Tops are more salient than bottoms

Abstract

Past research has verified that observers assume that objects are reliably oriented with respect to a gravitationally centered coordinate system. Observers also appear to attend more to specific parts of objects, like faces, that typically are closer to the top. In the present work, we explored whether or not observers have a generic bias to view tops as being more salient than bottoms. In three experiments, observers indicated whether random shapes appeared to be more similar to comparison shapes that shared identical tops rather than bottoms. Observers exhibited a reliable tendency to match figures with similarly shaped tops. Matching choice was also a function of global shape attributes such as axis of elongation or size. The fmdings are consistent with the notion that, in nature, tops tend to be the most visible part and to provide the best information with respect to important aspects of objects such as animal intentionality and artifact functionality.

Stimulus and response representations underlying orthogonal stimulus-response compatibility effects

“…The results obtained by Sholl and Egeth (1981) and Chambers et al (1999) have indicated that, as Clark (1973) originally suggested, in the vertical dimension the upper region is more salient than the lower region, both perceptually and linguistically. Even though Sholl and Egeth did not directly show the salience asymmetry in the spatial codes "up" and "down" in their experiments, they demonstrated the importance of the "up" region in the perceptual space.…”

“…Recently, Chambers, McBeath, Schiano, and Metz (1999) found the vertical asymmetry in a shape-comparison task. Subjects judged which of two comparison stimuli was more similar to a test stimulus.…”

The role of axes of elongation and symmetry in rotated object naming

“…This information about the location of the top of the image could constrain the direction of image rotation and result in smaller effects of orientation. Chambers, McBeath, Schiano, and Metz (1999) found that observers reliably classified objects as similar when their tops were matched, but not when their bottoms matched, indicating that tops are perceptually more salient than bottoms. However, when information about the location of the top of rotated objects was available prior to rotated object naming in the form of an orientation precue, no reduction in orientation effects was found (Gauthier & Tarr, 1997;Gibson & Peterson, 1994;McMullen et al, 1995).…”

Vertical asymmetries in pre-attentive detection of changes in motion direction

“…However, visual sensory constraints may also contribute to these asymmetries and therefore the LVF advantage cannot be solely explained by attentional biases across the visual field (Levine and McAnany, 2005). Moreover, upper visual field (UVF) advantages have been shown in various visual tasks such as visual search (Previc and Blume, 1993), and object recognition (Chambers et al, 1999).…”