Volume Estimation Through Mental Simulation

Although mental simulation underlies many day-to-day judgments, we identified a new domain influenced by simulation: volume estimation. Previous research has identified various ways in which volume estimates are biased but typically has not presented a psychological process by which such judgments are made. Our simulation-informs-perception account proposes that people often estimate a container's size by simulating filling it. First, this produces an orientation effect: The same container is judged larger when right side up than when upside down because of the greater ease of imagining filling an upright container. Second, we identified a cavern effect: Imagining pouring water through a narrow opening toward a relatively wide base produces a sense that the container is cavernous and large (compared with identically sized, wide-topped, narrow-based containers). By testing for and demonstrating the importance of simulation to these effects, we showed how complex perceptual judgments can be distorted by higher level cognitive influences even when they are necessarily informed by modularly processed perceptual input.