Abstract
The emotional relevance, or affective salience, of a stimulus is known to influence subjective time estimation. Paradigms typically used to measure such salience-driven distortions require the participant to judge stimulus duration. Yet these paradigms neglect to measure the temporal resolution of the moment-to-moment experience, and whether viewing affectively salient stimuli modulates visual sampling rate is not known. In two experiments we employed neutral, negative, and positive (approach-motivating) dessert images. First, to confirm previous findings we used these stimuli in a temporal bisection paradigm to assess affective distortion of stimulus duration judgment. Participants learned two standard durations, “short” (400 ms) and “long” (1600 ms). Subsequently, stimuli were presented for seven durations (400 to 1600 ms at 200 ms intervals) and were categorized by the participant as either “short” or “long”. Stimulus durations for negative stimuli were judged as longer than for the other two stimulus types. Second, we used a novel experimental paradigm to test affective distortion of moment-to-moment subjective temporal perceptual experience. We hypothesized that negatively valenced salient stimuli would increase visual sampling rate relative to neutral stimuli, leading to greater acuity in detecting changes between frames. In this task, participants viewed a “standard” stimulus fading to black over a 2000 ms period at 48 frames per second, immediately followed by a “target” stimulus fading to black over a 2000 ms period at 24, 48, or 72 frames per second. Participants then rated the smoothness of the target stimulus fade, as compared to the standard, where judgments of the target as less smooth suggest more ease in distinguishing frames and thus increased visual sampling rate. Negative stimuli were judged as fading less smoothly than other stimulus categories. These results suggest that negatively valenced stimuli increase temporal sampling rate, indicating a possible mechanism underlying influence of affective salience on perceived duration.
Meeting abstract presented at VSS 2015