Sparking insight in the lab
Researchers sometimes use two-tone images known as Mooney images to generate ‘aha!’ moments of sudden insight in study participants. The insight arrives when what’s shown in the image becomes clear. Can you solve these Mooney images created by the Nature art team?

For an extra challenge, add a 10-second time limit for each image.
Credit: Getty. Images processed with code created by: Imamoglu, F., Kahnt, T., Koch, C. & Haynes, J. D. Neuroimage 63, 1909–1917 (2012).