In a recent experiment, we looked for a dissociation between conscious perception and rapid target-directed action using the large and dramatic depth reversal of the hollow face, in which a realistic hollow mask appears as a convex face. The hollow-face illusion is a knowledge-based, top-down effect, where extensive and powerful (though implicit) knowledge of convex faces rejects the correct hollow perception in favor of reversed depth. The hollow-face illusion is thought to arise within the ventral stream and as a consequence should not affect visuomotor computations in the dorsal stream. Despite the presence of a strong illusion of a protruding convex face, participants in our experiment directed rapid flicking movements of their hand to the correct position of targets affixed to the surface of the hollow mask. In other words, the visuomotor system can use bottom-up sensory inputs (e.g., vergence) to guide behavior to veridical locations of targets in the real world, even when perceived positions are influenced, or even reversed, by top-down processing.
For more information about the hollow-face illusion and other interesting illusions, you are encouraged to explore Richard Gregory's website.
Kroliczak, G., Heard, P., Goodale, M.A., & Gregory, R.L. (2006). Dissociation of perception and action unmasked by the hollow-face illusion. Brain Research, 1080, 9-16. Download pdf