Lukas Danner

Facial expressions and autonomous nervous system responses elicited by tasting different juices

The aim of this study was to get a better understanding of reactions elicited by the taste of foods using the example of different juices. The reactions investigated were the rating behavior of self-reported spontaneous liking, various autonomous nervous system (ANS) responses and implicit as well as explicit facial expressions. Therefore, the following four hypotheses were tested: 1) Different sensory stimuli of juices elicit different ANS responses. 2) Differences in facial expressions elicited by sensory stimuli of juices used in an implicit and explicit measurement approach can be detected by using FaceReader 5. 3) Self-reported liking is correlated with the measured ANS parameters and the elicited facial expressions. 4) The measured ANS parameters, facial expressions and self-reported liking allow identical differentiations between samples. Skin conductance level (SCL), skin temperature (ST), heart rate (HR), pulse volume amplitude (PVA) and the facial expressions of 81 participants were analyzed during and shortly after tasting juice samples (implicit measurement approach). Additionally, participants were asked to show how much they liked the tasted sample with an intentional facial expression (explicit measurement approach). Banana, grapefruit, mixed vegetable, orange and sauerkraut juices were used as sensory stimuli. The juices elicited significant differences in SCL and PVA responses and intensities of several facial expressions. For these parameters a moderate correlation with self-reported liking was found, allowing a differentiation between liked, disliked and neutral rated samples. The results show that self-reported liking cannot simply be explained by the measured ANS and implicit facial expression parameters, instead providing different information. Significant differences in facial expressions between the implicit and explicit approach were observed. In the implicit approach participants showed hardly any positive emotions when tasting samples they liked, whereas in the explicit approach they displayed a high degree of positive emotions. In both cases negative emotions were shown more intensely for disliked samples.

Make a choice! Visual attention and choice behaviour in multialternative food choice situations

This study investigates the relationship between gazing behaviour and choice decision in multialternative forced choice tasks, focusing on the consistency across different food product groups including apple, beer, bread, chocolate, instant soup, salad, sausage, and soft drink. Each choice task consisted of pictures of four alternatives, similar in familiarity and liking ratings, of the corresponding product group. A Tobii T60 eye-tracker was used to present the stimuli and to analyse the gazing behaviour of 59 participants during decision-making. The results showed strong correlations between choice and gazing behaviour, in forms of more fixation counts, longer total dwell duration, and more dwell counts on the chosen alternative. No correlations for first fixation, time to first fixation, and first fixation duration were observed. These results were consistent across the eight tested product groups.

Eye Tracking in Consumer Research

Abstract This chapter provides a general overview of eye-tracking techniques and their applications in consumer research with a focus on the food area. First, the scientific approaches leading to the development of eye trackers are described, followed by a review of the principles and technical solutions of measuring gazing behavior. After a description of the factors influencing gaze behavior and a discussion of the relation between gaze, choice, and decision-making we present applications of eye tracking in the fields of packaging, label and menu design, in-store consumer behavior, emotional responses, and eating disorders. Finally, we discuss a case study involving the use of eye tracking for studying consumer food choice in more detail.

Comparison of Rate-All-That-Apply and Descriptive Analysis for the Sensory Profiling of Wine

The aim of this work was to investigate how useful the Rate-All-That-Apply (RATA) method with naive consumers is to profile a wide range of wines and how the sensory profiles obtained compare with those of classic descriptive analysis (DA). For this purpose, we conducted two studies. Study 1 presents preliminary work comparing the discrimination ability of RATA, undertaken by 84 naive consumers, with a traditional DA with 11 trained panelists. The vocabulary lists remained the same across the two methods, and the assessment was based on a set of six red table wines (from six different varieties). Study 2 aimed to further elucidate the discrimination ability of RATA with 71 naive consumers compared with traditional DA. It expanded on Study 1 by increasing the number of samples assessed (12 white table wines from six varieties) and by varying the vocabulary between methods (RATA used a generic white wine attribute list and the DA used a panel-generated attribute list). In addition, similarity of sample configuration in the sensory space between RATA and DA was assessed by means of multiple factor analysis (MFA) and regression vector (RV) coefficients. The results of both studies revealed that RATA and DA are highly similar in sample discrimination ability (in terms of number of attributes significantly discriminating among samples). Furthermore, the MFA indicated high agreement in sample configuration between RATA and DA, reinforced by highly significant RV coefficients of 0.97 for Study 1 and 0.92 for Study 2. Overall, this observation supports a trend toward more consumer-centric approaches for sensory profiling and suggests that RATA could be a valid, accurate, and rapid addition to existing profiling methods used for wine.

Automatic Facial Expressions Analysis in Consumer Science

Abstract This chapter provides an overview of the current state of automatic facial expression analysis and its application in the field of consumer research. The first part briefly reviews the significance of facial expressions as a means of nonverbal communication of emotions and their relevance in consumer research. The second part provides an overview of conventional and automatic facial expression analysis methods and discusses their advantages as well as their limitations. The third part describes selected published studies applying automatic facial expression analysis in the field of consumer research and concludes with future research directions.