The Shrunken Finger Illusion

Ed Yong has a great write-up of an interesting little study in Current Biology (Ekroll, Sayim, Vander Hallen & Wagemans, 2016) that caught my eye. The study reports an illusion (the 'shrunken finger illusion') that shows how amodal volume completion can make you feel like your finger has shrunk, and everyone is very excited about how this shows our experience of the hidden back-sides of objects is "real".

In this post, I'll review the results, do a little ecological finger wagging about the breathless write-up (Ekroll's, not Ed's) and think about some studies the ecological reframing of the effect might motivate. Briefly, I think this effect is definitely real, and that we really do genuinely perceive hidden objects under certain circumstances. Of course, this has nothing to do with amodal mental representations of what we think is there and everything to do with the information the system is interacting with, but you know that of course because this is always the answer!