Categorization of vocal and nonvocal stimuli in Guinea baboons (Papio papio)
Résumé
Categorization of vocal sounds apart from other sounds is one of the key abilities in human voice processing, but whether this ability is present in other animals, particularly non-human primates, remains unclear. In the present study, 25 socially-housed Guinea baboons (Papio papio) were tested on a vocal/non-vocal categorization task using Go/Nogo paradigm implemented on freely accessible automated learning devices. Three individuals from the group successfully learned to sort Grunt vocalizations from non-vocal sounds, and they generalized to new stimuli from the two categories, indicating that some baboons have the ability to develop open-ended categories in the auditory domain. Contrary to our hypothesis based on the human literature, these monkeys learned the non-vocal category faster than the Grunt category. Moreover, they failed to generalize their classification to new classes of conspecific vocalizations (Wahoo, bark, Yak, and copulation calls), and they categorized human vocalizations in the non-vocal category, suggesting that they had failed to represent the task as a vocal vs non vocal categorization problem. Thus, our results do not confirm the existence of a separate perceptual category for conspecific vocalizations in baboons. Interestingly, the three successful baboons are the youngest of the group, with less training in visual tasks, which supports previous reports of age and learning history as crucial factors in auditory laboratory experiments.
Origine : Fichiers produits par l'(les) auteur(s)