| The meaning of a word is more than definition. The comprehension of the words "love" or "death" entails a deep understanding of the social and emotional implications, as wells as contextual and motivational significance. In this dissertation, we explore the neuroscience of how emotional content, local context, and task demands influence word processing. In chapter I, we describe analytic approaches to these questions that model word processing as the convergence of the particulars of the item, the comprehender, and context. In chapter II, we apply these techniques to investigate how the semantic processing of infrequent words is facilitated if that word is also highly emotional, regardless of whether attention is oriented towards semantic features or emotional features. In chapter III, we present two experiments that investigate the role of valence in semantic processing by implementing a full cross of semantic priming and affective priming, finding radically different patterns of effects that suggest the two may rely on distinct mechanisms. And in chapter IV, we investigate how the semantic priming effect adapts to the local context as participants implicitly learn the statistical contingencies, using a novel trial-by-trial adaptation analysis that shows the evolution of the semantic priming effect through time. Overall, these data suggest that semantic processing is fundamentally supported by all pertinent knowledge, including knowledge of emotional significance and implicit contextual expectations. Language comprehension is as richly textured as the comprehenders. |
