Mary Cheves West Perky

Mary Cheves West Perky (1874 to 1940) was an American psychologist and one of the twenty-one female students who studied under Edward B. Titchener at Cornell University. She received a Ph.D. in 1910 for her work on visual, auditory and olfactory imagery. In her best-known experiment, participants looked at a blank screen and were asked to imagine an object such as a banana while a faint matching shape was projected at a brightness just above the threshold of visibility. None of them realised they were seeing a real image, and all took it to be a product of their own imagination. The result is now called the Perky effect, and it showed that mental imagery can be mistaken for sensory input. Her findings continued to inform imagery research into the twenty-first century, and a 2012 article in The American Journal of Psychology reviewed her contribution. She also studied the cooperative movement and served as Associate Secretary of the Cooperative League of America.