Journal of the International Neuropsychological Society

Research Articles

Mental motor imagery and chronic pain: The foot laterality task

H. BRANCH COSLETTa1 c1, JARED MEDINAa1, DASHA KLIOTa1 and ADAM BURKEYa2

a1 Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania

a2 Department of Anesthesiology, Division of Pain Medicine, University of Pennsylvania, Philadelphia, Pennsylvania

Abstract

Several lines of evidence suggest that mental motor imagery is subserved by the same cognitive operations and brain structures that underlie action. Additionally, motor imagery is informed by the anticipated sensory consequences of action, including pain. We reasoned that motor imagery could provide a useful measure of chronic leg or foot pain. Forty subjects with leg pain (19 bilateral, 11 right, and 10 left leg pain), 42 subjects with chronic pain not involving the legs, and 38 controls were shown 12 different line drawings of the right or left foot and asked to indicate which foot was depicted. Previous work suggests that subjects perform this task by mentally rotating their foot to match the visually presented stimulus. All groups of subjects were slower and less accurate with stimuli that required a greater degree of mental rotation of their foot. Subjects with leg pain were both slower and less accurate than normal and pain control subjects in responding to drawings of a painful extremity. Furthermore, subjects with leg pain exhibited a significantly greater decrement in performance for stimuli that required larger amplitude mental rotations. These data suggest that motor imagery may provide important insights into the nature of the pain experience. (JINS, 2010, 16, 603–612.)

(Received December 30 2009)

(Reviewed February 22 2010)

(Accepted March 01 2010)

Correspondence:

c1 Correspondence and reprint requests to: H. Branch Coslett, MD, Department of Neurology, Hospital of the University of Pennsylvania, 3400 Spruce St., Philadelphia, PA 19104. E-mail: hbc@mail.med.upenn.edu