We have a new study published in Consciousness and Cognition! Using the Anne Boleyn illusion, in which a person’s hands are placed on either side of a mirror and stroked synchronously from the thumb toward the empty space next to the reflected fifth finger, we investigated the perception of a supernumerary “sixth” finger.

We investigated several factors underlying this illusory embodiment. We found that stroking only one location on the hidden fifth finger did not reduce the illusion, despite previous theories that stimulation of two distinct locations was necessary. We also found that the starting location of the strokes influenced how participants categorized the perceived body part, suggesting an influence of pre-existing body representations. Finally, our results supported the anchoring hypothesis, which proposes that the proximity of the illusory sixth finger to the real hand contributes to the robustness of the illusion. Read about it here!