Periodic Reporting for period 1 - F.E.E.D. your mind (FEED your mind: Investigating the nature, ontogeny and evolution of cognitive processes underlying food behaviors, to pave a way toward efficient interventions promoting healthy eating in early life)
Berichtszeitraum: 2022-10-01 bis 2025-05-31
We make dozens of food choices on a daily basis. In many cultures, many of those choices are made during a trip to the grocery store where food items have been already processed and packaged by others. There we might pick up a can of tomatoes and ask ourselves: Are these healthy? or Are they suitable to serve at a fancy dinner party? but we certainly do not need to ask: Are they edible or harmful? or Are they even food? Instead, detailed food labels indicate all of the ingredients of a food product, the macronutrients present, its caloric content, and expiration date. This easy way of interacting with food is extremely new in our human history and may somehow blind us to the complexity of the task that is choosing appropriate foods to eat which have played a crucial role throughout human evolution, given food’s central importance for survival.
In fact, choosing what to eat is a crucial and difficult task. Humans are omnivores and need to gather a wide variety of foods to ensure nutritional health and infants are born into a world replete with objects (either food or non-food) that have different colors, shapes, odors… A few common taste preferences - such as tendencies to like sweet and salty tastes and dislike sour and bitter tastes are evident very early in life and likely emerged to guide human learners toward substances that are both safe to eat and nutritious. However, these common taste preferences do not account for the complexity of the human diet. Given the broad possibility space of potential foods and risks (e.g. ingesting harmful entities) across different environments, infants and young children instead must learn what to eat over the course of development, going away from eating just milk after weaning. This food learning task is particularly complex given that children do not only need to learn about the safety and palatability of the different entities in their environment but also about who eats what food in what context, absorbing social and cultural traditions surrounding food selection, as eating is largely a social phenomenon.
The objectives of the current project are to investigate in detail how infants and young children learn and choose what to eat, both individually and with the help of social partners. First, the project examines how young individuals learn to categorize which entities in their environment are candidate food items (Axis 1). Second, the project investigates the social learning mechanisms and attentional strategies young individuals use to avoid mistakes (i.e. ingesting something harmful) while learning what to eat (Axis 2). The strength of the project is in the combination of robust methods from neuroscience, cognitive and developmental psychology to conduct an innovative and interdisciplinary investigation of how humans learn and choose what to eat. Altogether, this research project enriches our understanding of the ontogenetic roots of human food cognition and eating behaviors, and pave a way toward designing evidence-based interventions for fostering healthy and sustainable eating especially in early life.
In fact, choosing what to eat is a crucial and difficult task. Humans are omnivores and need to gather a wide variety of foods to ensure nutritional health and infants are born into a world replete with objects (either food or non-food) that have different colors, shapes, odors… A few common taste preferences - such as tendencies to like sweet and salty tastes and dislike sour and bitter tastes are evident very early in life and likely emerged to guide human learners toward substances that are both safe to eat and nutritious. However, these common taste preferences do not account for the complexity of the human diet. Given the broad possibility space of potential foods and risks (e.g. ingesting harmful entities) across different environments, infants and young children instead must learn what to eat over the course of development, going away from eating just milk after weaning. This food learning task is particularly complex given that children do not only need to learn about the safety and palatability of the different entities in their environment but also about who eats what food in what context, absorbing social and cultural traditions surrounding food selection, as eating is largely a social phenomenon.
The objectives of the current project are to investigate in detail how infants and young children learn and choose what to eat, both individually and with the help of social partners. First, the project examines how young individuals learn to categorize which entities in their environment are candidate food items (Axis 1). Second, the project investigates the social learning mechanisms and attentional strategies young individuals use to avoid mistakes (i.e. ingesting something harmful) while learning what to eat (Axis 2). The strength of the project is in the combination of robust methods from neuroscience, cognitive and developmental psychology to conduct an innovative and interdisciplinary investigation of how humans learn and choose what to eat. Altogether, this research project enriches our understanding of the ontogenetic roots of human food cognition and eating behaviors, and pave a way toward designing evidence-based interventions for fostering healthy and sustainable eating especially in early life.
Axis 1
In this axis we examine whether high-level visual categorization of food is present already in the first year of life. An approach particularly suited to capture the development of visual categorization processes is the fast periodic visual stimulation paradigm (FPVS) coupled with electroencephalography (EEG). This FPVS-EEG approach relies on the property of the brain to synchronize with stimuli presented periodically, eliciting a periodic change of voltage amplitude in the EEG signal at the same frequency. In this paradigm, streams of visual stimuli (i.e. base stimuli) are presented at a fixed presentation rate (usually 6Hz, i.e. six images per second), eliciting an EEG response at the same frequency. Stimuli from a target category are periodically inserted in the sequence of images at a slower rate (e.g. every fifth images, that is at a 1.2Hz frequency, AAAABAAAAB…), eliciting an additional EEG response at this slower frequency if the brain discriminates between the base and target stimuli and generalized across target items
In axis 1, two groups of adults and two groups of infants (12-month-old and 6-months infants) were tested in an FPVS paradigm, with contrasts spanning the food / non-food distinction. Given the novelty of using food stimuli in FPVS paradigms, adults were tested to provide a reference for infants’ electrophysiological responses. Twelve-month-old infants were selected because they have some experience with solid foods: The typical age of food diversification in France is 4- to 6-months and by 12 months they already eat solid foods in pieces such as raw and cooked fruits and vegetables, starchy foods etc. (Somaraki et al., 2024; Nicolas, 2019). Six-month-old infants were chosen because it is around that age that infants are first introduced to solid food, allowing us to investigate if infants start to be able to categorize food as soon as they transition to solid foods.
In summary, our results from Axis 1 revealed that both adults and 12-month-old infants show neural responses indicative of visual categorization of food from natural kinds and artefacts, although infant categorization was less pronounced compared to adults. These results confirm the sensitivity of the FPVS paradigm in measuring adults’ and infants’ neural responses to food. Analysis with 6-month-old infants is ongoing. Overall, the study contributes to the development of methods such as FPVS to study cognitive development in infants and provide new insights into when visual category representations emerge in infants’ brains.
Axis 2
Food learning in early life relies on social learning and infants are selective in the way they use social information to learn about food: Infants learn that a particular entity is edible after observing an adult eating it, but not when they handle it in other ways. However, it is still unclear how infants react to negative information applied to food.
To examine this question, we conducted a series of looking time experiments with 14-month-olds because they have had experience with solid foods and often engage in social referencing, i.e. looking at an adult and adjusting their behavior based on the adult's behavior. We employed a violation of expectation (VoE) paradigm to test whether infants recognize that disgust, but not other negative emotions, carries information about (non) edibility. In VoE paradigms, infants watch a familiarization event. Then, they watch two test events, one coherent with the familiarization event and one incoherent and infants’ looking time during these two test events are recorded. A longer looking time during the incoherent event indicates that infants’ expectations have been violated. VoE paradigms are robust and extremely well-validated paradigms in developmental psychology.
In a first experiment, at familiarization I presented infants with an actor being disgusted by the sight of food A and displaying neutral emotion towards food B. At test phase, infants saw the same actor eating food A (incoherent event) and B (coherent event). I found longer looking times during the incoherent event, revealing that infants expect an adult to avoid eating food for which they have shown disgust previously. In a second experiment, I presented infants with an actor being angry at the sight of food A and displaying neutral emotion towards food B. At test phase, infants saw the same actor eating food A (incoherent event) and B (coherent event). In that second experiment, I did not find longer looking times during the incoherent event, suggesting that infants did not expect an adult to avoid eating a food for which they have shown anger previously. These are promising results, showing selectivity in how infants use negative information about food. In a third experiment, infants saw the same familiarization as in Experiment 1 but during the test phase they saw a second actor (E2) eating both foods. It remains to be tested whether infants interpret disgust expressions as conveying information that generalizes across individuals instead of a person-specific subjective feeling. In this experiment 3 infants looked longer during the incoherent event, revealing that they interpreted disgust expressions as conveying information that generalizes across individuals instead of a person-specific subjective feeling.
In this axis we examine whether high-level visual categorization of food is present already in the first year of life. An approach particularly suited to capture the development of visual categorization processes is the fast periodic visual stimulation paradigm (FPVS) coupled with electroencephalography (EEG). This FPVS-EEG approach relies on the property of the brain to synchronize with stimuli presented periodically, eliciting a periodic change of voltage amplitude in the EEG signal at the same frequency. In this paradigm, streams of visual stimuli (i.e. base stimuli) are presented at a fixed presentation rate (usually 6Hz, i.e. six images per second), eliciting an EEG response at the same frequency. Stimuli from a target category are periodically inserted in the sequence of images at a slower rate (e.g. every fifth images, that is at a 1.2Hz frequency, AAAABAAAAB…), eliciting an additional EEG response at this slower frequency if the brain discriminates between the base and target stimuli and generalized across target items
In axis 1, two groups of adults and two groups of infants (12-month-old and 6-months infants) were tested in an FPVS paradigm, with contrasts spanning the food / non-food distinction. Given the novelty of using food stimuli in FPVS paradigms, adults were tested to provide a reference for infants’ electrophysiological responses. Twelve-month-old infants were selected because they have some experience with solid foods: The typical age of food diversification in France is 4- to 6-months and by 12 months they already eat solid foods in pieces such as raw and cooked fruits and vegetables, starchy foods etc. (Somaraki et al., 2024; Nicolas, 2019). Six-month-old infants were chosen because it is around that age that infants are first introduced to solid food, allowing us to investigate if infants start to be able to categorize food as soon as they transition to solid foods.
In summary, our results from Axis 1 revealed that both adults and 12-month-old infants show neural responses indicative of visual categorization of food from natural kinds and artefacts, although infant categorization was less pronounced compared to adults. These results confirm the sensitivity of the FPVS paradigm in measuring adults’ and infants’ neural responses to food. Analysis with 6-month-old infants is ongoing. Overall, the study contributes to the development of methods such as FPVS to study cognitive development in infants and provide new insights into when visual category representations emerge in infants’ brains.
Axis 2
Food learning in early life relies on social learning and infants are selective in the way they use social information to learn about food: Infants learn that a particular entity is edible after observing an adult eating it, but not when they handle it in other ways. However, it is still unclear how infants react to negative information applied to food.
To examine this question, we conducted a series of looking time experiments with 14-month-olds because they have had experience with solid foods and often engage in social referencing, i.e. looking at an adult and adjusting their behavior based on the adult's behavior. We employed a violation of expectation (VoE) paradigm to test whether infants recognize that disgust, but not other negative emotions, carries information about (non) edibility. In VoE paradigms, infants watch a familiarization event. Then, they watch two test events, one coherent with the familiarization event and one incoherent and infants’ looking time during these two test events are recorded. A longer looking time during the incoherent event indicates that infants’ expectations have been violated. VoE paradigms are robust and extremely well-validated paradigms in developmental psychology.
In a first experiment, at familiarization I presented infants with an actor being disgusted by the sight of food A and displaying neutral emotion towards food B. At test phase, infants saw the same actor eating food A (incoherent event) and B (coherent event). I found longer looking times during the incoherent event, revealing that infants expect an adult to avoid eating food for which they have shown disgust previously. In a second experiment, I presented infants with an actor being angry at the sight of food A and displaying neutral emotion towards food B. At test phase, infants saw the same actor eating food A (incoherent event) and B (coherent event). In that second experiment, I did not find longer looking times during the incoherent event, suggesting that infants did not expect an adult to avoid eating a food for which they have shown anger previously. These are promising results, showing selectivity in how infants use negative information about food. In a third experiment, infants saw the same familiarization as in Experiment 1 but during the test phase they saw a second actor (E2) eating both foods. It remains to be tested whether infants interpret disgust expressions as conveying information that generalizes across individuals instead of a person-specific subjective feeling. In this experiment 3 infants looked longer during the incoherent event, revealing that they interpreted disgust expressions as conveying information that generalizes across individuals instead of a person-specific subjective feeling.
Axis 1
In summary, our results from Axis 1 revealed that both adults and 12-month-old infants show neural responses indicative of visual categorization of food from natural kinds and artefacts, although infant categorization was less pronounced compared to adults. These results confirm the sensitivity of the FPVS paradigm in measuring adults’ and infants’ neural responses to food. Analysis with 6-month-old infants is ongoing. Overall, the study contributes to the development of methods such as FPVS to study cognitive development in infants and provide new insights into when visual category representations emerge in infants’ brains.
Axis 2
In summary, our results from Axis 2 show that infants recognize that disgust carries information about (non)edibility as well as selectivity in how infants use negative information about food.
In summary, our results from Axis 1 revealed that both adults and 12-month-old infants show neural responses indicative of visual categorization of food from natural kinds and artefacts, although infant categorization was less pronounced compared to adults. These results confirm the sensitivity of the FPVS paradigm in measuring adults’ and infants’ neural responses to food. Analysis with 6-month-old infants is ongoing. Overall, the study contributes to the development of methods such as FPVS to study cognitive development in infants and provide new insights into when visual category representations emerge in infants’ brains.
Axis 2
In summary, our results from Axis 2 show that infants recognize that disgust carries information about (non)edibility as well as selectivity in how infants use negative information about food.