Emotional valence modulates the preference for curved objects

The Aesthetic Developmental Characteristics of Contour Features in Children and Adolescents with High- and Low- Level Visual Aesthetic Sensitivity across Grade Levels

This study examined the aesthetic developmental characteristics of contour features (curved and sharp corners) among children and adolescents with different levels (high and low) of visual aesthetic sensitivity in three grades (4, 6, and 8). The results revealed that (1) there was a significant main effect of contour features, with children and adolescents liking curved contours and perceiving them as more beautiful than sharp-angled contours; (2) there was a significant interaction with contour features in grades 6 and 4, and there was no significant difference in liking curved contours and perceiving them to be more beautiful between students in grades 6 and 4. However, grade 6 students disliked sharp-angled contours and perceived them as more unattractive than grade 4 students; and (3) there was a significant interaction between the level of visual aesthetic sensitivity and contour features, as children and adolescents with both high and low levels of visual aesthetic sensitivity preferred curved contours and considered them more beautiful. However, children and adolescents with high-level visual aesthetic sensitivity disliked sharp-angled contours and considered them more unattractive compared to students with low-level visual aesthetic sensitivity. The results proposed that children and adolescents preferred curved contours, 6th graders were more sensitive to curved contours than 4th graders, and children and adolescents with high-level visual aesthetic sensitivity were more sensitive to sharp-angled contours than children and adolescents with low-level visual aesthetic sensitivity.

Beauty and the sharp fangs of the beast: degree of angularity predicts perceived preference and threat

The evaluation of angular vs. curved forms has a long history in psychology but few of the many studies conducted have examined actual degree of angularity. In two experiments, we present observers with randomly positioned and randomly oriented texture displays of angles viewed within a circular frame. The angle conditions varied from 0° to 180° in 20° increments, covering the entire spectrum of possibilities including acute, obtuse, right, and straight line angles. In Experiment 1, 25 undergraduates rated the perceived beauty of these displays. In Experiment 2, the same stimulus set and procedure were used with 27 participants instead judging perceived threat. Based on the findings in the literature, we predicted that sharper angles would be judged less beautiful and more threatening. The results were mostly confirmed. Acute angles are preferred less but there are also distinct preferences for right angles and straight lines, perhaps due to their greater familiarity in constructed environments. There was a consistent and anticipated finding for threat in the second study: the sharper an angle, the greater its perceived threat. Fear of sharp objects as assessed in a personality questionnaire was found to positively correlate with threat judgements. Future work should look more closely at degree of angularity in embedded object contours and at individual response differences.

How universal is preference for visual curvature? A systematic review and meta-analysis

Evidence dating back a century shows that humans are sensitive to and exhibit a preference for visual curvature. This effect has been observed in different age groups, human cultures, and primate species, suggesting that a preference for curvature could be universal. At the same time, several studies have found that preference for curvature is modulated by contextual and individual factors, casting doubt on this hypothesis. To resolve these conflicting findings, we conducted a systematic meta-analysis of studies that have investigated the preference for visual curvature. Our meta-analysis included 61 studies which provided 106 independent samples and 309 effect sizes. The results of a three-level random effects model revealed a Hedges' g of 0.39-consistent with a medium effect size. Further analyses revealed that preference for curvature is moderated by four factors: presentation time, stimulus type, expertise, and task. Together, our results suggest that preference for visual curvature is a reliable but not universal phenomenon and is influenced by factors other than perceptual information.

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.

Swipes and Saves: A Taxonomy of Factors Influencing Aesthetic Assessments and Perceived Beauty of Mobile Phone Photographs

Digital images taken by mobile phones are the most frequent class of images created today. Due to their omnipresence and the many ways they are encountered, they require a specific focus in research. However, to date, there is no systematic compilation of the various factors that may determine our evaluations of such images, and thus no explanation of how users select and identify relatively “better” or “worse” photos. Here, we propose a theoretical taxonomy of factors influencing the aesthetic appeal of mobile phone photographs. Beyond addressing relatively basic/universal image characteristics, perhaps more related to fast (bottom-up) perceptual processing of an image, we also consider factors involved in the slower (top-down) re-appraisal or deepened aesthetic appreciation of an image. We span this taxonomy across specific types of picture genres commonly taken—portraits of other people, selfies, scenes and food. We also discuss the variety of goals, uses, and contextual aspects of users of mobile phone photography. As a working hypothesis, we propose that two main decisions are often made with mobile phone photographs: (1) Users assess images at a first glance—by swiping through a stack of images—focusing on visual aspects that might be decisive to classify them from “low quality” (too dark, out of focus) to “acceptable” to, in rare cases, “an exceptionally beautiful picture.” (2) Users make more deliberate decisions regarding one’s “favorite” picture or the desire to preserve or share a picture with others, which are presumably tied to aspects such as content, framing, but also culture or personality, which have largely been overlooked in empirical research on perception of photographs. In sum, the present review provides an overview of current focal areas and gaps in research and offers a working foundation for upcoming research on the perception of mobile phone photographs as well as future developments in the fields of image recording and sharing technology.

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.

Exploring Intraindividual Profiles for Home Buildings Based on Architectural Compositional Elements and Psychological Health Factors: A Transdisciplinary Approach

Based on the transactional and salutogenic perspectives, we explored individual profiles that integrate psychosocial factors and compositional elements of the built home environment. Adults with different socio-demographic characteristics completed several self-report measures on psychological factors (personality traits, self-efficacy, mental health, and happiness) and architectural elements constituting the ideal home environment. Adopting an individual-centered perspective, three distinct intra-individual psycho-architectural (person-environment) profiles were found with different compositional preferences and psychosocial characteristics in terms of functioning, health, and well-being: endopathic (characterized by higher levels of psychosocial resources and well-being indicating a highly adapted and successful profile, and architectural preferences corresponding to their identities and experiences—expression through spaces), assimilative (characterized by average levels in all regulatory parameters indicating moderately adaptive individuals, and architectural preferences of spaces created in interactive processes—introjection of spaces), and additive individuals (characterized by a comparatively dysfunctional, poorer psychosocial profile, and architectural preferences in line with provoking a restorative effect—change with spaces). An awareness of the psychosocial features of the users for whom the homes are built can help in designing spaces to inhabit that are adapted to them for an enhancement of their overall well-being. Therefore, a better understanding of the interconnections between psychology and architecture will help in designing healthy spaces.

A new type of pictorial database: The Bicolor Affective Silhouettes and Shapes (BASS)

We introduce the Bicolor Affective Silhouettes and Shapes (BASS): a set of 583 normed black-and-white silhouette images that is freely available via https://osf.io/anej6/. Valence and arousal ratings were obtained for each image from US residents as a Western population (n = 777) and Chinese residents as an Asian population (n = 869). Importantly, the ratings demonstrate that, notwithstanding their visual simplicity, the images represent a wide range of affective content (from very negative to very positive, and from very calm to very intense). In addition, speaking to their cultural neutrality, the valence ratings correlated very highly between US and Chinese ratings. Arousal ratings were less consistent between the two samples, with larger discrepancies in the older age groups inviting further investigation. Due to their simplistic and abstract nature, our silhouette images may be useful for intercultural studies, color and shape perception research, and online stimulus presentation in particular. We demonstrate the versatility of the BASS by an example online experiment.

Habitat selection and human aesthetic responses to flowers

Although the aesthetic appreciation of flowers is a well-known aspect of human behaviour, theories explaining its origin are missing. The only exception is the evolutionary theory of Heerwagen and Orians. Surprisingly, it has not yet been empirically tested. The authors suggest that humans aesthetically respond to flowers because they signal food availability. The logic of the theory implies that fruits are more reliable and direct food availability signals than flowers. Therefore, fruits should elicit stronger aesthetic responses than flowers. To test this assumption, we performed two online studies in the Czech Republic. The participants (n = 2792 and 744, respectively) indicated on a six-point scale their aesthetic response to photographs of 14 edible Czech plant species (study A) and 20 edible plant species from the African savannas (study B), varying in growth stage (flowering, fruiting). We found no difference between the Czech fruiting and flowering plants and a stronger aesthetic response to African flowering plants. A third study (n = 817) confirmed that flowers were preferred to fruits, using a forced-choice paradigm. Our results suggest that the theory cannot fully explain human aesthetic responses to flowers. We discuss alternative explanations. This topic deserves renewed attention from researchers working in related fields.

Circles Are Detected Faster Than Downward-Pointing Triangles in a Speeded Response Task

Simple geometric shapes are associated with facial emotional expressions. According to previous research, a downward-pointing triangle conveys the threatening perception of an angry facial expression, and a circle conveys the pleasant perception of a happy facial expression. Some studies showed that downward-pointing triangles have the advantage to capture attention faster than circles. Other studies proposed that curvature enhances visual detection and guides attention. We tested a downward-pointing triangle and a circle as target stimuli for a speeded response task. The distractors were two stimuli that resulted from the mixture of both targets to control for low-level features' balanced presentation. We used 3 × 3, 4 × 4, and 5 × 5 matrices to test whether these shapes led attention to an efficient response. In Experiment 1, participants responded faster to the circle than to the downward-pointing triangle. They also responded slower to both targets as the number of distractors increased. In Experiment 2, we replicated the main findings of Experiment 1. Overall, the circle was detected faster than the downward-pointing triangle with small matrices, but this difference decreased as the matrix size increased. We suggest that circles capture attention faster because of the influence of low-level features, that is, curvature in this case.

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.

Warm, lively, rough? Assessing agreement on aesthetic effects of artworks

The idea that simple visual elements such as colors and lines have specific, universal associations-for example red being warm-appears rather intuitive. Such associations have formed a basis for the description of artworks since the 18th century and are still fundamental to discourses on art today. Art historians might describe a painting where red is dominant as "warm," "aggressive," or "lively," with the tacit assumption that beholders would universally associate the works' certain key forms with specific qualities, or "aesthetic effects". However, is this actually the case? Do we actually share similar responses to the same line or color? In this paper, we tested whether and to what extent this assumption of universality (sharing of perceived qualities) is justified. We employed-for the first time-abstract artworks as well as single elements (lines and colors) extracted from these artworks in an experiment in which participants rated the stimuli on 14 "aesthetic effect" scales derived from art literature and empirical aesthetics. To test the validity of the assumption of universality, we examined on which of the dimensions there was agreement, and investigated the influence of art expertise, comparing art historians with lay people. In one study and its replication, we found significantly lower agreement than expected. For the whole artworks, participants agreed on the effects of warm-cold, heavy-light, and happy-sad, but not on 11 other dimensions. Further, we found that the image type (artwork or its constituting elements) was a major factor influencing agreement; people agreed more on the whole artwork than on single elements. Art expertise did not play a significant role and agreement was especially low on dimensions usually of interest in empirical aesthetics (e.g., like-dislike). Our results challenge the practice of interpreting artworks based on their aesthetic effects, as these effects may not be as universal as previously thought.

Replicability of the Curvature Effect as a Function of Presentation Time and Response Measure in Japanese Observers

Although objects with curved contours are generally preferred over those with sharp-angled contours, the strength of this preference varies according to several factors. In the present study, non-Western Japanese observers viewed and rated their preferences (e.g., liking or attractiveness) for real and meaningless objects with curved or sharp-angled contours. We varied the presentation time (90 ms vs. until a response was received) and the response measure (like/dislike vs. 1-100 rating scale). When using like/dislike ratings, a preference for curved objects was found only when images of real objects were presented briefly (90 ms), whereas this effect was reversed (i.e., increased preference for sharp-angled contours) when using the 1 to 100 scale under the until-response condition. In addition, the curvature effect was not observed for real objects when the like/dislike rating and the until-response condition were employed or when the 1 to 100 scale and 90 ms presentation time were used. The curvature effect for meaningless objects remained unstable regardless of presentation time or response measure. Similar to the preference for real objects, a preference for sharp-angled objects was observed when preference was measured using a 1 to 100 rating scale. Taken together, the present findings indicate that the preferences for curved objects were situation-dependent in Japanese observers.

Probing the Person-Patina Relationship: A Correlational Study on the Psychology of Senescent Environments

There is a lack of research on people’s psychological perceptions to decay or patina that is part of the historic environment. Built heritage conservation doctrine and law are based on the assumption that all people have a similar, positive aesthetic perception to patina in the built environment, although there are very few empirical studies that have attempted to confirm or challenge this assumption. This study is based on the statistical analysis of survey data from 864 people in the United States who ranked 24 images of old, decayed building materials and 7 control images of new building materials based on aesthetic qualities, condition, and perceived age. The results indicate that people do not like decayed earthen building materials, concrete, or ferrous metals and have a neutral opinion of the aesthetic qualities of aged brick, preferring new brick as well as aged wood. While there are small differences based on race, ethnicity, and gender, the largest difference in responses is between people who work in the historic preservation/CRM field and those who do not. This finding appears to indicate that people who work in these fields have a different psychological response to decay/patina in the built environment than laypeople, which has important ramifications in terms of decision-making processes regarding interventions in the older built environment.

Towards emotion recognition in texts: A sound-symbolic experiment

The purpose of this study is to investigate the relationship between the phonetic content of prose texts in English and the emotion that the texts inspire, namely - the effect of vowel-consonant bi-phones on subjects’ evaluation of positive or negative emotional valence when reading. The methodology is based on data from an experiment where the participants, native speakers of three different languages, evaluated the valence invoked in them by one-page texts from English books. The sub-lexical level of the texts was obtained using phonetic transcriptions of the words and their further decomposition into vowel-consonant bi-phones. The statistical investigation relies on density-measures of the investigated bi-phones over each text as a whole. The result shows that there exists a correlation between the obtained sub-lexical representation and the valence perceived by the readers. Concerning the type of the consonants in the bi-phones (abrupt or sonorant), the influence of the abrupt bi-phones is stronger. However, sub-sets of both types of bi-phones showed relatedness with the emotional valence conveyed by the texts. In conclusion, the speech, expressed in written form, is laden with emotional valence even when the words’ lexicological meaning is not taken into consideration and the words are apprehended as mere phonetic constructs. This prompts hypothesizing that words’ semantics itself is partly underpinned by some mental emotion-related level of conceptualization, influenced by sounds. For practical purposes, the result suggests that based on the syllabic content of a text it should be possible to predict the valence that the text would inspire in its readers.

The effects of presentation time on preference for curvature of real objects and meaningless novel patterns

Objects with curved contours are generally preferred to sharp-angled ones. In this study, we aim to determine whether different presentation times influence this preference. We used images of real objects (experiment 1) and meaningless novel patterns (experiment 2). Participants had to select one of two images from a contour pair, curved and sharp-angled versions of the same object/pattern. With real objects, the preference for curved versions was greatest when presented for 84 ms, and it faded when participants were given unlimited viewing time. Curved meaningless patterns were preferred when presented for 84 and 150 ms. However, in contrast to real objects, preference for meaningless patterns increased significantly in the unlimited viewing time condition. Participants discriminated poorly between the two versions (curved and sharp-angled) of the meaningless patterns in the 84- and 150-ms presentations (experiment 3). Therefore, in short times with meaningless patterns, participants selected mostly the curved version without being aware of the difference. In conclusion, presentation time, type of stimulus, and their interaction influence preference for curvature.

Natural Perspective: Mapping Visual Space with Art and Science

Following its discovery in fifteenth-century Italy, linear perspective has often been hailed as the most accurate method of projecting three-dimensional visual space onto a two-dimensional picture plane. However, when we survey the history of European art it is evident that few artists fully complied with its mathematical rules, despite many of them being rigorously trained in its procedures. In this paper, we will consider how artists have actually depicted visual space, and present evidence that images created according to a “natural” perspective (NP) used by artists are judged as better representations of visual space than those created using standard linear (LP) and curvilinear fisheye (FP) projective geometries. In this study, we built a real three-dimensional scene and produced photographs of the scene in three different perspectives (NP, LP and FP). An online experiment in which we asked people to rank the perspectives in order of preference showed a clear preference for NP compared to the FP and LP. In a second experiment, participants were asked to view the real scene and rate each perspective on a range of psychological variables. Results showed that NP was the most preferred and the most effective in depicting the physical space naturally. We discuss the implications of these results and the advantages and limitations of our approach for studying the global metric and geometrical structure of visual space.

On the perceptual aesthetics of interactive objects

This study examined the aesthetics of interactive objects (IOs), which are three-dimensional physical artefacts that exhibit autonomous behaviour when handled. The aim of the research was threefold: first, to investigate whether aesthetic preference for distinctive objects' structures emerges in compound stimulation; second, to explore whether there exists aesthetic preference for distinctive objects' behaviours; and, finally, to test whether there exists aesthetic preference for specific combinations of objects' structures and behaviours. The following variables were systematically manipulated: (a) IOs' contour (rounded vs angular), (b) IOs' size (small vs large), (c) IOs' surface texture (rough vs smooth), and (d) IOs' behaviour (lighting, sounding, vibrating, and quiescent). Results show that behaviour was the dominant factor: it influenced aesthetics more than any other characteristic; vibrating IOs were preferred over lighting and sounding IOs, supporting the importance of haptic processing in aesthetics. Results did not confirm the size and smoothness effects previously reported in vision and touch, respectively, which suggests that the aesthetic preference that emerges in isolated conditions may be different in compound stimulation. Results corroborate the smooth curvature effect. We suggest that behavior may be an aesthetic primitive.

Introduction: Art and the brain: From pleasure to well-being

Empirical aesthetics in general, and neuroaesthetics in particular, have been very much influenced by Berlyne's psychobiological program. For him, aesthetic appreciation involved the brain's reward and aversion systems. From this point of view, art constitutes a set of potentially rewarding stimuli. Research has certainly made great advances in understanding how the process of artistic valuation takes places, and which brain circuits are involved in generating the pleasure we obtain from artistic practices, performances, and works. But it also suggests that pleasure is not the only effect of the arts. The evidence rather suggests that the arts have other cognitive and emotional effects which are closely related to human psychobiological health and well-being. These are: (1) attentional focus and flow, (2) affective experience, (3) emotion through imagery, (4) interpersonal communication, (5) self-intimation, and (6) social bonding. These effects are beneficial and contribute to the individual's biopsychological health and well-being. The fact that artistic practice has these effects helps explain why the arts are so important to human life, and why they developed in the first place, i.e., as ways to foster these effects. Therefore, a biopsychological science of the arts is emerging, according to which the arts can be conceptualized as an important system of external self-regulation, as a set of activities that contribute to our homeostasis and well-being.

Angular Versus Curved Shapes: Correspondences and Emotional Processing

The present work aimed to systematically examine sensory and higher level correspondences to angular and curved shapes. Participants matched angular and curved abstract shapes to sensory experiences in five different modalities as well as to emotion, gender, and name attributes presented as written labels (Study 1) and real experiences (Study 2). The results demonstrated nonarbitrary mapping of angular and curved shapes to attributes from all basic sensory modalities (vision, audition, gustation, olfaction, and tactation) and higher level attributes (emotion, gender, and name). Participants associated curved shapes with sweet taste, quiet or calm sound, vanilla smell, green color, smooth texture, relieved emotion, female gender, and wide-vowel names. In contrast, they associated angular shapes with sour taste, loud or dynamic sound, spicy or citrus smell, red color, rough texture, excited or surprise emotion, male gender, and narrow-vowel names. These prevalent correspondences were robust across different shape pairs as well as all sensory and higher level attributes, presented as both verbal labels and real sensory experiences. The second goal of this research was to examine the relationship between the shape correspondences and individual differences in emotional processing, assessed by self-report and performance measures. The results suggest that heightened emotional ability is associated with making shape attributions that go along with the found prevalent trends.

Not all about sex: neural and biobehavioral functions of human dance

This paper provides an integrative review of neuroscientific and biobehavioral evidence about the effects of dance on the individual across cultural differences. Dance moves us, and many derive aesthetic pleasure from it. However, in addition-and beyond aesthetics-we propose that dance has noteworthy, deeper neurobiological effects. We first summarize evidence that illustrates the centrality of dance to human life indirectly from archaeology, comparative psychology, developmental psychology, and cross-cultural psychology. Second, we review empirical evidence for six neural and biobehavioral functions of dance: (1) attentional focus/flow, (2) basic emotional experiences, (3) imagery, (4) communication, (5) self-intimation, and (6) social cohesion. We discuss the reviewed evidence in relation to current debates in the field of empirical enquiry into the functions of human dance, questioning the positions that dance is (1) just for pleasure, (2) all about sex, (3) just for mood management and well-being, and (4) for experts only. Being a young field, evidence is still piecemeal and inconclusive. This review aims to take a step toward a systematization of an emerging avenue of research: a neuro- and biobehavioral science of dance.

Curve Appeal: Exploring Individual Differences in Preference for Curved Versus Angular Objects

A preference for smooth curvature, as opposed to angularity, is a well-established finding for lines, two-dimensional shapes, and complex objects, but little is known about individual differences. We used two-dimensional black-and-white shapes-randomly generated irregular polygons, and arrays of circles and hexagons-and measured many individual differences, including artistic expertise, personality, and cognitive style. As expected, people preferred curved over angular stimuli, and people's degree of curvature preference correlated across the two sets of shapes. Multilevel models showed varying patterns of interaction between shape and individual differences. For the irregular polygons, people higher in artistic expertise or openness to experience showed a greater preference for curvature. This pattern was not evident for the arrays of circles and hexagons. We discuss the results in relation to the nature of the stimuli, and we conclude that individual differences do play a role in moderating the preference for smooth curvature.

The Perceived Size and Shape of Objects in Peripheral Vision

Little is known about how we perceive the size and shape of objects in far peripheral vision. Observations made during an artistic study of visual space suggest that objects appear smaller and compressed in the periphery compared with central vision. To test this, we conducted three experiments. In Experiment 1, we asked participants to draw how a set of peripheral discs appeared when viewed peripherally without time or eye movement constraints. In Experiment 2, we used the method of constant stimuli to measure when a briefly presented peripheral stimulus appeared bigger or smaller compared with a central fixated one. In Experiment 3, we measured how accurate participants were in discriminating shapes presented briefly in the periphery. In Experiment 1, the peripheral discs were reported as appearing significantly smaller than the central disc, and as having an elliptical or polygonal contour. In Experiment 2, participants judged the size of peripheral discs as being significantly smaller when compared with the central disc across most of the peripheral field, and in Experiment 3, participants were quite accurate in reporting the shape of the peripheral object, except in the far periphery. Our results show that objects in the visual periphery are perceived as diminished in size when presented for long and brief exposures, suggesting diminution is an intrinsic feature of the structure of the visual space. Shape distortions, however, are reported only with longer exposures.

Affective responses to dance

The objective of the present work was the characterization of mechanisms by which affective experiences are elicited in observers when watching dance movements. A total of 203 dance stimuli from a normed stimuli library were used in a series of independent experiments. The following measures were obtained: (i) subjective measures of 97 dance-naïve participants' affective responses (Likert scale ratings, interviews); and (ii) objective measures of the physical parameters of the stimuli (motion energy, luminance), and of the movements represented in the stimuli (roundedness, impressiveness). Results showed that (i) participants' ratings of felt and perceived affect differed, (ii) felt and perceived valence but not arousal ratings correlated with physical parameters of the stimuli (motion energy and luminance), (iii) roundedness in posture shape was related to the experience of more positive emotion than edgy shapes (1 of 3 assessed rounded shapes showed a clear effect on positiveness ratings while a second reached trend level significance), (iv) more impressive movements resulted in more positive affective responses, (v) dance triggered affective experiences through the imagery and autobiographical memories it elicited in some people, and (vi) the physical parameters of the video stimuli correlated only weakly and negatively with the aesthetics ratings of beauty, liking and interest. The novelty of the present approach was twofold; (i) the assessment of multiple affect-inducing mechanisms, and (ii) the use of one single normed stimulus set. The results from this approach lend support to both previous and present findings. Results are discussed with regards to current literature in the field of empirical aesthetics and affective neuroscience.

What flowers do we like? The influence of shape and color on the rating of flower beauty

There is no doubt that people find flowers beautiful. Surprisingly, we know very little about the actual properties which make flowers so appealing to humans. Although the evolutionary aesthetics provides some theories concerning generally preferred flower traits, empirical evidence is largely missing. In this study, we used an online survey in which residents of the Czech Republic (n = 2006) rated the perceived beauty of 52 flower stimuli of diverse shapes and colors. Colored flowers were preferred over their uncolored versions. When controlling for flower shape, we found an unequal preference for different flower colors, blue being the most and yellow the least preferred. In the overall assessment of beauty, shape was more important than color. Prototypical flowers, i.e., radially symmetrical flowers with low complexity, were rated as the most beautiful. We also found a positive effect of sharp flower contours and blue color on the overall rating of flower beauty. The results may serve as a basis for further studies in some areas of the people-plant interaction research.

Preference for Curvature: A Historical and Conceptual Framework

That people find curved contours and lines more pleasurable than straight ones is a recurrent observation in the aesthetic literature. Although such observation has been tested sporadically throughout the history of scientific psychology, only during the last decade has it been the object of systematic research. Recent studies lend support to the idea that human preference for curved contours is biologically determined. However, it has also been argued that this preference is a cultural phenomenon. In this article, we review the available evidence, together with different attempts to explain the nature of preference for curvature: sensoriomotor-based and valuation-based approaches. We also argue that the lack of a unifying framework and clearly defined concepts might be undermining our efforts towards a better understanding of the nature of preference for curvature. Finally, we point to a series of unresolved matters as the starting point to further develop a consistent research program.

Common Visual Preference for Curved Contours in Humans and Great Apes

Among the visual preferences that guide many everyday activities and decisions, from consumer choices to social judgment, preference for curved over sharp-angled contours is commonly thought to have played an adaptive role throughout human evolution, favoring the avoidance of potentially harmful objects. However, because nonhuman primates also exhibit preferences for certain visual qualities, it is conceivable that humans’ preference for curved contours is grounded on perceptual and cognitive mechanisms shared with extant nonhuman primate species. Here we aimed to determine whether nonhuman great apes and humans share a visual preference for curved over sharp-angled contours using a 2-alternative forced choice experimental paradigm under comparable conditions. Our results revealed that the human group and the great ape group indeed share a common preference for curved over sharp-angled contours, but that they differ in the manner and magnitude with which this preference is expressed behaviorally. These results suggest that humans’ visual preference for curved objects evolved from earlier primate species’ visual preferences, and that during this process it became stronger, but also more susceptible to the influence of higher cognitive processes and preference for other visual features.

Comparing Angular and Curved Shapes in Terms of Implicit Associations and Approach/Avoidance Responses

Most people prefer smoothly curved shapes over more angular shapes. We investigated the origin of this effect using abstract shapes and implicit measures of semantic association and preference. In Experiment 1 we used a multidimensional Implicit Association Test (IAT) to verify the strength of the association of curved and angular polygons with danger (safe vs. danger words), valence (positive vs. negative words) and gender (female vs. male names). Results showed that curved polygons were associated with safe and positive concepts and with female names, whereas angular polygons were associated with danger and negative concepts and with male names. Experiment 2 used a different implicit measure, which avoided any need to categorise the stimuli. Using a revised version of the Stimulus Response Compatibility (SRC) task we tested with a stick figure (i.e., the manikin) approach and avoidance reactions to curved and angular polygons. We found that RTs for approaching vs. avoiding angular polygons did not differ, even in the condition where the angles were more pronounced. By contrast participants were faster and more accurate when moving the manikin towards curved shapes. Experiment 2 suggests that preference for curvature cannot derive entirely from an association of angles with threat. We conclude that smoothly curved contours make these abstract shapes more pleasant. Further studies are needed to clarify the nature of such a preference.

Everything's Relative? Relative Differences in Processing Fluency and the Effects on Liking

Explanations of aesthetic pleasure based on processing fluency have shown that ease-of-processing fosters liking. What is less clear, however, is how processing fluency arises. Does it arise from a relative comparison among the stimuli presented in the experiment? Or does it arise from a comparison to an internal reference or standard? To address these questions, we conducted two experiments in which two ease-of-processing manipulations were applied: either (1) within-participants, where relative comparisons among stimuli varying in processing ease were possible, or (2) between-participants, where no relative comparisons were possible. In total, 97 participants viewed simple line drawings with high or low visual clarity, presented at four different presentation durations, and rated for felt fluency, liking, and certainty. Our results show that the manipulation of visual clarity led to differences in felt fluency and certainty regardless of being manipulated within- or between-participants. However, liking ratings were only affected when ease-of-processing was manipulated within-participants. Thus, feelings of fluency do not depend on the nature of the reference. On the other hand, participants liked fluent stimuli more only when there were other stimuli varying in ease-of-processing. Thus, relative differences in fluency seem to be crucial for liking judgments.

Affective Analysis of Professional and Amateur Abstract Paintings Using Statistical Analysis and Art Theory

When artists express their feelings through the artworks they create, it is believed that the resulting works transform into objects with “emotions” capable of conveying the artists' mood to the audience. There is little to no dispute about this belief: Regardless of the artwork, genre, time, and origin of creation, people from different backgrounds are able to read the emotional messages. This holds true even for the most abstract paintings. Could this idea be applied to machines as well? Can machines learn what makes a work of art “emotional”? In this work, we employ a state-of-the-art recognition system to learn which statistical patterns are associated with positive and negative emotions on two different datasets that comprise professional and amateur abstract artworks. Moreover, we analyze and compare two different annotation methods in order to establish the ground truth of positive and negative emotions in abstract art. Additionally, we use computer vision techniques to quantify which parts of a painting evoke positive and negative emotions. We also demonstrate how the quantification of evidence for positive and negative emotions can be used to predict which parts of a painting people prefer to focus on. This method opens new opportunities of research on why a specific painting is perceived as emotional at global and local scales.

Do observers like curvature or do they dislike angularity?

Humans have a preference for curved over angular shapes, an effect noted by artists as well as scientists. It may be that people like smooth curves or that people dislike angles, or both. We investigated this phenomenon in four experiments. Using abstract shapes differing in type of contour (angular vs. curved) and complexity, Experiment 1 confirmed a preference for curvature not linked to perceived complexity. Experiment 2 tested whether the effect was modulated by distance. If angular shapes are associated with a threat, the effect may be stronger when they are presented within peripersonal space. This hypothesis was not supported. Experiment 3 tested whether preference for curves occurs when curved lines are compared to straight lines without angles. Sets of coloured lines (angular vs. curved vs. straight) were seen through a circular or square aperture. Curved lines were liked more than either angular or straight lines. Therefore, angles are not necessary to generate a preference for curved shapes. Finally, Experiment 4 used an implicit measure of preference, the manikin task, to measure approach/avoidance behaviour. Results did not confirm a pattern of avoidance for angularity but only a pattern of approach for curvature. Our experiments suggest that the threat association hypothesis cannot fully explain the curvature effect and that curved shapes are, per se, visually pleasant.

Impact of contour on aesthetic judgments and approach-avoidance decisions in architecture

On average, we urban dwellers spend about 90% of our time indoors, and share the intuition that the physical features of the places we live and work in influence how we feel and act. However, there is surprisingly little research on how architecture impacts behavior, much less on how it influences brain function. To begin closing this gap, we conducted a functional magnetic resonance imaging study to examine how systematic variation in contour impacts aesthetic judgments and approach-avoidance decisions, outcome measures of interest to both architects and users of spaces alike. As predicted, participants were more likely to judge spaces as beautiful if they were curvilinear than rectilinear. Neuroanatomically, when contemplating beauty, curvilinear contour activated the anterior cingulate cortex exclusively, a region strongly responsive to the reward properties and emotional salience of objects. Complementing this finding, pleasantness--the valence dimension of the affect circumplex--accounted for nearly 60% of the variance in beauty ratings. Furthermore, activation in a distributed brain network known to underlie the aesthetic evaluation of different types of visual stimuli covaried with beauty ratings. In contrast, contour did not affect approach-avoidance decisions, although curvilinear spaces activated the visual cortex. The results suggest that the well-established effect of contour on aesthetic preference can be extended to architecture. Furthermore, the combination of our behavioral and neural evidence underscores the role of emotion in our preference for curvilinear objects in this domain.

Perception of emotion in abstract artworks: a multidisciplinary approach

There is a long-standing and fundamental debate regarding how emotion can be expressed by fine art. Some artists and theorists have claimed that certain features of paintings, such as color, line, form, and composition, can consistently express an "objective" emotion, while others have argued that emotion perception is subjective and depends more on expertise of the observer. Here, we discuss two studies in which we have found evidence for consistency in observer ratings of emotion for abstract artworks. We have developed a stimulus set of abstract art images to test emotional priming, both between different painting images and between paintings and faces. The ratings were also used in a computational vision analysis of the visual features underlying emotion expression. Overall, these findings suggest that there is a strong bottom-up and objective aspect to perception of emotion in abstract artworks that may tap into basic visual mechanisms.