Perception of pointing gestures in 3D space

Pointing gestures are often used to refer to distant referents by indicating in which vertical and horizontal direction the referent is located relative to the pointer. In the present manuscript, we address whether and how both dimensions interact when people spatially interpret pointing gestures, or whether both dimensions are processed independently as reflected in many current models. We found that both dimensions interact on different levels. First, cross-dimensional effects were found on a between-gestures level. That is, the perception of the vertical position implied by a pointing gesture depended on horizontal arm and finger orientation. Conversely, the horizontal interpretation depended on vertical arm and finger orientation. Second, we found cross-dimensional interactions on the level of intra-individual biases. That is, participants' horizontal perceptual biases in interpretations (e.g., perceiving a gesture as directed more rightward than others) were related to their vertical perceptual biases. Third, we found cross-dimensional interactions on the level of intra-individual variability. That is, the vertical and horizontal interpretations of the same pointing gestures were correlated within participants and gestures. Together, these findings indicate that human spatial pointing perception is based on configural processing of a gesture on different levels of information processing.