Biology subjects

Phelipon, R.

Publications and source records attributed to Phelipon, R..

4 recordsLinked to original sources

bioRxiv2026

Sleep quality and quantity and their associations with age, salivary cortisol and abnormal behaviours: a preliminary field study in racing thoroughbreds.

Sleep plays a key role in both physical recovery and welfare. However, sleep patterns remain poorly documented in animals, particularly in athletic horses. This study aimed to provide a detailed description of sleep quantity and quality in training Thoroughbred racehorses and to investigate their relationships with age, abnormal behaviours, and cortisol. Thirteen Thoroughbreds (2-7 years old) were continuously monitored in their home environment over three consecutive days. An ethogram was used to quantify the two main phases of sleep: Non Rapid Eye Movement sleep (NREM) and Rapid Eye Movement sleep (REM), as well as sleep interruptions (from day 1 at 12:00 a.m. to day 3 at 12:00 a.m.). Sleep Quality Indices (SQI), defined as the quantity of sleep divided by the number of sleep interruptions (SI), were calculated. Behavioural observations of four indicators of poor welfare (alertness, stereotypies, inactivity, aggressiveness towards humans) were performed using scan sampling, and salivary cortisol was measured each morning. Linear models were used to assess the links between sleep quantity and quality, age, mean cortisol, and abnormal behaviours. Sleep quantity was significantly associated with age: positively for total NREM sleep (ANOVA: {chi}{superscript 2} = 5.26, p < 0.05) and, negatively for total REM sleep (ANOVA: {chi}{superscript 2} = 4.46, p <0.05) and total recumbency duration (ANOVA: {chi}{superscript 2} = 5.68, p < 0.05), suggesting an age-related shift favouring NREM over REM. Morning cortisol concentrations and the frequency of abnormal behaviours were significantly higher in horses with lower sleep quality (cortisol: Total SQI, ANOVA: F = 5.26, p < 0.05; Combined SQI, ANOVA: F = 5.40, p < 0.05; abnormal behaviours: Total SQI, ANOVA: F = 4.07, p = 0.074), pointing to a potential link between stress or altered welfare and poorer sleep quality. These findings suggest that, whilst the type and duration of equine sleep may be mainly affected byage, sleep quality is associated with both cortisol levels and the expression of abnormal behaviours, indicating that poor sleep quality may be linked to poor welfare in this population of horses. Thus, sleep appears to be closely linked with racehorse welfare, highlighting the need for further investigation into how it is influenced by factors such as husbandry, training load, recovery, and performance.

animal behavior and cognition↗

bioRxiv2025

Characterisation of facial expressions and behaviours of horses in response to positive and negative emotional anticipation using network analysis

The welfare of an animal is closely linked to their emotional experiences, making it essential to identify reliable indicators of these emotions. This study aimed to identify behaviours and facial movements in horses experiencing contrasting emotional valence, triggered by the anticipation of a positive condition (going to pasture) or a negative condition (going alone to a novel environment). Twenty horses were daily trained to wait in a starting box before being exposed to these two conditions. After one week of positive training or negative training, we analysed horses behaviours, cortisol variations, and facial movements while they waited in their starting box. First, we confirmed that the two conditions induced contrasting emotional valence, as evidenced by the shorter time taken to approach in the positive condition compared to the negative, and by the higher maximal heart rate and cortisol variation in the negative condition. Then using the Equine Facial Action Coding System (EquiFACS) and network analysis (NetFACS) we revealed distinct behaviours and facial expression profiles. In positive anticipation, the horses exhibited a greater range of behaviours, including shaking their heads from side to side, stepping back, sniffing, and pawing at the ground. Additionally, two distinct facial expression profiles were identified as specific to positive and negative anticipation. In positive anticipation, the horses displayed a higher neck, accompanied by a greater frequency of half-blinks and mouth movements. Conversely, in negative anticipation, the horses exhibited a medium neck, with ears backward accompanied by more flattened ears and expressed more nostril movements. The findings highlight the importance of these indicators in characterising horses emotions and emphasise their significance for assessing equine welfare.

animal behavior and cognition↗

bioRxiv2024

The interplay between executive functions and updating predictive representations

Modifying habits, particularly unwanted behaviors, is often challenging. Cognitive research has focused on understanding the mechanisms underlying habit formation and how habits can be rewired. A key mechanism is statistical learning, the continuous, implicit extraction of probabilistic patterns from the environment, which forms the basis of predictive processing. However, the interplay between executive functions (EF) and the rewiring - or updating - of these probabilistic representations remains largely unexplored. To address this gap, we conducted an experiment consisting of four sessions: 1) Learning Phase - acquisition of probabilistic representations, 2) Rewiring Phase - updating these probabilistic representations, 3) Retrieval Phase - accessing learned representations, and 4) EF assessment, targeting five key aspects: attentional control, inhibition, working memory, flexibility, and verbal fluency. We focused on the relationship between these EF measures and the updating of previously acquired knowledge using an interindividual differences approach. Our results revealed a positive relationship between rewiring and inhibition, suggesting that better inhibitory control may facilitate the adaptive restructuring of probabilistic predictive representations. Conversely, a negative relationship was identified between rewiring and semantic fluency, implying that certain underlying aspects of verbal fluency tasks, such as access to long-term memory representations, may hinder the updating process. We interpret this relationship through the lens of competitive memory network models. Our findings indicate that the rewiring of implicit probabilistic representations is a multifaceted cognitive process requiring both the suppression of proactive interference from prior knowledge through cognitive inhibition and a strong reliance on model-free functioning.

neuroscience↗

bioRxiv2021

Planum Temporale grey matter volume asymmetries in new-born monkeys (Papio anubis)

The Planum Temporale (PT) is one of the key hubs of the language network in the human brain. The gross asymmetry of this perisylvian region toward the left brain was considered as the most emblematic marker of hemispheric specialization of language processes in the brain. Interestingly, this neuroanatomical signature was documented also in newborn infants and preterms, suggesting the early brains readiness for language acquisition. Nevertheless, this latter interpretation was questioned by a recent report in nonhuman primates of a potential similar signature in newborn baboons Papio anubis based on PT surface measures. Whether this "tip of the iceberg" PT asymmetry is actually reflecting asymmetry of its underlying grey matter volume remain unclear but critical to investigate potential continuities of cortical specialization with human infants. Here we report a population-level leftward asymmetry of the Planum Temporale grey matter volume in in vivo 34 newborn baboons Papio anubis, which showed intra-individual positive correlation with PT surfaces asymmetry measures but also a more pronounced degree of leftward asymmetry at the population-level. This finding demonstrates that PT leftward structural asymmetry in this Old World monkey species is a robust phenomenon in early primate development, which clearly speaks for a continuity with early human brain specialization. Results also strengthen the hypothesis that early PT asymmetry might be not a human-specific marker for the pre-wired language-ready brain in infants.

neuroscience↗