Ebbinghaus illusion in the tactile modality

In this paper, we report the first evidence for the existence of the Ebbinghaus illusion in the tactile modality. Participants were asked to explore bimanually two sets of Ebbinghaus circles while blindfolded. The results shows that the participants are more likely to be deceived when an illusion-induced stimulus is present than when a control stimulus (no illusion) is present. These results contribute to the perception-action debate. The existence of the tactile equivalent of the Ebbinghaus illusion weighs in favor of the two-stream hypothesis that assumes the existence of separated pathways for action and perception.