title: Grasp posture alters visual processing biases near the hands.
abstract: Observers experience biases in visual processing for objects within easy reach of their hands; these biases may assist them in evaluating items that are candidates for action. I investigated the hypothesis that hand postures that afford different types of actions differentially bias vision. Across three experiments, participants performed global-motion-detection and global-form-perception tasks while their hands were positioned (a) near the display in a posture affording a power grasp, (b) near the display in a posture affording a precision grasp, or (c) in their laps. Although the power-grasp posture facilitated performance on the motion-detection task, the precision-grasp posture instead facilitated performance on the form-perception task. These results suggest that the visual system weights processing on the basis of an observer's current affordances for specific actions: Fast and forceful power grasps enhance temporal sensitivity, whereas detail-oriented precision grasps enhance spatial sensitivity.
authors: North Dakota State University laura.e.thomas@ndsu.edu.
authors: Laura E
authors: LE
authors: Thomas
mesh_terms: D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D015588:Observer Variation; D011187:Posture / Q000502:physiology*; D011930:Reaction Time; D014796:Visual Perception / Q000502:physiology*
keywords: embodied perception; visual processing