, we found a significant repetition priming effect on reaction times for both groups. However, we did not find any difference between same and different speaker conditions for either population.
Calculating d-prime for error rates, revealed a significant interaction between group and condition, representing the fact that only monolinguals score lower on the different speaker condition, while bilinguals do better overall and show no differences between conditions.
In conclusion, we interpret the results as indication that bilinguals process speaker information more efficiently when compared to monolinguals.