Phonotactic and lexical factors in talker discrimination and identification

Previous research has shown that listeners are better at processing talker information in their native language compared to an unfamiliar language, a phenomenon known as the language familiarity effect. Several studies have explored two mechanisms that support this effect: lexical status and phonological familiarity. Further support for the importance of phonological knowledge comes from studies showing that participants with poorer reading skills perform worse on talker processing tasks. Previous research also suggested that speech perception in individuals with poor reading skills may be task dependent, with poorer performance on identification tasks compared to discrimination tasks. In the current study, we explore talker perception while manipulating lexicality (words, nonwords) and phonotactic probability (high, low) in participants who differ in reading ability and phonological working memory using a talker discrimination task (Experiment 1) and a talker identification task (Experiment 2). Results from these experiments revealed an effect of lexical status and phonotactic probability in both the discrimination and the identification tasks. Effects of phonological working memory were found only for the identification task, where participants with higher scores identified more talkers correctly. These results suggest that listeners use both phonological and lexical information when processing talker information. The task-modulated results show that listeners with poorer phonological working memory perform worse on talker identification tasks that tap into long-term memory representations, but not on discrimination tasks that can be completed with more peripheral processing. This may suggest a more general link between phonological working memory and learning talker categories.