Food familiarity does not change nematode feeding behavior

Bacterial traits and quality contribute to the diet choice and survival of bacterial-feeding nematodes

Philippine ricefield rats (Rattus rattus mindanensis) that were accustomed to eating rice grain showed greatly increased preference for granulated rice when it was enriched by the volatiles from ground unpolished rice. This was the best of 11 formulations involving 8 rice components that were tested with an automated brief-exposure preference tester. This formulation was also highly preferred (P 2X ) of the treated bait and showed 88 percent mortality. These results indicate that intensifying the flavor cues associated with a familiar or preferred food is a fruitful approach in the development of an effective bait enhancer. J. WILDL. MANAGE. 41(2):290-297 The familiar problem of bait acceptance in rat control programs readily applies to the Philippine ricefield rat. In their 1971 Annual Report (p. 61) scientists of the Philippine Rodent Research Center (College Laguna, Philippines) stated: suspect that bait acceptance is a major factor limiting the effectiveness of acute toxicants as now used for rodent population reduction in Philippine ricefields; methods to improve acceptance need further investigation. Because of this need, we began a program to develop highly palatable baits for rat control in ricefields. The food preference behavior of wild rats is very complex. The drive to satisfy energy requirements affects preference (Schein and Orgain 1953, Cornwell and Bull 1967, Brooks and Bowerman 1973). Novelty also can be important (Welker and King 1962, Bronson 1966, Long and T pp 1967, Valle 1970). A novel stimulus may direct an animal's exploratory behavior and lead it to the bait, but consumption of the bait may or may not follow, depending n how much wariness the same novel cue elicits. As the bait's novelty decreases, so d es its ability to direct exploratory behavior (Long and Tapp 1967). Furthermore, novel factors such as taste, odor, color, and texture may provide cues for bait aversion (shyness). However, response to a familiar food is more predictable. Previous experience is an important factor (Barnett and Spencer 1953, Jackson 1965, Cornwell and Bull 1967, Reif 1969, Bull 1972, Howard and Marsh 1974). In tests and observations of feeding behavior, we have found that rats consistently prefer familiar foods over unfamiliar ones. The durability and strength of this response seem to increase when the familiar food has been a major diet item and is satisfying the animal's nutritional needs. Tigner (1972) found that when there is enough rice grain in the paddies to sustain ricefield rats, it makes up 60-85 percent of the 1 Investigations were supported by funds provided to the U.S. Fish and Wildlife Service by the Agency for International Development under the project Control of Vertebrate Pests: Rats, Bats and Noxious Birds PASA RA(ID) 1-67. 290 J. Wildl. Manage. 41(2):1977 This content downloaded from 207.46.13.148 on Sun, 11 Sep 2016 04:33:41 UTC All use subject to http://about.jstor.org/terms FLAVOR ENHANCEMENT OF RAT BAITS * Bullard and Shumake 291 volume of food in their stomachs. Thus, the most familiar food of the rats that damage rice plants is the rice grain itself. Could a rice fraction that intensified the familiar flavor cues of rice provide the key to developing a highly palatable bait? The series of studies described below was designed to answer this question. The authors gratefully acknowledge G. Holguin, S. E. Gaddis, and K. A. Crane for their technical assistance throughout the project. We also thank C. P. Breidenstein for statistical assistance and A. H. Bean for critical review of the manuscript.

Emotional state during food consumption is expected to affect food pleasantness. We hypothesize that a negative emotional state reduces food pleasantness and more so for novel foods than for familiar foods because novel foods have not yet been associated with previous emotions. Furthermore, we expect this effect to be stronger when judging the food again from memory without tasting. We induced a positive emotional state in 34 participants by telling them that they earned a monetary bonus and induced a negative emotional state in 35 other participants by subjecting them to a social stress test. After this emotion induction, both groups tasted and rated a (for them) novel soup (sumashi soup) and a familiar soup (vegetable soup). Several explicit and implicit measures of food pleasantness (rated valence, EsSense25, willingness-to-take-home and sip size) indicated that while the negative emotion group did not experience the soups as less pleasant than the positive emotion group, there was an interaction between food familiarity and emotional group. The positive emotion group experienced novel and familiar soups as equally pleasant, whereas the negative emotion group experienced the novel soup as relatively unpleasant and the familiar soup as pleasant. The latter result is consistent with a comforting effect of a familiar taste in a stressful situation. This effect remained in the ratings given 1 week later based on memory and even after retasting. Our results show that emotional state affects food pleasantness differently for novel and familiar foods and that such an effect can be robust.

In several mammalian species, prenatal exposure to odours can elicit later positive consummatory behaviour in response to substrates bearing that odorant. In birds, the sense of smell has been considerably underestimated, and very little is known about the effects of early sensory experience on the regulation of feeding behaviour. We tested the hypothesis that the feeding behaviour of the domestic chicken could be regulated by olfactory learning during the embryonic life. To that end, chicken embryos were exposed to an olfactory stimulus (blend of essential oil of orange and nature identical vanillin) from embryonic day (ED) 12 to ED20, and chicks were tested between 4 and 9 d of age. In short‐term choice tests, at day 4 and 5, chickens previously exposed to a low concentration (LC) of the olfactory stimulus spent a higher proportion of time eating a familiar or an unfamiliar food bearing the olfactory stimulus compared to non‐exposed control chickens. Conversely, chickens previously exposed to a high concentration (HC) of the olfactory stimulus were found to avoid all foods bearing the olfactory stimulus. On a 24‐ h time scale at day 7–8, LC and HC birds, but not controls, ingest significantly less familiar food containing the olfactory stimulus. This result indicated a long‐term effect of the early olfactory experience on feeding preferences. We demonstrated that chickens can utilize information from their pre‐hatch chemosensory environment to guide their later feeding behaviour. A pre‐hatch effect of the intensity of odour signals in the regulation of feeding behaviour is reported here for the first time.

Capuchins, like other primates, use feedback from sensory cues and digestion to make decisions about which foods to consume and which to avoid. However, little is known about how capuchins make consumption decisions when simultaneously presented with novel and familiar foods, or how food familiarity and macronutrient concentration together influence food choice, topics with potential implications for developmental and health research. In this study, we evaluated the role of familiarity, as well as fat and sugar concentration, in the food selections of captive tufted capuchins (Sapajus apella). In the first experiment, over 10 sessions, subjects were assigned to either a group that chose between one familiar and one novel food item both high in fat or sugar (high condition), or to a group that chose between one familiar and one novel food item both low in fat or sugar (low condition). In the second experiment, subjects were divided into three groups, familiarized with food over five feeding sessions, and then offered the familiarized food and a novel food that varied in fat or sugar for 10 sessions. When offered foods high in fat, capuchins showed no clear signs of neophobia, forming an initial preference for the novel food, rejecting foods less frequently, and selecting foods faster than when offered foods low in fat. These trends were generally not observed in response to foods with sugar. When presented with options that varied in macronutrient concentration, subjects showed an initial interest in the novel food irrespective of whether it was high in fat or sugar, yet formed a final preference for the higher-concentration item. Findings suggest that the concentration of fat or sugar in novel foods may be an important mediator of exploratory behavior and that capuchins rely on immediate feedback from taste and other sensory cues to make consumption decisions.

BACKGROUND Understanding the factors influencing food choice is critical for developing effective strategies to promote healthier eating habits and creating policies that support public health. Attentional bias, the inclination to focus attention on specific stimuli, plays a significant role in shaping food preferences by affecting how individuals perceive and react to various food-related elements. Various methodologies exist to examine attentional bias, including the dot-probe task, which measures reaction times to probes appearing after paired stimuli (eg, novel vs familiar food images); eye-tracking, which tracks gaze patterns and fixations to determine visual attention; and electroencephalography, which records brain activity, capturing early and late neural responses (eg, N100, P300) linked to attention processing; however, integrated approaches combining these methods to assess bias toward familiar versus novel foods remain underexplored. OBJECTIVE This study aims to examine differences in attention toward familiar versus novel food stimuli using integrated eye-tracking, dot-probe, and electroencephalography methods, and to explore associations with self-reported food choice. METHODS A total of 40 healthy adult participants will be recruited. Participants will be presented with pairs of familiar or novel food images, while their visual attention and brain activity are recorded concurrently. Eye-tracking metrics, including time to first fixation and total fixation duration, will be used to assess visual attention. Electroencephalography data will be collected to measure the amplitude of event-related potential components, such as P300 and N100, associated with attentional processing. Reaction times will also be recorded as a behavioral measure of attentional engagement with familiar versus novel food items. Data analysis will involve repeated measures ANOVA to examine the effects of food familiarity and novelty on attentional bias metrics. Correlation analyses will also be conducted to explore the relationships between eye-tracking, electroencephalography, and dot-probe measures. RESULTS This study was approved by the Ethics Committee of the Iran University of Medical Sciences in February 2021 and funded in January 2022. Data collection began in November 2022 and is expected to be completed in July 2025. As of the submission of this study, 36 individuals have been recruited. Data analysis has not yet commenced, but it is planned to begin upon the completion of data collection. The results are anticipated to be published by December 2025. The protocol was registered with the Open Science Framework in September 2024. CONCLUSIONS The main outcome of this study is identifying differences in attentional bias metrics toward familiar versus novel food stimuli at different presentation times. These findings will provide preliminary data on the application of an integrated approach for capturing attentional bias to food-based stimuli based on their familiarity or novelty, and how these biases may be linked to food choice behaviors. INTERNATIONAL REGISTERED REPORT DERR1-10.2196/69541

Valence, familiarity and arousal of different foods in relation to age, sex and weight

Effect of dietary history and algal traits on feeding rate and food preference in the green sea urchin Strongylocentrotus droebachiensis

The effects of novelty on food consumption in male and female rats

Understanding the factors influencing food choice is critical for developing effective strategies to promote healthier eating habits and creating policies that support public health. Attentional bias, the inclination to focus attention on specific stimuli, plays a significant role in shaping food preferences by affecting how individuals perceive and react to various food-related elements. Various methodologies exist to examine attentional bias, including the dot-probe task, which measures reaction times to probes appearing after paired stimuli (eg, novel vs familiar food images); eye-tracking, which tracks gaze patterns and fixations to determine visual attention; and electroencephalography, which records brain activity, capturing early and late neural responses (eg, N100, P300) linked to attention processing; however, integrated approaches combining these methods to assess bias toward familiar versus novel foods remain underexplored. This study aims to examine differences in attention toward familiar versus novel food stimuli using integrated eye-tracking, dot-probe, and electroencephalography methods, and to explore associations with self-reported food choice. A total of 40 healthy adult participants will be recruited. Participants will be presented with pairs of familiar or novel food images, while their visual attention and brain activity are recorded concurrently. Eye-tracking metrics, including time to first fixation and total fixation duration, will be used to assess visual attention. Electroencephalography data will be collected to measure the amplitude of event-related potential components, such as P300 and N100, associated with attentional processing. Reaction times will also be recorded as a behavioral measure of attentional engagement with familiar versus novel food items. Data analysis will involve repeated measures ANOVA to examine the effects of food familiarity and novelty on attentional bias metrics. Correlation analyses will also be conducted to explore the relationships between eye-tracking, electroencephalography, and dot-probe measures. This study was approved by the Ethics Committee of the Iran University of Medical Sciences in February 2021 and funded in January 2022. Data collection began in November 2022 and is expected to be completed in July 2025. As of the submission of this study, 36 individuals have been recruited. Data analysis has not yet commenced, but it is planned to begin upon the completion of data collection. The results are anticipated to be published by December 2025. The protocol was registered with the Open Science Framework in September 2024. The main outcome of this study is identifying differences in attentional bias metrics toward familiar versus novel food stimuli at different presentation times. These findings will provide preliminary data on the application of an integrated approach for capturing attentional bias to food-based stimuli based on their familiarity or novelty, and how these biases may be linked to food choice behaviors. DERR1-10.2196/69541.

Effect of expectations and the definition of product category on the acceptance of unfamiliar foods

Pregnancy in goats does not influence intake of novel or familiar foods with or without toxins

Sensory education decreases food neophobia score and encourages trying unfamiliar foods in 8–12-year-old children

Effect of social feeding environment on the feeding behaviour of dairy cows and their willingness to consume a novel feed

Children that do not reach their full growth potential in utero have an increased risk for developing glucose intolerance, increased adiposity and metabolic syndrome features as adults. As food intake and feeding behavior, along with energy expenditure, are major determinants in the development of such features, it is expected that these individuals will show altered feeding patterns over the life course. However, aside from increased appetite, only recently research has been dedicated to explore the effects that poor fetal growth can have on food preferences. Despite being a new focus of investigation, there is compelling evidence, both clinical and experimental, that exposure to fetal paucity of nutrients may have programming effects on feeding preferences and behaviors that can contribute to the development of diseases. Individuals born small for gestational age (SGA) have preferences towards highly caloric and palatable foods such as carbohydrates and fats, and eventually will display altered eating behaviors as well. These behaviors lead to small but persistent nutrient imbalances across the lifespan, increasing the risk of chronic, non-transmittable diseases in adult life in these individuals. Different animal models of poor fetal growth were developed, allowing a deeper understanding of the mechanisms potentially involved in these findings. Alterations in brain pathways, involved in the search and reward sensations associated with the intake of high palatable foods, such as the mesocorticolimbic dopamine and opioids pathways, as well as their modulators, seem to be involved. We review this evidence, discuss the mechanisms and propose points for future research and possible development of interventions to prevent these altered behaviors in this vulnerable population.