Publications

Articles scientifiques

Publications du LECD sur son site HAL

  • [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.
  • [hal-02326041] The roles of observation and manipulation in learning to use a tool
    22 octobre 2019
    We investigated how repeated, five-minute familiarization sessions occurring once a week over a 6-week period influenced infants’ knowledge about the functional properties of a rake-like tool and their ability to use it for retrieving an out of reach object by 16 months of age. We found that infants, who were not allowed to touch the rake, but only to observe an adult retrieve an object with it, improved their performance. On the other hand, infants who were allowed to manually manipulate the rake and touch and move other objects with it did not improve their performance. The results, which were replicated in a string-pulling task, suggest that, although both motor and cognitive limitations affect performance, it is rather cognitive limitations that prevent infants from understanding the functional properties of the tool and from succeeding in such tool-use tasks. Furthermore, infants can overcome these cognitive limitations with only a few, brief demonstrations spaced over several weeks.
  • [hal-01478443] What Does It Take for an Infant to Learn How to Use a Tool by Observation?
    12 janvier 2024
    Observational learning is probably one of the most powerful factors determining progress during child development. When learning a new skill, infants rely on their own exploration; but they also frequently benefit from an adult’s verbal support or from demonstration by an adult modeling the action. At what age and under what conditions does adult demonstration really help the infant to learn a novel behavior? In this review, we summarize recently published work we have conducted on the acquisition of tool use during the second year of life. In particular, we consider under what conditions and to what extent seeing a demonstration from an adult advances an infant’s understanding of how to use a tool to obtain an out-of-reach object. Our results show that classic demonstration starts being helpful at 18 months of age. When adults explicitly show their intention prior to demonstration, even 16-month-old infants learn from the demonstration. On the other hand, providing an explicit demonstration (“look at how I do it”) is not very useful before infants are ready to succeed by themselves anyway. In contrast, repeated observations of the required action in a social context, without explicit reference to this action, considerably advances the age of success and the usefulness of providing a demonstration. We also show that the effect of demonstration can be enhanced if the demonstration makes the baby laugh. Taken together, the results from this series of studies on observational learning of tool use in infants suggest, first, that when observing a demonstration, infants do not know what to pay attention to: demonstration must be accompanied by rich social cues to be effective; second, infants’ attention is inhibited rather than enhanced by an explicit demand of “look at what I do”; and finally a humorous situation considerably helps infants understand the demonstration.
  • [hal-01478439] Humour Production May Enhance Observational Learning of a New Tool-Use Action in 18-Month-Old Infants
    28 février 2017
    Many studies have shown that making children laugh enhances certain cognitive capacities such as attention, motivation, perception and/or memory, which in turn enhance learning. However, no study thus far has investigated whether laughing has an effect on learning earlier in infancy. The goal of this study was to see whether using humour with young infants in a demonstration of a complex tool-use task can enhance their learning. Fifty-three 18-month-old infants participated in this study and were included either in a humorous or a control demonstration group. In both groups infants observed an adult using a tool to retrieve an out-of-reach toy. What differed between groups was that in the humorous demonstration group, instead of playing with the toy, the adult threw it on the floor immediately after retrieval. The results show that infants who laughed at the demonstration in the humorous demonstration group reproduced significantly more frequent target actions than infants who did not laugh and those in the control group. This effect is discussed with regard to individual differences in terms of temperament and social capacities as well as positive emotion and dopamine release.
  • [hal-02326236] The emergence of tool use during the second year of life
    22 octobre 2019
    Despite a growing interest in the question of tool-use development in infants, no study so far has systematically investigated how learning to use a tool to retrieve an out-of-reach object progresses with age. This was the first aim of this study, in which 60 infants, aged 14, 16, 18, 20, and 22 months, were presented with an attractive toy and a rake-like tool. There were five conditions of spatial relationships between the toy and the tool, going from the toy and tool being connected to there being a large spatial gap between them. A second aim of the study was to evaluate at what age infants who spontaneously fail the task can learn this complex skill by being given a demonstration from an adult. Results show that even some of the youngest infants could spontaneously retrieve the toy when it was presented inside and touching the top part of the tool. In contrast, in conditions with a spatial gap, the first spontaneous successes were observed at 18 months, suggesting that a true understanding of the use of the tool has not been fully acquired before that age. Interestingly, it is also at 18 months that infants began to benefit from the demonstration in the conditions with a spatial gap. The developmental steps for tool use observed here are discussed in terms of changes in infants’ ability to attend to more than one item in the environment. The work provides insight into the progressive understanding of tool use during infancy and into how observational learning improves with age.
  • [hal-02326174] The emergence of use of a rake-like tool: a longitudinal study in human infants
    12 janvier 2024
    We describe the results of a longitudinal study on five infants from age 12 to 20 months, presented with an out of reach toy and a rake-like tool within reach. Five conditions of spatial relationship between toy and rake were tested. Outcomes and types of behavior were analyzed. There were successes observed around 12 months in the condition of spatial contiguity between rake and toy, but these could not be interpreted as corresponding to full understanding of the use of the rake. At this age and for the following months, in the conditions involving spatial separation between rake and toy, infants' strategies fluctuated between paying attention to the toy only, exploring the rake for its own sake, and connecting rake and toy but with no apparent attempt to bring the toy closer. Only between 16 and 20 months did infants fairly suddenly start to intentionally try to bring the toy closer with the tool: at this stage the infants also became able to learn from their failures and to correct their actions, as well as to benefit from demonstration from an adult. We examine the individual differences in the pattern of change in behaviors leading to tool use in the five infants, and find no increase in any one type of behavior that systematically precedes success. We conclude that sudden success at 18 months probably corresponds to the coming together of a variety of capacities.
  • [hal-02326156] Comparison of active and purely visual performance in a multiple-string means-end task in infants
    12 janvier 2024
    The aim of the present study was to understand what factors influence infants’ problem-solving behaviours on the multiple-string task. The main question focused on why infants usually solve the single string-pulling task at 12 months at the latest, whereas most 16-month-old infants still cannot solve the task when several strings are presented, only one of which is attached to the desired object. We investigated whether this difficulty is related to infants’ ability to inhibit their spontaneous immediate actions by comparing active and purely visual performance in this task. During the first part of the experiment, we assessed the ability of infants aged 16–20 months to solve the multiple-string task. The infants were then divided into three groups based on performance (a “failure” group, an “intermediate” group, and a “success” group). The results of this action task suggest that there were differences in infants’ performance according to their level of inhibitory control of their preferred hand. In the second part of the experiment, the three groups’ predictive looking strategies were compared when seeing an adult performing the task. We found that only infants who successfully performed the action task also visually anticipated which string the adult had to pull in the visual task. Our results suggests that inhibitory control was not the only factor influencing infants’ performance on the task. Furthermore, the data support the direct matching hypothesis (Rizzolatti and Fadiga, 2005), according to which infants need to be able to perform actions themselves before being able to anticipate similar actions performed by others.
  • [hal-01704322] Social competition and plasma testosterone profile in domesticated canaries: An experimental test of the challenge hypothesis
    8 février 2018
    The challenge hypothesis predicts that plasma testosterone (T) concentration is high when male – male competitions are high and decreases when males are engaged in paternal care. In monogamous species, T concentration increases at the beginning of the breeding period and decreases after egg laying. According to the challenge hypothesis, increasing competition should also lead to T increase. The aim of our study was to test this hypothesis. In a first experiment, we measured the T profile of domesticated canaries housed with their mate in separated cages without competition. In a second one, we created a competition by housing male and female domestic canaries together (in an aviary) and emphasized this competition by limiting food access. We also studied social status effect. Our results showed no effect of social status in both sexes and no differences in female's T concentration. Concerning males, we obtained a clear monogamous T profile from the ones housed in a low competition situation and a polygamous profile from the others housed in high competition situation. Thus, our results support the hypothesis of the plasticity of the mechanisms controlling T concentration according to environmental conditions. D
  • [hal-01480085] Psychological Disorders and Ecological Factors Affect the Development of Executive Functions: Some Perspectives
    3 février 2021
    The links between deficits in executive functions (EFs) (e.g., mental flexibility, inhibition capacities, etc.) and some psychological disorders (e.g., anxiety and depressive disorders) have been investigated in the past decades or so.
  • [hal-01478464] Young Children's Difficulties in Switching from Rhythm Production to Temporal Interval Production (>1 S)
    28 février 2017
    This study examined the young children's abilities to switch from rhythm production, with short 15 Inter-Taps Intervals (ITI), to temporal interval production, with long ITI (> 1 s), in a sensorimotor synchronization task. Children aged 3 and 5 years old were given 6 sessions of synchronization. In a control group, they had to synchronize their ITI to an Inter-Stimulus Interval (ISI) of 4 s. In the experimental group, they must progressively increase their ITI for one session to the next (from 0.4-s to 4.0-s ISI). Our results showed that the 5-year-olds produced longer ITI that the 3-year-olds in synchronization. However, the value of ITI in the 5-year-olds never exceeded 1.5 s, with more variable ITI in the control than in the experimental group. In addition, at 5 years, boys had more difficulties than girls in changing their tapping rhythm. These results suggest a temporal window in sensorimotor synchronization, beyond which the rhythm is lost and the synchronization becomes difficult.
  • [hal-01645042] Tempo Discrimination in 3- and 4-year-old children: performances and threshold
    22 novembre 2017
    Durations of less than one second are involved in all kinds of activities, such as music perception or rhythmical production tasks. It is therefore important to know how short durations are processed at a young age. This study aims to define discrimination performance between 3- and 4-year-olds (tempo discrimination). The first 4 years of life are essential for cognitive development and there is little data concerning those years due to the extreme difficulty of finding methods to assess children’s timing performances. Moreover, the results yielded by previous experiments are controversial. Our data revealed that discrimination performances improve significantly within only a few months. The discrimination data from 3 and 4 year-olds are compared to those from older children. The overall results are discussed in a developmental model context.
  • [hal-04133300] Young children’s difficulties in switching from rhythm production to temporal interval production (>1 s)
    19 juin 2023
    This study examined the young children's abilities to switch from rhythm production, with short inter-tap intervals (ITIs), to temporal interval production, with long ITI (>1 s), in a sensorimotor synchronization task. Children aged 3-and 5-year-olds were given six sessions of synchronization. In a control group, they had to synchronize their ITI to an inter-stimulus interval (ISI) of 4 s. In the experimental group, they must progressively increase their ITI for one session to the next (from 0.4 to 4.0-s ISI). Our results showed that the 5-yearolds produced longer ITI that the 3-year-olds in synchronization. However, the value of ITI in the 5-year-olds never exceeded 1.5 s, with more variable ITI in the control than in the experimental group. In addition, at 5 years, boys had more difficulties than girls in changing their tapping rhythm. These results suggest a temporal window in sensorimotor synchronization, beyond which the rhythm is lost and the synchronization becomes difficult.
  • [hal-02887838] Régulation rythmique avant 4 ans : effet d'un tempo auditif sur le tempo moteur
    2 juillet 2020
    L'objectif de cette étude est d'analyser les capacités de l'enfant âgé de 1 ½ à 3 ½ ans à modifier son tempo moteur spontané (TMS) en fonction de tempi auditifs. Les résultats montrent que le TMS reste constant entre 1 ½ et 3 ½ ans et que, parallèlement, il devient plus régulier. Les enfants les plus âgés modifient leurs rythmes de frappes si le tempo auditif diffère d'au moins 20 % de leurs propres rythmes. La capacité des enfants à ralentir leurs rythmes de frappes se met en place plus tardivement que leur accéléra-tion. Enfin, les modifications du rythme de frappes induisent une modification équivalente du TMS mais transitoire.
  • [hal-02887830] Tempo Discrimination in 3-and 4-year-old children: performances and threshold
    2 juillet 2020
    Durations of less than one second are involved in all kinds of activities, such as music perception or rhythmical production tasks. It is therefore important to know how short durations are processed at a young age. This study aims to define discrimination performance between 3-and 4-year-olds (tempo discrimination). The first 4 years of life are essential for cognitive development and there is little data concerning those years due to the extreme difficulty of finding methods to assess children's timing performances. Moreover, the results yielded by previous experiments are controversial. Our data revealed that discrimination performances improve significantly within only a few months. The discrimination data from 3 and 4 year-olds are compared to those from older children. The overall results are discussed in a developmental model context.
  • [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-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-01478441] Infants' Selectively Pay Attention to the Information They Receive from a Native Speaker of Their Language
    28 février 2017
    From the first moments of their life, infants show a preference for their native language, as well as toward speakers with whom they share the same language. This preference appears to have broad consequences in various domains later on, supporting group affiliations and collaborative actions in children. Here, we propose that infants' preference for native speakers of their language also serves a further purpose, specifically allowing them to efficiently acquire culture specific knowledge via social learning. By selectively attending to informants who are native speakers of their language and who probably also share the same cultural background with the infant, young learners can maximize the possibility to acquire cultural knowledge. To test whether infants would preferably attend the information they receive from a speaker of their native language, we familiarized 12-month-old infants with a native and a foreign speaker, and then presented them with movies where each of the speakers silently gazed toward unfamiliar objects. At test, infants' looking behavior to the two objects alone was measured. Results revealed that infants preferred to look longer at the object presented by the native speaker. Strikingly, the effect was replicated also with 5-month-old infants, indicating an early development of such preference. These findings provide evidence that young infants pay more attention to the information presented by a person with whom they share the same language. This selectivity can serve as a basis for efficient social learning by influencing how infants' allocate attention between potential sources of information in their environment.
  • [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-04531906] Microsatellite data show recent demographic expansions in sedentary but not in nomadic human populations in Africa and Eurasia
    4 avril 2024
    The transition from hunting and gathering to plant and animal domestication was one of the most important cultural and technological revolutions in human history. According to archeologists and paleoanthropologists, this transition triggered major demographic expansions. However, few genetic studies have found traces of Neolithic expansions in the current repartition of genetic polymorphism, pointing rather toward Paleolithic expansions. Here, we used microsatellite autosomal data to investigate the past demographic history of 87 African and Eurasian human populations with contrasted lifestyles (nomadic hunter-gatherers, semi-nomadic herders and sedentary farmers). Likely due to the combination of a higher mutation rate and the possibility to analyze several loci as independent replicates of the coalescent process, the analysis of microsatellite data allowed us to infer more recent expansions than previous genetic studies, potentially resulting from the Neolithic transition. Despite the variability in their location and environment, we found consistent expansions for all sedentary farmers, while we inferred constant population sizes for all hunter-gatherers and most herders that could result from constraints linked to a nomadic or semi-nomadic lifestyle and/or competition for land between herders and farmers. As an exception, we inferred expansions for Central Asian herders. This might be linked with the arid environment of this area that may have been more favorable to nomadic herders than to sedentary farmers. Alternatively, current Central Asian herders may descent from populations who have first experienced a transition from hunter-gathering to sedentary agropastoralism, and then a second transition to nomadic herding.
  • [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-04531876] Adaptive Value of Phenological Traits in Stressful Environments: Predictions Based on Seed Production and Laboratory Natural Selection
    4 avril 2024
    Phenological traits often show variation within and among natural populations of annual plants. Nevertheless, the adaptive value of post-anthesis traits is seldom tested. In this study, we estimated the adaptive values of pre- and post-anthesis traits in two stressful environments (water stress and interspecific competition), using the selfing annual species Arabidopsis thaliana. By estimating seed production and by performing laboratory natural selection (LNS), we assessed the strength and nature (directional, disruptive and stabilizing) of selection acting on phenological traits in A. thaliana under the two tested stress conditions, each with four intensities. Both the type of stress and its intensity affected the strength and nature of selection, as did genetic constraints among phenological traits. Under water stress, both experimental approaches demonstrated directional selection for a shorter life cycle, although bolting time imposes a genetic constraint on the length of the interval between bolting and anthesis. Under interspecific competition, results from the two experimental approaches showed discrepancies. Estimation of seed production predicted directional selection toward early pre-anthesis traits and long post-anthesis periods. In contrast, the LNS approach suggested neutrality for all phenological traits. This study opens questions on adaptation in complex natural environment where many selective pressures act simultaneously.
  • [hal-01495100] Behavioural measures of child's eating temperament and their link with BMI
    24 mars 2017
    Rothbart's model of temperament, defined as individual differences in reactivity and self-regulation, has a strong heuristic value with applications in a wide variety of children's outcomes. Our objective was to test Rothbart's model applied to children's food behaviours and BMI outcome through behavioural measures. Our hypotheses, according to Rothbart's model, were as follows: (i) self-regulation in eating modulates appetite reactivity; (ii) appetite reactivity increases the risk of excess BMI, whereas self regulation in eating limits this risk. One hundred and four children aged between 7 and 12 years completed four behavioural tasks to assess scores for two components of appetite reactivity (i.e. appetite arousal and appetite persistence) and two components of self-regulation in eating (i.e. self-regulation in eating without hunger and self-regulation in eating speed). Their heights and weights were measured in order to calculate their BMI-for-age. T-tests and regression analysis were used to verify our hypotheses. None of the scores of self-regulation in eating was directly associated with BMI but we observed a significant impact of self-regulation in eating without hunger on appetite arousal (p-value = 0.04), together with a modest but significant association between appetite persistence and BMI (p value = 0.02). We can thus conclude that our behavioural measures could be used for the determination of the child's eating temperament. Further studies are needed to investigate how to use these measures to improve the treatment of overweight in children. (C) 2016 Elsevier Ltd. All rights reserved.
  • [halshs-03844931] High Stress Levels and Trust toward the Government Are Associated with More Positive Attitudes toward COVID-19 Vaccines among French Students: A Pilot Study
    9 novembre 2022
    Mistrust in COVID-19 vaccines may hinder vaccination campaigns. We looked at cognitive determinants of vaccination intentions against COVID-19. We were interested in (i) the effects of stress and (ii) the effects of self-protection systems on attitudes and intentions to get COVID-19 vaccines. We conducted an online observational pilot study with 203 participants and used self-report questionnaires to assess perceived stress and vulnerability to disease, beliefs about a dangerous world, pandemic-related stressors, living conditions, attitudes and intentions toward the vaccines and trust in government management of the COVID-19 pandemic. The participants reporting high levels of trust in government and high levels of stress were more likely to have positive attitudes toward COVID-19 vaccines, although these two effects are at least partially independent of each other. We discuss how to improve the communication around COVID-19 vaccine policies.
  • [hal-04367165] Combinatory sound object play in cockatiels: a forerunner of music?
    29 décembre 2023
    Abstract An interest in producing sounds during play behaviour might be a forerunner for music. Thus, we explored object play behaviour involving sounds in cockatiels ( Nymphicus hollandicus ). We provided them with several objects producing sounds and recorded sound production, spontaneous warbles and drumming during breeding, pre- and post-breeding. Birds manipulated the objects in a playful way. They manipulated them less during breeding than during pre- and post-breeding, but the proportion of manipulations producing sounds were higher during post-breeding and breeding than during pre-breeding. Males manipulated the objects more frequently and produced more sounds than females. Youngsters manipulated the objects more than adults. One bird repeatedly put a bell on a xylophone; we discuss several possible explanations for the behaviour, including tool use. Only males warbled and drummed, and during breeding only. Our results suggest an enriching effect of the objects on the birds. Many aspects of musicality remain to be studied.

Médias

ACTUALITES

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)
https://philharmoniedeparis.fr/fr/activite/colloque/23002-pedagogie-du-chant-choral
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 ?"


ARCHIVES TELE / RADIO
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 :  http://www.franceinter.fr/em/vivre-avec-les-betes/105163 (05/2011)

ARCHIVES PRESSE ECRITE
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 ?

Ouvrages

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