Eye movements in the investigation of different properties of multi-word expressions: A systematic review

The last ten years have seen an increased use of the eye-tracking methodology in the investigation of vocabulary processing in both L1 and L2. In particular, some of the advantages afforded by this method – such as, the ability to analyse multiple areas of interest (AOIs) and to distinguish between early and late stages of processing – have contributed to our deeper understanding of the mechanisms behind the online processing of sequences above the word level, known as multi-word expressions (MWEs). One key finding widely reported in the eye-tracking literature is that MWEs are processed faster than novel sequences. Different properties of MWEs – frequency, figurativeness, literality, familiarity, transparency, predictability, collocation strength, contextual predictability, adjacency, flexibility, modifiability, and congruency – have been shown to contribute to this processing advantage and to affect different types of MWEs differently. In this review, we first focus on the specific methodological aspects that need to be considered in the application of eye-tracking in the investigation of MWEs. We then discuss how these aspects have been treated in the literature to examine the different properties of MWEs.