Abstract
Our visual experience is populated by both discrete objects (e.g. people and posters) and continuous entities (e.g. long walls on which posters may be affixed). We tend to distinguish such stimuli in categorization and language, but might we actually see such stimuli differently? Here we report a vivid illusion wherein discrete 'objecthood' changes what we see in an unexpected way — the one-is-more illusion. Observers viewed pairs of images presented simultaneously, and simply made a forced-choice judgment about which image looked longer (i.e. more spatially extended). One image was always a single continuous object (e.g. a long rectangle), and the other was a collection of discrete objects (e.g. two shorter rectangles separated by a gap). Across several types of images, observers perceived the continuous objects as longer than equated discrete objects, and this illusion was both large and exceptionally reliable (binomial test, p< .000001). In fact, observers often perceived the continuous objects as longer even when the discrete objects were in fact longer. Critically, the illusion persisted even when the images were equated for properties such as the number of intervening contours (e.g. when contrasting two rectangles vs. a single rectangle interrupted by a visible occluder). Moreover, this illusion extends beyond space, and also operates in time: when comparing two sequentially presented auditory stimuli, continuous tones were perceived as lasting longer than equated sets of discrete tones. Whereas previous work has emphasized the importance of objecthood for processes such as attention and visual working memory, these results often come out only in the statistical wash. In contrast, the one-is-more illusion provides a striking demonstration of how the segmentation of a display into discrete objects can change the perception of other visual properties in a way that you readily see (and hear!) with your own eyes (and ears!).
Meeting abstract presented at VSS 2017