The curious case of lexical ambiguity : using talker-specific characteristics and facial expressions to decode the puzzle

Abstract

This thesis investigates how facial expressions and the talker-specific characteristics (TSCs) of age, gender and sociolinguistic background affect language processing in Maltese. The main hypothesis within this study is that facial expressions and TSCs (talker-specific characteristics) guide language processing by categorising information, thus enabling superior usage and control of the information stream encountered during language processing. To test this, three experiments were carried out. The first was a behavioural study inspired by the McGurk paradigm, where facial expressions were expected to aid with the disambiguation of phonetically similar yet lexically diverse words. Here the results show attention to the facial features, however no specific effect of facial expressions in a single word situation. The second was an eye-tracking experiment containing biased sentence interpretations, based on common gender and age biases. Results show that participants could use speaker identity to guide language processing, albeit with some constraints. The third was a trial EEG study inspired by the second experiment, using biased sentences based on common gender and sociolinguistic biases. The results show no clear effects of speaker identity. Based on these results a series of limitations are discussed and ideas for future work are suggested. Overall, this thesis shows that language processing is a complex matter and much work still needs to be done (especially within the Maltese setting) to learn the extent of involvement of speaker identity and facial expressions within this process.