Abstraction, retrieval, and perceptual learning in the integrated processing of linguistic and talker-related information

During speech perception listeners receive both linguistic information about the speech content as well as information regarding the identity of the talker. While these two aspects have been traditionally studied in isolation, with a dominant interest for linguistic information over talker identity, it is now a widely accepted notion that these two kinds of information are processed in an integrated way. The inclusion of talker-related information in the domain of speech perception highlighted both benefits and challenges for listeners. On the one hand, linguistic and talker-identity information appear to be mutually beneficial for the extraction of both kinds of information from the speech signal. On the other hand, listeners must take care of the great acoustic variability that characterizes the physical dimensions linked to the two kinds of information. The aim of the present dissertation is to study three specific cognitive mechanisms that listeners can use to access the benefits of the integrated processing of linguistic and talker-related information as well as to deal with their intrinsic variability. Three empirical studies employing both behavioural and neurophysiological techniques highlight peculiar aspects of abstraction, memory retrieval and perceptual learning mechanisms in relation to the consequences of including the talker in the study of speech perception.