Crossmodal correspondences between taste and shape, and their implications for product packaging: A review

Pitch-based correspondences related to abstract concepts

Previous investigations have shown pitch-based correspondences with various perceptual and conceptual attributes. The present study reveals two novel pitch-based correspondences with highly abstract concepts. Three experiments with varying levels of implicitness of the association task showed that the concepts of future and in are associated with high-pitch sounds, while past and out are associated with low-pitch sounds. Hence, pitch-based correspondences can be observed even with temporal concepts that cannot be unambiguously represented in any perceptual format, at least, without spatial metaphorization. The correspondence effects were even more robust with the abstract temporal concepts of future/past than with more concrete spatial concepts of in/out. We propose that these effects might emerge from semantic multimodal abstraction processes mediated by affective dimensions of particular concepts.

Impact of warning label shapes on perceived healthfulness and consumer attention

Countries' regulations mandate front-of-package (FOP) labeling to promote awareness of healthy eating habits. In the Colombian context, this study examined the impact of FOP nutrient warnings on potato chip perceptions, considering the warning's shape. Experiment 1 found that warning shape (circle or octagon vs. control) had a similar effect on perceived healthfulness. Furthermore, the FOP warning reduced the perceived healthfulness of healthy chips but did not affect perceptions of potato chip packages. Experiment 2 assessed how warning shape influenced participants' attention to the warning. No differences were found between round and octagonal labels; however, the control condition showed higher fixation counts and fixation durations compared to the circular or octagonal conditions. The absence of significant findings regarding healthfulness perceptions and attention to FOP warnings suggests further research is needed to identify which label characteristics should be refined or whether additional public policies are required to enhance a population's nutritional opportunities. This study contributes to the FOP warning literature as more countries, particularly in Latin America, adopt warning labels to raise awareness and reduce the consumption of nutrient-poor foods. Therefore, practical and conceptual reasons exist for developing a unique and consistent label to encourage individuals to pause and consider their choices before consuming such products.

Colour/shape-taste correspondences across three languages in ChatGPT

Crossmodal correspondences, the tendency for a sensory feature / attribute in one sensory modality (either physically present or merely imagined), to be associated with a sensory feature in another sensory modality, have been studied extensively, revealing consistent patterns, such as sweet tastes being associated with pink colours and round shapes across languages. The present research explores whether such correspondences are captured by ChatGPT, a large language model developed by OpenAI. Across twelve studies, this research investigates colour/shapes-taste crossmodal correspondences in ChatGPT-3.5 and -4o, focusing on associations between shapes/colours and the five basic tastes across three languages (English, Japanese, and Spanish). Studies 1A-F examined taste-shape associations, using prompts in three languages to assess ChatGPT's association of round and angular shapes with the five basic tastes. The results indicated significant, consistent, associations between shape and taste, with, for example, round shapes strongly associated with sweet/umami tastes and angular shapes with bitter/salty/sour tastes. The magnitude of shape-taste matching appears to be greater in ChatGPT-4o than in ChatGPT-3.5, and ChatGPT prompted in English and Spanish than ChatGPT prompted in Japanese. Studies 2A-F focused on colour-taste correspondences, using ChatGPT to assess associations between eleven colours and the five basic tastes. The results indicated that ChatGPT-4o, but not ChatGPT-3.5, generally replicates the patterns of colour-taste correspondences that have previously been observed in human participants. Specifically, ChatGPT-4o associates sweet tastes with pink, sour with yellow, salty with white/blue, bitter with black, and umami with red across languages. However, the magnitude/similarity of shape/colour-taste matching observed in ChatGPT-4o appears to be more pronounced (i.e., having little variance, large mean difference), which does not adequately reflect the subtle nuances typically seen in human shape/colour-taste correspondences. These findings suggest that ChatGPT captures colour/shapes-taste correspondences, with language- and GPT version-specific variations, albeit with some differences when compared to previous studies involving human participants. These findings contribute valuable knowledge to the field of crossmodal correspondences, explore the possibility of generative AI that resembles human perceptual systems and cognition across languages, and provide insight into the development and evolution of generative AI systems that capture human crossmodal correspondences.

The effects of anxiety on taste perception: The role of awareness

Prior research indicate that emotional states can alter taste perception, but the underlying mechanisms remain unclear. This study explores whether taste perception changes due to the mere evocation of emotions or the cognitive awareness of emotions. The first experiment investigated how anxiety affects taste perception when individuals are aware of their anxiety. Participants watched videos inducing relaxation or anxiety, then were divided into groups focusing on their emotions and those who did not, and the taste perception was measure. The second experiment investigated the influence of awareness directed toward emotions on taste evaluation, without manipulating emotional states. This focused on cognitive processing of taste through evaluations of visual stimuli. Results showed that sweetness perception is suppressed by the evocation of anxiety, whereas bitterness perception is enhanced only by anxiety with awareness. These findings indicate that the mechanisms by which emotional states affect taste perception may differ depending on taste quality.

The influence of Bouba- and Kiki-like shape on perceived taste of chocolate pieces

In this paper, we present the findings of a study investigating the impact of shape on the taste perception of chocolate. Previous research has explored the influence of various sensory information on taste perception, but there has been little focus on the effect of food shape being eaten on taste perception. To explore this, we focused on the Bouba-Kiki effect, illustrating an interaction between shape and several modalities, and investigated the effect of Bouba- and Kiki-shaped (rounded and angular) foods eaten on taste perception. We utilized a 3D food printer to produce four different shapes of chocolate pieces based on the Bouba-Kiki. Participants tasted each piece and completed a chocolate flavor questionnaire. With Bayesian analysis, we determined that the Bouba-shaped chocolate pieces were perceived as sweeter than the Kiki-shaped ones, supporting earlier studies on crossmodal correspondences between shape and taste perception. However, there were no significant differences in ratings of other tastes, such as sourness and bitterness. Our research indicates that shape can affect taste perception during consumption and suggests that 3D food printers offer an opportunity to design specific shapes that influence taste experiences.

Shape-color associations in an unrestricted color choice paradigm

Since Kandinsky's claim for fundamental shape-color associations, several studies have revealed that those tendencies were not generalizable to the entire population and that different associations were more prevalent. Past studies, however, lacked a methodology that allowed participants to freely report their shape-color preferences. Here, we report data from 7,517 Danish individuals, using a free choice full color wheel for five different geometrical shapes. We find significant shape-hue associations for circle-red/yellow, triangle-green/yellow, square-blue, and pentagon/hexagon-magenta. The significant shape-hue associations are also more saturated than non-significant ones for the circle, triangle, and square. At the conceptual level, basic shapes, which show stronger associations, are linked to primary colors, and non-basic shapes to secondary colors. Shape-color associations seem indeed to follow the Berlin-Kay stages of entry into languages. This pattern had previously been described for graphemes and weekday-color associations. The methodology employed in our study can be repeated in different cultural contexts in the future. We also provide another instance of color associations for ordinal concepts that follow the stages of entry into languages.

Crossmodal correspondences between basic tastes and visual design features: A narrative historical review

People tend to associate abstract visual features with basic taste qualities. This narrative historical review critically evaluates the literature on these associations, often referred to as crossmodal correspondences, between basic tastes and visual design features such as color hue and shape curvilinearity. The patterns, discrepancies, and evolution in the development of the research are highlighted while the mappings that have been reported to date are summarized. The review also reflects on issues of cross-cultural validity and deviations in the matching patterns that are observed when correspondences are assessed with actual tastants versus with verbal stimuli. The various theories that have been proposed to account for different classes of crossmodal correspondence are discussed, among which the statistical and affective (or emotional-mediation) accounts currently appear most promising. Several critical research questions for the future are presented to address the gaps that have been identified in the literature and help validate the popular theories on the origin and operations of visual-taste correspondences.

Visual communication via the design of food and beverage packaging

A rapidly growing body of empirical research has recently started to emerge highlighting the connotative and/or semiotic meanings that consumers typically associate with specific abstract visual design features, such as colours (either when presented individually or in combination), simple shapes/curvilinearity, and the orientation and relative position of those design elements on product packaging. While certain of our affective responses to such basic visual design features appear almost innate, the majority are likely established via the internalization of the statistical regularities of the food and beverage marketplace (i.e. as a result of associative learning), as in the case of round typeface and sweet-tasting products. Researchers continue to document the wide range of crossmodal correspondences that underpin the links between individual visual packaging design features and specific properties of food and drink products (such as their taste, flavour, or healthfulness), and the ways in which marketers are now capitalizing on such understanding to increase sales. This narrative review highlights the further research that is still needed to establish the connotative or symbolic/semiotic meaning(s) of particular combinations of design features (such as coloured stripes in a specific orientation), as opposed to individual cues in national food markets and also, increasingly, cross-culturally in the case of international brands.

Consumer Preference for Yogurt Packaging Design Using Conjoint Analysis

With the growing consumption market of yogurt products, the continuous innovation of packaging design has become the major means of enterprise marketing for fast-moving consumer goods. Because different combinations of packaging design elements affect the consumers in different ways, the contradiction between the product packaging design and consumer demand has impacted the further development of these products’ marketing. To explore the relationship between the constituent elements of yogurt packaging design and consumer preferences, four kinds of factors to the purchased products’ attributes were selected from the packaging design, including the graphics, packaging colors, packaging shapes and label texts. The consumers’ preferences for different attributes of yogurt packaging design were quantitatively evaluated by the Conjoint Analysis Method (CAM). Consumers showed the strongest preference for yogurt packaging shapes (39.017%), and were the most satisfied with the concrete graphics of cool colors (31.330%); the level combination of attributes most preferred by consumers is that of concrete graphics, cool colors, gable-top boxes and simple labels. The packaging design satisfying consumer preferences gave rise to positive purchase attitudes. Such research results facilitated the understanding of the consumption market and provided the theoretical support necessary for the development of yogurt packaging design to match the consumers’ preferences.

Toward Healthier Cookie Habits: Assessing the Role of Packaging Visual Appearance in the Expectations for Dietary Cookies in Digital Environments

As we tend to consume more and more via e-commerce platforms, the digital version of a dietary product's package can be one of the most important touchpoints that the consumer has with such product during the purchasing stage of the consumer's journey. Hence, a dietary food/drink properly presented via its packaging in e-commerce is key, for example, to nudge consumers toward healthier purchase habits. In this study, we assessed the role of different configurations of visual cues commonly present in a product's packaging (jar vs. bag, transparent vs. opaque, labeled vs. unlabeled) in the expectations associated with dietary cookies when presented in a digital environment. A between-participants study was conducted where eight different packages with different combinations of the three aforementioned features were digitally evaluated by the participants. The results suggest that the presence (vs. absence) of labeling triggered the highest ratings on most assessed dimensions (product quality, healthiness, lightness, sweetness, crumbliness, price, tastiness, greediness for product, product/packaging liking). Moreover, transparent (vs. opaque) packaging tends to yield higher expectations concerning this product's quality (i.e., product liking, package liking, greediness), though it has an opposite effect on the expected healthiness for such cookies. Some particular interactions between these three visual cues were also observed and are discussed as part of the obtained results. In summary, our results point to how the visual appearance of packaging can be strategically used in order to potentially nudge consumers toward healthier cookie purchase habits.

Use of strawberry and vanilla natural flavors for sugar reduction: A dynamic sensory study with yogurt

Yogurt is a food with great acceptance by consumers. However, this product often contains excessive added sugar content. A potential strategy to reduce sugar content without compromising sensory quality is the addition of flavors. Thus, the objective of this work was to evaluate the relationship between flavors (vanilla and strawberry) and sweet taste, using a time-intensity analysis, temporal dominance of sensations (TDS) and acceptance test to verifying the viability of sugar reduction in yogurt with the addition of flavors. The results showed that 25% sugar reduction in yogurt with 0.2% vanilla flavor did not affect the sweetness, as shown in temporal profiles, and hedonic perception. The yogurt with 25% sugar reduction and 0.2% strawberry flavor proved to be as well accepted as samples with ideal concentration. Therefore, study of the flavor-taste interaction for the reformulation of foods represents an important strategy to reduce sucrose concentration, maintaining a similar temporal sweetness profile.

Strategies for Reducing Salt and Sugar Intakes in Individuals at Increased Cardiometabolic Risk

Non-communicable diseases (NCDs) are the first causes of death worldwide. Reduction in the dietary intake of salt and sugars is important lifestyle advice that is useful for NCD prevention. However, the simple recommendations of reducing salt and sugars by healthcare professionals are often ineffective; innovative strategies are therefore necessary. This review aimed at describing the current knowledge about the strategies to reduce dietary salt and sugar intake, including both strategies for the food industry to reduce the salt or sugar of its products and recommendations for health professionals in a clinical context, such as the replacement with substitutes in foods, the gradual reduction to allow a progressive consumer adaptation towards less intense taste, and the different spatial distribution of tastants within the food matrix with taste intensity enhancement. In addition, the cross-modal interaction between two or more different sensory modalities as an innovative strategy for enhancing sweetness and saltiness perception was described. Finally, the dietary tips for salt and sugar reduction were summarized in order to create a comprehensive guide of dietary advices for healthcare professionals for optimizing the management of patients at increased cardiometabolic risk.

Acceptability of generic versus innovator oral medicines: not only a matter of taste

Optimum use of generic products would require equivalence, not only in terms of quality, safety, and efficacy in clinical studies, but also patient acceptability to not jeopardize treatment success because of non-adherence which would de facto limit the potential cost saving anticipated by their use. Although acceptability is a requirement for the authorization of pediatric innovator products, a survey of European Union (EU) regulatory authorities showed that few have a formal process for assessing patient acceptability of generic products during the registration processes. The current International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) focus on unifying guidance for the development and scrutiny of generics but should include acceptability alongside the other factors being considered for harmonization.

Cross-Modal Correspondences Between Temperature and Taste Attributes

Temperature is an important characteristic of food and drink. In addition to food-intrinsic temperature (i.e., serving temperature), consumers often experience food-extrinsic temperature (e.g., physical warmth). Emerging research on cross-modal correspondence has revealed that people reliably associate temperature with other sensory features. Building on the literature on cross-modal correspondence and sensation transference theory, the present study aimed to reveal mental representations of temperature–taste correspondence and cross-modal mental representations influencing corresponding sensory/hedonic perceptions of beverages, with a focus on manipulating food-extrinsic warmth. To reveal mental representations of temperature–taste correspondence, Experiment 1 investigated whether temperature words (warm, cool) are associated with sensory/hedonic attributes (e.g., sweet, sour, salty, bitter). The results of Experiment 1 demonstrated that warm (vs. cool) was matched more with saltiness, tastiness, healthfulness, and preference (intention to buy), whereas cool (vs. warm) was matched more with sourness and freshness. Experiment 2 assessed whether cross-modal mental representations influence corresponding sensory/hedonic perceptions of beverages. The participants wore hot and cold pads and rated sensory/hedonic attributes of Japanese tea (Experiment 2a) or black coffee (Experiment 2b) before and after tasting it. The results of Experiment 2a demonstrated that physical warmth (vs. coldness) increased healthfulness and the intention to buy Japanese tea. The results of Experiment 2b did not reveal any effects of physical warmth on sensory/hedonic ratings. These findings provide evidence of taste–temperature correspondence and provide preliminary support for the influence of food-extrinsic warmth on taste attributes related to positivity.

Visual Design Cues Impacting Food Choice: A Review and Future Research Agenda

This review aims to tackle the challenge of understanding how visual design cues can affect behavioural outcomes in a food context. The review answers two key questions: (1) What are the effects of the most important visual design cues on behavioural outcomes and how can they be explained? (2) What are the research gaps in this area? We start from a comprehensive taxonomy of visual design cues delineating the most important visual design cues. Next, we evaluate the extant research based on a structured, narrative literature review on visual design cues in the food domain. We differentiate between object processed and spatially processed visual design cues in food choice contexts and show how they affect behavioural outcomes through a range of psychological processes (attention, affective-, cognitive- and motivational reactions, food perceptions and attitudes). We end with recommendations which take into account the current food store context, the state-of-art in measuring psychological processes and behavioural outcomes and the specific food-, person- and context-related moderators. This review offers guidance for research to untangle the complexity of the effect of visual design cues in a food choice context.

Assessing the Relationship Between Drive for Thinness and Taste-Shape Correspondences

Eating disorder tendencies are psychological characteristics that are prevalent in healthy young females and are known to be among the risk factors for eating disorders such as anorexia and bulimia nervosa. People with greater eating disorder tendencies strongly associate sweet and fatty foods with weight gain and strictly avoid consuming such foods. However, little is known about how eating disorder tendencies influence the association between taste and body shape impression. Research on crossmodal correspondences suggests that people preferentially associate sweet tastes with round shapes, and individual differences affect the degree of such associations. This study investigates how the degree of taste-shape matching is related to eating disorder tendencies with a preliminary investigation of what mediates this relationship. Two experiments were conducted: in Experiment 1, healthy participants rated the degree of association between basic taste words (sweet/sour/salty/bitter) and roundness of shape and subsequently completed questionnaires addressing eating disorder tendencies. In Experiment 2, participants answered additional questionnaires addressing obsessiveness, dichotomous thinking, and self-esteem. The results of Experiment 1 indicated a positive correlation between drive for thinness, which is one indicator of an eating disorder tendency, and the degree of matching sweetness to round shape. Experiment 2 replicated the results of Experiment 1 and revealed the mediating effect of obsessiveness. These findings suggest a relationship between individual differences in taste-shape matching and eating disorder tendency and the preliminary mediating role of obsessiveness. The present study provides new insight into the role of sweet-round matching in eating disorder tendencies and the associated psychological mechanisms.

Heaviness-brightness correspondence and stimulus-response compatibility

Cross-sensory correspondences can reflect crosstalk between aligned conceptual feature dimensions, though uncertainty remains regarding the identities of all the dimensions involved. It is unclear, for example, if heaviness contributes to correspondences separately from size. Taking steps to dissociate variations in heaviness from variations in size, the question was asked if a heaviness-brightness correspondence will induce a congruity effect during the speeded brightness classification of simple visual stimuli. Participants classified the stimuli according to whether they were brighter or darker than the mid-gray background against which they appeared. They registered their speeded decisions by manipulating (e.g., tapping) the object they were holding in either their left or right hand (e.g., left for bright, right for dark). With these two otherwise identical objects contrasting in their weight, stimuli were classified more quickly when the relative heaviness of the object needing to be manipulated corresponded with the brightness of the stimulus being classified (e.g., the heavier object for a darker stimulus). This novel congruity effect, in the guise of a stimulus-response (S-R) compatibility effect, was induced when heaviness was isolated as an enduring feature of the object needing to be manipulated. It was also undiminished when participants completed a concurrent verbal memory load task, countering claims that the heaviness-brightness correspondence is verbally mediated. Heaviness, alongside size, appears to contribute to cross-sensory correspondences in its own right and in a manner confirming the far-reaching influence of correspondences, extending here to the fluency with which people communicate simple ideas by manipulating a hand-held object.

Impact of Common Food Labels on Consumer Liking in Vanilla Yogurt

As competition on super market shelves is higher than ever, the importance of product concepts, communicated through labels, can dictate a product’s success or failure. However, it is possible for labels to affect a consumer’s experience, changing the overall response to the product. In this study, we tested samples of vanilla yogurt with one of four commonly used labeling concepts (high-protein, low-fat, made with stevia and all-natural) on sensory perception, consumer liking, expected consumption amount, and willingness to pay (WTP) in a consumer test (n = 108). Each participant evaluated five samples of the same vanilla yogurt identified with one of the labels, or an unlabeled control. Results showed panelists liked the samples labeled with low-fat and high-protein to the greatest degree, with all-natural scoring the lowest. Those more concerned with protein content found the samples less satiating, dependent on sex. Sweetness was also perceived more highly in younger panelists, with panelists WTP dependent on their liking of the labels. Results highlight the importance of labeling as an extrinsic cue affecting liking ratings, with potential ramification for ultimate product success. Understanding consumers’ response to labels, as well as their attitudes, has broad implications for food marketing, as well as public health and the study of eating habits.

The relation between symmetry in food packaging and approach and avoidance words

Research on aesthetic science has demonstrated that people generally prefer symmetrical over asymmetrical compositions. However, it remains unclear whether and how such compositions relate to the concepts of approach and avoidance motivation, especially in consumer contexts. In addition, it is not known how symmetry may influence such concepts in contexts where objects can differ in terms of their hedonic values (symmetry/product taste congruency). In the present research, we evaluated the relation between visual symmetry of the packaging of products with different hedonic value (sweet, non-sweet, non-food) and approach and avoidance words. In two experiments, we found evidence that people associate symmetrical designs with approach words more often than asymmetrical designs. Importantly, however, we did not find evidence that such an effect is influenced by the hedonic value of the products. Our results have value for scholars and practitioners interested in the effect of aesthetic features of brand elements (such as a product's packaging) on consumer motivation.

The Role of Intrinsic and Extrinsic Sensory Factors in Sweetness Perception of Food and Beverages: A Review

When it comes to eating and drinking, multiple factors from diverse sensory modalities have been shown to influence multisensory flavour perception and liking. These factors have heretofore been strictly divided into either those that are intrinsic to the food itself (e.g., food colour, aroma, texture), or those that are extrinsic to it (e.g., related to the packaging, receptacle or external environment). Given the obvious public health need for sugar reduction, the present review aims to compare the relative influences of product-intrinsic and product-extrinsic factors on the perception of sweetness. Evidence of intrinsic and extrinsic sensory influences on sweetness are reviewed. Thereafter, we take a cognitive neuroscience perspective and evaluate how differences may occur in the way that food-intrinsic and extrinsic information become integrated with sweetness perception. Based on recent neuroscientific evidence, we propose a new framework of multisensory flavour integration focusing not on the food-intrinsic/extrinsic divide, but rather on whether the sensory information is perceived to originate from within or outside the body. This framework leads to a discussion on the combinability of intrinsic and extrinsic influences, where we refer to some existing examples and address potential theoretical limitations. To conclude, we provide recommendations to those in the food industry and propose directions for future research relating to the need for long-term studies and understanding of individual differences.

Round Faces Are Associated with Sweet Foods: The Role of Crossmodal Correspondence in Social Perception

In retail settings, social perception of other peoples' preferences is fundamental to successful interpersonal interactions (e.g., product recommendations, gift-giving). This type of perception must be made with little information, very often based solely on facial cues. Although people are capable of accurately predicting others' preferences from facial cues, we do not yet know how such inferences are made by crossmodal correspondence (arbitrary sensory associations) between facial cues and inferred attributes. The crossmodal correspondence literature implies the existence of sensory associations between shapes and tastes, and people consistently match roundness and angularity to sweet and sour foods, respectively. Given that peoples' faces have dimensions characterized by roundness and angularity, it may be plausible that people infer others' preferences by relying on the correspondence between facial roundness and taste. Based on a crossmodal correspondence framework, this study aimed to reveal the role of shape⁻taste correspondences in social perception. We investigated whether Japanese participants infer others' taste (sweet/sour) preferences based on facial shapes (roundness/angularity). The results showed that participants reliably inferred that round-faced (vs. angular-faced) individuals preferred sweet foods (Study 1). Round-faced individuals and sweet foods were well matched, and the matching mediated the inference of other person's preferences (Study 2). An association between facial roundness and inference of sweet taste preferences was observed in more natural faces, and perceived obesity mediated this association (Study 3). These findings advance the applicability of crossmodal correspondences in social perception, and imply the pervasiveness of prejudicial bias in the marketplace.

A Critical Analysis of Colour-Shape Correspondences: Examining the Replicability of Colour-Shape Associations

Research on the topic of colour-shape correspondences started in the early 20th century with the Bauhaus artist Wassily Kandinsky. However, more recently, the topic has been examined using the empirical framework of crossmodal correspondences research. The field remains one in which consistent results and generalisable hypotheses about the existence and nature of colour-shape correspondences are lacking. The replicability and consistency of findings concerning colour-shape correspondences are examined in three online colour-shape matching experiments using the same procedure and study design while varying the sets of shape stimuli that are evaluated. Participants matched one of 36 colours to each shape as well as made preference and arousal appraisal ratings for each of the shapes and colours. The complexities of analysing colour-shape correspondence data are discussed and illustrated by classifying and analysing shape and colours in a variety of different ways, including using continuous perceptual and objective measures. Significant colour-shape associations were found. However, as hypothesised, limited consistent results in regard to what perceptual shape characteristics predicted colour choices were documented across the three stimuli sets. This was the case both within and across different analysis methods. The factors that may be responsible for these inconsistencies are critically discussed. Intriguingly, however, evidence for emotional mediation, whereby shape and colour liking and arousal appraisals appear to influence the colour-shape correspondences made by participants, was found across all three experiments.