Shared perception: evidence for a perceptual organization account

It has been reported that shared perception—being aware of an object as also experienced by others—amplifies perceptual salience. We tested an alternative hypothesis: that sharing modifies the relational structure of perceptual processing rather than simply enhancing sensitivity. Across four experiments ( N = 60 in each), we employed a novel threshold task to compare solo perception with confederate-present sessions, while controlling for joint attention and demand characteristics. Participants adjusted stimuli until a target feature was barely perceptible. In Experiment 1, we assessed low-level contrast sensitivity using Gabor patches. Shared perception did not reliably lower contrast thresholds relative to a control session, indicating no amplification at the level of early visual processing. In Experiments 2 and 3, participants adjusted morphed faces until they displayed minimally perceivable emotional expressions. When participants believed they were perceiving the same face as the confederate, emotion thresholds decreased significantly, indicating enhanced sensitivity. Experiment 3 replicated this effect with a modified seating arrangement. In Experiment 4, participants adjusted facial sex characteristics using realistic synthetic faces. Again, shared perception lowered thresholds relative to control. Additional analyses ruled out expectancy effects. The selective modulation of high-level (configural) but not low-level (local) processing suggests that sharing reorganizes perceptual structure rather than merely amplifying input strength. We interpret these findings within a Gestalt-inspired framework whereby perceptual experience incorporates awareness of the other’s concurrent engagement. Shared perception appears to involve structural transformation of experience, linking experimental social perception to broader theoretical accounts of intersubjectivity.