title: The continuous end-state comfort effect: weighted integration of multiple biases.
abstract: The grasp orientation when grasping an object is frequently aligned in anticipation of the intended rotation of the object (end-state comfort effect). We analyzed grasp orientation selection in a continuous task to determine the mechanisms underlying the end-state comfort effect. Participants had to grasp a box by a circular handle-which allowed for arbitrary grasp orientations-and then had to rotate the box by various angles. Experiments 1 and 2 revealed both that the rotation's direction considerably determined grasp orientations and that end-postures varied considerably. Experiments 3 and 4 further showed that visual stimuli and initial arm postures biased grasp orientations if the intended rotation could be easily achieved. The data show that end-state comfort but also other factors determine grasp orientation selection. A simple mechanism that integrates multiple weighted biases can account for the data.
authors.affiliation: Department of Psychology, University of Würzburg, Röntgenring 11, 97070, Würzburg, Germany. oliver.herbort@psychologie.uni-wuerzburg.de
authors.forename: Oliver
authors.initials: O
authors.lastname: Herbort
authors.forename: Martin V
authors.initials: MV
authors.lastname: Butz
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D006225:Hand; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D009949:Orientation / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D012399:Rotation; D055815:Young Adult