ABSTRACT
This chapter reviews the effects of semantic distance upon true-false reaction times. The levels that were the independent variable in Collins and Quillian's experiment were derived from an intuitively defined noun hierarchy. Later investigators showed that Collins and Quillian's levels were confounded with other variables, notably sentence frequency. Three experiments were performed in order to investigate the importance of various surface structure features that present problems even with the simple sentences used. In the experiment, subjects were instead asked to judge whether sentences were semantically acceptable, but the same kind of relationships between semantic distance and reaction times are expected to hold. In accordance with experimental hypothesis, verb and adjective sentences have been combined and will be referred to as property sentences. In addition, the syntactic form of the test sentences was also investigated, using nouns, verbs, or adjectives as predicates. No systematic differences due to this variable were observed, terminating speculations about a possible noun priority in semantic memory.
