Articles scientifiques

Publications du LECD sur son site HAL

  • [hal-04589873] Object play and problem solving in infancy: Insights into tool use
    27 mai 2024
    Tool use is primarily, but not exclusively, present in species with otherwise advanced cognitive traits. However, the interaction between such traits and conspecific inter-individual variation in the presence, complexity, or intensity of tool use is far from being established. We addressed this matter among human infants, seeking factors that relate to differences in tool use. We examined, both correlationally and experimentally, whether the propensity to engage in object combinations predicts performance in means–end problem-solving tasks involving or not involving the use of a tool. We tested 71 infants aged 15, 18, 21, and 24 months, dividing them into two subgroups: one exposed to an adult demonstrating object–object combinations (i.e., “prompting” infants to combine objects together) and another with comparable social exposure but where the adult demonstrated single-object manipulations. We found a correlation between the combined level of spontaneous and prompted object combinations and problem-solving performance regardless of the involvement of tools in the problem. However, we did not find differences in tool-use performance between the two demonstration subgroups. The correlational analysis suggests that complexity of play, as measured by the frequency of combining objects, is linked to infants’ problem-solving skills rather than being specifically associated with tool use, as previously suggested in the literature.
  • [hal-04233451] Limb Preference in Animals: New Insights into the Evolution of Manual Laterality in Hominids
    28 mai 2024
    Until the 1990s, the notion of brain lateralization—the division of labor between the two hemispheres—and its more visible behavioral manifestation, handedness, remained fiercely defined as a human specific trait. Since then, many studies have evidenced lateralized functions in a wide range of species, including both vertebrates and invertebrates. In this review, we highlight the great contribution of comparative research to the understanding of human handedness’ evolutionary and developmental pathways, by distinguishing animal forelimb asymmetries for functionally different actions—i.e., potentially depending on different hemispheric specializations. Firstly, lateralization for the manipulation of inanimate objects has been associated with genetic and ontogenetic factors, with specific brain regions’ activity, and with morphological limb specializations. These could have emerged under selective pressures notably related to the animal locomotion and social styles. Secondly, lateralization for actions directed to living targets (to self or conspecifics) seems to be in relationship with the brain lateralization for emotion processing. Thirdly, findings on primates’ hand preferences for communicative gestures accounts for a link between gestural laterality and a left-hemispheric specialization for intentional communication and language. Throughout this review, we highlight the value of functional neuroimaging and developmental approaches to shed light on the mechanisms underlying human handedness.
  • [hal-01478449] Female Signalling to Male Song in the Domestic Canary, Serinus Canaria
    28 février 2017
    Most studies on sexual selection focus on male characteristics such as male song in songbirds. Yet female vocalizations in songbirds are growing in interest among behavioural and evolutionary biologists because these vocalizations can reveal the female's preferences for male traits and may affect male display. This study was designed to test whether male song performance influences the different female signals in the domestic canary (Serinus canaria). Female canaries were exposed to three types of song performance, differing in the repetition rate of sexy syllables. This experiment demonstrates that female birds are engaged in multimodal communication during sexual interaction. The results support the copulation solicitation hypothesis for female-specific trills: these trills were positively correlated and had a similar pattern to the copulation solicitation displays; responses were higher to the songs with higher performance and responses decreased with the repetition of the stimulation. Also, we observed a sensitization effect with the repetition of the song of the highest performance for the simple calls. Simple trills and other calls were more frequent during the broadcast of canary songs compared with the heterospecific control songs. The differential use of female signals in response to different song performance reveals a highly differentiated female signalling system which is discussed in light of the role of female traits to understand sexual selection in a broader perspective.
  • [hal-04307298] Skin-to-skin SDF positioning: The key to intersubjective intimacy between mother and very preterm newborn—A pilot matched-pair case-control study
    21 mai 2024
    Background Skin-to-skin contact (SSC) has been widely studied in NICU and several meta-analyses have looked at its benefits, for both the baby and the parent. However, very few studies have investigated SSC’ benefits for communication, in particular in the very-preterm newborn immediately after birth. Aims To investigate the immediate benefits of Supported Diagonal Flexion (SDF) positioning during SSC on the quality of mother—very-preterm newborn communication and to examine the coordination of the timing of communicative behaviors, just a few days after birth. Subjects and study design Monocentric prospective matched-pair case-control study. Thirty-four mothers and their very preterm infants (27 to 31 + 6 weeks GA, mean age at birth: 30 weeks GA) were assigned to one of the two SSC positioning, either the Vertical Control positioning ( n = 17) or the SDF Intervention positioning ( n = 17). Mother and newborn were filmed during the first 5 min of their first SSC. Outcome measures Infants’ states of consciousness according to the Assessment of Preterm Infants’ Behavior scale (APIB). Onset and duration of newborns’ and mothers’ vocalizations and their temporal proximity within a 1-s time-window. Results In comparison with the Vertical group, very preterm newborns in the SDF Intervention Group spent less time in a drowsy state and more in deep sleep. At 3.5 days of life, newborns’ vocal production in SSC did not differ significantly between the two groups. Mothers offered a denser vocal envelope in the SDF group than in the Vertical group and their vocalizations were on average significantly longer. Moreover, in a one-second time-frame, temporal proximity of mother-very preterm newborn behaviors was greater in the SDF Intervention Group. Conclusion Although conducted on a limited number of dyads, our study shows that SDF positioning fosters mother-very preterm newborn intimate encounter during the very first skin to skin contact after delivery. Our pioneer data sheds light on the way a mother and her very preterm vocally meet, and constitutes a pilot step in the exploration of innate intersubjectivity in the context of very preterm birth.
  • [hal-04531901] Inference of sex‐specific expansion patterns in human populations from Y ‐chromosome polymorphism
    4 avril 2024
    Studying the current distribution of genetic diversity in humans has important implications for our understanding of the history of our species. We analyzed a set of linked STR and SNP loci from the paternally inherited Y chromosome to infer the past demography of 55 African and Eurasian populations, using both the parametric and nonparametric coalescent‐based methods implemented in the BEAST application. We inferred expansion events in most sedentary farmer populations, while we found constant effective population sizes for both nomadic hunter‐gatherers and seminomadic herders. Our results differed, on several aspects, from previous results on mtDNA and autosomal markers. First, we found more recent expansion patterns in Eurasia than in Africa. This discrepancy, substantially stronger than the ones found with the other kind of markers, may result from a lower effective population size for men, which might have made male‐transmitted markers more sensitive to the out‐of‐Africa bottleneck. Second, we found expansion signals only for sedentary farmers but not for nomadic herders in Central Asia, while these signals were found for both kind of populations in this area when using mtDNA or autosomal markers. Expansion signals in this area may result from spatial expansion processes and may have been erased for the Y chromosome among the herders because of restricted male gene flow. Am J Phys Anthropol 157:217–225, 2015. © 2015 Wiley Periodicals, Inc.
  • [hal-04531896] Different kinds of genetic markers permit inference of Paleolithic and Neolithic expansions in humans
    4 avril 2024
    Recent population genetic studies have provided valuable insights on the demographic history of our species. However, some issues such as the dating of the first demographic expansions in human populations remain puzzling. Indeed, although a few genetic studies argued that the first human expansions were concomitant with the Neolithic transition, many others found signals of expansion events starting during the Palaeolithic. Here we performed a simulation study to show that these contradictory findings may result from the differences in the genetic markers used, especially if two successive expansion events occurred. For a large majority of replicates for each scenario tested, microsatellite data allow only detecting the recent expansion event in that case, whereas sequence data allow only detecting the ancient expansion. Combined with previous real data analyses, our results bring support to the ideas that (i) a first human expansions started during the Palaeolithic period, (ii) a second expansion event occurred later, concomitantly with the Neolithic transition.
  • [hal-04531919] Human genetic data reveal contrasting demographic patterns between sedentary and nomadic populations that predate the emergence of farming
    4 avril 2024
    Demographic changes are known to leave footprints on genetic polymorphism. Together with the increased availability of large polymorphism data sets, coalescent-based methods allow inferring the past demography of populations from their present-day patterns of genetic diversity. Here, we analyzed both nuclear (20 noncoding regions) and mitochondrial (HVS-I) resequencing data to infer the demographic history of 66 African and Eurasian human populations presenting contrasting lifestyles (nomadic hunter-gatherers, nomadic herders, and sedentary farmers). This allowed us to investigate the relationship between lifestyle and demography and to address the long-standing debate about the chronology of demographic expansions and the Neolithic transition. In Africa, we inferred expansion events for farmers, but constant population sizes or contraction events for hunter-gatherers. In Eurasia, we inferred higher expansion rates for farmers than herders with HVS-I data, except in Central Asia and Korea. Although isolation and admixture processes could have impacted our demographic inferences, these processes alone seem unlikely to explain the contrasted demographic histories inferred in populations with different lifestyles. The small expansion rates or constant population sizes inferred for herders and hunter-gatherers may thus result from constraints linked to nomadism. However, autosomal data revealed contraction events for two sedentary populations in Eurasia, which may be caused by founder effects. Finally, the inferred expansions likely predated the emergence of agriculture and herding. This suggests that human populations could have started to expand in Paleolithic times, and that strong Paleolithic expansions in some populations may have ultimately favored their shift toward agriculture during the Neolithic.
  • [hal-03636218] Les peurs des adolescents concernant leur avenir scolaire et professionnel : structure et variations selon le niveau scolaire, le sexe et la classe sociale
    9 avril 2022
    Les peurs des adolescents concernant leur avenir scolaire et professionnel 2 Les peurs des adolescents concernant leur avenir scolaire et professionnel : structure et variations selon le niveau scolaire, le sexe et la classe sociale. Résumé : La présente recherche vise à valider auprès d'adolescents un nouveau construit psychologique : l'anxiété suscitée par l'avenir scolaire et professionnel. Les résultats suggèrent que ce motif général d'anxiété se décline en trois motifs spécifiques : la peur d'échouer, la peur de décevoir ses parents, et la peur de s'éloigner de ses autruis significatifs, dans le cadre de ses parcours scolaire et professionnel. La force de ces motifs d'anxiété présente des différences significatives selon la classe sociale, le sexe et les performances scolaires. Les analyses de régression multiple révèlent que les différences persistent en dépit du contrôle du niveau scolaire. Cette anxiété peut être interprétée comme une composante d'un habitus de classe sociale ou de rôle sexué.
  • [hal-03636219] Comment les adolescents perçoivent-ils la relation avec leur camarade préféré(e) ?
    9 avril 2022
    Le premier objectif de cette recherche était d’apporter un soutien empirique à un modèle tridimensionnel de la perception qu’ont les adolescents de la relation avec leur camarade de classe préféré. Les trois dimensions étaient : l’attachement émotionnel au camarade, le sentiment qu’il serait prêt à apporter son aide pour réussir une activité scolaire, et le fait de s’attendre à ce qu’il offre son soutien en cas d’agression par d’autres élèves. Le deuxième objectif était de tester des hypothèses concernant les facteurs de variation de cette perception. Dans le cadre d’une enquête nationale, un échantillon représentatif des élèves français en classe de 3ème, âgés en moyenne de 15 ans et 4 mois, a répondu à un questionnaire destiné à évaluer cette perception. Une analyse factorielle confirmatoire (AFC) indique que le modèle tridimensionnel est bien ajusté aux réponses des élèves. Les trois sous-échelles sont positivement mais modérément inter-corrélées. Une analyse multivariée de la variance a révélé que la relation avec le camarade de classe préféré est mieux perçue par les filles que par les garçons, qu’elle est évaluée à un niveau plus élevé lorsque ce camarade est le meilleur ami en dehors du collège et aussi lorsque cette préférence n’est pas trop récente.
  • [hal-01478471] A Potential Role for Parasites in the Maintenance of Color Polymorphism in Urban Birds
    28 février 2017
    Urbanization is a major challenge for biodiversity conservation, yet the evolutionary processes taking place in urbanized areas remain poorly known. Human activities in cities set new selective forces in motion which need to be investigated to predict the evolutionary responses of animal species living in urban areas. In this study, we investigated the role of urbanization and parasites in the maintenance of melanin-based color polymorphism in the feral pigeon Columba livia. Using a correlative approach, we tested whether differently colored genotypes displayed alternative phenotypic responses to urbanization, by comparing body condition, blood parasite prevalence and parasite load between colored morphs along an urbanization gradient. Body condition did not vary with urbanization, but paler individuals had a higher body condition than darker individuals. Moreover, paler morphs were less often parasitized than darker morphs in moderately urbanized habitats, but their parasite prevalence increased with urbanization. In contrast, darker morphs had similar parasite prevalence along the urbanization gradient. This suggests that paler morphs did better than darker morphs in moderately urbanized environments but were negatively affected by increasing urbanization, while darker morphs performed equally in all environments. Thus, differently colored individuals were distributed non-randomly across the urban habitat and suffered different parasite risk according to their location (a gene-by-environment interaction). This suggests that melanin-based coloration might reflect alternative strategies to cope with urbanization via different exposure or susceptibility to parasites. Spatial variability of parasite pressures linked with urbanization may, thus, play a central role in the maintenance of plumage color polymorphism in this urban species.
  • [hal-04532112] Working with dogs in olfactory searches in the French Armed Forces and national Police Forces
    4 avril 2024
    This study aims to investigate the relationships and cooperation within human-dog teams working in olfactory search in the French Armed Forces and in national Police Forces. Twenty-six semi-structured interviews were carried out with canine handlers. The main topic concerned working with their dog during olfactory searches. Among the themes that stand out are relationships with their dog and canine knowledge and practices. Minor differences and similarities between dyads of the two institutions are identified in human-dog relationships. Regarding relationships with dogs, two main differences are linked to the long missions abroad experienced by Armed Forces handlers and the possibility of welcoming dogs into their homes for Police Forces. The constitution of canine knowledge and practices is rooted in experiences and transactions with dogs, but also in social transmission. Even though there is no major differences between the two institutions, this study highlights the interest of having a situated approach.
  • [hal-03484132] French handlers’ perspectives on Animal-Assisted Interventions
    24 mai 2023
    BackgroundAnimal-Assisted Interventions (AAI) are well implemented in human healthcare, in France as elsewhere; yet there are still difficulties in characterizing these practices and misconceptions about their mechanisms - little is known about the French practice of AAI and about the human-animal team.ObjectivesThis study aims to characterize AAI by exploring their specificities through French handlers’ perspectives.Material and methodAn online survey addressed to French handlers working in AAI with mainly one dog was carried out. This research included questions about their practice in AAI (registration status, beneficiaries, and animals) and their background (training in AAI, training in the medico-social field, training in animal behavior). We then examined a phenomenological understanding of handlers’ definitions of their practice in AAI, their motivations to work with these approaches, and the expectations of the human-animal team. We used an open coding strategy and created major themes from their answers.Results111 handlers participated in this study. The quantitative data highlighted a heterogeneity of handlers' profiles and professional backgrounds, although most profiles had previous training in healthcare. Five themes characterizing AAI emerged from the qualitative analysis: (1) AAI as additional approaches to care settings, (2) AAI as person-centered approaches, (3) the complementarity between handlers and their animal(s), (4) the shared role of mediator, and (5) handlers’ beliefs about the human-animal relationship related to their personal experiences. This survey allowed us to understand how the French use AAI and its role in the care system.ConclusionThe benefits of AAI are numerous both for care settings and for the caregivers mainly by making the care more humane. AAI seem to put the wellbeing of beneficiaries and the relationship with the caregiver at the center of the care. The complementarity of the human-animal team is the common feature of these practices and is critical to their success. Future interdisciplinary studies are required to explore the particularities of these interspecific approaches and the differences between countries.
  • [hal-03484139] The State of Animal-Assisted Interventions in France: Is the IAHAIO Model Relevant?
    26 mars 2024
    Animal-assisted interventions (AAI) became more generalized in health care settings and their development in Europe is increasing. In France, the practice has grown in the absence of official recognition and regulation. In this context, we aim to identify the main characteristics of the French practice of AAI that can influence the establishment of a local regulation. Second, we aim to question the relevance of the model proposed by the International Association of Human-Animal Interaction Organizations (IAHAIO) distinguishing animal-assisted therapies (AAT) and (AAA) animal-assisted activities from the French practice of AAI. We interviewed 111 French handlers in AAI that work with at least one dog through an online questionnaire about their professional backgrounds and the main features of their practices of AAI (characteristics, beneficiaries, and animals). Our results indicated that AAI are at an important moment of expansion and are currently under autonomous regulation. Practices and handlers' backgrounds are heterogeneous, as well as training centers in AAI, which reflect the fragmentation of the field. This snapshot of the French practice of AAI underlined that regulations should focus first on a mandatory training, a common standard for each training center, and specific guidelines for each pathology and animal species involved. In addition, the influence of handlers' backgrounds on the type of AAI they practice must be taken into account in regulations. As animals are central in AAI, regulations should focus on their welfare and the certification of dogs to ensure both their safety and the safety of beneficiaries during sessions. Finally, the initial training in the medico-social field seems to influence the practices. Therefore, the common model distinguishing AAT and AAA could be a basis to regulate AAI in France, as in Italy. Indeed, our results underlined that a first categorization between AAI as a professional specialization or an independent profession could be useful. Still, whatever the type of practices, animal and beneficiary welfare should be at the center of regulations in a One Health perspective. As a result, the French government needs to support AAI development such as in other European countries (Sweden, Austria, and Italy) and should collaborate with handlers, organizations, health care facilities, animal professions, and scientists.
  • [hal-01478480] Horizontal Transmission of the Father's Song in the Zebra Finch (Taeniopygia Guttata)
    21 novembre 2017
    As is the case for human speech, birdsong is transmitted across generations by imitative learning. Although transfer of song patterns from adults to juveniles typically occurs via vertical or oblique transmission, there is also evidence of horizontal transmission between juveniles of the same generation. Here, we show that a young male zebra finch (Taeniopygia guttata) that has been exposed to its father during the sensitive period for song learning can lead a brother, that has never heard the paternal song, to imitate some sounds of the father. Moreover, song similarity between the two brothers was higher than the similarity measured between the paternal song and the song of the brother that had a week-long exposure to the father. We speculate that the phenomenon of within-generation song learning among juveniles may be more widespread than previously thought and that when a juvenile evaluates potential models for imitative learning, a sibling may be as salient as an adult.
  • [hal-04559319] Update on mental health of infants and children of parents affected with mental health issues
    25 avril 2024
    This paper highlights the most recent publications, in the field of psychiatry, on offspring of patients with psychiatric illnesses such as schizophrenia and bipolar disorder, and then summarizes what we know about the progeny of adults with mood disorders, the most prevalent of parental disorders. Studies examining personality disorders and contextual factors such as stress and trauma are examined with a focus on the crucial question of development and attachment status in children. Findings converge to reveal that offspring of parents (generally mothers) with most major psychiatric disorders present a higher risk for all mental disorders, and a wide range of disorders are also found in children, adolescent, and finally adult offspring of mothers with mood and anxiety disorders. Developmental psychopathology and infant and child psychiatry have focused on early relationship formation through social interaction and attachment patterns as pathways affected by vulnerability or resilience factors. First year of life longitudinal studies following mothers and infants has shown that maternal psychopathology is positively correlated with higher risk of attachment issues. It would seem that pathology appears when adaptation to real-life contexts becomes difficult in association with an accumulation of negative individual characteristics and environmental circumstances. We suggest that in order to move forward psychiatry should embrace a developmental cascade model, which posits a cumulative pathway for the emergence of psychopathology in the developing child. We propose that we have sufficient knowledge today to start implementing multilevel approaches to enhance the health and mental health of the next generation.
  • [hal-01704391] Sexually attractive phrases increase yolk androgens deposition in Canaries (Serinus canaria)
    8 février 2018
    The androgen concentration in birds' eggs varies with laying order, breeding conditions, and mate attractiveness. In passerine birds, mate attractiveness depends upon song quality. The aim of our study was to evaluate the eVect of one criterion used by females to assess male song quality that is to say the presence of sexually attractive phrases on yolk androgen deposition. Twenty-Wve female Canaries were assigned to three experimental groups; in the Wrst group, the females were allowed to hear songs made up with attractive phrases; in the second group, they were allowed to hear songs made up with non-attractive phrases; and in the control group, the females could not hear any song. Our results show that females allowed to hear songs with attractive phrases deposit signiWcantly higher amounts of androgens (mostly testosterone) in their eggs than females without acoustical stimulation. The females exposed to songs with non-attractive phrases had androgen amounts halfway between the two other groups. This suggests that when females are paired with mates able to sing attractive phrases they can allocate more androgens in their eggs during the pre-laying period.  2004 Elsevier Inc. All rights reserved.
  • [hal-00187117] Sexually attractive phrases increase yolk androgens deposition in Canaries (Serinus canaria)
    13 novembre 2007
    The androgen concentration in birds' eggs varies with laying order, breeding conditions, and mate attractiveness. In passerine birds, mate attractiveness depends upon song quality. The aim of our study was to evaluate the eVect of one criterion used by females to assess male song quality that is to say the presence of sexually attractive phrases on yolk androgen deposition. Twenty-Wve female Canaries were assigned to three experimental groups; in the Wrst group, the females were allowed to hear songs made up with attractive phrases; in the second group, they were allowed to hear songs made up with non-attractive phrases; and in the control group, the females could not hear any song. Our results show that females allowed to hear songs with attractive phrases deposit signiWcantly higher amounts of androgens (mostly testosterone) in their eggs than females without acoustical stimulation. The females exposed to songs with non-attractive phrases had androgen amounts halfway between the two other groups. This suggests that when females are paired with mates able to sing attractive phrases they can allocate more androgens in their eggs during the pre-laying period.
  • [hal-04559312] Exposure to human voices has beneficial effects on preterm infants in the neonatal intensive care unit.
    25 avril 2024
    We reviewed the literature up to March 2016 on the effects of nonmaternal voices on preterm infants’ clinical outcomes. Of the 11 studies that met the inclusion criteria, 10 focused on short‐term outcomes and one looked at long‐term effects. The studies mainly showed that vocal stimuli increased preterm infants’ stability in terms of heart rate, respiratory rate, oxygen saturation and behavioural measures. Improvements in feeding skills were also reported. The methods and the measures used in the studies were heterogeneous, making it difficult to draw reliable conclusions. Conclusion Vocal stimuli increased preterm infants’ stability, but further studies are needed.
  • [hal-04559299] Father–newborn vocal interaction: A contribution to the theory of innate intersubjectivity.
    25 avril 2024
    We studied the timing of the spontaneous vocalization that occurs in dyadic interactions of fathers and their neonates. We recorded 21 fathers speaking to their 2 to 4‐day‐old newborns at the maternity ward and accurately coded all beginnings and endings of paternal and neonatal vocalization, using sound visualization software. Temporal relations between successive and overlapping newborn and father vocalizations were analysed. Results strongly suggest that newborn infants' vocalization timing is related to the timing of fathers' speech and that both newborns and fathers respond to each other within a 1–3 s temporal window, giving rise to sequences of turn‐taking. This study not only shows newborns' awareness of the timing of their partner's expressions but also fathers' readiness to communicate with them right from birth. We discuss the relevance of these findings to the theory of innate intersubjectivity.
  • [hal-04559278] Fathers’ and mothers’ infant directed speech influences preterm infant behavioral state in the NICU
    25 avril 2024
    Preterm infants’ behavioral state and physiological parameters are affected by environmental noise and adult voices. Only a handful of studies have explored the effects of direct maternal vocal communication on preterm infants’ autonomous nervous system responses. Furthermore, to our knowledge, no study to date has investigated the effect of the father’s voice on preterm infant’s behaviors and physiological parameters. This study evaluated the effects of both mothers’ and fathers’ infant-directed speech on preterm infants’ behavioral states. Fourteen stable, premature infants serving as their own controls were videotaped while their mother and father were speaking to them for 5 min over 2 consecutive days. Infants’ behavioral states and state lability were coded for each voice presentation (father and mother), in the three different conditions, before, during, and after the intervention. Present results show an interaction between vocal intervention and infant behavioral state. Both maternal and paternal speech modified infant behavioral state, but no significant difference in the behavioral state distribution was observed between mother’s and father’s voice presentation. Infants spent more time in a quiet alert state when they heard both voices compared to no vocalization baseline. These findings indicate the importance of both the fathers’ and the mothers’ voice for preterm infants. The parental vocal intervention has an awakening effect. Further studies are needed to better identify the benefits for preterm infants of a relational care approach.
  • [hal-04559272] Vocal responsiveness of preterm infants to maternal infant-directed speaking and singing during skin-to-skin contact (Kangaroo Care) in the NICU.
    25 avril 2024
    Vocalizations of full-term newborns occur in a short latency time during the neonatal period. Contingent response time of preterm babies is still unknown. An increase of preterm babies’ vocalizations following exposure to parental speech was also observed. Mothers and babies co-modulate their vocalizations in preterm dyads. Purpose: To observe temporal features of maternal and infants’ vocalizations in speaking and singing conditions in preterm dyads. Methods: In a NICU mothers (N = 36) were invited to speak and to sing to their preterm infants during Kangaroo Care. Microanalysis of temporal units were performed with ELAN Software. Results and conclusions: Preterm infants vocalize less often while their mothers speak and sing than during baseline and their vocalizations tend to be more alternating in the speaking condition and more overlapping in the singing condition. It is also concluded that preterm infants take more time to respond to maternal speaking than to maternal singing.
  • [hal-04531882] Grandmothering and cognitive resources are required for the emergence of menopause and extensive post-reproductive lifespan
    4 avril 2024
    Menopause, the permanent cessation of ovulation, occurs in humans well before the end of the expected lifespan, leading to an extensive post-reproductive period which remains a puzzle for evolutionary biologists. All human populations display this particularity; thus, it is difficult to empirically evaluate the conditions for its emergence. In this study, we used artificial neural networks to model the emergence and evolution of allocation decisions related to reproduction in simulated populations. When allocation decisions were allowed to freely evolve, both menopause and extensive post-reproductive life-span emerged under some ecological conditions. This result allowed us to test various hypotheses about the required conditions for the emergence of menopause and extensive post-reproductive life-span. Our findings did not support the Maternal Hypothesis (menopause has evolved to avoid the risk of dying in childbirth, which is higher in older women). In contrast, results supported a shared prediction from the Grandmother Hypothesis and the Embodied Capital Model. Indeed, we found that extensive post-reproductive lifespan allows resource reallocation to increase fertility of the children and survival of the grandchildren. Furthermore, neural capital development and the skill intensiveness of the foraging niche, rather than strength, played a major role in shaping the age profile of somatic and cognitive senescence in our simulated populations. This result supports the Embodied Capital Model rather than the Grand-Mother Hypothesis. Finally, in simulated populations where menopause had already evolved, we found that reduced post-reproductive lifespan lead to reduced children's fertility and grandchildren's survival. The results are discussed in the context of the evolutionary emergence of menopause and extensive post-reproductive life-span.
  • [hal-04389963] Can Infants Generalize Tool Use From Spoon to Rake at 18 Months?
    12 janvier 2024
    Infants start to use a spoon for self-feeding at the end of the first year of life, but usually do not use unfamiliar tools to solve problems before the age of 2 years. We investigated to what extent 18-month-old infants who are familiar with using a spoon for self-feeding are able to generalize this tool-use ability to retrieve a distant object. We tested 46 infants with different retrieval tasks, varying the tool (rake or spoon) and the target (toy or food). The tasks were presented in a priori descending order of difficulty: rake–toy condition, then either spoon–toy or rake–food, and finally spoon–food. Then, the same conditions were presented in reverse order to assess the transfer abilities from the easiest condition to the most difficult retrieval task. Spontaneously, 18-month-old infants performed the retrieval tasks better with the familiar tool, the easiest task being when the spoon was associated with food. Moreover, the transfer results show that being able to use a familiar tool in an unusual context seems necessary and sufficient for subsequent transfer to an unfamiliar tool in the unusual context, and that early and repetitive training of self-feeding with a spoon plays a positive role in later tool use.
  • [hal-03130944] Sensorimotor Contingencies as a Key Drive of Development: From Babies to Robots
    4 février 2021
    Much current work in robotics focuses on the development of robots capable of autonomous unsupervised learning. An essential prerequisite for such learning to be possible is that the agent should be sensitive to the link between its actions and the consequences of its actions, called sensorimotor contingencies. This sensitivity, and more particularly its role as a key drive of development, has been widely studied by developmental psychologists. However, the results of these studies may not necessarily be accessible or intelligible to roboticians. In this paper, we review the main experimental data demonstrating the role of sensitivity to sensorimotor contingencies in infants’ acquisition of four fundamental motor and cognitive abilities: body knowledge, memory, generalization, and goal-directedness. We relate this data from developmental psychology to work in robotics, highlighting the links between these two domains of research. In the last part of the article we present a blueprint architecture demonstrating how exploitation of sensitivity to sensorimotor contingencies, combined with the notion of “goal,” allows an agent to develop new sensorimotor skills. This architecture can be used to guide the design of specific computational models, and also to possibly envisage new empirical experiments.
  • [hal-03677989] Development of body knowledge as measured by arm differentiation in infants: From global to local?
    25 mai 2022
    The ability to sense and use the body parts in an organized and differentiated manner is a precursor of body knowledge in infancy. To acquire this ability, the infant's brain might explore the perceptual consequences of its bodily actions. Undifferentiated body movements would gradually be replaced by more precise actions. Only a very few studies have tested this ‘global-to-local’ hypothesis, and none of them have so far been replicated. In this study, we assessed arm differentiation in 4-, 6-, and 8-month-old infants using a new contingency detection task in which infants have to detect a contingency between one of their arms’ activity and an audiovisual stimulus on a screen. We found that 4- to 8-month-old infants seem to be able to use their arms in a differentiated manner. However, surprisingly, we were not able to show a developmental trend in arm differentiation between 4 and 8 months of age.
  • [hal-03919211] Premises of social cognition: Newborns are sensitive to a direct versus a faraway gaze
    2 janvier 2023
    Previous studies evidenced that already from birth, newborns can perceive differences between a direct versus an averted gaze in faces both presented in static and interactive situations. It has been hypothesized that this early sensitivity would rely on modifications of the location of the iris (i.e. the darker part of the eye) in the sclera (i.e. the white part), or that it would be an outcome of newborns’ preference for configurations of faces with the eye region being more contrasted. One question still remains: What happens when the position of the iris is not modified in the sclera, but the look is ‘faraway’, that is when the gaze is toward the newborns’ face but above his or her own eyes? In the present study, we tested the influence of a direct versus a faraway gaze (i.e., two gazes that only differed slightly in the position of the iris on the vertical axis and not on the horizontal axis) on newborns’ face recognition. The procedure was identical to that used in previous studies: using a familiarization-test procedure, we familiarized two groups of newborns (N = 32) with videos of different talking faces that were presented with either a direct or a faraway gaze. Newborns were then tested with photographs of the face seen previously and of a new one. Results evidenced that newborns looked longer at the familiar face, but only in the direct gaze condition. These results suggest that, already from birth, infants can perceive slight differences of gazes when someone is addressing to them.
  • [hal-01478473] Ostensive Cues Orient 10-Month-Olds' Attention toward the Task But Delay Learning
    28 février 2017
    The aim of this study is to investigate how ostensive cues modify infants' visual attention to task demonstration, and the extent to which this enhances the performance in an imitative learning task. We hypothesized that ostensive cues would help orient infants' attention toward relevant parts of the demonstration. We investigated the looking behavior of 41 10-month-old infants while observing an adult demonstrating a novel target action after having either provided ostensive cues or not. Infants' looking behavior was measured using an eye tracker. Two areas of interest were analyzed: the targeted object and the adult's face. Infants' performance after demonstration was also analyzed. The results show that infants' looking behavior varied across groups. When ostensive cues were not provided, infants looked mainly at the experimenter's face. However, when ostensive cues were provided, infants oriented their attention toward the targeted object. These results suggest that ostensive cues help infants orient their attention toward task-relevant parts of the scene. Surprisingly, infants in the non-ostensive group improved their performance faster after demonstration than infants in the ostensive group. These results are discussed in terms of a video effect and dissociation between separate cognitive systems for social and non-social cognition.
  • [hal-02326108] When do infants understand that they can obtain a desired part of a composite object by grasping another part?
    12 janvier 2024
    When do infants start to understand that they can grasp an object by its handle when the interesting part is out of reach? Whereas it is known from preferential looking tasks that already at three months of age infants show surprise when all parts of an object do not move together, little is known about when infants are able to use such knowledge in an active grasp situation. To answer this question we presented six, eight, and 10 month-old infants in a cross-sectional and a longitudinal study with a white cardboard handle within reach and a bright ball at the end of the handle and out of reach. A trick condition, where the handle and the ball seem attached but were not, was added to get an indication of the infant's expectation by observing a possible surprise reaction. Results show that 6-month-olds' most frequent first behaviors consisted in pointing toward the ball without grasping the handle, or grasping the handle without looking at the ball until it moved. In addition, they often did not look surprised in the trick condition. Eight- and 10-month-olds most often grasped the handle while looking at the ball, and showed clear surprise in the trick condition. This was interpreted as showing that around eight or 10 months, infants take a significant step in understanding the cohesiveness of composite objects during grasping.
  • [hal-02326012] The Emergence of Tool Use in Preterm Infants
    12 janvier 2024
    Preterm born children without neurological impairments have been shown to present some visual-manual coordination deficits, more or less depending on their tonicity and the degree of prematurity. In this paper, we compare the development of tool use in 15– 23-month-old preterm infants born after 33–36 weeks of gestation without neurological complications with that of full-term infants according to corrected age. Understanding the affordance of a tool is an important cognitive milestone in early sensorimotor period. Using a tool to bring within reach an out-of-reach object, for instance, has been shown to develop during the 2nd year in full-term infants. Here we presented preterm infants with an attractive toy out of reach and with a rake-like tool within reach in five conditions of spatial relationships between the toy and the tool. Like full-terms, preterm infants used the tool with success in conditions of spatial contiguity around 15–17 months. In conditions of a spatial gap between tool and toy, i.e., the only conditions which shows without ambiguity that the infant understands the affordance of the tool, preterm infants as a group showed no delay for tool use: the frequency of spontaneous successes started to increase after 18 months, and demonstration became effective after that age. However, further analyses showed that only the preterm infants without hypotonia and born after 36 weeks of pregnancy developed tool use without delay. Hypotonic preterm infants were still largely unsuccessful in the conditions of spatial gap, even at the end of the study. The degree of prematurity also influenced the performance at tool use. These results, following the observation of a delay in the development of bimanual coordination and of handedness in the same infants at 10–12 months in a previous study, show that low risk preterm infants can still be impaired for the development of new manual skills beyond the 1st year. Thus, hypotonic preterm infants and infants born before 36 weeks of pregnancy should be followed and might benefit from early intervention programs.
  • [hal-02326210] Handedness in infants' tool use
    22 octobre 2019
    In this study, we investigated whether hand preference influences infants' choice of what hand to use in grasping a new tool presented at the midline, and whether this will change in the course of learning the functionality of a tool. The tool was a rake within reach placed beside an out‐of‐reach toy presented either to its right or to its left. Forty‐eight infants from 16 to 22 months of age were tested. The results show that use of the right‐preferred hand to grasp the rake is strong as of 16 months of age and does not change significantly with age in the condition where using the right hand leads to a better outcome than using the left hand. In the condition where using the left‐non‐preferred hand makes toy retrieval easier, infants increasingly use the left hand with age. Thus, when grasping the tool, younger infants are more influenced by their hand preference than older infants, who are better at anticipating the most successful strategies.
  • [hal-01478455] Suprasegmental Information Affects Processing of Talking Faces at Birth
    28 février 2017
    From birth, newborns show a preference for faces talking a native language compared to silent faces. The present study addresses two questions that remained unanswered by previous research: (a) Does the familiarity with the language play a role in this process and (b) Are all the linguistic and paralinguistic cues necessary in this case? Experiment 1 extended newborns' preference for native speakers to non-native ones. Given that fetuses and newborns are sensitive to the prosodic characteristics of speech, Experiments 2 and 3 presented faces talking native and nonnative languages with the speech stream being low-pass filtered. Results showed that newborns preferred looking at a person who talked to them even when only the prosodic cues were provided for both languages. Nonetheless, a familiarity preference for the previously talking face is observed in the "normal speech" condition (i.e., Experiment 1) and a novelty preference in the "filtered speech" condition (Experiments 2 and 3). This asymmetry reveals that newborns process these two types of stimuli differently and that they may already be sensitive to a mismatch between the articulatory movements of the face and the corresponding speech sounds.
  • [hal-01478472] Condition-Dependent Choosiness For Highly Attractive Songs In Female Canaries
    28 février 2017
    Partner choice in animals has evolved under the effects of intra- and inter-sexual selection. Even if a consensus between females is often observed towards some males, certain females can drastically change their mating decision. Different conditions such as early learning, mate-choice copying, prior experience or subtle intrinsic factors can interfere with the decision. One of them is body condition of the females at the time of choosing. In this experiment, the flight feathers of female canaries Serinus canaria were cut, thus decreasing their flight ability. After a short period in a flight room, two types of artificial songs containing different tempi of the test 'A' phrase (16 vs. 8 syllables per second) were played to these females. It is known that only A phrases with a high tempo provoke a high level of sexual response in females. Female preference was evaluated by counting the number of Copulation Solicitation Displays (CSDs). The results show that, in both (normal and physically reduced) conditions, females prefer songs containing an A16 phrase. However, the strength of this preference is lower in females with compromised body condition than in females from the control group, suggesting a decreased choosiness in the poor body condition females.
  • [hal-02326354] Comment le bébé accède-t-il à la notion d’outil ?
    22 octobre 2019
    L’utilisation d’un outil permet de dépasser les limites de son propre corps pour interagir avec l’environnement. Après avoir appris à contrôler sa main pour prendre des objets, le bébé découvre peu à peu qu’un objet peut permettre d’agir sur un autre objet. Dans cet article nous nous intéressons à la fonction particulière de l’outil qui permet de rapprocher un objet présenté hors de portée. Nous passons d’abord en revue les comportements précurseurs de cette habileté, comme l’utilisation de moyens intermédiaires pour atteindre un but secondaire (means-end), ainsi que les premières études consacrées à l’utilisation d’outil pour rapprocher un objet. Dans un deuxième temps nous posons la question des mécanismes sous-jacents à la découverte de cette utilisation de l’outil à partir des résultats d’une étude où nous avons suivi quatre bébés pendant près d’un an à partir de 12 mois en leur présentant un jouet hors de portée et un râteau à portée de main. Nos résultats montrent que les bébés mettent plusieurs séances avant de comprendre l’utilité du râteau, séances pendant lesquelles soit ils explorent le râteau, soit ils quémandent le jouet, soit ils associent le râteau et le jouet mais pas pour essayer de rapprocher le jouet. Ce n’est que vers 18 mois, relativement soudainement, que les bébés ont semblé comprendre que le râteau pouvait leur permettre de rapprocher le jouet. Au vu des résultats, nous concluons que les mécanismes « essai-erreur » et apprentissage par observation nécessitent un certain niveau d’intuition de la solution pour être efficaces, mais que l’intuition elle-même nécessite une longue phase d’exploration qui permet dans un premier temps à la fois d’améliorer la manipulation du râteau (qui devient un prolongement de la main ?) et d’en découvrir les affordances.
  • [hal-01478462] The Development of Sensorimotor Influences in the Audiovisual Speech Domain: Some Critical Questions
    28 février 2017
    Speech researchers have long been interested in how auditory and visual speech signals are integrated, and recent work has revived interest in the role of speech production with respect to this process. Here we discuss these issues from a developmental perspective. Because speech perception abilities typically outstrip speech production abilities in infancy and childhood, it is unclear how speech-like movements could influence audiovisual speech perception in development. While work on this question is still in its preliminary stages, there is nevertheless increasing evidence that sensorimotor processes (defined here as any motor or proprioceptive process related to orofacial movements) affect developmental audiovisual speech processing. We suggest three areas on which to focus in future research: i) the relation between audiovisual speech perception and sensorimotor processes at birth, ii) the pathways through which sensorimotor processes interact with audiovisual speech processing in infancy, and iii) developmental change in sensorimotor pathways as speech production emerges in childhood.
  • [hal-03620213] Design of a robotic zebra finch for experimental studies on developmental song learning
    25 mars 2022
    ABSTRACT Birdsong learning has been consolidated as the model system of choice for exploring the biological substrates of vocal learning. In the zebra finch (Taeniopygia guttata), only males sing and they develop their song during a sensitive period in early life. Different experimental procedures have been used in the laboratory to train a young finch to learn a song. So far, the best method to achieve a faithful imitation is to keep a young bird singly with an adult male. Here, we present the different characteristics of a robotic zebra finch that was developed with the goal to be used as a song tutor. The robot is morphologically similar to a life-sized finch: it can produce movements and sounds contingently to the behaviours of a live bird. We present preliminary results on song imitation, and other possible applications beyond the scope of developmental song learning.
  • [hal-01429925] Newborns’ Sensitivity to the Visual Aspects of Infant-Directed Speech: Evidence From Point-Line Displays of Talking Faces
    9 janvier 2017
    The first time a newborn is held, he is attracted by the human’s face. A talking face is even more captivating, as it is the first time he or she hears and sees another human talking. Older infants are relatively good at detecting the relationship between images and sounds when someone is addressing to them, but it is unclear whether this ability is dependent on experience or not. Using an intermodal matching procedure, we presented newborns with 2 silent point-line displays representing the same face uttering different sentences while they were hearing a vocal-only utterance that matched 1 of the 2 stimuli. Nearly all of the newborns looked longer at the matching point-line face than at the mismatching 1, with prior exposure to the stimuli (Experiment 1) or without (Experiment 2). These results are interpreted in terms of newborns’ ability to extract common visual and auditory information of continuous speech events despite a short experience with talking faces. The implications are discussed in the light of the language processing and acquisition literature.



2023/06/30 - Articles de Johana Ryšavá

2022/04/07 - Michel Kreutzer, sur France Culture (du 04/04/2022 au 07/04/2022 - disponible en podcast en intégralité dès le lundi après la diffusion du premier épisode), dans l'émission LSD -  Série documentaire "L'intelligence du vivant", de Franck Bessière, réalisée par Anne Fleury
1er épisode - "Définir le vivant" « Depuis pas mal d'années, on se rend compte que les êtres vivants, les organismes, notamment les vertébrés supérieurs, les oiseaux, les mammifères, recherchent également ce qui est source de plaisir. Un vivant, c'est donc aussi un être qui recherche des plaisirs et qui essaie d'éviter les déplaisirs. C'est une des raisons sans doute pour laquelle aujourd'hui, on donne tant d'importance à la souffrance animale et qu'on estime que l'on doit se donner des règles éthiques dans nos relations avec les animaux. »
2ème épisode - "L'humain un vivant d'exception"
3ème épisode - "Dans la tête des animaux" « Les émotions entrent pleinement dans les études éthologiques, qui ne se limitent donc plus seulement aux comportements. »
4ème épisode - "Le génie du vivant"

2022/03/30 - Michel Kreutzer, au Musée du Quai Branly - Université populaire 2021/2022, Thème 2 : Le corps - "L'"apprendre animal" : comment le savoir se transmet et s'apprend chez les animaux" 
2021/12/07 - Rana Esseily, Carla Aimé, Dalila Bovet et Maya Gratier, à la Philharmonie de Paris - Colloque "Pédagogie du chant choral" - "Résultats de l'étude scientifique -  impacts sur les capacités psychosociales, les apprentissages scolaires et le bien-être des enfants" (10h20)
2021/10/26 - Michel Kreutzer, sur France Inter, dans l’émission "Grand bien vous fasse" - "Autour des ‘Folies animales'"
2021/10/13 - Michel Kreutzer interviewé par Caroline Lachowski, sur RFI , dans l'émission "Autour de la question" - "La folie est-elle le propre de l’homme ?"
2021/10/11 - Rana Esseily sur France Culture, dans l'émission "La méthode scientifique" - "Rire : c’est du sérieux!"
2021/03/28 - Michel Kreutzer, interviewé par Octave Larmagnac-Matheron, dans Philosophie magazine - "Zoopsychiatrie : À la découverte des folies animales"
2021/03/25 - Michel Kreutzer, invité de l’association CVA (Connaissance et Vie d’Aujourd’hui) de Lille - Conférence "Éthologie : sommes-nous tous des bêtes ?"

2017/10/26 : France Infos junior - "Que se passe-t-il dans la tête des bébés ?"
2017/03/26 : France Inter - "Les Savanturiers" - en direct du salon du livre (à partir de 40 min 20) pour la promotion de La science à Contrepied paru aux éditions Belin.
2017/04/12 : France 3 - Le monde de Jamy : "Ces animaux si proches de nous"
2015/01/02 : France 5 - C dans l'air : "Mon chat est-il une personne ?"
2014/07/07 : France culture - Les matins d'été, 2ème partie : Les invités culture/Idées. "Malin comme un corbeau", avec deux éthologues Agatha Lievin-Bazin et Valérie Dufour (à partir de la 98ème minute).
2013/06 : NBC News - "Finches sing like birds and their dad taught them how"
2014/04 : France Culture - "L'intelligence du perroquet"
2013/10 : France Culture - Emission Continent Science : "L’homosexualité animale" (audio 54').
Cité des sciences et de l'industrie - Cycle de conférences Universciences "Corps et esprit : indissociables" : "Accéder à la vie subjective des animaux" - Michel Kreutzer.
2012/12 : The Telegraph "Parrot listens to Scissor Sisters' music".
2012/12 : France 5 - Emission "On n'est pas que des cobayes" : "Les éléphants ont-ils peur des souris".
2011/05 : France Inter - Emission "Vivre avec les bêtes", 29 mai : (05/2011)

2019/11/30 : The Economist - Male nightingales spend the winter practising.
2019/11/26 : New Scientist - Nightingales practise new songs in winter to impress mates in spring.
2017/03 :  Sciences Psy - Le tempo de notre quotidien - Et si nous prenions le temps ?, pp.30.
2014/12 : Santé magazine, n°469 sur l'empathie.
2014/09/03 : BMC - The unheard message of larksong.
2014/06 : JDD - L'intelligence des corbeaux
2013/11 : JDD - Comment les oiseaux apprennent-ils à chanter ?
2012/03&04 : Cerveau&Psycho - Le perroquet mentaliste.
2011 : Le Pigeon en Ville - La vie sociale du pigeon Bizet.
2011/12 : Le Républicain Lorrain - Les pigeons sont physionomistes.
2011/08 : Futura Sciences Les canaris font leur show... et s'adaptent à leur public !
2011/08 : Les Echos - Le perroquet, une langue et un cerveau.
2011/05 : BBC News - Parrots choose to work together.
2011/05 : Maxisciences - Intelligence du perroquet gris : collaboration et personnalité.
2011/05 : PhysOrg - Parrots display teamwork and decision-making skills.
2009/04 : Science Actualité, Universciences - Des piafs malins comme des singes.
2005/02 : BBC News - Sleep helps birds sing better.
A good night's sleep helps young birds master the art of singing, but only after a rather groggy start, Nature magazine has reported.
Savoirs Essonne - Masculin/féminin : le genre existe-t-il chez les animaux ?


Michel Kreutzer (2021), Folies Animales, Le Pommier, Paris.

Bernard Thierry & Michel Kreutzer (dir, 2021), Témoignages sur la naissance d’une science, Les développements de l’éthologie en France (1956-1990), ouvrage collectif, Presses Universitaires de Paris Nanterre.

Franck Péron (2011), L'intelligence des perroquets: l'hypothèse du cerveau social: Compétition et coopération chez les psittacidés, Editions universitaires européennes.


Mis à jour le 23 novembre 2023