Bombarded by a tremendous amount of information, the visual system uses a system of shortcuts to grasp the gist of the scene, temporarily bypassing its specific details. One such shortcut is object categorization, a major perceptual process defining objects by which side they lie of between-neighboring-category boundaries, or by their proximity to typical category objects or prototypes. Another recently studied gist perceiving shortcut is ensemble perception. When viewing groups of somewhat similar images, we rapidly perceive their average size, shape, angle, brightness, and so on. Amazingly, this extends even to perceiving the average emotion of groups of encountered faces. Noam Khayat and Shaul Hochstein found that such ensemble perception is automatic, subconscious, and on-the-fly. They now report surprising similarities between characteristics of ensemble perception and categorization, relating group average to category prototype, and group range to category boundaries. They suggest that the brain might use similar gist-extraction mechanisms for representing categories and other ensembles.
Paper of the month
Hochstein's Lab: Relating categorization to set summary statistics perception
Attention, Perception, & Psychophysics on June (2019)