Depth of Automatic Spreading Activation: Mediated Priming Effects in Pronunciation but Not in Lexical Decision

Lexical decision and pronunciation experiments were conducted to investigate whether activation automatically spreads beyond directly associated concepts within the memory network. Prime-target pairs were constructed such that there was a relation between the prime (e.g., lion) and the target (e.g., stripes) only through a mediating concept (e.g., tiger). The lexical decision results yielded facilitation of directly related priming conditions (e.g., lion-tiger and tiger-stripes); however, the mediated condition (e.g., lion-stripes) did not facilitate performance compared to either a neutral prime or an unrelated prime condition. In contrast, the pronunciation results yielded facilitation of both directly related and mediated priming conditions. The results were viewed as supporting the notion that activation spreads beyond directly related concepts in semantic memory. It is suggested that characteristics of the lexical decision task masked the appearance of a mediated priming effect. Implications of an automatic spread of activation beyond directly related concepts are discussed.