Perky's imagery study (1910) had participants describe images of objects that were dimly projected onto a screen. The significance of Perky's results was thata. screen images interfered with people's ability to form mental images.b. people were influenced by the projected images when forming their mental images, even when they were unaware that the projected images were present.c. the screen images had no effect on people's mental images.d. people "used" the screen images to create their mental images but only when the objects were unfamiliar.
