A. Angrilli et al., Emotional impairment after right orbitofrontal lesion in a patient withoutcognitive deficits, NEUROREPORT, 10(8), 1999, pp. 1741-1746
THE present study describes a patient, M.L., with right orbitofrontal lesio
n, who showed no impairment on main neuropsychological tests, including tho
se measuring frontal functions. Nevertheless, he had deeply affected emotio
nal responses. In line with Damasio's work, the patient had lower skin cond
uctance during the projection of a standardized set of emotional slides. Fu
rthermore, he showed altered facial expressions to unpleasant emotions, dis
playing low corrugator supercilii electromyographical activity associated w
ith reduced recall of unpleasant stimuli. During a task focusing on imagery
of emotional situations, M.L.'s heart rate and skin conductance responses
were affected during both pleasant and unpleasant conditions. Facial expres
sions to unpleasant imagery scripts were also impaired. Thus, the orbitofro
ntal cortex proved to play a critical role in retrieval of psychophysiologi
cal emotional patterns, particularly to unpleasant material. These results
provide the first evidence that orbitofrontal lesions are associated with e
motional impairment at several psychophysiological levels. NeuroReport 10:1
741-1746 (C) 1999 Lippincott Williams & Wilkins.