On how adults identify the orientation of a shape

It is generally assumed that the orientation of a shape is judged only by identifying the location of a particular feature. In contrast, it is argued here that the basis of orientation judgments depends on the task; this proposal is examined for judgments of upside down and sideways. Pictures of mono-oriented objects were presentedone at a time, and adults identified the orientations of each in a RT paradigm. One condition presented successively upright and upside-down pictures or upright and sideways pictures. Another condition presented successively upside-down and sideways pictures. As predicted, the time to identify orientation was longer for the condition presenting two nonuprights, because specific identifications of upside down and sideways were required, whereas the other condition required only that uprightness be distinguished from nonuprightness. The notion that the nature of a judgment of shape orientation depends on the contrasts provided by the task has implications for theory and experimental design that are discussed for both realistic and geometric shapes.