Benoist Schaal

French National Centre for Scientific Research | CNRS · Centre des Sciences du Goût (Center for taste smell

To navigate their environment, infants rely on intersensory facilitation when unisensory perceptual demand is high, a principle known as inverse effectiveness. Given that this principle was mainly documented in the context of audiovisual stimulations, here we aim to determine whether it applies to olfactory‐to‐visual facilitation. We build on previ...

While sheep can detect and discriminate human emotions through visual and vocal cues, their reaction to human body odors remains unknown. The present study aimed to determine whether sheep (Ovis aries) can detect human odors, olfactorily discriminate stressed from non-stressed individuals, and behave accordingly based on the emotional valence of th...

During infancy, intersensory facilitation declines gradually as unisensory perception develops. However, this trade‐off was mainly investigated using audiovisual stimulations. Here, fifty 4‐ to 12‐month‐old infants (26 females, predominately White) were tested in 2017–2020 to determine whether the facilitating effect of their mother's body odor on...

To navigate their environment, infants rely on intersensory facilitation when unisensory perceptual demand is high, a principle known as inverse effectiveness. Given that this principle was mainly documented in the context of audiovisual stimulations, here we aim to determine whether it applies to olfactory-to-visual facilitation. We build on previ...

Human milk odor is attractive and appetitive for human newborns. Here, we studied behavioral and heart‐rate (HR) responses of 2‐day‐old neonates to the odor of human colostrum. To evaluate detection in two conditions of stimulus delivery, we first presented the odor of total colostrum against water. Second, the hedonic specificity of total colostru...

The ‘mammary pheromone’ (2-methyl-but-2-enal, 2MB2-al) regulates the interactions between rabbit (Oryctolagus cuniculus) females and their newborn pups. Released into milk, it first elicits pups’ sucking of nipples. A second function is its ability to engage learning of contingent odorants, which become then as potent as the mammary pheromone itsel...

Odorant compounds that mammalian females ingest during pregnancy/lactation permeate to their perinatal offspring, impinging on progeny’s developing chemoreception and shaping subsequent preferences and behaviour. Long-term effects of these earliest experience have been repeatedly found with single flavour qualities, which induce postnatal selectivi...

During infant development, intersensory facilitation declines gradually as unisensory perception improves. However, this developmental trade-off has been mainly investigated using audiovisual stimulations. Here, fifty 4- to 12-month-old infants were tested to determine whether the facilitating effect of their mother's body odor on neural face categ...

Although chemical signaling is an essential mode of communication in most vertebrates, it has long been viewed as having negligible effects in humans. However, a growing body of evidence shows that the sense of smell affects human behavior in social contexts ranging from affiliation and parenting to disease avoidance and social threat. This article...

We thank Dr Alves for his comments on our paper entitled “Flavor Sensing in Utero and Emerging Behaviors in the Human Fetus” (Ustun et al., 2022). As we acknowledge and Dr Alves highlights, the behavioural responsiveness of the human fetus to chemosensory stimuli delivered in utero has so far been rarely investigated in utero, contrary to rat or ov...

Mammalian newborns depend on their mother’s milk to satisfy their initial needs of protection and nutrition. They reach the source of milk in following visual, tactile and olfactory cues. In particular, parturient ewes produce an odorous wax in the inguinal glands close to the teats. When presented separately to newly born lambs, this inguinal wax...

The diet of pregnant women exposes fetuses to a variety of flavors consisting of compound sensations involving smell, taste, and chemesthesis. The effects of such prenatal flavor exposure on chemosensory development have so far been measured only postnatally in human infants. Here, we report the first direct evidence of human fetal responsiveness t...

The odor of human milk induces search-like movements and oral activation in newborns, which increases their chances of taking advantage of milk intake and benefits. However, the underlying volatile fraction of human milk remains understudied. This study aimed to devise a simple method to extract a wide range of volatile compounds from small-volume...

Infants’ ability to discriminate facial expressions has been widely explored, but little is known about the rapid and automatic ability to discriminate a given expression against many others in a single experiment. Here we investigated the development of facial expression discrimination in infancy with fast periodic visual stimulation coupled with...

The damage caused to crops by wildlife, particularly birds, represent a major challenge for farmers. This study aimed to preliminarily assess feeding behaviour of Carrion crows (Corvus corone) on sunflower seeds in field conditions. The crows’ preferences were tested along a visual cue (seed colour: blue vs. uncoloured) and a taste cue (pepper coat...

This chapter focuses on the role of flavors in adaptive responsiveness of perinatal mammals, including humans. Specifically, it will address mechanisms by which flavor experience gained in the amniotic environment prepares more or less selective responsiveness in the postnatal flavor environment, especially in the context of colostrum and milk inge...

Olfactory cues of individuals of the same species or from different species may induce changes in behaviors and physiological reactions in mammals. However, there are few studies on the influence of human odor on animal behavior and welfare, especially those of rodents and farm animals. The present study aimed to investigate whether the odor of a s...

A recent body of research has emerged regarding the interactions between olfaction and other sensory channels to process social information. The current review examines the influence of body odors on face perception, a core component of human social cognition. First, we review studies reporting how body odors interact with the perception of invaria...

Significance The adult human brain is organized in unimodal regions responding selectively to categories of environmental sensory stimuli. Here, we document the origin of category-selective visual brain responses in infancy, demonstrating the key contribution of other senses. Visual categorization is recorded neurally in 4-mo-old infants presented...

The influence of odor valence on expressive-face perception remains unclear. Here, three “valenced” odor contexts (pleasant, unpleasant, control) were diffused while scalp electroencephalogram (EEG) was recorded in 18 participants presented with expressive faces alternating at a 6-Hz rate. One facial expression (happiness, disgust or neutrality) re...

A growing literature shows that perception and action are already tightly coupled in the newborn. The current study aimed to examine the nature of the coupling between olfactory stimuli from the mother and the newborn's crawling and rooting (exploratory movements of the head). To examine the coupling, the crawling and rooting behavior of 28 2-day-o...

Objectives: Colostrum is the initial milk secretion which ingestion by neonates warrants their adaptive start in life. Colostrum is accordingly expected to be attractive to newborns. The present study aims to assess whether colostrum is olfactorily attractive for 2-day-old newborns when presented against mature milk or a control. Methods: The he...

Background We recently demonstrated that chronic dietary exposure to a mixture of pesticides at low-doses induced sexually dimorphic obesogenic and diabetogenic effects in adult mice. Perinatal pesticide exposure may also be a factor in metabolic disease etiology. However, the long-term consequences of perinatal pesticide exposure remain controvers...

Studies on aging and hedonic judgment of odors have never been addressed within the empirical frameworks of age-related changes in emotion which state that advancing age is associated with a reduced negativity bias and a less pronounced differentiation between hedonic valence and emotional intensity judgments. Our aim was to examine and extend thes...

Supporting information for the main article: Categorization of objects and faces in the infant brain and its sensitivity to maternal odor: further evidence for the role of intersensory congruency in perceptual development Published July 2020 in Cognitive Development 55:100930 doi: 10.1016/j.cogdev.2020.100930

The nipple odor of lactating mice (Mus musculus) plays a crucial role in attracting newborn pups and motivating them to suck milk. The characteristic odor of a lactating murine nipple is assumed to be a mixture of multiple odorous substrates, that is, milk, dam's and pups’ saliva, skin glands’ secretions, and amniotic fluid. The present study aimed...

According to recent evidence, rapid categorization of natural face images in the infant brain is enhanced by concomitant maternal odor (Leleu et al., 2020). To test whether this effect is selective to faces, we recorded scalp electroencephalogram (EEG) in 4-month-old infants presented with variable exemplars of a nonface visual category - cars - ap...

The impact of the olfactory sense is regularly apparent across development. The fetus is bathed in amniotic fluid (AF) that conveys the mother’s chemical ecology. Transnatal olfactory continuity between the odours of AF and milk assists in the transition to nursing. At the same time, odours emanating from the mammary areas provoke appetitive respon...

Although anthropologists frequently report the centrality of odours in the daily lives and cultural beliefs of many small-scale communities, Western scholars have historically considered the sense of smell as minimally involved in human communication. Here, we suggest that the origin and persistence of this latter view might be a consequence of the...

To successfully interact with a rich and ambiguous visual environment, the human brain learns to differentiate visual stimuli and to produce the same response to subsets of these stimuli despite their physical difference. Although this visual categorization function is traditionally investigated from a unisensory perspective, its early development...

Specific anosmia is defined as the inability to detect a particular odorant, despite a normal olfactory function. Previous studies reported sex-related difference in detection threshold to steroid odorants, like androstenone or androstadienone during adolescence, and boys showed an increased detection threshold with age. However, such investigation...

Little is known about the effects of olfaction on visual processing during infancy. We investigated whether and how an infant's own mother's body odor or another mother's body odor affects 4-month-old infants’ looking at their mother's face when it is paired with a stranger's face. In Experiment 1, infants were exposed to their mother's body odor o...

Murine milk conveys an odor factor that is both attractive and appetitive to conspecific newborns. Up to now, little is known about the temporal dynamic of this odor factor and about the stability of its behavioral activity after milk ejection. We aim to characterize the conditions in which the attractive and appetitive potency of milk to newborns...

Olfaction is one of the most commonly used senses for communication among animals and is of particular importance to mother-offspring recognition in mammals. The use of smell in offspring recognition has been well studied, however, we often lack information about the underlying mechanistic basis for olfactory recognition. Using gas chromatography–m...

Recognition of individuals or classes of individuals plays an important role in the communication systems of many mammals. The ability of otariid (i.e., fur seal and sea lion) females to locate and identify their offspring in colonies after returning from regular foraging trips is essential to successful pup rearing. It has been shown that olfactio...

Infants' olfactory experience begins before birth and extends after birth through milk and complementary foods. Until now, studies on the effects of chemosensory experience in utero and/or through human milk focused on experimentally controlled exposure to only one target food bearing a specific odor quality and administered in sizeable amounts. Th...

Human milk odour has for long elicited research interest with regard to its function in breastfeeding initiation. The present review aims to provide an overview of the behavioural effects of human milk odour in the human neonate, considering different types of response measures in a feeding or non-feeding context. Further, an overview of the curren...

Efficient decoding of even brief and slight intensity facial expression changes is important for social interactions. However, robust evidence for the human brain ability to automatically detect brief and subtle changes of facial expression remains limited. Here we built on a recently developed paradigm in human electrophysiology with full-blown ex...

To interact with an unlabeled rich visual world, the human developing brain learns to differentiate visual events and to generalize across some of them despite their physical variability. Although this perceptual categorization process has been traditionally investigated from a unisensory perspective, the early development of visual categorization...

Robert Soussignan, Nicolas Dollion, Benoist Schaal, Karine Durand, Nadja Reissland & Jean-Yves Baudouin (2018) Mimicking emotions: how 3–12-month-old infants use the facial expressions and eyes of a model, Cognition and Emotion, 32:4, 827-842, DOI: 10.1080/02699931.2017.1359015 ABSTRACT While there is an extensive literature on the tendency to mim...

Robert Soussignan, Nicolas Dollion, Benoist Schaal, Karine Durand, Nadja Reissland & Jean-Yves Baudouin (2018) Mimicking emotions: how 3–12-month-old infants use the facial expressions and eyes of a model, Cognition and Emotion, 32:4, 827-842, DOI: 10.1080/02699931.2017.1359015 ABSTRACT While there is an extensive literature on the tendency to mi...

S19 in proceedings " XXVIIth Annual Meeting of the European Chemoreception Research Organization, ECRO"

Y3 in proceedings " XXVIIth Annual Meeting of the European Chemoreception Research Organization"

There is evidence that human-produced androstenes affect attitudinal, emotional, and physiological states in a context-dependent manner, suggesting that they could be involved in modulating social interactions. For instance, androstadienone appears to increase attention specifically to emotional information. Most of the previous work focused on one...

Résumé Les recherches récentes sur le développement sensoriel et perceptif du fœtus humain utilisent des techniques d’imagerie cérébrale, comme la Magnétoencéphalographie (MEG) ou la Résonance magnétique nucléaire fonctionnelle (fMRI). Cette approche neurophysiologique de la réactivité cérébrale du fœtus aux stimulations sensorielles représente cer...

In humans, stress can be contagiously transmitted via chemosignals on a subconscious level. This study investigates how pregnancy affects neural responses to anxiety chemosignals. Using cotton pads, 28 men donated axillary sweat immediately before an academic examination (anxiety sweat) and during ergometer training (control). Via a constant-flow o...

We investigated the occurrence and underlying processes of odor-color associations in French and American 6- to 10-year-old children (n = 386) and adults (n = 137). Nine odorants were chosen according to their familiarity to either cultural group. Participants matched each odor with a color, gave hedonic and familiarity judgments, and identified ea...

Recent fetal research has explored brain correlates of prenatal sensory and perceptual development using imaging technologies, such as the MEG or fMRI. Such neurophysiological research seeks to map early neural development and will eventually be beneficial for early diagnosis and intervention for developmental disorders. However, the pioneering res...

While there is an extensive literature on the tendency to mimic emotional expressions in adults, it is unclear how this skill emerges and develops over time. Specifically, it is unclear whether infants mimic discrete emotion-related facial actions, whether their facial displays are moderated by contextual cues and whether infants’ emotional mimicry...

While there is an extensive literature on the tendency to mimic emotional expressions in adults, it is unclear how this skill emerges and develops over time. Specifically, it is unclear whether infants mimic discrete emotion-related facial actions, whether their facial displays are moderated by contextual cues and whether infants’ emotional mimicry...

Chemosensory anxiety signals effectively prime motor responses related to withdrawal behavior, such as the startle reflex, in adult humans. As the reproductive status strongly affects the response to social chemosignals, the current study examined whether chemosensory anxiety signals would augment the startle response in prepubertal children as it...

Conjugated forms of odorants contributing to sweat odor occur not only in human sweat but also in amniotic fluid, colostrum, and milk. However, it is unclear whether the released odorants are detected and hedonically discriminated by human newborns. To investigate this issue, we administered highly diluted solutions of (R)/(S)-3-methyl-3-sulfanylhe...

This chapter summarizes research on the development of human olfactory skills to rely on different cues conveyed by odorants, such as odor quality, intensity, position in space, novelty/familiarity, and hedonic value. The sensory, neural, and psychological dimensions at the root of these early aptitudes remain poorly explored in humans, but one can...

Ce dossier a préalablement été publié par l’Inra sur son site : http://institut.Inra.fr/Missions/Eclairer-les-decisions/Expertises/Toutes-les-actualites/Conscience-animale

Ce dossier a préalablement été publié par l’Inra sur son site : http://institut.Inra.fr/Missions/Eclairer-les-decisions/Expertises/Toutes-les-actualites/Conscience-animale

Although evolution has selected newborn organisms that possess the physiological and behavioral keys leading to adapt to this harsh psychobiological challenge, their capabilities cannot be considered separately from the maternal organism and the environment she creates. Mammalian females provide indeed passive (physiological) and/or active (behavio...

This chapter focuses on chemical communication, including olfaction and gustation, plays a central role in structuring primate social relationships, including 'microsmatic' Old World species including humans. Chemical communication is a widespread mechanism used by most living species, including human and non-human primates, incorrectly considered...

Perceiving emotional expressions from faces is essential for social interactions. However, while the intensity of facial expressions is highly variable in everyday-life, perceptual tuning to facial expression of various intensities remains largely unknown. Here we recorded scalp electroencephalogram (EEG) from 18 adult participants during fast peri...

Résumé Il existe une abondante littérature, depuis plusieurs décennies, sur les liens entre olfaction et dépression. La revue de la littérature proposée ici n’a donc pas vocation à être exhaustive sur les travaux publiés mais vise plutôt à mettre en exergue les études les plus récentes et leurs apports à la compréhension des mécanismes olfactifs da...

This article proposes a methodological consideration for the use of "head free" eye-Tracking systems, which allowed to extend this technique to the study of infant skills. It explores how the technological developments enable a more qualitative approach, which offers the possibility of considering "how" in addition to "how long" the infant looks at...

A large part of the literature on sensory perception and behavior in dolphins is devoted to its well-developed vocal and echolocation abilities. In this review, we aim to augment current knowledge by examining the literature on dolphins' entire “Merkwelt” (which refers to everything a subject perceives, creating a crucial part of the subject's Umwe...

Chemosensory perception in cetaceans remains an intriguing issue as morphological, neuroanatomical and genetic studies draw unclear conclusions, while behavioral data suggest that dolphins may use it for food selection or socio-sexual interactions. Experimental approaches have been scarce due to the practical difficulties of testing chemoreception...

Children’s vegetable consumption falls below current recommendations, highlighting the need to identify strategies that can successfully promote better acceptance of vegetables. Recently, experimental studies have reported promising interventions that increase acceptance of vegetables. The first, offering infants a high variety of vegetables at wea...

Eating behavior is strongly regulated by intrinsic physiological factors and largely influenced by the individual and cultural environments. Excessive food intake and sedentary lifestyle are the main reasons for the global epidemic of obesity. The influence of family background on eating habits makes no doubt but the fact that the nutritional, meta...

Newborn rabbits locate mother’s nipples through typical orocephalic movements elicited by odour stimuli, in particular by the mammary pheromone (MP). The MP also promotes neonatal odour learning: after single pairing with the MP, an initially neutral odorant becomes able to elicit sucking-related head searching-oral grasping movements. However, the...