We tested the effects of different face displays - the illusory face, and its normal and hollow counterparts - on the perception of target position and the control of target-directed flicking. Methods. 8 right-handed participants (1) estimated with a paper-based method, and with slow pointing movements, the perceived location of a small target presented on a face at two different depth locations (the forehead and the side of the cheek near the ear), and in a different block (2) quickly flicked the target off the face. Participants’ non-dominant eye was defocused which preserved low-frequency binocular information but allowed the illusion to be perceived within reaching distance. Both pointing and flicking were performed without visual feedback. To ensure that visual information was being used, the distance of the display was randomized over trials. Results. With the paper-based test, targets on the illusory face were reported as being located in front of the plane of the display, though the distance between them was compressed as compared to their perceived positions on the normal face. The targets on the hollow mask were perceived as lying behind the display plane. Comparable perceptual reports were obtained with pointing movements. In the rapid flicking task, however, the end points of the movements with the illusory face were located well behind the plane of the display just as they were for the hollow mask. End points for flicking movements to the normal face were always in front of the plane of the display. Indeed, at the point of maximum velocity, participants had already reached out further for both the illusory face and the hollow mask than they had for the normal face. Conclusion. The visuomotor system can continue to respond accurately to the real location of targets despite the presence of a striking hollow-face illusion.

Supported by Canadian Institutes of Health Research (MAG), and the Gatsby Charitable Foundation (RLG).