Measuring wanting and liking from animals to humans: A systematic review

Animal research has shown it is possible to want a reward that is not liked once obtained. Although these findings have elicited interest, human experiments have produced contradictory results, raising doubts about the existence of separate wanting and liking influences in human reward processing. This discrepancy could be due to inconsistences in the operationalization of these concepts. We systematically reviewed the methodologies used to assess human wanting and/or liking and found that most studies operationalized these concepts in congruency with the animal literature. Nonetheless, numerous studies operationalized wanting in similar ways to those that operationalized liking. These contradictions might be driven by a major source of confound: expected pleasantness. Expected pleasantness underlies cognitive desires and does not correspond to animal liking, a hedonic experience, or to animal wanting, which relies on affective relevance, consisting of the perception of a cue associated with a relevant reward for the organism’s current physiological state. Extending the concept of affective relevance and differentiating it from expected pleasantness might improve measures of human wanting and liking

Mindful regulation of positive emotions: a comparison with reappraisal and expressive suppression

It is often acknowledged that mindfulness facilitates emotion regulation on a long-term scale. Only few empirical studies support the hypothesis that even a brief mindfulness induction among subjects without previous experience of meditation allows an effective reduction of both positive and negative emotions. To the best of our knowledge, this hypothesis has never been tested when comparing mindfulness to other regulation strategies known to be effective. The current study investigates the effects of mindfulness, reappraisal and expressive suppression during the regulation of positive emotions. Forty-five participants without previous meditation experience watched four positive video clips while applying a specific regulation strategy: mindful attention, reappraisal, expressive suppression or no strategy (control condition). Video clips were matched for intensity and positive emotions index. Each of them was evaluated on two dimensions, valence (negative/positive) and arousal (calming/exciting). Moreover, participants’ facial expressions were recorded during the presentation of the video clips. Results showed that (a) participants report less positive affect in reappraisal and mindful attention conditions compared to expression suppression and a control condition; and (b) the facialexpression – activation of AU12 (lip corner pull) and AU6 (cheek raiser) – varies with the regulation strategy applied. Results demonstrate the effectiveness of mindfulness in decreasing both the evaluative judgment of positive video clips and the related facial expression, among participants without previous mindfulness experience

Variability of Affective Responses to Odors: Culture, Gender, and Olfactory Knowledge

Emotion and odor scales (EOS) measuring odor-related affective feelings were recently developed for three different countries (Switzerland, United Kingdom, and Singapore). The first aim of this study was to investigate gender and cultural differences in verbal affective response to odors, measured with EOS and the usual pleasantness scale. To better understand this variability, the second aim was to investigate the link between affective reports and olfactory knowledge (familiarity and identification). Responses of 772 participants smelling 56-59 odors were collected in the three countries. Women rated odors as more intense and identified them better in all countries, but no reliable sex differences were found for verbal affective responses to odors. Disgust-related feelings revealed odor-dependent sex differences, due to sex differences in identification and categorization. Further, increased odor knowledge was related to more positive affects as reported with pleasantness and odor-related feeling evaluations, which can be related to top-down influences on odor representation. These top-down influences were thought, for example, to relate to beliefs about odor properties or to categorization (edible vs. nonedible). Finally, the link between odor knowledge and olfactory affect was generally asymmetrical and significant only for pleasant odors, not for unpleasant ones that seemed to be more resistant to cognitive influences. This study, for the first time using emotional scales that are appropriate to the olfactory domain, brings new insights into the variability of affective responses to odors and its relationship to odor knowledg

Emotional Processing of Odors: Evidence for a Nonlinear Relation between Pleasantness and Familiarity Evaluations

Pleasantness, familiarity, and intensity are 3 interdependent dimensions commonly used to describe the perceived qualities of an odor. In particular, many empirical studies have demonstrated a positive correlation between familiarity and pleasantness. However, on the basis of both theoretical and methodological perspectives, we questioned the validity of such a relation for malodors. We report 2 studies based on subjective judgments of a large sample of odorants (Experiment 1) associated with autonomic recordings (Experiment 2). Multivariate exploratory analysis performed on the data splits the whole odorant set into 2 subsets composed, respectively, of unpleasant and pleasant odorants. Subsequent correlation analyses have shown that the relation between pleasantness and familiarity is specific for the pleasant odors in the 2 experiments. Moreover, autonomic activity was more important in response to malodors than to pleasant odors and was significantly correlated with unpleasantness ratings in the subset of unpleasant odors. These 2 studies argue in favor of a functional dissociation in the relations between both subjective and autonomic responses to odors as a function of pleasantness and indicate that researchers in the olfactory domain should consider the relations between pleasantness and familiarity as more complex than linea

Mapping the Semantic Space for the Subjective Experience of Emotional Responses to Odors

Two studies were conducted to examine the nature of the verbal labels that describe emotional effects elicited by odors. In Study 1, a list of terms selected for their relevance to describe affective feelings induced by odors was assessed while participants were exposed to a set of odorant samples. The data were submitted to a series of exploratory factor analyses to 1) reduce the set of variables to a smaller set of summary scales and 2) get a preliminary sense of the differentiation of affective feelings elicited by odors. The goal of Study 2 was to replicate the findings of Study 1 with a larger sample of odorant samples and participants and to validate the preliminary model obtained in Study 1 by using confirmatory factor analysis. Overall, the findings point to a structure of affective responses to odors that differs from the classical taxonomies of emotion such as posited by discrete or bidimensional emotion theories. These findings suggest that the subjective affective experiences or feelings induced by odors are structured around a small group of dimensions that reflect the role of olfaction in well-being, social interaction, danger prevention, arousal or relaxation sensations, and conscious recollection of emotional memorie

Affective semantic space of scents. Towards a universal scale to measure self-reported odor-related feelings

Measuring self-reported affective feelings to odors and odorous products is a recent challenge for the food and cosmetic field, requiring the development of suited instruments. This paper finalizes a line of studies aimed at developing Emotion and Odor Scales (EOSs) in several cultures. Previously available for Switzerland, the United Kingdom and Singapore, new EOSs are presented here for the United States, Brazil, and China. These scales, developed with 350-540 participants per country, have been conceived to allow the measurement of affective feelings (e.g., emotions, moods, attitudes) in response to a wide range of odors including pleasant and unpleasant, food and non-food ones. Several affective categories were recurrent in the countries examined here: Disgust/Irritation, Happiness/Well-being, Sensuality/Desire, Energy, but also Soothing/Peacefulness and Hunger/Thirst, indicating a potential link between emotion and adaptive universal functions of olfaction such as danger avoidance, ingestion and social communication. For these common categories, similarity in affective responses generally reflected geographic proximity indicating also a strong influence of cultural aspects. Exceptions to this pattern were Singapore and China, with affective responses of Singaporeans being closer to those of Europeans. This series of studies allows us to propose a universal scale (UniGEOS) that might be used in the future for examination of other cultures. This scale comprises affective categories that we found to be culturally shared, enclosing the most frequently shared affective terms, and several culture-specific aspects that may be relevant in other cultures. This tool can be used in its complete form (25 affective terms) or as a short version with nine categories entitled Unpleasant feelings, Happiness/Delight, Sensuality/Desire, Energy, Soothing/ Peacefulness, Hunger/Thirst, Interest, Nostalgia and Spirituality

Cross-modal associations of human body odour attractiveness with facial and vocal attractiveness provide little support for the backup signals hypothesis: A systematic review and meta-analysis

Assessing the attractiveness of potential mating partners typically involves multiple sensory modalities, including the integration of olfactory, visual, and auditory cues. However, predictions diverge on how the individual modalities should relate to each other. According to the backup signals hypothesis, multimodal cues provide redundant information, whereas the multiple messages hypothesis suggests that different modalities provide independent and distinct information about an individual's mating-related quality. The backup signals hypothesis predicts a positive association between assessments based on different modalities, whereas no substantial correlation across modalities is expected under the multiple messageshypothesis. Previous studies testing the two hypotheses have provided mixed results, and a systematic evaluation is currently missing. We performed a systematic review and a meta-analysis of published and unpublished studies to examine the congruence in assessments between human body odour and facial attractiveness, and between body odour and vocal attractiveness. We found positive but weak associations between ratings of body odours and faces (r = 0.1, k = 25), and between body odours and voices (r = 0.1, k = 9). No sex differences were observed in the magnitude of effects. Compared to judgments of facial and vocal attractiveness, our results suggest that assessment of body odour provides independent and non-redundant information about human mating-related quality. Our findings thus provide little support for the backup signals hypothesis and may be better explained by the multiple messages hypothesis

When Flexibility Is Stable: Implicit Long-Term Shaping of Olfactory Preferences

Preferences are traditionally assumed to be stable. However, empirical evidence such as preference modulation following choices calls this assumption into question. The evolution of such postchoice preference over long time spans, even when choices have been explicitly forgotten, has so far not been studied. In two experiments, we investigated this question by using a variant of the free choice paradigm: In a first session, participants evaluated the pleasantness of a number of odors. We then formed pairs of similarly rated odors, and asked participants to choose their favorite, for each pair. Participants were then presented with all odors again, and asked for another pleasantness rating. In a second session 1 week later, a third pleasantness rating was obtained, and participants were again asked to choose between the same options. Results suggested postchoice preference modulation immediately and 1 week after choice for both chosen and rejected options, even when choices were not explicitly remembered. A third experiment, using another paradigm, confirmed that choice can have a modulatory impact on preferences, and that this modulation can be long-lasting. Taken together, these findings suggest that although preferences appear to be flexible because they are modulated by choices, this modulation also appears to be stable over time and even without explicit recollection of the choice. These results bring a new argument to the idea that postchoice preference modulation could rely on implicit mechanisms, and are consistent with the recent proposal that cognitive dissonance reduction could to some extent be implicit