Biology subjects

Philippe, R.

Publications and source records attributed to Philippe, R..

3 recordsLinked to original sources

bioRxiv2026

Vocal Signatures of Stress Relief: Effects of Appeasing Harness and Synthetic Pheromone on Puppy Whine Acoustics in Separation Context (Canis familiaris)

In mammals, loud, high-pitched, and harsh-sounding calls typically accompany heightened emotional arousal, particularly during distress such as separation. However, whether subtle arousal reductions can be detected through acoustic analysis within a single negative context remains unclear. We investigated whether source-related acoustic parameters of puppy whines reflect arousal modulations induced by calming interventions during maternal separation. Thirty-five eight-week-old Beagle puppies were recorded under four conditions combining synthetic appeasing pheromone and a pressure harness. Vocal behavior, activity, whine duration, and intensity, did not significantly differ across treatments, suggesting interventions did not suppress separation-related vocal responses. Nevertheless, calming products selectively altered acoustic parameters known to index arousal in dog vocalizations. Puppies receiving combined treatments produced whines with lower fundamental frequency (fo) and reduced fo variability, while pheromone exposure increased call tonality, reflected by reduced jitter and shimmer and elevated harmonics-to-noise ratios. Spectral entropy remained unchanged, possibly because the proportion of whines containing nonlinear phenomena did not vary across conditions. Reductions in fo, fo variability, and acoustic roughness are consistent with established correlates of lower arousal in mammals, suggesting source-related vocal parameters sensitively capture subtle arousal shifts even when overt vocal behavior remains stable, supporting their use as bioacoustic indicators for evaluating welfare interventions.

animal behavior and cognition↗

bioRxiv2023

Causal Role of the Medial Prefrontal Cortex in Learning Social Hierarchy

Social hierarchy is a fundamental principle of social organization and an important attribute of community stability and development. Yet, little is known about the causal role of specific brain regions in learning hierarchies. Here, using transcranial direct current stimulation (tDCS), we investigated the causal role of the medial prefrontal cortex (mPFC) in learning social and non-social hierarchies. In the Training phase, participants(N=128) acquired knowledge of social and non-social hierarchy in parallel, by trial and error. During the Test phase, they were presented with two items from hierarchies that were never encountered together and required to make transitive inferences. Anodal stimulation over mPFC impaired social hierarchy learning compared with non-social learning and this modulation was influenced by the relative social rank of the members (i.e. higher or lower status). Anodal stimulation also impaired transitive inference making, but only during early blocks before learning was established. Together, our results provide causal evidence of mPFC engagement in learning social ranks by observation.

neuroscience↗

bioRxiv2018

Bayesian Inference of Other Minds Explains Human Decisions in a Group Decision Making Task

To make decisions in a social context, humans have to predict the behavior of others, an ability that is thought to rely on having a model of other minds known as theory of mind. Such a model becomes especially complex when the number of people one simultaneously interacts is large and the actions are anonymous. Here, we show that in order to make decisions within a large group, humans employ Bayesian inference to model the \"mind of the group,\" making predictions of others decisions while also considering the effects of their own actions on the group as a whole. We present results from a group decision making task known as the Volunteers Dilemma and demonstrate that a Bayesian model based on partially observable Markov decision processes outperforms existing models in quantitatively explaining human behavior. Our results suggest that in group decision making, rather than acting based solely on the rewards received thus far, humans maintain a model of the group and simulate the groups dynamics into the future in order to choose an action as a member of the group.

neuroscience↗