Asymmetry in facial expression of emotions by chimpanzees

Fernández-Carriba, Samuel; Loeches, Angela; Morcillo, Ana; Hopkins, William D.

doi:10.1016/s0028-3932(02)00028-3

Cited by 87 publications

(78 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For instance, while long-distance pant hoots did not lead to lateralization of the brain, listening to short-distance social calls such as grunts or barks elicited a right bias in activation. A rightsided activation of the brain was also suggested by research in the emotional domain: monkeys and great apes both show orofacial asymmetries during vocal production, as evidenced by more pronounced grimaces on the left side of the mouth, which is suggestive of right hemisphere dominance (Fernández-Carriba et al, 2002;Hauser, 1993;Hauser and Akre, 2001;Hook-Costigan and Rogers, 1998), as has been documented in humans (Moreno et al, 1990). These leftward orofacial asymmetries have been most often associated with the emotional state of the animal: for instance, in chimpanzees they are found in emotionally loaded expressions such as "silent-bared teeth face," "playface," and "scream face" (Fernández-Carriba et al, 2002).…”

Section: Lateralization Of the Brain For Vocal And Emotional Processimentioning

confidence: 76%

A comparative neurological approach to emotional expressions in primate vocalizations

Gruber

Grandjean

2017

Neuroscience & Biobehavioral Reviews

View full text Add to dashboard Cite

a b s t r a c tDifferent approaches from different research domains have crystallized debate over primate emotional processing and vocalizations in recent decades. On one side, researchers disagree about whether emotional states or processes in animals truly compare to those in humans. On the other, a long-held assumption is that primate vocalizations are innate communicative signals over which nonhuman primates have limited control and a mirror of the emotional state of the individuals producing them, despite growing evidence of intentional production for some vocalizations. Our goal is to connect both sides of the discussion in deciphering how the emotional content of primate calls compares with emotional vocal signals in humans. We focus particularly on neural bases of primate emotions and vocalizations to identify cerebral structures underlying emotion, vocal production, and comprehension in primates, and discuss whether particular structures or neuronal networks solely evolved for specific functions in the human brain. Finally, we propose a model to classify emotional vocalizations in primates according to four dimensions (learning, control, emotional, meaning) to allow comparing calls across species.

show abstract

Section: Lateralization Of the Brain For Vocal And Emotional Processimentioning

confidence: 76%

A comparative neurological approach to emotional expressions in primate vocalizations

Gruber

Grandjean

2017

Neuroscience & Biobehavioral Reviews

View full text Add to dashboard Cite

show abstract

“…Several studies of non-human primates have shown and discussed facial asymmetries in monkeys [69,70], marmosets [71], and chimpanzees [72], all of which can be viewed as precursors to human brain functional and anatomical asymmetries, as well as the beginnings of the co-evolution of human face and brain. Indeed, there is a myriad of behavioral asymmetries in animals (reviewed by Vallortigara and Rogers [73]), and those could not have developed without the brain of the perceiver being neuronally wired-up to perceive them.…”

Section: Discussionmentioning

confidence: 99%

Asymmetry and Symmetry in the Beauty of Human Faces

Zaidel

Hessamian

2010

Symmetry

View full text Add to dashboard Cite

Abstract:The emphasis in the published literature has mostly been on symmetry as the critical source for beauty judgment. In fact, both symmetry and asymmetry serve as highly aesthetic sources of beauty, whether the context is perceptual or conceptual. The human brain is characterized by symbolic cognition and this type of cognition facilitates a range of aesthetic reactions. For example, both art and natural scenery contain asymmetrical elements, which nevertheless render the whole effect beautiful. A further good case in point is, in fact, human faces. Normally, faces are structurally left-right symmetrical content-wise but not size-wise or function-wise. Attractiveness has often been discussed in terms of content-wise full-face symmetry. To test whether or not attractiveness can be gleaned only from the presence of left-right full-faces we tested half faces. Three separate groups of participants viewed and rated the attractiveness of 56 full-faces (women's and men's), their 56 vertical left hemi-faces and 56 vertical right hemi-faces. We found no statistically significant differences in the attractiveness ratings of full-and hemi-faces (whether left or right). Instead, we found a strong and significant positive correlation between the ratings of the hemi-and full-faces. These results are consistent with the view that the underpinning of human facial beauty is complex and that bilateral symmetry does not constitute a principle factor in beauty assessment. We discuss that the highly evolved human brain, compared to other animals, as well as symbolic and abstract cognition in humans enable a wide variety of aesthetic reactions.

show abstract

“…Therefore, it is reasonable to suggest that lateralization revealed in trunk movements during malefemale contacts may potentially be analogous to asymmetric facial expression of emotions typical for human and non-human primates (e.g., Fernández-Carriba et al, 2002). The direction of bias in facial expressions (greater involvement of the left side of the face), however, is opposite to that observed in elephants' trunk contacts.…”

Section: Animal Behaviourmentioning

confidence: 95%

Context-dependent lateralization of trunk movements in wild Asian elephants

Giljov

Silva

Karenina

2017

BioComm

View full text Add to dashboard Cite

Asymmetrical trunk use in elephants represents a distinctive example of motor lateralization. Previous studies have shown that trunk movements in the elephant behaviour associated with feeding is lateralized at the individual, but not the population level. The manifestation of lateralized behaviour depends on the nature of the behaviour and is usually more pronounced in social context. Therefore, we hypothesized that population-level lateralization of trunk use in elephants is manifested in social behaviour. One-sided biases in trunk movements were assessed in wild individually-identified Asian elephants during feeding (tearing off a tuft of grass) and social interactions (trunk-to-mouth contacts and trunk-to-genitals contacts between male initiator and female recipient). In feeding, lateralization at the individual and population levels was estimated based on 50 lateral trunk uses per individual. In social interactions, only the population-level bias was assessed using a single trunk contact from each individual. For trunk movements during feeding, elephants showed robust individual preferences, but no population-level lateralization. The distribution of right-and left-trunkers in the present study did not differ significantly from that obtained in previous studies of both the same elephant population and geographically distinct population. No population-level bias in trunk movements during trunk-to-mouth contacts was revealed. In trunk-to-genitals contacts, in contrast, a population-level lateralization was found. Right-sided trunk movements prevailed in males touching females. While individual preferences for feeding, combined with the absence of one-sided population bias, is obviously a species-typical characteristic of Asian elephants, social behaviour, such as male-female socio-sexual contacts, can elicit population-level lateralization of trunk use in this species. The right-sided bias in trunk-to-genitals contacts may reflect lateralization of olfactory perception. If this is the case, the revealed lateralization indicates a right-hemispheric advantage in the processing of social information which is consistent with the general tendency in mammals.

show abstract

Asymmetry in facial expression of emotions by chimpanzees

Cited by 87 publications

References 37 publications

A comparative neurological approach to emotional expressions in primate vocalizations

A comparative neurological approach to emotional expressions in primate vocalizations

Asymmetry and Symmetry in the Beauty of Human Faces

Context-dependent lateralization of trunk movements in wild Asian elephants

Contact Info

Product

Resources

About