Vertical Attention Bias for Tops of Objects and Bottoms of Scenes

Past research demonstrated a top-salience bias in object identification, with random shapes appearing more similar when they share the same top versus the same bottom. This is consistent with tops of natural objects and lifeforms tending to be more informative locations of intentionality and functionality, leading observers to favor attending to tops. However, this bias may also reflect a generic downward vantage tendency that occurs with more informative interactive aspects of scenes typically lying below the horizon. Two experiments test for this overall pattern of vertical attention bias (VAB) for both objects and scenes. Participants observed picture triptychs and judged if the center object or scene appeared more similar to flanking comparison figures that contain the same top versus same bottom. Experiment 1 used vertically informationbalanced impoverished stimuli, either polygon objects or polygon-array scenes. Experiment 2 extended the triptych stimuli to naturalistic objects or scenes. Results generally support a VAB for object tops and scene bottoms that varies as a function of the informative aspects of visually attended stimuli. This pattern held for information-balanced objects but not scenes, however, with more ecologically valid naturalistic stimuli, VAB was large and robust, consistent with a vertical information imbalance that drives a generic downward vantage.