Area perception
Relevant projects:
Yousif, S. R., Alexandrov, E.*, Bennette, E.*, Aslin, R. N., and Keil, F. C. (2022). Do children estimate area using an 'Additive-Area Heuristic'? Developmental Science.
Yousif, S. R. and Keil, F. C. (2021). How we see area and why it matters. Trends in Cognitive Sciences, 25, 554-557.
Bennette, E.*, Keil, F. C., and Yousif, S. R. (2021). A ubiquitous illusion of volume: Are impressions of 3D volume captured by an ‘Additive Heuristic’? Perception, 50, 462-469.
Yousif, S. R., Aslin, R. N., and Keil, F. C. (2020). Judgments of spatial extent are fundamentally illusory: ‘Additive-area’ provides the best explanation. Cognition, 205, 104439.
Yousif, S. R. and Keil, F. C. (2020). Area, not number, dominates estimates of visual quantities. Scientific Reports, 10, 1-13.
Yousif, S. R., and Keil, F. C. (2019). The ‘Additive-Area Heuristic’: An efficient but illusory means of visual area approximation. Psychological Science, 30, 495–503.
How we see area and why it matters (Trends in Cognitive Sciences)
A large and growing literature examines how we see the visual quantities of number, area, and density. The literature rests on an untested assumption: that our perception of area is veridical. Here, we discuss a systematic distortion of perceived area and its implications for quantity perception more broadly.
The Additive-Area Heuristic: An Efficient but Illusory Means of Visual Area Approximation (Psychological Science)
How do we determine how much of something is present? A large body of research has investigated the mechanisms and consequences of number estimation, yet surprisingly little work has investigated area estimation. Indeed, area is often treated as a pesky confound in the study of number. Here, we describe the additive-area heuristic, a means of rapidly estimating visual area that results in substantial distortions of perceived area in many contexts, visible even in simple demonstrations. We show that when we controlled for additive area, observers were unable to discriminate on the basis of true area, per se, and that these results could not be explained by other spatial dimensions. These findings reflect a powerful perceptual illusion in their own right but also have implications for other work, namely, that which relies on area controls to support claims about number estimation. We discuss several areas of research potentially affected by these findings.
Judgments of spatial extent are fundamentally illusory: ‘Additive-area’ provides the best explanation (Cognition)
How do we represent extent in our spatial world? Recent work has shown that even the simplest spatial judgments — estimates of 2D area — present challenges to our visual system. Indeed, area judgments are best accounted for by ‘additive area’ (the sum of objects' dimensions) rather than ‘true area’ (i.e., a pixel count). But is ‘additive area’ itself the right explanation — or might other models better explain the results? Here, we offer two direct and novel demonstrations that ‘additive area’ explains area judgments. First, using stimuli that are simultaneously equated for number and all other confounding dimensions, we show that area judgments are nevertheless explained by ‘additive area’. Next, we show how ‘scaling’ models of area fail to explain even basic illusions of area. By contrasting squares with diamonds (i.e., the same squares, but rotated), we show a robust tendency to perceive the diamonds as having more area — an effect that no other model of area perception would predict. These results not only confirm the fundamental role of ‘additive area’ in judgments of spatial extent, but they highlight the importance of accounting for this dimension in studies of other features (e.g., density, number) in visual perception.
Area, not number, dominates estimates of visual quantities (Scientific Reports)
The study of numerical estimation collectively spans hundreds of papers and hundreds of thousands of citations. Interest in this topic hinges on one assumption: that we can approximate number independently of continuous spatial dimensions (e.g., area). Accordingly, many studies have specifically tried to demonstrate sensitivity specific to number while controlling other dimensions. However, recent work demonstrates that perceived area (based on psychophysical judgments) differs from true area (i.e., a precise pixel count). This difference raises concerns about most past studies of approximate number, by asking if they have systematically controlled for the wrong dimension(s). Building on recent findings that the percept of area may be systematically illusory, the current study examines the relation between perceived area and number. Four experiments reveal that (1) perceived area, but not mathematical area, strongly influences numerosity judgments, (2) perceived area influences perceived number but not the reverse, (3) number acuity is greatly reduced in stimuli controlled for perceived area, and (4) the ability to make area discriminations on the basis of ‘additive area’ but not mathematical area predicts number discrimination ability. Together, these findings highlight a potentially serious confound in prior work, raising new theoretical and methodological challenges for the field.