Mental motor imagery and chronic pain: the foot laterality task.
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.
Coslett
H Branch
HB
Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. hbc@mail.med.upenn.edu
Medina
Jared
J
Kliot
Dasha
D
Burkey
Adam
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002908:Chronic Disease; D005260:Female; D005528:Foot; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D019018:Imagery, Psychotherapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D010146:Pain / Q000503:physiopathology / Q000534:rehabilitation*; D010147:Pain Measurement; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012399:Rotation; D013223:Statistics as Topic; D055815:Young Adult