The small step toward asymmetry: Aesthetic judgment of broken symmetries

The Order & Complexity Toolbox for Aesthetics (OCTA): A systematic approach to study the relations between order, complexity, and aesthetic appreciation

Do individuals prefer stimuli that are ordered or disordered, simple or complex, or that strike the right balance of order and complexity? Earlier research mainly focused on the separate influence of order and complexity on aesthetic appreciation. When order and complexity were studied in combination, stimulus manipulations were often not parametrically controlled, only rather specific types of order (i.e., balance or symmetry) were usually studied, and/or the multidimensionality of order and complexity was largely ignored. Progress has also been limited by the lack of an easy way to create reproducible and expandible stimulus sets, including both order and complexity manipulations. The Order & Complexity Toolbox for Aesthetics (OCTA), a Python toolbox that is also available as a point-and-click Shiny application, aims to fill this gap. OCTA provides researchers with a free and easy way to create multi-element displays varying qualitatively (i.e., different types) and quantitatively (i.e., different levels) in order and complexity, based on regularity and variety along multiple element features (e.g., shape, size, color, orientation). The standard vector-based output is ideal for experiments on the web and the creation of dynamic interfaces and stimuli. OCTA will not only facilitate reproducible stimulus construction and experimental design in research on order, complexity, and aesthetics. In addition, OCTA can be a very useful tool in any type of research using visual stimuli, or even to create digital art. To illustrate OCTA's potential, we propose several possible applications and diverse questions that can be addressed using OCTA.

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.

Perspective Slant Makes Symmetry Harder to Detect and Less Aesthetically Appealing

Abstract symmetric patterns are generally preferred to less regular patterns. Here, we studied 2D patterns presented as 2D images in the plane, and therefore producing a symmetric pattern on the retina, and the same patterns seen in perspective. This perspective transformation eliminates the presence of perfect symmetry in terms of retinotopic coordinates. Stimuli were abstract patterns of local coplanar elements, or irregular polygons. In both cases they can be understood as 2D patterns on a transparent glass pane. In the first study we found that perspective increased reaction time and errors in a classification task, even when the viewing angle was kept constant over many images. In a second study we tested a large sample (148 participants) and asked for a rating of beauty for the same images. In addition, we used the Cognitive Reflection Test (CRT) to test the hypothesis that people who tend to give the more immediate and intuitive answer would also show a stronger preference for the symmetry presented in the frontoparallel plane (in the image and on the retina). Preference for symmetry was confirmed, and there was a cost for perspective viewing. CRT scores were not related to preference, thus not supporting the hypothesis of a stronger preference for symmetry in the image when people follow a more immediate and intuitive gut response.

Evaluative judgment across domains: Liking balance, contour, symmetry and complexity in melodies and visual designs

Evaluative judgment-i.e., assessing to what degree a stimulus is liked or disliked-is a fundamental aspect of cognition, facilitating comparison and choosing among alternatives, deciding, and prioritizing actions. Neuroimaging studies have shown that evaluative judgment involves the projection of sensory information to the reward circuit. To investigate whether evaluative judgments are based on modality-specific or modality-general attributes, we compared the extent to which balance, contour, symmetry, and complexity affect liking responses in the auditory and visual modalities. We found no significant correlation for any of the four attributes across sensory modalities, except for contour. This suggests that evaluative judgments primarily rely on modality-specific sensory representations elaborated in the brain's sensory cortices and relayed to the reward circuit, rather than abstract modality-general representations. The individual traits art experience, openness to experience, and desire for aesthetics were associated with the extent to which design or compositional attributes influenced liking, but inconsistently across sensory modalities and attributes, also suggesting modality-specific influences.

An Information Theory Approach to Aesthetic Assessment of Visual Patterns

The question of beauty has inspired philosophers and scientists for centuries. Today, the study of aesthetics is an active research topic in fields as diverse as computer science, neuroscience, and psychology. Measuring the aesthetic appeal of images is beneficial for many applications. In this paper, we will study the aesthetic assessment of simple visual patterns. The proposed approach suggests that aesthetically appealing patterns are more likely to deliver a higher amount of information over multiple levels in comparison with less aesthetically appealing patterns when the same amount of energy is used. The proposed approach is evaluated using two datasets; the results show that the proposed approach is more accurate in classifying aesthetically appealing patterns compared to some related approaches that use different complexity measures.

Preferring and Detecting Face Symmetry: Comparing Children and Adults Judging Human and Monkey Faces

Background: Visual symmetry is often found attractive. Symmetry may be preferred either due to a bias in the visual system or due to evolutionary selection pressures related to partner preference. Simple perceptual bias views predict that symmetry preferences should be similar across types of stimuli and unlikely to be related to factors such as age. Methods: The current study examined preferences for symmetry across age groups (pre-puberty vs post-puberty) and stimuli type (human face vs monkey face). Pairs of images manipulated for symmetry were presented and participants asked to choose the image they preferred. Participants repeated the task and were asked to detect symmetry. Results: Both age of observer and stimuli type were associated with symmetry preferences. Older observers had higher preferences for symmetry but preferred it most in human vs monkey stimuli. Across both age groups, symmetry preferences and detection abilities were weakly related. Conclusions: The study supports some ideas from an evolutionary advantage view of symmetry preference, whereby symmetry is expected be higher for potential partners (here human faces) and higher post-puberty when partner choice becomes more relevant. Such potentially motivational based preferences challenge perceptual bias explanations as a sole explanation for symmetry preferences but may occur alongside them.

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.

Global Image Properties Predict Ratings of Affective Pictures

Affective pictures are widely used in studies of human emotions. The objects or scenes shown in affective pictures play a pivotal role in eliciting particular emotions. However, affective processing can also be mediated by low-level perceptual features, such as local brightness contrast, color or the spatial frequency profile. In the present study, we asked whether image properties that reflect global image structure and image composition affect the rating of affective pictures. We focused on 13 global image properties that were previously associated with the esthetic evaluation of visual stimuli, and determined their predictive power for the ratings of five affective picture datasets (IAPS, GAPED, NAPS, DIRTI, and OASIS). First, we used an SVM-RBF classifier to predict high and low ratings for valence and arousal, respectively, and achieved a classification accuracy of 58–76% in this binary decision task. Second, a multiple linear regression analysis revealed that the individual image properties account for between 6 and 20% of the variance in the subjective ratings for valence and arousal. The predictive power of the image properties varies for the different datasets and type of ratings. Ratings tend to share similar sets of predictors if they correlate positively with each other. In conclusion, we obtained evidence from non-linear and linear analyses that affective pictures evoke emotions not only by what they show, but they also differ by how they show it. Whether the human visual system actually uses these perceptive cues for emotional processing remains to be investigated.

What Experts Appreciate in Patterns: Art Expertise Modulates Preference for Asymmetric and Face-Like Patterns

This study set out to investigate whether and how aesthetic evaluations of different types of symmetric, as well as abstract vs. representational patterns are modulated by art expertise. To this end, we utilized abstract asymmetric, symmetric, and “broken” patterns slightly deviating from symmetry, as well as more representational patterns resembling faces (also symmetric or broken). While it has already been shown that symmetry preference decreases with art expertise, it was still unclear whether an already established relationship between art expertise and preference for abstract over representational art can be similarly found as a preference for abstract over representational patterns, as these are non-art objects. Nevertheless, we found profound differences in aesthetic preferences between art experts and laypersons. While art experts rated asymmetric patterns higher than laypersons, as expected, they rated face-like patterns lower than laypersons. Also, laypersons rated all other types of patterns higher than asymmetric patterns, while art experts rated the other patterns similar or lower than asymmetric patterns. We found this both for liking and for interest ratings. As no differences between art experts and laypersons were found regarding memory recognition of new and old patterns, this effect is not likely due to differences in memory performance. In sum, this study further extends our knowledge about the influence of art expertise on aesthetic appreciation.

Anticipatory Defocusing of Attention and Contextual Response Priming but No Role of Aesthetic Appreciation in Simple Symmetry Judgments when Switching between Tasks

Visual attention can be adjusted to task requirements. We asked participants to switch between judging the symmetry of vertically presented three-letter strings and identifying the central stimulus (i.e., Eriksen task) to investigate anticipatory adjustment of attention. Our experiments provide evidence for anticipatory adjustment of visual attention, depending on the cued task (i.e., focusing and defocusing of attention after the Eriksen task cue and after the symmetry task cue, respectively). Although, symmetry judgments were, overall, considerably slower than the identification of the central letter, the effects of response congruency between tasks were comparable in the two tasks, which suggested strong response priming from concurrent symmetry judgment in Eriksen task trials. Symmetry judgment performance was best for homogeneous letter strings (e.g., HHH), worst for strings that were symmetrical and inhomogeneous (e.g., XHX), and intermediate for asymmetrical strings (e.g., HHX). The difficulty of categorizing symmetrical-inhomogeneous items markedly deviated from the aesthetic ratings of the stimuli, displaying a pronounced preference for symmetrical strings, but only little difference among the symmetrical items, and might be accounted by conflict with response priming based on inhomogeneity detection. Although our study provides little evidence for an effect of aesthetic appreciation in simple symmetry judgments, it demonstrates the strong role of contextual dependencies.

A new conception of visual aesthetic sensitivity

Aesthetic sensitivity has been defined as the ability to recognize and appreciate beauty and compositional excellence, and to judge artistic merit according to standards of aesthetic value. The Visual Aesthetic Sensitivity Test (VAST) has often been used to assess this ability, but recent research has revealed it has several psychometric problems. Such problems are not easily remedied, because they reflect flawed assumptions inherent to the concept of aesthetic sensitivity as traditionally understood, and to the VAST itself. We introduce a new conception of aesthetic sensitivity defined as the extent to which someone's aesthetic valuation is influenced by a given feature. Experiment 1 aimed to characterize aesthetic sensitivity to four prominent features in visual aesthetics: complexity, symmetry, contour, and balance. Experiment 2 aimed to replicate the findings of Experiment 1 and to assess the test-retest reliability of an instrument designed to measure aesthetic sensitivity to these features using an abridged set of stimuli. Our results reveal that people differ remarkably in the extent to which visual features influence their liking, highlighting the crucial role of individual variation when modelling aesthetic preferences. We did not find clear relations between the four measures of aesthetic sensitivity and personality, intelligence, and art interest and knowledge. Finally, our measurement instrument exhibited an adequate-to-good test-retest reliability.

Effects of liking on visual attention in faces and paintings

The visual aesthetics of an object increases visual attention towards the object. It is argued that this relation between liking and attention is an evolutionary adaptation in sexual and natural selection. If this is the case, we would expect this relation to be domain specific, and thus, stronger for biological than for non-biological objects. To test this hypothesis, we conducted two eye-tracking studies, in which we compared the relation between liking and gaze patterns in images of biological (faces) and non-biological (paintings) stimuli. In Study 1, we presented randomly combined image pairs for 20 s in a free-viewing paradigm. Participants then selected the image they liked more in a 2-AFC task and rated the liking of each image on a Likert-scale. In Study 2, we employed the same paradigm but this time, images were combined based on pre-rated liking to ensure that images in each pair were clearly different. In both studies, we found a strong relation between liking and visual attention. Against our expectations, these effects were of similar magnitude for faces as for paintings. We conclude that the relation between liking and visual attention is not limited to biological objects but that its effects are domain general. The evolutionary function of the relation between liking and visual attention might stem from evolutionary adaptations, nonetheless, this link seems to be a rather basic phenomenon that applies across domains.

The sound of beauty: How complexity determines aesthetic preference

Stimulus complexity is an important determinant of aesthetic preference. An influential idea is that increases in stimulus complexity lead to increased preference up to an optimal point after which preference decreases (inverted-U pattern). However, whereas some studies indeed observed this pattern, most studies instead showed an increased preference for more complexity. One complicating issue is that it remains unclear how to define complexity. To address this, we approached complexity and its relation to aesthetic preference from a predictive coding perspective. Here, low- and high-complexity stimuli would correspond to low and high levels of prediction errors, respectively. We expected participants to prefer stimuli which are neither too easy to predict (low prediction error), nor too difficult (high prediction error). To test this, we presented two sequences of tones on each trial that varied in predictability from highly regular (low prediction error) to completely random (high prediction error), and participants had to indicate which of the two sequences they preferred in a two-interval forced-choice task. The complexity of each tone sequence (amount of prediction error) was estimated using entropy. Results showed that participants tended to choose stimuli with intermediate complexity over those of high or low complexity. This confirms the century-old idea that stimulus complexity has an inverted-U relationship to aesthetic preference.

Implicit and Explicit Evaluation of Visual Symmetry as a Function of Art Expertise

In perception, humans typically prefer symmetrical over asymmetrical patterns. Yet, little is known about differences in symmetry preferences depending on individuals' different past histories of actively reflecting upon pictures and patterns. To address this question, we tested the generality of the symmetry preference for different levels of individual art expertise. The preference for symmetrical versus asymmetrical abstract patterns was measured implicitly, by an Implicit Association Test (IAT), and explicitly, by a rating scale asking participants to evaluate pattern beauty. Participants were art history and psychology students. Art expertise was measured using a questionnaire. In the IAT, art expertise did not alter the preference for symmetrical over asymmetrical patterns. In contrast, the explicit rating scale showed that with higher art expertise, the ratings for the beauty of asymmetrical patterns significantly increased, but, again, participants preferred symmetrical over asymmetrical patterns. The results are discussed in light of different theories on the origins of symmetry preference. Evolutionary adaptation might play a role in symmetry preferences for art experts similarly to nonexperts, but experts tend to emphasize the beauty of asymmetrical depictions, eventually considering different criteria, when asked explicitly to indicate their preferences.

Visual cortex activation predicts visual preference: Evidence from Britain and Egypt

The term “Perceptual goodness” refers to the strength, obviousness, or salience of a visual configuration. Recent work has found strong agreement between theoretical, neural, and behavioural measures of perceptual goodness across a wide range of different symmetrical visual patterns. We used these pattern types again to explore the relationship between perceptual goodness and aesthetic preference. A group of 50 U.K. participants rated the patterns on a 0 to 100 scale. Preference ratings positively correlated with four overlapping measures of perceptual goodness. We then replicated this finding in Egypt, suggesting that our results reflect universal aspects of human preference. The third experiment provided consistent results with a different stimulus set. We conclude that symmetry is an aesthetic primitive that is attractive because of the way it is processed by the visual system.

Predicting perceived visual complexity of abstract patterns using computational measures: The influence of mirror symmetry on complexity perception

Visual complexity is relevant for many areas ranging from improving usability of technical displays or websites up to understanding aesthetic experiences. Therefore, many attempts have been made to relate objective properties of images to perceived complexity in artworks and other images. It has been argued that visual complexity is a multidimensional construct mainly consisting of two dimensions: A quantitative dimension that increases complexity through number of elements, and a structural dimension representing order negatively related to complexity. The objective of this work is to study human perception of visual complexity utilizing two large independent sets of abstract patterns. A wide range of computational measures of complexity was calculated, further combined using linear models as well as machine learning (random forests), and compared with data from human evaluations. Our results confirm the adequacy of existing two-factor models of perceived visual complexity consisting of a quantitative and a structural factor (in our case mirror symmetry) for both of our stimulus sets. In addition, a non-linear transformation of mirror symmetry giving more influence to small deviations from symmetry greatly increased explained variance. Thus, we again demonstrate the multidimensional nature of human complexity perception and present comprehensive quantitative models of the visual complexity of abstract patterns, which might be useful for future experiments and applications.

It felt fluent but I did not like it: fluency effects in faces versus patterns

Whether you like a person or not is often appraised in a glance. However, under such short presentation durations stimuli are harder to perceive and, according to hedonic fluency theory-which holds that higher fluency is linked to higher liking-thus, are liked less. Given that liking considerably influences person perception, we tested how shorter and longer presentation durations affect liking for faces and compared this with abstract patterns. To capture facets of fluency of processing we assessed felt fluency, liking, and certainty ratings. Following predictions of fluency theory, longer presentation durations led to higher felt fluency, certainty, and positively affected liking judgments in the abstract patterns. In faces, felt fluency and certainty also increased with longer durations. However, with longer durations, faces were liked less, and liking was not related to felt fluency. In other words, in contrast to hedonic fluency theory, faces are more attractive when only seen for a short amount of time. Thus, fluency does not inevitably lead to more positive evaluations—it rather depends on the stimulus category. We discuss these findings in terms of the special status that faces have with regard to human perception and evaluation.

Private and Shared Taste in Art and Face Appreciation

Whether beauty is in the eye of the beholder or shared among individuals is a longstanding question in empirical aesthetics. By decomposing the variance structure of data for facial attractiveness, it has been previously shown that beauty evaluations comprise a similar amount of private and shared taste (Hönekopp, 2006). Employing the same methods, we found that, for abstract artworks, components that vary between individuals and relate to personal taste are particularly strong. Moreover, we instructed half of our participants to disregard their own taste and judge stimuli according to the taste of others instead. Ninety-five women rated 100 abstract artworks for liking and 100 faces for attractiveness. We found that the private taste proportion was much higher in abstract artworks, accounting for 75% of taste compared to 40% in the face condition. Abstract artworks were also less affected than faces by the instruction to rate according to others' taste and therefore less susceptible to incorporation of external beauty standards. Together, our findings support the notion that art-and especially abstract art-crystallizes private taste.

Effects of presentation duration on measures of complexity in affective environmental scenes and representational paintings

Complexity constitutes an integral part of humans' environment and is inherent to information processing. However, little is known about the dynamics of visual complexity perception of affective environmental scenes (IAPS pictures) and artworks, such as affective representational paintings. In three experiments, we studied the time course of visual complexity perception by varying presentation duration and comparing subjective ratings with objective measures of complexity. In Experiment 1, 60 females rated 96 IAPS pictures, presented either for 1, 5, or 25s, for familiarity, complexity, pleasantness and arousal. In Experiment 2, another 60 females rated 96 representational paintings. Mean ratings of complexity and pleasantness changed according to presentation duration in a similar vein in both experiments, suggesting an inverted U-shape. No common pattern of results was observed for arousal and familiarity ratings across the two picture sets. The correlations between subjective and objective measures of complexity increased with longer exposure durations for IAPS pictures, but results were more ambiguous for paintings. Experiment 3 explored the time course of the multidimensionality of visual complexity perception. Another 109 females rated the number of objects, their disorganization and the differentiation between a figure-ground vs. complex scene composition of pictures presented for 1 and 5s. The multidimensionality of visual complexity only clearly emerged in the 5-s condition. In both picture sets, the strength of the correlations with objective measures depended on the type of subdimension of complexity and was less affected by presentation duration than correlations with general complexity in Experiments 1 and 2. These results have clear implications for perceptual and cognitive theories, especially for those of esthetic experiences, in which the dynamical changes of complexity perception need to be integrated.

Incompleteness, aesthetic sensitivity, and the obsessive-compulsive need for symmetry

BACKGROUND AND OBJECTIVES

The "need for symmetry" is a well recognized yet little understood feature of obsessive-compulsive (OC) experience. In light of the strong associations between the OC-related trait of incompleteness and symmetry-related behaviors and symptoms, and between perceptual symmetry and aesthetic judgments, this study examined whether trait incompleteness is associated with enhanced natural aesthetic skill and/or aesthetic sensitivity, particularly as they pertain to visual symmetry.

METHODS

A quasi-experimental design was used to compare the responses of nonclinical individuals with high versus average levels of trait incompleteness on self-report measures and two performance measures of aesthetic judgment.

RESULTS

Compared to controls, participants high in incompleteness reported higher levels of self-perceived symmetry-related concerns and behaviors, and displayed greater aesthetic sensitivity in the form of substantially heightened preferences for symmetry in images. Contrary to the hypothesis relating to aesthetic skill, however, the two groups did not differ in their capacity to estimate accurately the objective aesthetic value of images. Nor did they differ in self-reported aesthetics interests and background.

LIMITATIONS

A clinical sample was not included.

CONCLUSIONS

Findings provide evidence that high trait incompleteness is associated not just with symptomatic symmetry-related concerns but with a nonspecific heightened preference for visual symmetry. Conceptual implications are discussed, particularly the potential value of the perceptual fluency theory of symmetry and aesthetic response for explaining the association between incompleteness and symmetry preferences and symptoms.

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.

Do I really feel it? The contributions of subjective fluency and compatibility in low-level effects on aesthetic appreciation

The causes for the liking of objects are multifaceted. According to the processing fluency account, the ease with which an object is processed leads to a subjective feeling of fluency. This subjective feeling is then interpreted as a positive reaction toward the object resulting higher liking. However, evidence regarding the processes underlying this relation is scarce. To show that the subjective feeling can indeed be responsible for liking, we experimentally manipulated processing ease by providing false physiological feedback (varying skin conductance indicated varying feelings of fluency) and by varying presentation times between 100 and 400 ms while participants viewed line drawings of objects and rated them for liking. A first experiment showed that both false physiological feedback and presentation duration influenced liking. Stimuli primed with a (fake) visualization of a physiological correlate of high ease of processing were liked more than stimuli primed with a low ease of processing. Liking ratings in a no-feedback condition fell between the high and low feedback conditions. To explore possible compatibility effects of coupling visual feedback to the fluency interpretation, in a second experiment we reversed the feedback interpretation—visualization of high skin conductance now indicated low ease of processing. The results show a similar pattern, though the effect was subtler. This indicates that when the coupling of feedback to fluency is less apparent or less compatible, the feeling is less strongly linked to liking. Our results support the claim that variations in the feeling of fluency affect the appreciation of objects in terms of liking. Together, the experiments suggest the contributions of processing ease as well as compatibility to the experience of liking.

Seeing and liking: biased perception of ambiguous figures consistent with the "inward bias" in aesthetic preferences

Aesthetic preferences are ubiquitous in visual experience. Indeed, it seems nearly impossible in many circumstances to perceive a scene without also liking or disliking it to some degree. Aesthetic factors are only occasionally studied in mainstream vision science, though, and even then they are often treated as functionally independent from other aspects of perception. In contrast, the present study explores the possibility that aesthetic preferences may interact with other types of visual processing. We were inspired, in particular, by the inward bias in aesthetic preferences: When an object with a salient "front" is placed near the border of a frame (say, in a photograph), observers tend to find the image more aesthetically pleasing if the object faces inward (toward the center) than if it faces outward (away from the center). We employed similar stimuli, except that observers viewed framed figures that were ambiguous in terms of the direction they appeared to be facing. The resulting percepts were influenced by the frames in a way that corresponded to the inward bias: When a figure was placed near a frame's border, observers tended to see whichever interpretation was facing inward. This effect occurred for both abstract geometric figures (e.g., ambiguously-oriented triangles) and meaningful line drawings (e.g., left-facing ducks or right-facing rabbits). The match between this new influence on ambiguous figure perception and the previously studied aesthetic bias suggests new ways in which aesthetic factors may relate not only to what we like, but also to what we see in the first place.

Birds of a feather... Generalization of facial structures following massive familiarization

Three experiments examined the effects of symmetry and complexity, as facial structures, on the aesthetic judgments of faces, and how these effects are modulated by moderate or massive familiarization. Results showed that symmetrical faces were judged as more attractive than nonsymmetrical faces, and simple faces were judged as more attractive than complex faces-with complexity defined as the number of facial elements. Complexity in faces seemed to have overridden the usually positive effects of facial symmetry. Moreover, while moderate familiarization did not modulate the effects, massive familiarization to a specific face type resulted in structural generalization effects: participants provided higher aesthetic judgments to faces that were new, but similarly structured to those which they were familiarized. This latter result contrasts previous studies that have found structural contrast effects following familiarization to meaningless, abstract stimuli. Taken together, these results reflect the greater biological and social significance of faces as compared to other objects in the world. They also show that people are drawn to those with familiar characteristics.