The role of episodic memory in language comprehension and linguistic flexibility: A behavioural and neuroscientific investigation

Over the past two decades, multiple lines of psycholinguistic investigation have provided evidence for an important role of learning mechanisms in support of various aspects of language comprehension. At the same time, there has been a proliferation of psycholinguistic research that has applied specific theories from the wider memory literature to the study of human language processing and comprehension. Following in this line of research, the overarching aim of this thesis was to investigate the contribution of episodic memory to language comprehension and linguistic flexibility using a combination of behavioural and neuroscientific methods. Firstly, across four behavioural experiments, I investigated the effect of predictability on the updating of stored word meanings and incidental memory for language input. The findings from these behavioural experiments revealed no effects of predictability, which may place some constraints on the reach of episodic memory effects in language processing. Secondly, I report an electroencephalography (EEG) study which aimed to elucidate the oscillatory mechanisms supporting the processing of lexically ambiguous words and their link to subsequent recognition memory. The behavioural and oscillatory findings are consistent with a view in which episodic memory contributes to the processing of lexically ambiguous and semantically incongruent words, although the results might also be explained by alternative accounts. Finally, I present data from a magnetoencephalography (MEG) study investigating the neural underpinnings of flexible language comprehension. The central aim was to determine the neural correlates of lexical-semantic updating, with a particular focus on theta oscillations, which have repeatedly been linked to episodic memory. The MEG study provided the strongest evidence for the involvement of episodic memory in flexible language comprehension, with both the behavioural and neurocognitive analyses revealing results that point to an important role for episodic memory processes. While future investigations are required to further characterise the reach of episodic memory and the potential involvement of other learning mechanisms, overall, the findings presented in this thesis provide novel evidence for the involvement of episodic memory processes in language comprehension and linguistic flexibility.