The Fate of the Unattended Revisited: Can Irrelevant Speech Prime the Non-dominant Interpretation of Homophones?

Abstract

Whether the post-categorical, semantic properties of task-irrelevant speech are processed has been a source of debate between two central accounts. The first, a structural account, proposes that the semantic content of irrelevant speech is filtered out early on, and thus remains unprocessed. The second account proposes that the semantic content of speech is, in fact, processed and can influence later behaviour. The present research offers a resolution between these two prominent accounts by examining whether semantic processing of task-irrelevant speech occurs despite explicit instructions to ignore it. During a visual-verbal serial recall paradigm, participants were auditorily presented with non-dominant homophones plus their close associates, or close associates without the homophone itself and asked to ignore this irrelevant speech containing these semantic primes. In a subsequent “unrelated” phase, we assessed whether the spelling of homophones was influenced by the irrelevant speech that had occurred earlier in the serial recall phase. We found evidence of semantic priming in conditions wherein the homophone was present, as well as conditions wherein only associates of the homophone were present. Regardless of whether they were presented, homophones were more likely to be spelt in accordance with their non-dominant meaning, and most participants did not report awareness of this fact. We suggest that semantic processing of irrelevant speech occurs even when there is an explicit direction to ignore it and does not result in any material disruptive effect on serial recall performance.