Accuracy in detecting referents of pointing gestures unaccompanied by language

Abstract

It has been claimed that the perceptual accuracy with which people comprehend distal pointing gestures is low. But this claim is at odds with research showing that detection of other indexical signals, e.g., eye gaze, is very accurate. We conducted three experiments to assess people’s detection accuracy of targets of distal pointing gestures, using a paradigm adapted from the study of eye gaze. Pairs of people were seated next to each other. One person pointed at targets among 70 points arranged in a horizontal (Experiment 1) or vertical line (Experiment 2). The other person guessed the target. Bias in detection was substantially less than previously shown (approximately 3° in vertical and horizontal conditions), and comparable to levels of accuracy for eye gaze detection. Furthermore, and contrary to previous research, detection accuracy was lower for peripheral targets than for central ones. Experiment 3 replicated Experiments 1 and 2 within one study and further demonstrated that partial occlusion of the pointing arm (from shoulder to elbow) did not adversely affect accuracy.