Assessing subjective prime awareness on a trial-by-trial basis interferes with masked semantic priming effects.

Asking participants to rate their awareness of a briefly flashed, masked word during a semantic priming experiment changes the underlying cognitive processes. In two groups performing a lexical decision task, masked primes were shown for 20, 40, or 60 milliseconds. One group also rated prime visibility trial-by-trial using the Perceptual Awareness Scale; the other did not. Reaction-time and drift-diffusion modeling showed general priming effects on reaction time and drift rate only in the group without the rating task. In the rating group, residual priming effects appeared only on trials where participants reported seeing the prime, and affected non-decisional processing time. The concurrent rating task interferes with semantic priming, likely because it diverts attention to identifying the masked prime.

Study at a glance

Abstract

Ratings of perceptual experience on a trial-by-trial basis are increasingly used in masked priming studies to assess prime awareness. It is argued that such subjective ratings more adequately capture the content of phenomenal consciousness compared to the standard objective psychophysical measures obtained in a session after the priming experiment. However, the concurrent implementation of the ratings within the priming experiment might alter magnitude and processes underlying semantic priming, because participants try to identify the masked prime. In the present study, we therefore compared masked semantic priming effects assessed within the classical sequential procedure, in which prime identification is psychophysically assessed after the priming experiment, with those obtained in a condition, in which prime awareness is rated within the priming experiment. Two groups of participants performed a lexical decision task (LDT) on targets preceded by masked primes of 20, 40, or 60 ms durations, to induce the variability of prime awareness. One group additionally rated prime visibility trials-wise using the Perceptual Awareness Scale (PAS), whereas the other group only performed the LDT. Analysis of reaction times (RTs) as well as drift diffusion modeling revealed general priming effects on RT and drift rate only in the PAS-absent group. In the PAS-present group, residual priming effects on RT and the non-decisional component t0 were obtained for trials with rated prime awareness. This shows that assessing subjective perceptual experience on a trial-by-trial basis heavily interferes with semantic processes underlying masked priming, presumably due to attentional demands associated with concurrent prime identification. (PsycInfo Database Record (c) 2023 APA, all rights reserved).