February 2021





THE BLURRY HEART ILLUSION
BY KOHSKE TAKAHASHI, RYOSUKE NIIMI, AND KATSUMI WATANABE
UNIVERSITY OF TOKYO, JAPAN



How to See the Illusion: Shifting your gaze from one cross to the next makes the blurry heart "beat" while the clear heart remains stationary.





How the Illusion Works: To understand this illusion we need to understand a bit of eye anatomy. Our retinas, the light sensitive organ in the back of the eye have many special cells all working together to perceive vision. There are some specialized cells that perceive color, others that perceive motion, and even cells that help regulate your sleep cycle. One of these specialized cells is the Direction Selective (DS) Cell which is a neuron that responds to the direction of a visual stimulus. This illusion works because DS Cells in our peripheral retina are activated by the blurred edges of the blurry heart, but not the sharp edges of the clear heart, as we move our eyes around the image. The DS Cells then tell our brain that the blurred heart must be moving, so the brain perceives it as expanding for a brief moment, then contracting to its original size.