An autonomous, automated and mobile device to concurrently assess several cognitive functions in group-living non-human primates.

Research methods in cognitive neuroscience using non-human primates have undergone notable changes over the last decades. Recently, several research groups have described freely accessible devices equipped with a touchscreen interface. Two characteristics of such systems are of particular interest: some apparatuses include automated identification of subjects, while others are mobile. Here, we designed, tested and validated an experimental system that, for the first time, combine automatization and mobility. Moreover, our system allows autonomous learning and testing of cognitive performance in group-living subjects, including follow-up assessments. The mobile apparatus is designed to be available 24h a day, 7days a week, in a typical confined primate breeding and housing facility. Here we present as proof of concept, the results of two pilot studies. We report that rhesus macaques (Macaca mulatta) learned the tasks rapidly and achieved high-level of stable performance. Approaches of this kind should be developed for future pharmacological and biomedical studies in non-human primates.

A review of the 5-Choice Serial Reaction Time (5-CSRT) task in different vertebrate models.

Within cognitive and behavioural research, the 5-Choice Serial Reaction Time task is widely recognized as a valuable test of attention in rats. However, technical and methodological developments required for extending its usefulness are still at an early stage. In view of advances in knowledge about cognition and other areas of biology, issues surrounding attention are increasingly important, and appear to require new methodological approaches. These changes may concern (i) the evolution of the protocol itself, (ii) adaptations in how tasks are implemented (e.g. use of new technologies such as touchscreens), and (iii) applying existing tasks to species presenting an emerging potential. From a primarily methodological perspective, this review focuses on work that has successively built upon the original 5-CSRT task. We address the strengths and weaknesses of new approaches as well as some of the new possibilities they offer.

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

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.

Tonkean macaques communicate with their right hand.

There are two conflicting hypotheses to explain the origins of language. Vocal origin theory states that language results from the gradual evolution of animals' vocal communication, but gestural origin theory considers that language evolved from gestures, with the initial left-hemispheric control of manual gestures gradually encompassing vocalizations. To contribute to this debate, we investigated functional hemispheric specialization related to hand biases when grasping or showing an object through manual gesture in Tonkean macaques. The results of this study, the first quantitative study on Tonkean macaques' handedness, showed a remarkable convergence of the Tonkean macaques' handedness patterns with those of baboons and human infants, with hand preferences for manual communicative gestures significantly favoring the use of the right hand. Our findings support the hypothesis that left hemispheric lateralization for language is derived from a gestural communication system that was present in the common ancestor of macaques, baboons and humans.