Semantic processing of metaphor: A case-study of deep dyslexia

Abstract

Abstract Deep dyslexia is characterized by the production of semantic errors (e.g., reading the word weird aloud as odd) during oral reading and greater difficulty reading aloud abstract words than concrete words. In this paper, we examine whether deep dyslexia affects higher-order semantic processing; namely, metaphor comprehension. To that end, we asked GL, a participant with deep dylexia, to rate novel metaphors (e.g., language is a bridge) for comprehensibility. The topics of the metaphors (e.g., “language” in the item above) varied on concreteness, such that they were either abstract or concrete. Also, the semantic neighbourhood density (SND) of the constituent nouns (e.g., “language”, “bridge”) was manipulated. In addition to metaphors, GL also rated literal (e.g., a gorilla is an ape) and semantically anomalous sentences (e.g., arrival is a shoestring). GL rated the literal sentences as maximally comprehensible and he also rated the abstract-low SND metaphors as comprehensible. However, other, more semantically rich metaphors (i.e., those with concrete constituents or high-SND constituents) were treated as non-comprehensible with ratings indistinguishable from ratings given to anomalous sentences. We discuss how GL’s data align with models of deep dyslexia and metaphor processing.