TY - JOUR
T1 - Brain temperature asymmetries and emotional perception in chimpanzees, Pan troglodytes
AU - Parr, L. A.
AU - Hopkins, W. D.
N1 - Funding Information:
This investigation was supported by grants RR-00165 from the NIH/NCRR to the Yerkes Regional Primate Research Center, NS-36605 and NS-29574 to W.D. Hopkins, and NSF doctoral dissertation award IBN-9801464 to L.A. Parr. The authors thank Michel Cabanac, Agnès Lacreuse, and two anonymous reviewers for their comments on an earlier version of this manuscript. Thanks also go to Lauren Fowler for her help in data collection and animal training, Frans de Waal for the use of video material, and the animal care staff at the Yerkes Regional Primate Research Center. The APA standards for the ethical treatment of animals were adhered to during these studies. The Yerkes Primate Center is fully accredited by the American Association for Accreditation of Laboratory Animal Care.
PY - 2000/11/1
Y1 - 2000/11/1
N2 - The lateralization of emotion has received a great deal of attention over the last few decades, resulting in two main theories. The Right Hemisphere Theory states that the right hemisphere is primarily responsible for emotional processes, while the Valence Theory suggests that the right hemisphere regulates negative emotion and the left hemisphere regulates positive emotion. Despite the important implications of these theories for the evolution of emotion processes, few studies have attempted to assess the lateralization of emotion in non-human primates. This study uses the novel technique of measuring tympanic membrane temperature (Tty) to assess asymmetries in the perception of emotional stimuli in chimpanzees. The tympanic membrane is an indirect, but reliable, site from which to measure brain temperature, and is strongly influenced by autonomic and behavioral activity. Six chimpanzees were shown positive, neutral, and negative emotional videos depicting scenes of play, scenery, and severe aggression, respectively. During the negative emotion condition, right Tty was significantly higher than the baseline temperature. This effect was relatively stable, long lasting, and consistent across subjects. Temperatures did not change significantly from baseline in the neutral or positive emotion condition, although a significant number of measurements showed increased left Tty during the neutral emotion condition. These data suggest that viewing emotional stimuli results in asymmetrical changes in brain temperature, in particular increased right Tty during the negative emotion condition, evidence of emotional arousal in chimpanzees, and in providing partial support of both the Right Hemisphere and Valence Theories of emotional lateralization in our closest living ancestor.
AB - The lateralization of emotion has received a great deal of attention over the last few decades, resulting in two main theories. The Right Hemisphere Theory states that the right hemisphere is primarily responsible for emotional processes, while the Valence Theory suggests that the right hemisphere regulates negative emotion and the left hemisphere regulates positive emotion. Despite the important implications of these theories for the evolution of emotion processes, few studies have attempted to assess the lateralization of emotion in non-human primates. This study uses the novel technique of measuring tympanic membrane temperature (Tty) to assess asymmetries in the perception of emotional stimuli in chimpanzees. The tympanic membrane is an indirect, but reliable, site from which to measure brain temperature, and is strongly influenced by autonomic and behavioral activity. Six chimpanzees were shown positive, neutral, and negative emotional videos depicting scenes of play, scenery, and severe aggression, respectively. During the negative emotion condition, right Tty was significantly higher than the baseline temperature. This effect was relatively stable, long lasting, and consistent across subjects. Temperatures did not change significantly from baseline in the neutral or positive emotion condition, although a significant number of measurements showed increased left Tty during the neutral emotion condition. These data suggest that viewing emotional stimuli results in asymmetrical changes in brain temperature, in particular increased right Tty during the negative emotion condition, evidence of emotional arousal in chimpanzees, and in providing partial support of both the Right Hemisphere and Valence Theories of emotional lateralization in our closest living ancestor.
KW - Brain temperature
KW - Chimpanzees
KW - Emotion
KW - Laterality
KW - Tympanic membrane
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U2 - 10.1016/S0031-9384(00)00349-8
DO - 10.1016/S0031-9384(00)00349-8
M3 - Article
C2 - 11150569
AN - SCOPUS:0034319089
SN - 0031-9384
VL - 71
SP - 363
EP - 371
JO - Physiology and Behavior
JF - Physiology and Behavior
IS - 3-4
ER -