Neural and behavioural mechanisms underlying the processing of negated meanings : Words, pictures and sentences

Abstract: This thesis combines a number of methodologies and measures in order to address the processing of two types of negation (with not and un) in relation to each other and to non-negated affirmative meanings. The four investigations in this thesis target the processing of these meanings at different levels, namely the word level (Study 1) and sentence level (Studies 2–4). In two artificial language learning experiments, Study 1 focuses on the cognitive operations behind the processing of the negated meanings expressed by not and un in English. Negated and non-negated meanings are presented through artificial prefixes in order to do away with factors inherent to natural language (i.e., frequency and length). The meaning ranges associated with the negated types are manipulated and tested. The results reveal that the processing difficulty of these negation types can be modulated by the scopal ranges that they cover. This study can be taken to serve as a baseline for the future research on the processing of negated meanings that involve similar cognitive operations. Using event-related brain potentials (ERPs), Studies 2–4 target the time-course of processing negation in sentence comprehension. Affirmative, prefixally negated and sententially negated adjectives (authorized, unauthorized, not authorized) are presented in complex sentential contexts using both visual (Study 2 and Study 4) and auditory (Study 3) stimuli. The results of these investigations reveal a number of discursive factors that modulate the processing of these forms in sentence comprehension. More specifically, the results reveal that factors such as visual or auditory input, order of presentation, relevance and immediacy of the information presented all affect the processing of negated meanings in context. Overall, the findings of the studies in this thesis contribute new knowledge to a dynamic view of meaning and language processing and suggest that the processing of negated meanings, similar to many other linguistic phenomena, is not only sensitive to the properties of individual words and expressions but is also modulated by contextual factors.