Neural mechanisms underlying the hierarchical construction of perceived aesthetic value

The Beholder's Share: Bridging art and neuroscience to study individual differences in subjective experience

Our experience of the world is inherently subjective, shaped by individual history, knowledge, and perspective. Art offers a framework within which this subjectivity is practiced and promoted, inviting viewers to engage in interpretation. According to art theory, different forms of art-ranging from the representational to the abstract-challenge these interpretive processes in different ways. Yet, much remains unknown about how art is subjectively interpreted. In this study, we sought to elucidate the neural and cognitive mechanisms that underlie the subjective interpretation of art. Using brain imaging and written descriptions, we quantified individual variability in responses to paintings by the same artists, contrasting figurative and abstract paintings. Our findings revealed that abstract art elicited greater interindividual variability in activity within higher-order, associative brain areas, particularly those comprising the default-mode network. By contrast, no such differences were found in early visual areas, suggesting that subjective variability arises from higher cognitive processes rather than differences in sensory processing. These findings provide insight into how the brain engages with and perceives different forms of art and imbues it with subjective interpretation.

Body dysmorphic disorder

Body dysmorphic disorder (BDD) is an obsessive-compulsive disorder-related psychiatric condition characterized by an intense preoccupation with perceived physical flaws that are not observable by others. BDD affects ~2% of the adult population but is underdiagnosed, partly owing to limited clinician awareness, and undertreated, partly due to limited access to treatment. Research on the aetiology of BDD is scarce but likely involves an interplay between genetic and environmental factors. A few studies suggest functional and structural brain differences (compared with controls) in the regions involved in visual and emotional processing, although firm conclusions about the pathophysiology of the disorder cannot be made at this stage. Diagnosis requires the presence of repetitive behaviours or mental acts typically aimed at checking, correcting or concealing perceived flaws. The disorder typically has its onset before 18 years of age, with a female preponderance in youth but no major gender disparity in adults. Quality of life is markedly impaired across multiple domains and suicide risk is considerable. Evidence-based treatments include cognitive behavioural therapy and selective serotonin reuptake inhibitors. Future research should focus on understanding the biological and environmental factors that increase the risk of BDD, and on improving access to effective treatments, thereby addressing a critical gap in care for this often misunderstood and overlooked disorder.

Using machine learning to predict judgments on Western visual art along content-representational and formal-perceptual attributes

Art research has long aimed to unravel the complex associations between specific attributes, such as color, complexity, and emotional expressiveness, and art judgments, including beauty, creativity, and liking. However, the fundamental distinction between attributes as inherent characteristics or features of the artwork and judgments as subjective evaluations remains an exciting topic. This paper reviews the literature of the last half century, to identify key attributes, and employs machine learning, specifically Gradient Boosted Decision Trees (GBDT), to predict 13 art judgments along 17 attributes. Ratings from 78 art novice participants were collected for 54 Western artworks. Our GBDT models successfully predicted 13 judgments significantly. Notably, judged creativity and disturbing/irritating judgments showed the highest predictability, with the models explaining 31% and 32% of the variance, respectively. The attributes emotional expressiveness, valence, symbolism, as well as complexity emerged as consistent and significant contributors to the models' performance. Content-representational attributes played a more prominent role than formal-perceptual attributes. Moreover, we found in some cases non-linear relationships between attributes and judgments with sudden inclines or declines around medium levels of the rating scales. By uncovering these underlying patterns and dynamics in art judgment behavior, our research provides valuable insights to advance the understanding of aesthetic experiences considering visual art, inform cultural practices, and inspire future research in the field of art appreciation.

Aesthetic valence: Psychophysical perspectives

Comparisons of aesthetic valence and of sensory magnitude are subject to similar order effects, indicating an evolved mechanism that sharpens also aesthetic discrimination. As the foundation of pleasantness and aesthetic valence of an object, an optimal level of evoked arousal or, in more recent research, of information load, has been proposed. According to discrepancy theory, this evoked effect is modulated by the object's deviation from the current adaptation level (AL). The AL is built up and updated by pooling recent stimulation. A model based on these concepts is proposed here, and it is illustrated by results of empirical studies by the author's students. For everyday objects such as cars and ladies' clothes, rated beauty was related by a U-shaped function to rated modernity. Minimal beauty occurred for intermediate modernity. For ladies' clothes, this minimum was situated higher on the modernity scale for females and extraverts. As modernity can be seen as the amount of deviation from the AL which represents the usual, this shift could be explained by faster upward adjustment of the AL. In contrast, for paintings the relation between modernity and beauty was inversely U-shaped. This could be due to paintings intrinsically carrying more information than other objects, as indicated by ratings of hard-to-access, with which rated beauty had an inverse U-shaped relation. In a factor-analytic study of preference for 42 paintings four orthogonal factors were extracted, interpreted as High and Low modernity, and High and Low information content. This could yield a rudimentary empirical typology of art.

Multimodal fusion for anticipating human decision performance

Anticipating human decisions while performing complex tasks remains a formidable challenge. This study proposes a multimodal machine-learning approach that leverages image features and electroencephalography (EEG) data to predict human response correctness in a demanding visual searching task. Notably, we extract a novel set of image features pertaining to object relationships using the Segment Anything Model (SAM), which enhances prediction accuracy compared to traditional features. Additionally, our approach effectively utilizes a combination of EEG signals and image features to streamline the feature set required for the Random Forest Classifier (RFC) while maintaining high accuracy. The findings of this research hold substantial potential for developing advanced fault alert systems, particularly in critical decision-making environments such as the medical and defence sectors.

Unveiling the factors of aesthetic preferences with explainable AI

The allure of aesthetic appeal in images captivates our senses, yet the underlying intricacies of aesthetic preferences remain elusive. In this study, we pioneer a novel perspective by utilizing several different machine learning (ML) models that focus on aesthetic attributes known to influence preferences. Our models process these attributes as inputs to predict the aesthetic scores of images. Moreover, to delve deeper and obtain interpretable explanations regarding the factors driving aesthetic preferences, we utilize the popular Explainable AI (XAI) technique known as SHapley Additive exPlanations (SHAP). Our methodology compares the performance of various ML models, including Random Forest, XGBoost, Support Vector Regression, and Multilayer Perceptron, in accurately predicting aesthetic scores, and consistently observing results in conjunction with SHAP. We conduct experiments on three image aesthetic benchmarks, namely Aesthetics with Attributes Database (AADB), Explainable Visual Aesthetics (EVA), and Personalized image Aesthetics database with Rich Attributes (PARA), providing insights into the roles of attributes and their interactions. Finally, our study presents ML models for aesthetics research, alongside the introduction of XAI. Our aim is to shed light on the complex nature of aesthetic preferences in images through ML and to provide a deeper understanding of the attributes that influence aesthetic judgements.

Integrative processing in artificial and biological vision predicts the perceived beauty of natural images

Previous research shows that the beauty of natural images is already determined during perceptual analysis. However, it is unclear which perceptual computations give rise to the perception of beauty. Here, we tested whether perceived beauty is predicted by spatial integration across an image, a perceptual computation that reduces processing demands by aggregating image parts into more efficient representations of the whole. We quantified integrative processing in an artificial deep neural network model, where the degree of integration was determined by the amount of deviation between activations for the whole image and its constituent parts. This quantification of integration predicted beauty ratings for natural images across four studies with different stimuli and designs. In a complementary functional magnetic resonance imaging study, we show that integrative processing in human visual cortex similarly predicts perceived beauty. Together, our results establish integration as a computational principle that facilitates perceptual analysis and thereby mediates the perception of beauty.

Naturalistic reinforcement learning

Humans possess a remarkable ability to make decisions within real-world environments that are expansive, complex, and multidimensional. Human cognitive computational neuroscience has sought to exploit reinforcement learning (RL) as a framework within which to explain human decision-making, often focusing on constrained, artificial experimental tasks. In this article, we review recent efforts that use naturalistic approaches to determine how humans make decisions in complex environments that better approximate the real world, providing a clearer picture of how humans navigate the challenges posed by real-world decisions. These studies purposely embed elements of naturalistic complexity within experimental paradigms, rather than focusing on simplification, generating insights into the processes that likely underpin humans' ability to navigate complex, multidimensional real-world environments so successfully.

Influence of colour vision on attention to, and impression of, complex aesthetic images

Humans exhibit colour vision variations due to genetic polymorphisms, with trichromacy being the most common, while some people are classified as dichromats. Whether genetic differences in colour vision affect the way of viewing complex images remains unknown. Here, we investigated how people with different colour vision focused their gaze on aesthetic paintings by eye-tracking while freely viewing digital rendering of paintings and assessed individual impressions through a decomposition analysis of adjective ratings for the images. Gaze-concentrated areas among trichromats were more highly correlated than those among dichromats. However, compared with the brief dichromatic experience with the simulated images, there was little effect of innate colour vision differences on impressions. These results indicate that chromatic information is instructive as a cue for guiding attention, whereas the impression of each person is generated according to their own sensory experience and normalized through one's own colour space.

A clearing in the objectivity of aesthetics?

As subjective experiences go, beauty matters. Although aesthetics has long been a topic of study, research in this area has not resulted in a level of interest and progress commensurate with its import. Here, we briefly discuss two recent advances, one computational and one neuroscientific, and their pertinence to aesthetic processing. First, we hypothesize that deep neural networks provide the capacity to model representations essential to aesthetic experiences. Second, we highlight the principal gradient as an axis of information processing that is potentially key to examining where and how aesthetic processing takes place in the brain. In concert with established neuroimaging tools, we suggest that these advances may cultivate a new frontier in the understanding of our aesthetic experiences.