Moon illusion in pictures: a multimechanism approach

Area of Science:

• Psychology
• Visual Perception
• Cognitive Science

Background:

• The moon illusion is a long-standing phenomenon in visual perception.
• Previous research primarily used astronomical observations, not controlled stimuli.
• Understanding the illusion's mechanisms is key to understanding human visual processing.

Purpose of the Study:

• To investigate the moon illusion in pictorial representations.
• To determine if the illusion persists in 2D stimuli.
• To explore the role of depicted depth cues in the illusion's magnitude.

Main Methods:

• Six experiments were conducted using pictorial stimuli.
• Participants judged the size of moons depicted at the horizon versus high in the sky.
• Participants also drew horizon and elevated moons to assess reproduction accuracy.

Main Results:

• The horizon moon was consistently perceived as larger than the elevated moon in pictures.
• The distance paradox (horizon moon appearing closer) was also observed in pictorial representations.
• The strength of both size and distance effects correlated with the salience of depicted depth cues.

Conclusions:

• The moon illusion is replicable in pictorial stimuli, suggesting cognitive contributions.
• Pictorial stimuli allow for the dissociation of cognitive and potential physiological factors.
• The illusion likely results from multiple interacting perceptual and cognitive mechanisms.