Facial expressions in school-aged children are a good indicator of ‘dislikes’, but not of ‘likes’

Sensorimotor regulation of facial expression - An untouched frontier

Facial expression is a critical form of nonverbal social communication which promotes emotional exchange and affiliation among humans. Facial expressions are generated via precise contraction of the facial muscles, guided by sensory feedback. While the neural pathways underlying facial motor control are well characterized in humans and primates, it remains unknown how tactile and proprioceptive information reaches these pathways to guide facial muscle contraction. Thus, despite the importance of facial expressions for social functioning, little is known about how they are generated as a unique sensorimotor behavior. In this review, we highlight current knowledge about sensory feedback from the face and how it is distinct from other body regions. We describe connectivity between the facial sensory and motor brain systems, and call attention to the other brain systems which influence facial expression behavior, including vision, gustation, emotion, and interoception. Finally, we petition for more research on the sensory basis of facial expressions, asserting that incomplete understanding of sensorimotor mechanisms is a barrier to addressing atypical facial expressivity in clinical populations.

Face your fears: direct and indirect measurement of responses to looming threats

This study investigated the emotional and behavioural effects of looming threats using both recalled (self-reported valence) and real-time response measurements (facial expressions). The looming bias refers to the tendency to underestimate the time of arrival of rapidly approaching (looming) stimuli, providing additional time for defensive reactions. While previous research has shown negative emotional responses to looming threats based on self-reports after stimulus exposure, facial expressions offer valuable insights into emotional experiences and non-verbal behaviour during stimulus exposure. A face reading experiment examined responses to threats in motion, considering stimulus direction (looming versus receding motion) and threat strength (more versus less threatening stimuli). We also explored the added value of facial expression recognition compared to self-reported valence. Results indicated that looming threats elicit more negative facial expressions than receding threats, supporting previous findings on the looming bias. Further, more (vs. less) threatening stimuli evoked more negative facial expressions, but only when the threats were looming rather than receding. Interestingly, facial expressions of valence and self-reported valence showed opposing results, suggesting the importance of incorporating facial expression recognition to understand defensive responses to looming threats more comprehensively.

Risk, Trust, and Emotion in Online Pharmacy Medication Purchases: Multimethod Approach Incorporating Customer Self-Reports, Facial Expressions, and Neural Activation

BACKGROUND

Online pharmacies are used less than other e-commerce sites in Germany. Shopping behavior does not correspond to consumption behavior, as online purchases are predominantly made for over-the-counter (OTC) medications.

OBJECTIVE

The objective of this study was to understand the purchasing experiences of online pharmacy customers in terms of critical factors for online pharmacy adoption.

METHODS

This study examined the perceived risk, perceived trust, and emotions related to purchasing medications online and, consequently, the purchase intention toward online pharmacies. In a within-subjects design (N=37 participants), 2 German online pharmacies with different perceptions of risk and trust were investigated for their main business, namely OTC and prescription drugs. The results of a preliminary study led to 1 online pharmacy with high and 1 with significantly low self-reported risk by the prestudy sample. Emotions were measured with a multimethod approach during and after the purchase situation as follows: (1) neural evaluation processes using functional near-infrared spectroscopy, (2) the automated direct motor response during the use of the online pharmacy via facial expression analysis (FaceReader), and (3) subjective evaluations through self-reports. Following the shopping experiences at both pharmacies for both product types, risk, trust, and purchase intention toward the pharmacies were assessed using self-assessments.

RESULTS

The 2 online pharmacies were rated differently in terms of risk, trust, emotions, and purchase intention. The high-risk pharmacy was also perceived as having lower trust and vice versa. Significantly stronger negative emotional expressions on customers' faces and different neural activations in the ventromedial prefrontal cortex and dorsomedial prefrontal cortex were measured when purchasing prescription drugs from the high-risk pharmacy than from the low-risk pharmacy, combined with OTC medications. In line with this, customers' self-ratings indicated higher negative emotions for the high-risk pharmacy and lower negative emotions for the low-risk pharmacy. Moreover, the ratings showed lower purchase intention for the high-risk pharmacy.

CONCLUSIONS

Using multimethod measurements, we showed that the preceding neural activation and subsequent verbal evaluation of online pharmacies are reflected in the customers' immediate emotional facial expressions. High-risk online pharmacies and prescription drugs lead to stronger negative emotional facial expressions and trigger neural evaluation processes that imply perceived loss. Low-risk online pharmacies and OTC medications lead to weaker negative emotional facial expressions and trigger neural evaluation processes that signify certainty and perceived reward. The results may provide an explanation for why OTC medications are purchased online more frequently than prescription medications.

Predicting Perceived Hedonic Ratings through Facial Expressions of Different Drinks

Previous studies have established the utility of facial expressions as an objective assessment approach for determining the hedonics (overall pleasure) of food and beverages. This study endeavors to validate the conclusions drawn from preceding research, illustrating that facial expressions prompted by tastants possess the capacity to forecast the perceived hedonic ratings of these tastants. Facial expressions of 29 female participants, aged 18-55 years, were captured using a digital camera during their consumption of diverse concentrations of solutions representative of five basic tastes. Employing the widely employed facial expression analysis application FaceReader, the facial expressions were meticulously assessed, identifying seven emotions (surprise, happiness, scare, neutral, disgust, sadness, and anger) characterized by scores ranging from 0 to 1-a numerical manifestation of emotional intensity. Simultaneously, participants rated the hedonics of each solution, utilizing a scale spanning from -5 (extremely unpleasant) to +5 (extremely pleasant). Employing a multiple linear regression analysis, a predictive model for perceived hedonic ratings was devised. The model's efficacy was scrutinized by assessing emotion scores from 11 additional taste solutions, sampled from 20 other participants. The anticipated hedonic ratings demonstrated robust alignment and agreement with the observed ratings, underpinning the validity of earlier findings even when incorporating diverse software and taste stimuli across a varied participant base. We discuss some limitations and practical implications of our technique in predicting food and beverage hedonics using facial expressions.

Children's physiological and behavioural response evoked by the observation, olfaction, manipulation, and consumption of food textures. Part 1: Liquid products

Children are thought to prefer homogeneous and simple textures that are easy to manipulate in the mouth. Although scientific research has been done on children's acceptance for food textures, there is a lack of knowledge regarding the emotional response elicited by textures in this group of population. Physiological and behavioural methods could be an appropriate approach to measure food-evoked emotions in children since they require a low cognitive effort and allow a real-time measure. In this regard, a study that combined the measure of skin conductance response (SCR) and facial expressions was conducted: (i) to provide a first insight into food-evoked emotions induced by liquid food products that only vary in texture, (ii) to capture the emotional response evoked by the observation, olfaction, manipulation, and consumption of the products, and (iii) to overcome methodological drawbacks that are frequently associated to these methods. To achieve these goals, 50 children (5-12 yrs old) evaluated three liquids designed to only vary in texture (from slightly thick to extremely thick), following four sensory tasks: observation, olfaction, manipulation, and consumption. After each sample was tasted, children rated liking with a 7-pt hedonic scale. Facial expressions and SCR were monitored during the test, and they were analysed as action units (AUs) and basic emotions as well as changes in SCR. Results showed that the extremely thick liquid was less liked by the children and induced a more negative emotional response, whereas the slightly thick liquid was more liked and evoked a more positive emotional response. The combined method used in this study showed good discrimination ability among the three samples tested, obtaining the best discrimination during the manipulation task. The codification of the AUs located in the upper side of the face allowed us to measure the emotional response evoked by the consumption of the liquids, without the artifacts caused by the oral processing of the products. This study provides a child-friendly approach to be used during the sensory evaluation of food products in a broad range of sensory tasks minimising the methodological drawbacks.

Emotional responses to taste and smell stimuli: Self-reports, physiological measures, and a potential role for individual and genetic factors

Taste and olfaction elicit conscious feelings by direct connection with the neural circuits of emotions that affects physiological responses in the body (e.g., heart rate and skin conductance). While sensory attributes are strong determinants of food liking, other factors such as emotional reactions to foods may be better predictors of consumer choices even for products that are equally-liked. Thus, important insights can be gained for understanding the full spectrum of emotional reactions to foods that inform the activities of product developers and marketers, eating psychologist and nutritionists, and policy makers. Today, self-reported questionnaires and physiological measures are the most common tools applied to study variations in emotional perception. The present review discusses these methodological approaches, underlining their different strengths and weaknesses. We also discuss a small, emerging literature suggesting that individual differences and genetic variations in taste and smell perception, like the genetic ability to perceive the bitter compound PROP, may also play a role in emotional reactions to aromas and foods.

Specifics of the Emotional Response of Patients Suffering From Major Depressive Disorder to Imagined Basic Tastes of Food

Nowadays, the major depressive disorder (MDD) is a common disease that negatively affects the life quality of many people around the world. As MDD symptoms are closely related with the changes in food and eating, the relation between patients’ emotional responses and food tastes could be used as criteria for diagnostic. Until now, studies on the emotional response to different food tastes for patients affected by MDD have been poorly described in literature. Therefore, the aim of this study was to evaluate the emotional response of patients suffering from MDD to the imagined different food tastes and to compare the results with a control group. Emotional responses in tested participants were induced by using cards with words of basic food tastes such as “sweet,” “salty,” “bitter,” “sour,” and “neutral.” The assessment of emotional response was performed with FaceReader 6 software. The outcome of this study showed that participants with MDD expressed lower “happy” and “contempt” and higher “surprised” emotions, along with a higher negative valence mean, in comparison with controls for all tested basic tastes of food (p ≤ 0.05). When Likert scale was used, significant differences (p ≤ 0.001) in response were only found for “sour” and “salty” imaginary tastes between healthy group and patients with MDD. The findings of this study provide the additional data on food–associated emotion analysis of MDD patients and could be useful for the further development of the contactless method for early diagnosis of MDD.

Characteristics of Nutraceutical Chewing Candy Formulations Based on Fermented Milk Permeate, Psyllium Husk, and Apple By-Products

The aim of this study was to develop nutraceutical chewing candy (CCN) formulations based on fermented milk permeate (MP) (source of galactooligosaccharides (GOS) and viable lactic acid bacteria (LAB)), psyllium husk (source of desirable hydrocolloids), and apple by-products (source of phenolic compounds). For CCN preparation, gelatin (Gel) and agar were tested; also, to provide CCN prepared using agar with a desirable hard texture, citric acid (cit) was changed to ascorbic acid. To select the optimal quantities of the ingredients, overall acceptability (OA) and emotions (EMs) induced in consumers by different CCN formulations were evaluated. Furthermore, viable LAB count during storage, texture, colour, and antioxidant characteristics were analysed. The highest OA (score 8.5) was shown for samples consisting of MP, psyllium husk (Ph), apple by-products (App), cit and xylitol (Xy); a very strong correlation was found between OA and the EM “happy” (r = 0.907**). After 14 days of storage, Gel+MP+Ph+App+cit samples showed a LAB count higher than 6.0 log₁₀ CFU g⁻¹; however, better antioxidant properties were found for the CCN prepared with agar. Finally, it can be stated that fermented MP, Ph, and App can be used for preparation of added-value CCN in a sustainable manner, and the recommended formulation is Gel+ MP+Ph+App+cit+Xy.

Self-Reported Emotions and Facial Expressions on Consumer Acceptability: A Study Using Energy Drinks

Emotional responses elicited by foods are of great interest for new product developers and marketing professionals, as consumer acceptance proved to be linked to the emotions generated by the product in the consumers. An emotional measurement is generally considered an appropriate tool to differentiate between the products of similar nutritional value, flavour, liking and packaging. Novel methods used to measure emotions include self-reporting verbal and visual measurements, and facial expression techniques. This study aimed to evaluate the explicit and implicit emotional response elicited during the tasting of two different brands (A and B) of energy drinks. The explicit response of consumers was assessed using liking (nine-point hedonic scale), and emotions (EsSense Profile^®—Check-All-That-Apply questionnaire), and implicit emotional responses were evaluated by studying facial expressions using the Affectiva Affdex^® software. The familiarity of the product and purchase intent were also assessed during the study. The hedonic rating shows a significant difference in liking between the two brands of energy drink during the tasting session. For the explicit emotional responses, participants elicited more positive emotions than the negative emotions for both energy drinks. However, participants expressed “happy”, “active” and “eager” emotions more frequently for energy drink A. On the other hand, the implicit emotional responses through facial expressions indicated a high level of involvement of the participants with energy drink B as compared to energy drink A. The study showed that overall liking and the explicit and implicit emotional measurements are weakly to moderately correlated.

Development of a direct mapping model between hedonic rating and facial responses by dynamic facial expression representation

Consumer tests are one of the most important activities in product development. More evidence indicates that consumer emotions in real life are mostly driven by unconscious mechanisms, and implicit measurements are regarded as beneficial by an increasing number of sensory and consumer scientists. Nonverbal manner such as facial expression analysis is a supplement to the declarative method and brings very insightful results. Up until now, the facial expression analysis for consumers' acceptance identification is limited to investigate the relationship between hedonic rating and facial expression descriptors, such as facial coding system (FACS or MAX), discrete facial expressions (i.e. happiness, sadness, surprise, fear, anger, and disgust), and affective dimensional model (valence and activation). In this study, we attempt to develop a direct mapping model between the hedonic rating and facial responses evoked by various taste stimuli. Basic taste solutions (sourness, sweetness, bitterness, umami, and saltiness) with six levels, and five types of juice are used as stimuli. Firstly, the hedonic rating categories are defined based on the nine-point hedonic scale, with a coarse-to-fine division of scale levels based on two directions of like and dislike. Secondly, the facial dynamic optical flow method is employed to analyze facial characteristics of the subjects' facial responses evoked by taste stimuli. And the genetic algorithm is conducted to select facial regions that have high contribution to hedonic rating identification. It indicates that the texture changes of eye area, wrinkles at the nasal root, and mouth area can effectively reflect the facial reaction corresponding to hedonic rating. The research shows that it is feasible to establish a direct mapping model between hedonic rating and facial responses. The hedonic rating can be predicted through automatic facial reading technology, without extra transformation from predefined emotional models. In general, this is the first try to discuss the direct prediction of hedonic rating through facial expressions up to now, and it is a complex problem due to various influence factors.

Multimodal affect analysis of psychodynamic play therapy

Objective: We explore state of the art machine learning based tools for automatic facial and linguistic affect analysis to allow easier, faster, and more precise quantification and annotation of children's verbal and non-verbal affective expressions in psychodynamic child psychotherapy. Method: The sample included 53 Turkish children: 41 with internalizing, externalizing and comorbid problems; 12 in the non-clinical range. We collected audio and video recordings of 148 sessions, which were manually transcribed. Independent raters coded children's expressions of pleasure, anger, sadness and anxiety using the Children's Play Therapy Instrument (CPTI). Automatic facial and linguistic affect analysis modalities were adapted, developed, and combined in a system that predicts affect. Statistical regression methods (linear and polynomial regression) and machine learning techniques (deep learning, support vector regression and extreme learning machine) were used for predicting CPTI affect dimensions. Results: Experimental results show significant associations between automated affect predictions and CPTI affect dimensions with small to medium effect sizes. Fusion of facial and linguistic features work best for pleasure predictions; however, for other affect predictions linguistic analyses outperform facial analyses. External validity analyses partially support anger and pleasure predictions. Discussion: The system enables retrieving affective expressions of children, but needs improvement for precision.

The State of Automated Facial Expression Analysis (AFEA) in Evaluating Consumer Packaged Beverages

In the late 1970s, analysis of facial expressions to unveil emotional states began to grow and flourish along with new technologies and software advances. Researchers have always been able to document what consumers do, but understanding how consumers feel at a specific moment in time is an important part of the product development puzzle. Because of this, biometric testing methods have been used in numerous studies, as researchers have worked to develop a more comprehensive understanding of consumers. Despite the many articles on automated facial expression analysis (AFEA), literature is limited in regard to food and beverage studies. There are no standards to guide researchers in setting up materials, processing data, or conducting a study, and there are few, if any, compilations of the studies that have been performed to determine whether any methodologies work better than others or what trends have been found. Through a systematic Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) review, 38 articles were found that were relevant to the research goals. The authors identified AFEA study methods that have worked and those that have not been as successful and noted any trends of particular importance. Key takeaways include a listing of commercial AFEA software, experimental methods used within the PRISMA analysis, and a comprehensive explanation of the critical methods and practices of the studies analyzed. Key information was analyzed and compared to determine effects on the study outcomes. Through analyzing the various studies, suggestions and guidance for conducting and analyzing data from AFEA experiments are discussed.

Influences of sensory attribute intensity, emotional responses, and non-sensory factors on purchase intent toward mixed-vegetable juice products under informed tasting condition

Product-related sensory and non-sensory cues have been studied in the past to understand purchase behavior among consumers. However, there has been little research related to integrating emotional responses with such cues to achieve better prediction of consumer purchase behavior. This study aimed to determine the impacts of sensory attribute intensities (SAI), non-sensory factors (NSF), and emotions on purchase intent and consumer choice. Emotional responses were measured using a self-reported emotion questionnaire (EQ), facial expression analysis (FE), and autonomic nervous system responses (ANS). Sixty-nine adults were asked to view product labels, and look at, smell, and drink five commercially-available vegetable juice samples. For each sample, SAI, NSF, EQ, FE, ANS, and purchase intent ratings were measured. Participants were also asked to select the one they would be most likely to buy. Results showed that the five samples differed significantly with respect to SAI, NSF, and emotional responses measured by EQ and FEs. SAI (bitterness intensity) and NSF (brand liking) played an extremely important role in purchase-related behavior of vegetable juice products. Correlation analysis and a PLSR prediction model further revealed that products with higher ratings of purchase intent elicited lower levels of negative emotions and higher levels of positive emotions, as measured by EQ as well as FE. In conclusion, this study shows that NSF in combination with SAI and emotions measured using EQ and FE can modulate consumer purchase intent toward vegetable juice products under informed tasting conditions.

An unfamiliar social presence reduces facial disgust responses to food stimuli

Consumers' emotional responses complement sensory and hedonic ratings in the prediction of food choice and consumption behaviour. The challenge with the measurement of consumption emotions is that emotions are highly context dependent. For emotion evaluations to bring greater insight to food research and development, it is essential that the influence of contextual variables on emotion are quantified. The present study contributes to the discussion with an investigation of the effect of an unfamiliar social presence on affective facial responses to visual food stimuli. Seventy participants (52 female and 18 male) viewed food images of varying acceptability either alone, or in the presence of the researcher. Subjective liking ratings were measured using a labelled affective magnitude scale, and facial muscle activity from zygomaticus major (contracted during smiling), corrugator supercilii (contracted during frowning) and levator labii superioris (contracted during nose wrinkling) were measured with an EMG recording system. Controlling for individual differences in facial expressivity and food image acceptability using linear mixed models, it was found that social context did not predict smiling or frowning muscle activity. Social context did predict the intensity of muscle activity indicative of a disgust response, with participants in the observed condition exhibiting less levator activity than participants in the alone condition. Regardless of social context, each muscle was found to have a relationship with subjective liking, with the direction of effects as expected. The results indicate that emotional stimuli and social context both influence food-evoked facial expression and provides support for the utility of facial EMG in measuring food-evoked emotion.

Physiological Responses to Basic Tastes for Sensory Evaluation of Chocolate Using Biometric Techniques

Facial expressions are in reaction to basic tastes by the response to receptor stimulation. The objective of this study was to assess the autonomic nervous system responses to basic tastes in chocolates and to identify relationships between conscious and unconscious responses from participants. Panelists (n = 45) tasted five chocolates with either salt, citric acid, sugar, or monosodium glutamate, which generated four distinctive basic tastes plus bitter, using dark chocolate. An integrated camera system, coupled with the Bio-Sensory application, was used to capture infrared thermal images, videos, and sensory responses. Outputs were used to assess skin temperature (ST), facial expressions, and heart rate (HR) as physiological responses. Sensory responses and emotions elicited during the chocolate tasting were evaluated using the application. Results showed that the most liked was sweet chocolate (9.01), while the least liked was salty chocolate (3.61). There were significant differences for overall liking (p < 0.05) but none for HR (p = 0.75) and ST (p = 0.27). Sweet chocolate was inversely associated with angry, and salty chocolate positively associated with sad. Positive emotion-terms were associated with sweet samples and liking in self-reported responses. Findings of this study may be used to assess novel tastes of chocolate in the industry based on conscious and emotional responses more objectively.

Personality traits affect the influences of intensity perception and emotional responses on hedonic rating and preference rank toward basic taste solutions

This study aimed at determining, based on independent predictors of taste intensity and emotional response, whether individual personality traits could affect prediction models of overall liking and preference rank toward basic taste solutions. Sixty-seven participants rated taste intensities (TI) of four basic-taste solutions at both low and high concentrations, and of plain water. Emotional responses toward each sample were measured using a self-reported emotion questionnaire (SE), facial expressions (FE), and/or autonomic nervous system responses (ANS). Participants rated overall liking of the samples and ranked their preferences. Based on the results of a hierarchical cluster analysis of five personality traits measured using the Big Five Inventory, participants were classified into two clusters: cluster N (high neuroticism) and cluster E (high extraversion). Results showed that the SE measure for both clusters N and E was better than the TI, FE, and ANS measures in explaining variances of overall liking or preference rank. A measurement of effect size found that using FE and/or taste intensity measures, along with self-reported emotion measure, could enhance model predictability of overall liking or preference rank toward taste samples for cluster N, while the contribution to the prediction model for cluster E was minimal. ANS measures showed little contribution to the prediction model of overall liking for either cluster. In conclusion, this study shows that personality traits, in particular traits of extraversion and neuroticism, affect not only optimum measures of emotional responses, but also modulate predicting overall liking and preference rank toward basic taste solutions.

Acceptability of placebo multiparticulate formulations in children and adults

Patient acceptability is an important consideration in the design of medicines for children. The aim of this study was to investigate acceptability of multiparticulates in healthy children and adults. A randomised, single-blind acceptability testing was performed involving 71 children (4-12 years) and 61 adults (18-37 years). Each participant received three 500 mg samples of microcrystalline cellulose pellets administered on a medicine spoon with water at 5-10 minutes intervals. Acceptability was measured based on voluntary intake of the samples, facial expressions, ratings on hedonic scales and reported willingness to take multiparticulates everyday as a medicine. Multiparticulates were voluntarily swallowed by 92% of children and 100% of adults. However, palatability issues were identified, with emphasis on textural aspects. Grittiness perception received negative ratings on hedonic scales by 60% of children and 51% of adults. Researcher observations revealed that 72% of children and 42% of adults displayed negative facial expressions towards the samples. Children reported their willingness to take multiparticulates as a medicine in 30% of the cases, compared to 74% in adults. This study demonstrates that multiparticulates may be a suitable formulation platform for children and adults, although palatability concerns have been highlighted. Additional work is required to define acceptability criteria and to standardise methodologies.

Methods for Evaluating Emotions Evoked by Food Experiences: A Literature Review

Besides sensory characteristics of food, food-evoked emotion is a crucial factor in predicting consumer's food preference and therefore in developing new products. Many measures have been developed to assess food-evoked emotions. The aim of this literature review is (i) to give an exhaustive overview of measures used in current research and (ii) to categorize these methods along measurement level (physiological, behavioral, and cognitive) and emotional processing level (unconscious sensory, perceptual/early cognitive, and conscious/decision making) level. This 3 × 3 categorization may help researchers to compile a set of complementary measures (“toolbox”) for their studies. We included 101 peer-reviewed articles that evaluate consumer's emotions and were published between 1997 and 2016, providing us with 59 different measures. More than 60% of these measures are based on self-reported, subjective ratings and questionnaires (cognitive measurement level) and assess the conscious/decision-making level of emotional processing. This multitude of measures and their overrepresentation in a single category hinders the comparison of results across studies and building a complete multi-faceted picture of food-evoked emotions. We recommend (1) to use widely applied, validated measures only, (2) to refrain from using (highly correlated) measures from the same category but use measures from different categories instead, preferably covering all three emotional processing levels, and (3) to acquire and share simultaneously collected physiological, behavioral, and cognitive datasets to improve the predictive power of food choice and other models.

Validity of assessing child feeding with virtual reality

Assessment of parents' child feeding behavior is challenging, and there is need for additional methodological approaches. Virtual reality technology allows for the creation of behavioral measures, and its implementation overcomes several limitations of existing methods. This report evaluates the validity and usability of the Virtual Reality (VR) Buffet among a sample of 52 parents of children aged 3-7. Participants served a meal of pasta and apple juice in both a virtual setting and real-world setting (counterbalanced and separated by a distractor task). They then created another meal for their child, this time choosing from the full set of food options in the VR Buffet. Finally, participants completed a food estimation task followed by a questionnaire, which assessed their perceptions of the VR Buffet. Results revealed that the amount of virtual pasta served by parents correlated significantly with the amount of real pasta they served, rs = 0.613, p < .0001, as did served amounts of virtual and real apple juice, rs = 0.822, p < .0001. Furthermore, parents' perception of the calorie content of chosen foods was significantly correlated with observed calorie content (rs = 0.438, p = .002), and parents agreed that they would feed the meal they created to their child (M = 4.43, SD = 0.82 on a 1-5 scale). The data presented here demonstrate that parent behavior in the VR Buffet is highly related to real-world behavior, and that the tool is well-rated by parents. Given the data presented and the potential benefits of the abundant behavioral data the VR Buffet can provide, we conclude that it is a valid and needed addition to the array of tools for assessing feeding behavior.

Correlation between hedonic liking and facial expression measurement using dynamic affective response representation

Emotional reactions towards products play an essential role in consumers' decision making, and are more important than rational evaluation of sensory attributes. It is crucial to understand consumers' emotion, and the relationship between sensory properties, human liking and choice. There are many inconsistencies between Asian and Western consumers in the usage of hedonic scale, as well as the intensity of facial reactions, due to different culture and consuming habits. However, very few studies discussed the facial responses characteristics of Asian consumers during food consumption. In this paper, explicit liking measurement (hedonic scale) and implicit emotional measurement (facial expressions) were evaluated to judge the consumers' emotions elicited by five types of juices. The contributions of this study included: (1) Constructed the relationship model between hedonic liking and facial expressions analyzed by face reading technology. Negative emotions "sadness", "anger", and "disgust" showed noticeable high negative correlation tendency to hedonic scores. The "liking" hedonic scores could be characterized by positive emotion "happiness". (2) Several emotional intensity based parameters, especially dynamic parameter, were extracted to describe the facial characteristic in sensory evaluation procedure. Both amplitude information and frequency information were involved in the dynamic parameters to remain more information of the emotional responses signals. From the comparison of four types of emotional descriptive parameters, the maximum parameter and dynamic parameter were suggested to be utilized for representing emotional state and intensities.

Is food refusal in autistic children related to TAS2R38 genotype?

Several studies suggest that atypical eating behaviors, in particular food selectivity, are more frequent in children with autism spectrum disorder (ASD). A link between bitter taste perception, namely PROP/PTC sensitivity and food preferences is known in healthy children. The aim of this study is to investigate whether genetic variants of the TAS2R38 taste receptor responsible for different bitter sensitivity could affect foods preferences and consequently food refusal in ASD children. We recruited 43 children with ASD and 41 with normotypic development (TD) with or without food selectivity, aged between 2 and 11 years. Children were characterized for bitter sensitivity by means of PROP strips and FACS analysis and genotyped for TAS2R38 polymorphisms. Food selectivity was assessed by a validated food preference questionnaire filled by parents. A statistically significant correlation between PROP sensitivity and food refusal was observed. Furthermore, a prevalence of the PAV-sensitive haplotype compared to the AVI-insensitive one was seen in ASD children with food selectivity. In agreement with the initial hypothesis the results show that food refusal in ASD children is mediated by bitter taste sensitivity thus suggesting that the bitter sensitivity test may be used as a device to orientate tailored food proposals for the practical management of food selectivity in ASD. Autism Res 2018, 11: 531-538. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

LAY SUMMARY

A variation of the gene TAS2R38, associated with bitter taste sensitivity, can cause a different perception of some foods. In particular, some children are hypersensitive to bitterness and show a more restricted repertoire of accepted foods. We evaluate bitter sensitivity in ASD children with or without food selectivity, through a simple bitter taste test with edible strips. The results show that food refusal in ASD children can be mediated by bitter taste sensitivity thus suggesting that the bitter sensitivity test may be used as a device to orientate tailored food proposals for the practical management of food selectivity in ASD.

Predicting consumer liking and preference based on emotional responses and sensory perception: A study with basic taste solutions

Traditional methods of sensory testing focus on capturing information about multisensory perceptions, but do not necessarily measure emotions elicited by these food and beverages. The objective of this study was to develop an optimum model of predicting overall liking (rating) and preference (choice) based on taste intensity and evoked emotions. One hundred and two participants (51 females) were asked to taste water, sucrose, citric acid, salt, and caffeine solutions. Their emotional responses toward each sample were measured by a combination of a self-reported emotion questionnaire (EsSense25), facial expressions, and autonomic nervous system (ANS) responses. In addition, their perceived intensity and overall liking were measured. After a break, participants re-tasted the samples and ranked them according to their preference. The results showed that emotional responses measured using self-reported emotion questionnaire and facial expression analysis along with perceived taste intensity performed best to predict overall liking as well as preference, while ANS measures showed limited contribution. Contrary to some previous research, this study demonstrated that not only negative emotions, but also positive ones could help predict consumer liking and preference. In addition, since there were subtle differences in the prediction models of overall liking and preference, both aspects should be taken into account to understand consumer behavior. In conclusion, combination of evoked emotions along with sensory perception could help better understand consumer acceptance as well as preference toward basic taste solutions.

Development of a new in-home testing method to assess infant food liking

The objective of this study was to develop a new elaborate method to evaluate infants' liking of foods that could be applied at home and to compare the results of this elaborate method with those of a basic method. Mothers of infants aged 4 to 7 (n = 44) and 12-15 months (n = 46) participated in this study. For the basic method, mothers were asked to assess their infant's global liking at the end of a meal. Then, for the elaborate method, mothers received detailed instructions on how to feed their infant, how infants might express like/dislike and when to stop the meal. During the first nine spoons, they were asked to report the presence/absence of positive and negative behaviours after each spoon, and the infant's initial liking was reported after each triplet of spoons. They also assessed their infant's global liking at the end of the meal. Both methods were applied using three commercial familiar baby foods adapted to each age range. In 4-7-month-olds, the elaborate method showed a significant difference across products for liking, whereas the basic method did not show any difference. In 12-15-month-olds, the elaborate method showed more differences across products for liking than the basic method. In both age groups, negative behaviours, despite being less frequently reported, provided better liking discrimination than positive behaviours. In conclusion, the elaborate method produced better product liking discrimination than the basic method by focusing maternal attention on infants' eating behaviours since the first spoons.

Asians' Facial Responsiveness to Basic Tastes by Automated Facial Expression Analysis System

Growing evidence shows that consumer choices in real life are mostly driven by unconscious mechanisms rather than conscious. The unconscious process could be measured by behavioral measurements. This study aims to apply automatic facial expression analysis technique for consumers' emotion representation, and explore the relationships between sensory perception and facial responses. Basic taste solutions (sourness, sweetness, bitterness, umami, and saltiness) with 6 levels plus water were used, which could cover most of the tastes found in food and drink. The other contribution of this study is to analyze the characteristics of facial expressions and correlation between facial expressions and perceptive hedonic liking for Asian consumers. Up until now, the facial expression application researches only reported for western consumers, while few related researches investigated the facial responses during food consuming for Asian consumers. Experimental results indicated that facial expressions could identify different stimuli with various concentrations and different hedonic levels. The perceived liking increased at lower concentrations and decreased at higher concentrations, while samples with medium concentrations were perceived as the most pleasant except sweetness and bitterness. High correlations were founded between perceived intensities of bitterness, umami, saltiness, and facial reactions of disgust and fear. Facial expression disgust and anger could characterize emotion "dislike," and happiness could characterize emotion "like," while neutral could represent "neither like nor dislike." The identified facial expressions agree with the perceived sensory emotions elicited by basic taste solutions. The correlation analysis between hedonic levels and facial expression intensities obtained in this study are in accordance with that discussed for western consumers.

Implicit and Explicit Measurements of Affective Responses to Food Odors

One of the main functions of olfaction is to activate approach/avoidance behavior, toward or away from people, foods, or other odor sources. These behaviors are partly automated and therefore poorly accessible via introspection. Explicit tests need therefore be complemented by implicit tests to provide additional insights into the underlying processes of these behaviors. Affective responses to seven food odors plus one control nonodor were assessed in 28 female participants (18-30 years) using explicit tests [pleasantness, intensity, and non-verbal emotional ratings (PrEmo)] as well as implicit tests that reflect dynamic expressive emotional reactions (facial expressions) as well as behavioral-preparation responses (autonomic nervous system responses: heart rate, skin conductance, and skin temperature). Explicit tests showed significant differences in pleasantness (P < 0.05), and all PrEmo emotions (P < 0.05) except shame. Explicit emotional responses were summarized by valence (explaining 83% of the responses variance) and arousal (14%) as principal components. Early implicit facial and ANS responses (after 1s) seem to reflect the odors' arousal, whereas later ANS responses (after 3-4s) reflected the odors' valence. The results suggest that explicit measures primarily reflect the odors' valence, as result of from relatively long (conscious) processing, which may be less relevant for odor acceptance in the real world where fast and automated processes based on arousal may play a larger role.