Semantic and form priming in fragment completion. Evidence for subliminal activation in a complex language-task.

Abstract

The present experiments investigated subliminal semantic and form priming-effects on word-generation in a fragment-completion task. Gap-words with a dominant and a subordinate solution were preceded by form-related or by semantically related words. The aim of the present study was to show that priming is observable under efficient masking, and to show that the observed effects are not based on processes apart from genuine semantic activation. Priming of the subordinate solution was assessed in Experiments 1 and 5b, relative to a neutral prime condition. Both solutions were primed in Experiments 2-5a. Effects of word-material (e.g. word frequency) were analyzed in Experiment 3, different prime recognition tasks were contrasted in Experiments 3 and 4. In the last chapter (Experiments 5a and 5b) subliminal and supraliminal priming effects were compared, hinting at different quantity and quality of conscious as compared to unconscious priming. Influences of stimulus onset asynchrony (SOA) (Experiments 2-5b), mask duration (Experiment 2b) and shifted prime presentations (Experiment 5a) were determined, indicating no clear modulation of SOA on priming, nor an increase of the effect with shorter masks, substantiating the independency of priming from conscious processing. Shifting primes one trial back produced no clear-cut effects, though subliminal priming was observable on a descriptive level. Essentially, semantic and form primes both reliably increased the probability with which the primed solution was given, although participants formed no conscious representation of the prime. Within this variant of fragment completion, response priming can be ruled out as explanation. Moreover, effects were already present at the first target and prime presentation, excluding an interpretation in terms of partial awareness due to repetition. The present experiments thus demonstrate automatic activation at both form and semantic levels in the absence of conscious awareness.