Physiological arousal underlies preferential access to visual awareness of fear-conditioned (and possibly disgust-conditioned) stimuli.

Abstract

Fear and disgust have been associated with opposite influences on visual processing, even though both constitute negative emotions that motivate avoidance behavior and entail increased arousal. In the current study, we hypothesized that (a) homeostatic relevance modulates early stages of visual processing, (b) through widespread physiological responses, and that (c) the direction of these modulations depends on whether an emotion calls for immediate regulatory behavior or not. Specifically, we expected that increased arousal should facilitate the detection of fear-related stimuli, and inhibit the detection of disgust-related stimuli. These hypotheses were tested in two preregistered experiments (data collected in 2022, total N = 120, ethnically homogeneous Polish sample). Using a novel, response bias-free version of the breaking continuous flash suppression paradigm, we examined localization and discrimination of fear-and disgust-conditioned stimuli at individually determined perceptual thresholds. Our first hypothesis was confirmed: fear-conditioned stimuli were detected and discriminated better than neutral stimuli, and the magnitude of conditioning-related perceptual preference was related to arousal during conditioning acquisition. In contrast with our second hypothesis, perceptual access to disgust-conditioned stimuli was not diminished. Exploratory analyses suggest that discrimination of disgust-conditioned stimuli was also enhanced, although these effects appeared weaker than those evoked by fear conditioning. The current study strengthens previous evidence for facilitated perception of threatening objects and shows for the first time that stimuli evoking disgust might also gain preferential access to awareness. The results imply that homeostatically relevant stimuli are prioritized by the visual system and that this preference is grounded in the underlying arousal levels.

Statistical Learning Facilitates Access to Awareness

“…If for a specific presentation duration (e.g., yielding ~80% localization accuracy on average across high and low-probability conditions), participants have more information about (e.g., the identity or location of) a stimulus in condition A compared to condition B, we can establish that conscious access of the stimulus (location/identity) was faster in condition A than in condition B. This precludes any effect of decisional biases and post-detection effects, as it exhaustively measures the amount of information available to the participant within a specific timeframe (Litwin et al, 2023).…”

“…The goal of Experiment 3 was to test whether statistical learning affects conscious access, by excluding processing differences emerging after conscious access (e.g., shifts in response criterion, which affect RTs). To this aim, we used an accuracy-based variant of the b-CFS paradigm (Litwin et al, 2023) in which we compared the localization accuracy for high-probability versus low-probability features, given the same stimulus presentation time. The methods and hypothesis of this experiment were preregistered before data collection (https://osf.io/exp3).…”

“…Participants. Based on the effect size (Cohen's d = 0.34) of a previous study that used the bias-free b-CFS paradigm to measure conscious access (Litwin et al, 2023), a sample of 55 participants was needed for an experimental power of 80% with an alpha level of 0.05 for a planned one-tailed paired-samples t-test (power calculation performed in G*Power). We opted to preregister a one-tailed test because we had clear predictions on the directionality of the effect following Experiments 1-2 and the supplementary experiment (see Supplementary Materials 2).…”

“…To exclude the possibility that differential reaction times in b-CFS can reflect differences emerging after conscious access (e.g., decisional and post-perceptual processes, Stein & Peelen, 2021), we further conducted two follow-up experiments. In Experiment 3, we used an accuracy-based b-CFS paradigm (Litwin et al, 2023) in which the localization accuracy for interocularly suppressed high and low probability feature stimuli were compared. In addition, a supplementary experiment (Supplementary Materials 2) used a visual masking technique (Stein & Peelen, 2021) to compare the localization sensitivity to masked high and low probability feature stimuli.…”