1
|
Gallot Q, Tillé Y, Depriester C, Moran S, Zuberbühler K. A primate grammar enabling incremental processing. iScience 2025; 28:112229. [PMID: 40241766 PMCID: PMC12003008 DOI: 10.1016/j.isci.2025.112229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2024] [Revised: 01/13/2025] [Accepted: 03/12/2025] [Indexed: 04/18/2025] Open
Abstract
Characterizing the structure and function of animal communication systems provides insights into the cognitive and evolutionary processes shaping signal complexity. One key question is whether and how call sequences allow potential listeners to make predictions about the call-eliciting referents. Here, we investigated whether primate call sequences contained properties that enabled such predictive processing. We analyzed several years of experimentally elicited alarm responses from a West African forest primate, wild olive colobus monkeys. Using Kullback-Leibler divergence and prediction gain approaches, we identified a simple primate grammar that allowed predictions of referents from only minimal input. In particular, sequence-initial positions reliably discriminated urgent from non-urgent threats while the following positions increased the referential specificity regarding two main predators (eagles and leopards) and non-predatory disturbances (falling tree parts). Sequences often contained further calls, which may allow callers to either confirm the referent or to alter the conveyed information. We concluded that animal communication can contain features adapted for predictive, incremental processing, suggesting evolutionary roots older than language.
Collapse
Affiliation(s)
- Quentin Gallot
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Taï Monkey Project, Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Ivory Coast, Côte d’Ivoire
| | - Yves Tillé
- Institute of Statistics, University of Neuchâtel, Neuchâtel, Switzerland
| | - Cassandre Depriester
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Taï Monkey Project, Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Ivory Coast, Côte d’Ivoire
- ENES Bioacoustics Research Laboratory, CRNL, University of Saint-Etienne, Saint-Etienne, France
| | - Steven Moran
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Department of Anthropology, University of Miami, Coral Gables, FL, USA
- Linguistic Research Infrastructure, University of Zurich, Zurich, Switzerland
| | - Klaus Zuberbühler
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Taï Monkey Project, Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Ivory Coast, Côte d’Ivoire
- School of Psychology and Neuroscience, University of St Andrews, St. Andrews, UK
| |
Collapse
|