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

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.

The Relation between Subjective and Objective Measures of Visual Awareness: Current Evidence, Attempt of a Synthesis and Future Research Directions

“…In case of subjective ratings slopes tended to be shallower compared to objective ratings (for similar slope difference, see de Graaf et al, 2012). Nevertheless, this study (Kiefer et al, 2023a) and related work (de Graaf et al, 2012;Garric et al, 2019;Jimenez et al, 2023;Kiefer et al, 2023b;Lamy et al, 2015;Peters & Lau, 2015) demonstrate that objective performance measures and subjective ratings of visual experience can convey similar information on the feature-content of a percept.…”

“…Several studies indicate that subjective and objective measures similarly capture the content of awareness. Comparable subjective and objective measures of awareness were found in brain-damaged patients without blindsight or blindsense (Garric et al, 2019) as well as in neurologically intact observers during continuous flash suppression (Lamy, Alon, Carmel, & Shalev, 2015) and visual pattern masking (Jimenez et al, 2023;Kiefer et al, 2023b): Both measures similarly differentiated between stimulus unawareness and awareness. Peters and Lau (2015) specifically investigated the validity of the blindsight phenomenon in neurologically intact observers, i.e.…”

“…Performing visibility ratings in addition to the priming task abolished priming effects, attributed to the attentional demands inherent in this dual-task situation (Jimenez, Prieto, Gómez, Hinojosa, & Montoro, 2023;Kiefer, Harpaintner, Rohr, & Wentura, 2023b). At least within the context of priming research, the use of trial-wise visibility ratings cannot be recommended.…”

“…Visibility ratings require an appropriate mapping of the sensory experiences to the different levels of the scale. In order to ensure a consistent, intended use of the scale, an intense training including feedback from the experiment can improve an accurate report of the quality of the sensory experience (for discussions, see Kiefer et al, 2023a;Kiefer et al, 2023b;Overgaard & Sandberg, 2021). Furthermore, the type of the visibility scale might be important: While there is an agreement that a dichotomous unseen/seen judgement leads to invalid number of false unseen reports (e.g., Jimenez et al, 2024;Koivisto & Neuvonen, 2020), the optimal layout of the scale is discussed.…”

Subjective and objective measures of visual awareness converge

“…This shows that our observation of a converging pattern of subjective and objective thresholds is not trivial and merely an expression of a structural interdependence of measures. Although introduction of subjective ratings can in principle influence performance in the same [ 52 ] or in the next trial [ 44 ], we do not see how interactions between subjective and objective awareness tasks could induce a convergence of thresholds. Nevertheless, to specifically examine cross-task interactions, future studies could collect subjective and objective awareness measures in different trials (for a further discussion, see below).…”