What happens when two objects are filled in in the blind spot, but the resulting percepts contradict each other? As in many other ambiguous situations, you perceive rivalry! This new paper by Mandy Chen, together with Gerrit, David Whitney from Berkeley and Rachel Denison at NYU shows how.
The paper also includes the cool new Jumping Pen Illusion. Try it out for yourself!
The jumping pen illusion, a demonstration of filling-in rivalry. (A) Step 1: Use a strip of paper with a fixation cross and a blind spot indicator (red circle) to find your blind spot. With the cross on the left, close your left eye, fixate the cross, and move the strip toward or away from you until the red circle disappears. (B) Step 2: While keeping the blind spot indicator in your blind spot, take a pen and hold it vertically behind the card. Slide the pen behind the card into your blind spot. The pen may appear to jump in front of the strip. When the pen and strip are held in fixed positions, the pen and strip can alternate as the object seen in front. Anecdotally, increasing the saliency of the pen using motion (e.g. wiggling the pen) or color (e.g. a red pen with a neutral-colored strip) tends to increase the perceptual dominance of the pen.