Measures of angularity in digital images

In light of the growing interest in studying the affective and aesthetic attributes of curvature, the present paper describes four digital image processing techniques that can be used to objectively discriminate between angular and curvilinear stimuli. MATLAB scripts for each of the techniques accompany the paper. Three studies are then reported that evaluate the efficacy of five metrics, derived from the four techniques, at quantifying the degree of angularity depicted in an image. Images of simple polygons (Study 1), artistic drawings of everyday objects (Study 2), and real-world objects, typefaces, and abstract patterns (Study 3) were analyzed. Logistic regression models were used to determine the relative importance of the metrics at distinguishing between angular and curvilinear items. With one exception, all of the metrics were capable of distinguishing between angular and curvilinear items at a level above chance, but some metrics were better at doing so than others, and their discriminative capacity was influenced by the characteristics of the image. The strengths and limitations of the metrics are discussed, as well as some practical recommendations.

Shape variety of food can boost its visual appeal

We investigated whether food shape and its variety within a group affect visual appeal using a four-shaped fast-food chicken product known as Chicken McNuggets®. In Experiment 1, participants rated the visual appeal of each nugget shape both individually and when presented in groups of variously shaped nuggets. The results revealed that the rounder nugget was less visually appealing than those of other shapes. Additionally, assortments featuring various shapes were rated as more appealing than those of a single shape. In Experiment 2, the visual appeal of individual nuggets presented in groups and alone was assessed using a visual analog scale. The visual appeal of one specific nugget (target nugget) was higher when presented in a group than alone. Furthermore, a target nugget presented in a group with various shapes was more visually appealing than when presented in a group with the same shape, regardless of the shape of the target nugget. These results suggest that a food product with low visual appeal can be perceived as more appealing when it is presented alongside various food shapes. Indeed, the variety of food shapes presented in a group affected the perceived appeal both of the group and of the individual food item. These findings offer novel insights into the impact of food's visual variation on its appeal.

Marble melancholy: using crossmodal correspondences of shapes, materials, and music to predict music-induced emotions

Introduction

Music is known to elicit strong emotions in listeners, and, if primed appropriately, can give rise to specific and observable crossmodal correspondences. This study aimed to assess two primary objectives: (1) identifying crossmodal correspondences emerging from music-induced emotions, and (2) examining the predictability of music-induced emotions based on the association of music with visual shapes and materials.

Methods

To achieve this, 176 participants were asked to associate visual shapes and materials with the emotion classes of the Geneva Music-Induced Affect Checklist scale (GEMIAC) elicited by a set of musical excerpts in an online experiment.

Results

Our findings reveal that music-induced emotions and their underlying core affect (i.e., valence and arousal) can be accurately predicted by the joint information of musical excerpt and features of visual shapes and materials associated with these music-induced emotions. Interestingly, valence and arousal induced by music have higher predictability than discrete GEMIAC emotions.

Discussion

These results demonstrate the relevance of crossmodal correspondences in studying music-induced emotions. The potential applications of these findings in the fields of sensory interactions design, multisensory experiences and art, as well as digital and sensory marketing are briefly discussed.

Crossmodal correspondences between visual features and tastes in preschoolers: an exploratory study

Introduction

Adults possess a natural inclination to associate sensory cues derived from distinct modalities, such as the pairing of sweet with pink. However, studies exploring crossmodal correspondences in children, particularly in the sensory pairing of visual features and tastes, are scant, leaving unanswered questions regarding the developmental trajectory of crossmodal correspondences. The present study investigates whether Japanese preschool children demonstrate specific biases in shape-color, shape-taste, and color-taste associations.

Methods

In a series of in-person experiments, 92 children between 3 to 6 years of age completed matching tasks utilizing paper stimuli.

Results

Children exhibit crossmodal correspondences in shape-color (circle-red and asymmetrical star-yellow), shape-taste (triangle-salty and circle-sweet), and color-taste (yellow-sour, black-bitter, and pink-sweet) associations. Moreover, children's choices are not influenced by their individual preferences.

Discussion

The crossmodal correspondences observed in this study have been observed in previous research on adults from the same (Japanese) culture, although adults showed more crossmodal correspondences than the children in this study (e.g., pink-circle, triangle-sour, and green-bitter). Thus, while some crossmodal correspondences emerge during childhood, others may require additional time to develop, thereby highlighting the importance of understanding the cognitive mechanisms underlying crossmodal correspondences from an ontogenic perspective.

An fMRI study of visual geometric shapes processing

Cross-modal correspondence has been consistently evidenced between shapes and other sensory attributes. Especially, the curvature of shapes may arouse the affective account, which may contribute to understanding the mechanism of cross-modal integration. Hence, the current study used the functional magnetic resonance imaging (fMRI) technique to examine brain activity’s specificity when people view circular and angular shapes. The circular shapes consisted of a circle and an ellipse, while the angular shapes consisted of a triangle and a star. Results show that the brain areas activated by circular shapes mainly involved the sub-occipital lobe, fusiform gyrus, sub and middle occipital gyrus, and cerebellar VI. The brain areas activated by angular shapes mainly involve the cuneus, middle occipital gyrus, lingual gyrus, and calcarine gyrus. The brain activation patterns of circular shapes did not differ significantly from those of angular shapes. Such a null finding was unexpected when previous cross-modal correspondence of shape curvature was considered. The different brain regions detected by circular and angular shapes and the potential explanations were discussed in the paper.

A taste for beauty: On the expected taste, hardness, texture, and temperature of geometric shapes

Rounded shapes, which have been shown to enhance sweetness, were compared to the perfectly symmetrical Platonic solids. In a first online experiment, participants were presented with a rotating three-dimensional geometric shape (a sphere, the five Platonic solids, and three irregular angular/rounded/naturalistic controls), and indicated their liking for the shape, as well as its perceived hardness, and its expected temperature. The sphere was liked best, followed by the Platonic solids. The sphere was also evaluated as softest, and received the warmest temperature ratings. By contrast, the Platonic solids were rated as harder and significantly colder than the sphere. Experiment 2 investigated whether the liked shapes were also evaluated as looking tastier. Ratings of expected tastiness and the appearance of five shapes selected based on high liking scores and fitted with edible and inedible visual textures were recorded. The sphere was rated as looking tastiest, with edible-textured rounded shapes resulting in significantly tastier ratings. Experiment 3 assessed the taste corresponding to each shape. A sweet and umami preference for rounded shapes was documented, with sour and bitter typically matched to angular shapes. Importantly, the Platonic solids were associated with several tastes. These findings are explained in terms of current theories of crossmodal correspondences, while considering how temperature and texture can be used to modulate expected liking.

Exploring Group Differences in the Crossmodal Correspondences

There has been a rapid growth of interest amongst researchers in the cross-modal correspondences in recent years. In part, this has resulted from the emerging realization of the important role that the correspondences can sometimes play in multisensory integration. In turn, this has led to an interest in the nature of any differences between individuals, or rather, between groups of individuals, in the strength and/or consensuality of cross-modal correspondences that may be observed in both neurotypically normal groups cross-culturally, developmentally, and across various special populations (including those who have lost a sense, as well as those with autistic tendencies). The hope is that our emerging understanding of such group differences may one day provide grounds for supporting the reality of the various different types of correspondence that have so far been proposed, namely structural, statistical, semantic, and hedonic (or emotionally mediated).

How Food Shape Influences Calorie Content Estimation: The Biasing Estimation of Calories

Whether for improving health or keeping in shape, consumers are beginning to pay attention to calorie intake. However, although a growing number of studies have focused on the impact of food attributes on consumers, the sensory correspondence between food shape and calorie estimation is an underresearched topic. This review, therefore, reports on three studies investigating the effect of food shape on calorie content estimation, whereby participants perceived food in a square shape to have a higher calorie content than food in a circular shape. Perceived food weight plays a mediating role in the relationship between food shape and calorie estimation. Moreover, the more mindful participants were about calorie intake, the weaker the mediation effect of perceived weight. Conversely, the mediation effect of perceived weight was stronger for people who did not care about their calorie intake. These findings break novel ground by presenting food shape as a relevant factor for calorie content estimation. It not only pays attention to the information brought by the visual sense of food, but also complements the relevant literature in the field of food marketing, and has implications for marketing management.

Masked emotions: Do face mask patterns and colors affect the recognition of emotions?

Previous research has shown that face masks impair the ability to perceive social information and the readability of emotions. These studies mostly explored the effect of standard medical, often white, masks on emotion recognition. However, in reality, many individuals prefer masks with different styles. We investigated whether the appearance of the mask (pattern: angular vs. curvy and color: black vs. white) affected the recognition of emotional states. Participants were asked to identify the emotions on faces covered by masks with different designs. The presence of masks resulted in decreasing accuracy and confidence and increasing reaction times, indicating that masks impair emotion recognition. There were no significant effects of angularity versus curvature or color on emotion recognition, which suggests that mask design may not impair the recognition beyond the effect of mere mask wearing. Besides, we found relationships between individual difference variables such as mask wearing attitudes, mask design preferences, individual traits and emotion recognition. The majority of participants demonstrated positive attitudes toward mask wearing and preferred non-patterned black and white masks. Preferences for white masks were associated with better emotion recognition of masked faces. In contrast, those with negative attitudes toward masks showed marginally poorer performance in emotion recognition for masked faces, and preferred patterned more than plain masks, perhaps viewing masks as a fashion item rather than a necessity. Moreover, preferences to wear patterned masks were negatively related to actual wearing of masks indoors and perceived risks of COVID.

The Living Space: Psychological Well-Being and Mental Health in Response to Interiors Presented in Virtual Reality

There has been a recent interest in how architecture affects mental health and psychological well-being, motivated by the fact that we spend the majority of our waking time inside and interacting with built environments. Some studies have investigated the psychological responses to indoor design parameters; for instance, contours, and proposed that curved interiors, when compared to angular ones, were aesthetically preferred and induced higher positive emotions. The present study aimed to systematically examine this hypothesis and further explore the impact of contrasting contours on affect, behavior, and cognition. We exposed 42 participants to four well-matched indoor living rooms under a free-exploration photorealistic virtual reality paradigm. We included style as an explorative second-level variable. Out of the 33 outcome variables measured, and after correcting for false discoveries, only two eventually confirmed differences in the contours analysis, in favor of angular rooms. Analysis of style primarily validated the contrast of our stimulus set, and showed significance in one other dependent variable. Results of additional analysis using the Bayesian framework were in line with those of the frequentist approach. The present results provide evidence against the hypothesis that curvature is preferred, suggesting that the psychological response to contours in a close-to-reality architectural setting could be more complex. This study, therefore, helps to communicate a more complete scientific view on the experience of interior spaces and proposes directions for necessary future research.

Contour features predict valence and threat judgements in scenes

Quickly scanning an environment to determine relative threat is an essential part of survival. Scene gist extracted rapidly from the environment may help people detect threats. Here, we probed this link between emotional judgements and features of visual scenes. We first extracted curvature, length, and orientation statistics of all images in the International Affective Picture System image set and related them to emotional valence scores. Images containing angular contours were rated as negative, and images containing long contours as positive. We then composed new abstract line drawings with specific combinations of length, angularity, and orientation values and asked participants to rate them as positive or negative, and as safe or threatening. Smooth, long, horizontal contour scenes were rated as positive/safe, while short angular contour scenes were rated as negative/threatening. Our work shows that particular combinations of image features help people make judgements about potential threat in the environment.

People With High Autistic Traits Show Fewer Consensual Crossmodal Correspondences Between Visual Features and Tastes

Crossmodal correspondences between visual features (e.g., color/shape) and tastes have been extensively documented in recent years. Visual colors and shapes have been shown to consensually match to specific tastes. Meanwhile, individuals with autism spectrum disorder are reported to have atypical sensory processing and deficits in multisensory integration. However, the influence of autistic traits on the formation of such correspondences is relatively unknown. Here, we examined whether autistic traits could influence visual–taste associations using an online questionnaire survey among Japanese participants. The results showed that the participants exhibited strong color–taste, shape–taste, and shape–color associations, and the proportions of choosing the consensual color–taste/shape–color associations were significantly associated with autistic traits. The participants with higher autistic quotient scores chose fewer of the consensual color–taste/shape–color associations while there was no difference in choosing shape–taste associations. We interpreted the results as statistical learning with a reduced prior knowledge effect in participants with higher autistic quotient scores.

Olfactory-colour crossmodal correspondences in art, science, and design

The last few years have seen a rapid growth of interest amongst researchers in the crossmodal correspondences. One of the correspondences that has long intrigued artists is the putative association between colours and odours. While traditionally conceptualised in terms of synaesthesia, over the last quarter century or so, at least 20 published peer-reviewed articles have assessed the consistent, and non-random, nature of the colours that people intuitively associate with specific (both familiar and unfamiliar) odours in a non-food context. Having demonstrated such consistent mappings amongst the general (i.e. non-synaesthetic) population, researchers have now started to investigate whether they are shared cross-culturally, and to document their developmental acquisition. Over the years, several different explanations have been put forward by researchers for the existence of crossmodal correspondences, including the statistical, semantic, structural, and emotional-mediation accounts. While several of these approaches would appear to have some explanatory validity as far as the odour-colour correspondences are concerned, contemporary researchers have focussed on learned associations as the dominant explanatory framework. The nature of the colour-odour associations that have been reported to date appear to depend on the familiarity of the odour and the ease of source naming, and hence the kind of association/representation that is accessed. While the bidirectionality of odour-colour correspondences has not yet been rigorously assessed, many designers are nevertheless already starting to build on odour-colour crossmodal correspondences in their packaging/labelling/branding work.

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.

The shape of the pill: Perceived effects, evoked bodily sensations and emotions

Current research examined the differential effects of pills’ shape (angular vs. curvy) on the perceived efficacy of the medicine, evoked bodily sensations and emotions. We investigated these effects by using different types of angular vs. curved stimuli: abstract drawn shapes (Study 1), 3D-printed mockup pills (Study 2) and photographs of the existing pills (Study 3). Participants were asked to imagine ‘taking’ angular and curved pills. They had to focus on the bodily sensations and report the evoked activations/deactivations in different body parts. Across three studies, we found that the angular pills evoke overall more activations in the body compared to curvy pills. We further reported differences in the topography of angular vs. curved pills’-triggered sensations in different body parts. Our results also revealed that angularity is linked with an energizing effect while roundness is associated with a calming effect. The shape effects were demonstrated not only in self-reported energized vs. calm subjective feelings but also in performance on a timed cognitive test. Compared to incongruent designs, pill designs (angular vs. curved) congruent with proposed drug benefits (energizing vs. calming) were perceived as more effective. Moreover, we found differences in emotions triggered by pills of different shapes. The present research provided new findings on angularity vs. curvature perception that may be valuable for cognitive psychology, marketing, pharmaceutical and supplements industry, and other applied fields.

Aesthetic Perception of Line Patterns: Effect of Edge-Orientation Entropy and Curvilinear Shape

Curvilinearity is a perceptual feature that robustly predicts preference ratings for a variety of visual stimuli. The predictive effect of curved/angular shape overlaps, to a large degree, with regularities in second-order edge-orientation entropy, which captures how independent edge orientations are distributed across an image. For some complex line patterns, edge-orientation entropy is actually a better predictor for what human observers like than curved/angular shape. The present work was designed to disentangle the role of the two features in artificial patterns that consisted of either curved or angular line elements. We systematically varied these patterns across two more dimensions, edge-orientation entropy and the number of lines. Eighty-three participants rated the stimuli along three aesthetic dimensions (pleasing, harmonious, and complex). Results showed that curved/angular shape was a stronger predictor for ratings of pleasing and harmonious if the stimuli consisted of a few lines that were clearly discernible. By contrast, edge-orientation entropy was a stronger predictor for the ratings if the stimuli showed many lines, which merged into a texture. No such differences were obtained for complexity ratings. Our findings are in line with results from neurophysiological studies that the processing of shape and texture, respectively, is mediated by different cortical mechanisms.

I am physically and personality-wise warmer when wearing round eyeglasses: Shape priming influences personality judgments and estimated temperature

Shapes are considered to be related to different personality traits, and particularly, in terms of metaphorical associations, the round shape has been related to the warmth trait, and the square shape to the competence trait. The present study used a pre-post design to replicate these associations. Moreover, it was investigated whether round shapes enhanced the estimation of physical warmth as suggested by contemporary debates on cross-modal correspondences. The results indicated that the round shape increased the perception of warmth (p = .004) and the square shape enhanced the perception of competence (p = .025), which confirmed round-warm and square-competent associations. Furthermore, estimates of the room temperature were higher in the round condition, compared to the square condition (p = .023). The theoretical implications of these findings and directions for further research are discussed.

Edge-Orientation Entropy Predicts Preference for Diverse Types of Man-Made Images

We recently found that luminance edges are more evenly distributed across orientations in large subsets of traditional artworks, i.e., artworks are characterized by a relatively high entropy of edge orientations, when compared to several categories of other (non-art) images. In the present study, we asked whether edge-orientation entropy is associated with aesthetic preference in a wide variety of other man-made visual patterns and scenes. In the first (exploratory) part of the study, participants rated the aesthetic appeal of simple shapes, artificial ornamental patterns, facades of buildings, scenes of interior architecture, and music album covers. Results indicated that edge-orientation entropy predicts aesthetic ratings for these stimuli. However, the magnitude of the effect depended on the type of images analyzed, on the range of entropy values encountered, and on the type of aesthetic rating (pleasing, interesting, or harmonious). For example, edge-orientation entropy predicted about half of the variance when participants rated facade photographs for pleasing and interesting, but only for 3.5% of the variance for harmonious ratings of music album covers. We also asked whether edge-orientation entropy relates to the well-established human preference for curved over angular shapes. Our analysis revealed that edge-orientation entropy was as good or an even better predictor for the aesthetic ratings than curvilinearity. Moreover, entropy could substitute for shape, at least in part, to predict the aesthetic ratings. In the second (experimental) part of this study, we generated complex line stimuli that systematically varied in their edge-orientation entropy and curved/angular shape. Here, edge-orientation entropy was a more powerful predictor for ratings of pleasing and harmonious than curvilinearity, and as good a predictor for interesting. Again, the two image properties shared a large portion of variance between them. In summary, our results indicate that edge-orientation entropy predicts aesthetic ratings in diverse man-made visual stimuli. Moreover, the preference for high edge-orientation entropy shares a large portion of predicted variance with the preference for curved over angular stimuli.