Neuropsychological processes in verbal irony comprehension: an event-related potentials (ERPs) investigation

Objective: Irony is part of our daily experience, that is probably the reason why a lot of studies have been trying to define its nature and the way we are able to understand the pragmatic intentions lying behind ironic communication. This study addresses the issue of pragmatic comprehension of language by analysing the differences or similarities in processing literal and non-literal (ironic) language. The aim of the study is specifically to investigate neuropsychological correlates (ERPs) of irony decoding. Previous outcomes of RT (Reading Times) responses studies showed that non-conventional ironies took longer to process than literal interpretations of the same sentences. That seems to indicate irony comprehension requires more complicated processes. ERPs studies on non-literal language processing revealed the presence of N400, a negative component associated to semantic integration of the discourse (Kutas & Federmeier, 2002). Participants and Methods: In our study, 120 sentences, equally shared in literal and ironic (with true or false content) trials, were presented to 10 subjects. Results: ERPs morphological analyses showed, for any trials, two negative peaks at 300ms (N3) and 400ms (N4) latencies, with an amplitude increase for both components in the ironic condition. These findings suggest that literal and ironic decoding is qualitatively similar, but irony comprehension requires extra inferential processes thus resulting in an increasing of the demand for the cognitive system. Conclusions: Implications on the opportunity of a distinction between literal and figurative language, as far as comprehension processes are concerned, are discussed.