The visual world behind the head.

After a 5-minute inspection of 7 objects laid out on a shelf, subjects were seated with the objects behind them and answered questions about the locations and orientations of objects by throwing a switch left or right. The "visual image" subjects were told to imagine that the objects were still in front of them and to respond accordingly. The "real space" (RS) subjects were told to respond in terms of the positions of the objects in real space behind them. Thus correct responses (left vs. right) were completely opposite for the 2 groups. A control group responded while facing a curtain concealing the objects. The task was harder, by time and error criteria, for group RS than for the other 2 groups, but not dramatically so. All RS subjects denied using a response-reversal strategy. Some reported translating the objects from back to front and thus responding as to a mirror-image of the array. When this evasion was discouraged, RS subjects typically reported responding in terms of visual images located behind them and viewed as if by "eyes in the back of the head." The paradox of a visual image that corresponds to no possible visual input is discussed.