MSense Small experiments and illusions to try on yourself or run in a classroom. They run in any modern browser, on laptops and phones, and send no data anywhere.
Perception demos
Experiment · 3 min
Same or different?
Match letters by shape and by name, and measure how long your brain needs to retrieve a letter's name.
Posner & Mitchell (1967)
IllusionWhere is the flash?
A flash aligned with a moving bar seems to lag behind it, unless the bar stops.
Nijhawan (1994)
Demo · needs a blue filterA blind spot for blue
See the blue-blind spot in the centre of your eye, and watch the brain carry a moving dot into it.
Shi & Nijhawan (2012)
Classroom toolA single glance
Flash your own photographs for 80 ms with a mask. What do people see before they can move their eyes?
Davenport & Potter (2004)
IllusionBumps or dents?
Shading alone tells you which way a disk goes, because the brain assumes light comes from above. Rotate the picture and bumps turn into dents.
Ramachandran (1988)
IllusionWhich arch is bigger?
Two identical arches, yet the lower one looks larger. Slide it above the other and the illusion flips.
Jastrow (1892)
IllusionSize in context
The same circle looks smaller among large neighbours and larger among small ones.
Roberts et al. (2005)
IllusionGhosts at the crossings
Grey smudges appear at the intersections of a grid, and vanish as soon as the lines wiggle.
Hermann (1870); Geier et al. (2008)
IllusionTilted by the surround
A grating looks tilted away from the orientation of the grating that surrounds it.
Gibson & Radner (1937)
Illusion · needs soundBounce or stream?
Two crossing discs pass through each other, until a click makes them bounce.
Sekuler, Sekuler & Lau (1997)