Dissociation of emotional processes in response to visual and olfactory stimuli following frontotemporal damage

Neurocase. 2005 Apr;11(2):114-28. doi: 10.1080/13554790590922513.

Abstract

Contemporary neuropsychological studies have stressed the widely distributed and multicomponential nature of human affective processes. Here, we examined facial electromyographic (EMG) (zygomaticus and corrugator muscle activity), autonomic (skin conductance and heart rate) and subjective measures of affective valence and arousal in patient TG, a 30 year-old man with left anterior mediotemporal and left orbitofrontal lesions resulting from a traumatic brain injury. Both TG and a normal control group were exposed to hedonically valenced visual and olfactory stimuli. In contrast with control subjects, facial EMG and electrodermal activity in TG did not differentiate among pleasant, unpleasant and neutral pictures. In addition, the controls reacted spontaneously with larger corrugator EMG activity and higher skin conductance to unpleasant odors. By contrast, the subjective feeling states (pleasure and arousal ratings) remained preserved in TG. The covariation between facial and self-report measures of negative valence was also a function of the nature of the olfactory task in the patient only. Taken together, the data suggest a functional dissociation between brain substrates supporting generation of emotion and those supporting representation of emotion.

Publication types

  • Case Reports

MeSH terms

  • Accidents, Traffic
  • Adult
  • Autonomic Nervous System / physiology
  • Brain Injuries / diagnostic imaging
  • Brain Injuries / pathology
  • Brain Injuries / psychology
  • Electromyography
  • Emotions / physiology*
  • Facial Muscles / physiology
  • Frontal Lobe / diagnostic imaging
  • Frontal Lobe / injuries*
  • Frontal Lobe / pathology
  • Galvanic Skin Response
  • Glasgow Coma Scale
  • Heart Rate / physiology
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Neuropsychological Tests
  • Photic Stimulation
  • Psychomotor Performance / physiology
  • Smell / physiology*
  • Stimulation, Chemical
  • Temporal Lobe / diagnostic imaging
  • Temporal Lobe / injuries*
  • Temporal Lobe / pathology
  • Tomography, Emission-Computed, Single-Photon
  • Visual Perception / physiology*