Patterns of hemispheric specialization for a communicative gesture in different primate species

Abstract

We review four studies investigating hand preferences for grasping versus pointing to objects at several spatial positions in human infants and three species of nonhuman primates using the same experimental setup. We expected that human infants and nonhuman primates present a comparable difference in their pattern of laterality according to tasks. We tested 6 capuchins, 6 macaques, 12 baboons, and 10 human infants. Those studies are the first of their kind to examine both human infants and nonhuman primate species with the same communicative task. Our results show remarkable convergence in the distribution of hand biases of human infants, baboons and macaques on the two kinds of tasks and an interesting divergence between capuchins' and other species' hand preferences in the pointing task. They support the hypothesis that left-lateralized language may be derived from a gestural communication system that was present in the common ancestor of macaques, baboons and humans.

Baboons' hand preference resists to spatial factors for a communicative gesture but not for a simple manipulative action

“…Three main points are worth noting in the present contribution. First, the differential distribution of hand biases for gesturing toward a partner and for grasping an item corroborates previous results obtained in baboons and other species (Meunier et al, ; Meunier et al, ) and stresses that these two manual actions seem not to be processed similarly by the brain. Second, this investigation sheds light on the relative influence of the strength of hand preference in distinguishing communicative from non‐communicative tasks in an old‐world‐monkey.…”

“…As it is the case for children (Esseily, Jacquet, & Fagard, ; Jacquet et al, ; Vauclair & Imbault, ), the population‐level right biases found in both species were stronger for communicative gestures than for object‐directed manual actions, (e.g., baboons: Meguerditchian & Vauclair, ; chimpanzees: Hopkins et al, ; Meguerditchian et al, ). Consequently, a similar pattern of hand preference can be observed in human and in some non‐human primates (see also Meunier, Vauclair, & Fagard, ; Meunier et al, ), albeit in different proportions. Taken together, these data suggest that the left‐hemisphere dominance in linguistic functioning is not modality‐specific and may have deep phylogenetic origins (Corballis et al, ; Meguerditchian, Cochet, & Vauclair, ; Vauclair, ).…”

“…Hand preference was sampled by recording the hand used to pick up each card. This task has been thereafter adapted to non‐human primates in a very comparable set‐up (Chapelain et al, ; Meunier et al, ; Meunier et al, ). We provide a brief description of the experimental set‐up here.…”

“…The prediction was that switching hand across positions indicated weaker preferences than keeping hand consistent across positions. Adaptations of this task for children (Esseily et al, ; Jacquet et al, ) and non‐human primates & (Chapelain et al, ; Meunier, Blois‐Heulin, & Vauclair, ; Meunier et al, ; Meunier et al, ) have proved recently successful in highlighting the influence of situational factors on handedness for reaching actions.…”

Asymmetry of brain and behavior in animals: Its development, function, and human relevance

“…Although some punctuated changes in brain laterality may have taken place with the evolution of humans (see Teffer and Semendeferi, 2012, for example), asymmetrical function of the brain was already firmly established well before humans evolved. Even left hemispheric specialization for speech in humans seems to be an elaboration of this hemisphere's superiority in sequential processing (Bradshaw and Nettleton, 1981) and for communication (Meunier et al, 2013), both of which evolved well before humans (MacNeilage et al, 2009;Meguerditchian et al, 2013). The right hemisphere is specialized for broad attention and response to unexpected stimuli, to recognize faces and express strong emotions, and all of these functions had evolved well before humans (Bradshaw and Nettleton, 1981;Fox et al, 2006;MacNeilage et al, 2009).…”