Chapter 1. Mental Rotation

1.1 Introduction

This experiment is a replication of one of the most important experiments in the history of psychology. For decades, researchers thought the study of mental images was beyond the reach of science, and questioned their very existence. No one knew how to develop rigorous measures that could indicate mental images existed and explain how we use and manipulate them. The measures had to be clearly interpretable and repeatable by other researchers. Finally, Roger Shepherd, Lynn Cooper, and colleagues developed a methodology in which they rotated two images relative to each other and measured how long it took participants to determine if the images were the same or mirror images. The results provided both a rigorous and a replicable set of findings that allowed mental images to be examined for the first time in a scientific study.

Cooper, L. (1975). Mental rotation of random two-dimensional shapes. Cognitive Psychology, 7(1), 20-43.

Cooper, L. A. & Shepard, R. N. (1973). Chronometric studies of the rotation of mental images. In W.G. Chase (Ed.), Visual information processing (pp. 75-176). New York: Academic Press.

Metzler, J. & Shepard, R. N. (1974). Transformational studies of the internal representation of three-dimensional objects. In R L. Solso (Ed.), Theories of cognitive psychology: The Loyola symposium (pp.147-202). Potomac, MD: Lawrence Erlbaum.

1.2 Experiment Setup

Figure 1.1

1.3 Instructions

You will need to press the space bar to begin the experiment. A fixation mark will then appear in the center of the screen. Please look at this mark. After a brief period, two images will appear, one on either side of the fixation mark. The two images will be the same or mirror images of each other. Your task is to decide, quickly and accurately, if these images are the same or mirror images. You may respond by clicking on the buttons below the images or using your keyboard.

Keyboard Responses

1.4 Experiment

Figure 1.2

1.5 Results

Figure 1.3

1.6 Quiz