Perception and integration of social information

The assessment of individuals’ capacities to perceive and to decode vocal and language cues is crucial to ascertain the functions of these acoustic and linguistic variations. Moreover, vocal signals are not produced in isolation, but are part of vocal exchanges that are governed by precise rules. As vocal signals are produced in a multisensory environment, a good knowledge of the multimodality of signals is fundamental for our investigations.

Perception and decoding of vocal signals

As primates can form polyspecific associations in the wild, individuals not only interact with conspecifics but also with members of other species. Therefore, we are interested by how they perceive, discriminate and possibly decode information carried by vocalizations of individuals [FIG6] both of their own and of other species. We investigate relationships between humans’ knowledge of sociolinguistic norms and their acquisition of linguistic variations by studying children’s social evaluations of linguistic varieties during development.

From vocal signals to vocal interactions: communication rules

Influence of interlocutors’ characteristics
Social partners are not all equally-preferred or valid interlocutors. We investigate the choice or acceptance of a partner in relation to its characteristics (age, sex, social status) by both non-human primates and human children.

Conversation: a skill to acquire
Non-human primates’ vocal exchanges are organized as primitive forms of conversation. We study the temporal synchronization of vocal emissions (overlap avoidance and turn-taking) together with the interlocutors' characteristics, such as their age and social status. [FIG7]

Diversity of sensory experiences

The Umwelt of species: some unexplored sensory modalities
The Umwelt of an individual is its subjective world based on its perception range, its action range and their combination. To understand the various ways an individual reacts to its physical and social environment, we need to know its Umwelt, its pertinent world, precisely, in addition to the study of its major sensory skill. The models we focus on to develop this topic are dolphins [FIG8] and humans, in particular newborns.

Dolphins: evidence for vocal copying

Indeed, from an applied point of view, a better knowledge of newborns' Umwelt would help develop new ways to evaluate routine care protocols in neonatology units. [FIG9]

new ways to evaluate routine care protocols in neonatology units

Perceptual laterality
Perceptual laterality induces different responses to different types of stimuli. We assess the influence of stimulus characteristics, through its familiarity or its social value [FIG10], on non-human primates’ visual and auditory laterality.

Social pressures on population-level laterality

Main features

  • Stallion’s voice, an indicator of fertility and a basis for female choice. [FIG6]
  • Female Campbell’s monkeys learn how to “converse” properly. [FIG7]
  • Nocturnal rehearsal of daily shows by bottlenose dolphins when at rest: evidence from vocal copying. [FIG8]
  • Preterm babies’ clothing impacts their postures, and possibly their comfort. [FIG9]
  • Social pressure on laterality for an interactive social behaviour: kissing cheek as a greeting. [FIG10]