Summary
Red light causes overestimation of perceived duration compared to blue light under subjective equiluminance, but this effect disappears when luminance is matched based on pupillary light reflex responses. This suggests that lighting designers using colored light must account for PLR-driven differences in effective retinal illuminance, not just photometric equiluminance, when predicting perceptual and physiological effects.
Key Findings
- Red stimuli were perceived as longer in duration than blue stimuli under subjective equiluminance conditions (Experiment 1), confirming prior reports of red-driven time overestimation.
- The temporal overestimation effect for red versus blue stimuli disappeared when luminance was equated based on pupillary light reflex (PLR) response (Experiment 2), implicating pupil-mediated retinal illuminance as the underlying mechanism.
- Blue light induces a larger PLR than red light even at subjective equiluminance, meaning blue effectively delivers less retinal illuminance post-constriction, which confounds color-perception comparisons not controlled for PLR.
- Results highlight that equiluminance method (subjective vs. PLR-based) critically determines experimental outcomes in color-perception research, with direct implications for standardizing lighting stimuli in psychophysical and circadian studies.
Categories
The Science of Light: Investigates how pupillary light reflex (PLR) differences between red and blue stimuli affect temporal perception, directly relevant to understanding melanopic and photoreceptor-driven responses to colored light.
Eye Health & Vision: Examines pupillary responses to equiluminant colored stimuli and how pupil-mediated changes in incident light influence perception, with implications for visual system responses to colored lighting.
Author(s)
Y Kinzuka, F Sato, T Minami, S Nakauchi
Publication Year
2022
Number of Citations
3
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