Neuroaesthetics

The following sections are included:

• Foreword
• Contents

In this and subsequent issues in the PsyCh Journal, we are publishing a set of papers that can be grouped together broadly under the title of “neuroaesthetics”. This is a relatively new field, or rather a subfield, which aims to understand the brain mechanisms that are engaged during aesthetic and allied experiences in the widest sense. That, of course, encompasses a vast area: It amounts to trying to understand what neural mechanisms underpin inherited aesthetic predispositions compared to acquired ones, the extent to which aesthetic judgments are subjective, and the relationship of aesthetic and perceptual judgments to the experience of pleasure, desire, love, and hate, among other topics, with all the complexities that such sentiments involve.

The loud beating of gongs, proclaiming interdisciplinarity and risk-taking as hallmarks of a new attitude to research, one that will reap rich rewards in extravagant cash for further work, would have sounded like a re-invention of the wheel — and a poorly constructed wheel at that — to Polykleitos, Phidias, Michelangelo, and Leonardo, among many others. It would probably have sounded strange even to Einstein (1936), who once wrote that “the whole of science is nothing more than a refinement of everyday thinking. It is for this reason that the critical thinking of the physicist cannot possibly be restricted to the examination of the concepts of his own specific field. He cannot proceed without considering critically a much more difficult problem, the problem of analysing the nature of everyday thinking.” This can be taken as a clear invitation to the physicist to enquire more deeply into the knowledge-acquiring system of the brain, through which all knowledge, including that in physics, is acquired. One can look at this re-invented wheel and consider much of the hype behind it as nothing more than guff, which indeed it largely is. Even so, it is nevertheless more than welcome and perhaps will mature eventually into what it promises to be but has so far rarely been…

Art and science have a common root. In spite of occasional misunderstandings between the sciences and the humanities representing different academic disciplines, a bridge between art and science can be built to allow broader perspectives in understanding and foster new creativities both for artists and scientists. We provide examples from the visual arts, music, and poetry. In particular, the spatial configuration in pictures or the temporal structure in music and poetry are addressed. They directly represent a conceptual link between artistic appreciation and mechanisms of information processing in the brain.

This is the claim: Human knowledge expresses itself in three different modes — explicit, implicit, and sensory (e.g., visual) knowledge. The reference to knowledge as explicit knowledge only (as it is usually done) neglects the other modes of knowledge. Instead of using the noun “knowledge”, it is suggested that we use “knowing” as a term to stress the active mode in cognition. The three modes of knowing are reflected in different mechanisms of cognitive and neural processing; these can already be observed in classical documents of humankind. This unity of the different modes of knowing can also be extracted from cultural artifacts, such as poetry. Although possessing different characteristics, the three modes of knowing are related to each other in a complementary way, thus providing an integrative network for cognition. We suggest that a unifying frame of the modes of knowing lies in aesthetic principles. These different modes of knowing with their unifying frame reflect some general features of cognition. We stress that basic concepts in “artificial or machine intelligence” do not match at all human modes of knowing.

During the 18th century, debates about what constituted the sublime flourished in Europe, particularly in Germany. These debates were nourished by two different visions: The Kantian concept supposed that the sublime is supra-sensible and rooted in reason (Logos) rather than in the object, thus provoking a mental state of tension between nature and art; Edmund Burke’s concept, on the other hand, conceived of the sublime as a bodily immersive experience, which we here define as “sensitive” sublime. In summary, Burke’s view of the sublime is rooted in the senses and not in the power of reason, unlike Kant’s. This was to disrupt the mainstream ideas of that time, unconsciously anticipating some of the recent neuroaesthetic acquisitions regarding the central role played by the sensory apparatus in the experience of beauty and of the sublime.

After reviewing some publications in the field of neuroaesthetics, we find that in experiments on tasks about aesthetic appreciation, many cortical areas are involved. Combining experimental data with theoretical concepts like complementarity as a generative principle, logistic and content functions, and three modes of knowing, i.e., explicit, implicit, and sensory knowledge, we argue that aesthetic appreciation is both an early implicit reaction (feeling) and a late explicit evaluation (thinking), representing pre-semantic bottom-up and conscious top-town processing, respectively. On a strategic level, we propose that neuroaesthetics can serve as a conceptual bridge to bring together neuroscientific and psychological research, and we can link it to psychoanalytical considerations. A critical parameter of research in neuroaesthetics may be the cultural frame. Thus, to explore aesthetic appreciation in different cultures, we used a semantic differential questionnaire in Chinese, Japanese, Italian, and Farsi with male and female subjects to evaluate the concept of “beautiful”. In spite of some similarities in these cultures, important differences in aesthetic appreciation were observed; our result suggests that semantic frames may also be relevant to other theoretical concepts.

Understanding how art makes impressions upon the perceiver has been a fundamental topic of philosophical interest since the time of ancient Greece. However, the extent of artistic perception and aesthetic appreciation has been the topic of empirical studies only recently, following the emergence of psychology as an independent field of science. This chapter discusses the hypothesis that the impression created by an artwork on the viewer can be predicted by examining the activity of neuronal networks. In particular, we focus on neural activity evoked by abstract stimuli that matches elements of the viewers’ previously learned conceptual dictionary. We show that artistic appreciation fundamentally depends on how easily the author’s intent expressed in his or her artwork can be abstracted and decoded, on a neuronal level, into new or merged concept networks. More diverse intellectual and personal experiences — and their corollary neural networks — may facilitate the creation of new networks. These new networks, in turn, modulate the extent to which art can be apprehended and appreciated.

We here address the question of the extent to which judgments of mathematical beauty (which we categorize as biological beauty) are resistant to revision through external opinion. A total of 100 mathematicians of different national and ethnic origins were asked to rate 60 mathematical equations for their beauty; after being presented a fictitious “expert rating,” they were asked to re-rate the same equations. Results showed that the judgments of mathematical beauty had a high level of resistance to external opinion. This is in line with the resistance to revision of judgments for other categories of biological beauty.

Using fMRI, a core evaluation mechanism was found for aesthetic judgments with add-on neural activities for moral and commercial judgments. We propose that aesthetic evaluations serve as a basic core mechanism implicitly for moral and commercial judgments.

The objective of this chapter is a holistic view of aesthetics, ethics, and neuroaesthetics. After a few introductory case studies, aesthetics is systematically introduced as a philosophical subdiscipline. This perspective is then expanded from aesthetics to neuroaesthetics. Using various art forms as well as current media formats, the aspects of beauty and ugliness are discussed, and aesthetic properties are expanded to include ethical implications. These can be expressed through ideals of beauty and the compulsion for body transformation. This perspective is then expanded from aesthetics to neuroaesthetics. From this point of view of art, the so-called golden ratio will play a central role. It is shown how representations affect people and what ethical implications are associated with the effects. Therefore, this chapter first has to look at art from the perspective of neuroaesthetics and then consider the ethical aspects of the beautiful and the ugly. The considerations lead to a brief discussion of Socrates’s three sieves.

In Gödel’s incompleteness theorems, for every mathematical system, there are correct statements that cannot be proven to be correct within that system. We here extend this to address the question of axiomatic statements that are perceived (or known) to be correct but which mathematics, as presently constituted, cannot prove. We refer to these as perceptual axioms.

Art in general perception is something that transcends our notion of reality. In view of the earliest findings in Paleolithic sites, their abstract appearance and sometimes ceremonial context increased their status of a secret language. Even the first figurative cave paintings remained in the context of an encoded semantic whole. The highly symbolic value of art seemed invulnerable. It was just the claim for mimesis in Greek antiquity (Plato) that urged artists to “realistically” depict what can be seen — as to stay in track of eternal messages behind. This devaluated the artistic oeuvre to a purely imitating craft and had to overcome at once several inherent obstacles. First, that reality (the phenomenal world) is in general only a pale reflection of what lays behind (Platonic ideas) and second, that the human eye, unlike the human mind, cannot penetrate to more than ephemeral impressions. Moreover, it mixed up reality with what we are able to see (i.e., visual perception), thus supposing a pinpoint representation of the world by our senses. Aristotle was the first to qualify art as picturing more than we usually are meant to see, filling the gap between the sensual and the spiritual world. Aristotelian aesthetics includes concepts of reduction and selection of composition and emotion, thus a summarized view within any performance of poetics or painting. And it took centuries to close the gap between natural and aesthetic perception or art. Life sciences in the 20th century discovered the evolutionary basis of sensory perception as being highly biased and organized, concept as emotion-driven and thus, mentally equipped as well. This sets a new approach in our understanding of perception, art, and aesthetics as an ongoing communication in process on common bases. Art may cooperate or disagree but never can cut the nexus with its perceptual prejudices and substrate.

The golden ratio (GR) is an irrational number (close to 1.618) that repeatedly occurs in nature as well as in masterpieces of art. The GR has been considered a proportion perfectly representing beauty since ancient times, and it was investigated in several scientific fields but with conflicting results. This study aims at investigating if this proportion is associated with a judgment of beauty independently of the type of the stimulus, and the factors that may affect this aesthetic preference. In Experiment 1, an online psychophysical questionnaire was administered to 256 volunteers asked to choose among three possible proportions between the parts of the same stimulus (GR, 1.5, and 1.8). In Experiment 2, we recorded eye movements of 15 participants who had to express an aesthetic judgment on the same stimuli as Experiment 1. The results revealed a slight overall preference for GR (53%, p < 0.001), with higher preferences for stimuli representing humans, anthropomorphic sculptures, and paintings, regardless of the cultural level. In Experiment 2, a shorter dwell time was significantly associated with a better aesthetic judgment (p = 0.005), suggesting the possibility that GR could be associated with easier visual processing, and it could be hence considered as a visual affordance.

Can neurosciences explain art? No, but it can help us to understand why some images are more memorable and, thus, more successful than others. This chapter aims to identify certain factors that may influence the artistic success of photographic images. These factors are discussed within the contexts of basic neuropsychological concepts, visual perception, and visual memory. A new computational and neuroscientifically based model, the predictive coding theory, provides a powerful frame-work for integrating social and individual factors that influence aesthetic experience and activity. A case study of Dorothea Lange’s iconic photograph Migrant Mother demonstrates the importance of identifiable factors that influence and determine a photograph’s potential success. We are convinced that a future systemic approach will enable the complementary integration of neuroscientific, perceptual, cognitive, emotional, and sociopsychological insights through the framework of predictive coding theory with socioscientific, art-theoretical, and art-historical as well as neuro- and behavioral-economical models.

The eminent Chinese artist LaoZhu has created a homogeneous set of abstract pictures that are referred to as the “third abstraction.” By definition, these pictures are meant to be representations of the artist’s personal involvement and as such to create an internal point of view in the observer on an implicit level of processing. Aiming at investigating whether the artist’s choice of a specific color is experienced in a specific way by the recipient, we assessed both explicit and implicit (i.e., neuro-cognitive) correlates in naive viewers of LaoZhu’s pieces. The behavioral results reveal a preference of the original red paintings over color-changed counterparts in green or black. Paradoxically and inconsistent with predictions, we found higher levels of neural activation in several brain regions (predominantly in the frontal and parietal cortices) for the color-changed compared to the original red conditions. These observations add empirically to the complementarity of early visual pathways and higher-order cognition as well as of explicit and implicit information processing during aesthetic appreciation. We discuss our findings in light of processing effort and top-down control of the color-changed paintings. With regard to the third abstraction as defined by LaoZhu, in particular to the distinction between an external and internal point of view when viewing abstract art, our results contribute to an understanding of “abstraction and empathy” as a fundamental part of aesthetic appreciation.

“Habent sua fata libelli”: This classical Latin sentence says that books have their own fate. This applies also to pictures. In the moment an artist opens the atelier and invites the visitors to look at the pictures, they start a new life, their ownership is now shared by others. This happened to the two of us when we visited LaoZhu in his atelier. He looked at one of us (EP) who looked in this moment at a picture of the Zhu Mo series (Figure 1). LaoZhu spontaneously said that the picture is now part of you. Indeed, in this moment it became a part of one of us (EP) but also a part of the other one of us (YB), although in a different way, when she looked at the same picture. Different bridges were created between our seeing eyes and our inner eyes, the representation in our mind. Even LaoZhu may have created in this moment a new bridge to his pictures because of our physical presence and our shared ownership. Although every one of us saw the picture in a different way possibly shaped by our different cultural imprinting (Chinese and German), by prior experiences, implicit expectations, hidden prejudices, we were connected with each other by the one picture, the artist and we visitors. Although every one of us was (and always is) a “victim” of a very personal process of abstraction when seeing a picture, unity was created in this moment by a common reference, namely, this one picture. The founder of aesthetics in modern times, Alexander Baumgarten (1750/58), asked this question in his classic book Aesthetica: quid enim est abstractio, si iactura non est? — “what else means abstraction than a loss?” But how much have we gained by the abstract bridges to the one picture in spite of the necessary theoretical loss due to abstraction; we three found ourselves together in this moment at one location in an abstract space, enchanted in the multiverse of LaoZhu…

The creation of artwork requires motor activity. However, few empirical studies have directly explored the relationship between the experience of an artist’s action and aesthetic experience. This study aimed to examine the effect of observing and imagery of the artist’s action on the participants’ aesthetic preferences. In Experiments 1 and 2, we took hard-pen and brush-pen Chinese calligraphy images as the stimulus, respectively, to explore the influence of action observation on the aesthetic preference by manipulating the artists’ actions. The results of both Experiments 1 and 2 show that when participants observed the artists’ actions, they tended to report a higher preference for calligraphy images compared with the control condition. In Experiments 3 and 4, we used instructions to manipulate the motor imagery tasks and investigated the effect of imaging the artist’s action on the participants’ aesthetic preferences. The results showed that both kinesthetic imagery and visual imagery increased the participants’ preferences. In general, our study shows that both action observation and motor imagery contribute to participants’ aesthetic preferences. The results are discussed in terms of how artists’ actions possibly influence the aesthetic preference of Chinese calligraphy.

The aim of this study is to explore the factor structure of audiences’ physical experience and their related bodily sensations when watching dance choreographies. This study also includes the process of developing an instrument for measuring the observers’ physical experience of dance choreographies and their related kinesthetic responses to watching dance. In the main study, participants rated their physical experiences and kinesthetic responses when watching 16 different dance choreographies of various dance forms, including contemporary dance, jazz, tango, and hip-hop. Three factors of the observers’ physical experiences when watching dance were identified: Action Tendency, Arousal, and Relaxation. Furthermore, the results show that the structure of the observers’ kinesthetic responses when watching dance consisted of three factors: Focus, Excitement, and Embodied Anticipation. The spectators’ physical experiences and bodily sensations in response to an observed dance are the result of their engagement in the dance, the pleasure they draw from the dance, the emotions provoked in them, and their admiration for the performance. These findings are in line with the concept of kinesthetic empathy, which can be understood as the experience of sharing a dancer’s movements.

Colors are critical for understanding the emotional aspect of the human artistic mind, such as that found in painting a landscape, still life, or portrait. First, we report how single colors are memorized in the brain; second, how pairs of colors harmonize in the dissociated brain under the influence of the emotional brain; third, we see how colored paintings are appreciated as beautiful or ugly in the dissociated brain areas led by the intrinsic reward system in the human brain. The orbitofrontal brain is probably one of the vital brain areas that brings us a value-based reward system that makes a unique contribution to emotional neuroaesthetics.

Contemporary art is often challenging for the viewer, especially when it violates classic rules of representation. Also, viewers usually have little knowledge about this type of art, making its reception even more difficult. Our main research question was how the cognitive challenge associated with contemporary art affects eye movement. In particular, we aimed to assess the impact on eye movements of (a) object-related cognitive challenge in terms of image properties (syntactic and semantic violations) and (b) subject-related cognitive challenge (composite subjective estimate of image inconsistency, ambiguity, and complexity). The eye movements of expert and naive participants were recorded while they freely viewed digital copies of contemporary paintings (four groups of five paintings each, differing in the presence of semantic and syntactic violations). We found that neither violations nor art expertise alone predicted eye movements, although perceived, subjectively experienced cognitive challenge did. In particular, subject-related cognitive challenge was associated with an increase in visual exploration (longer and more numerous fixations, bigger area of exploration, and longer viewing time). The roles of object-related and subject-related indicators of cognitive challenge in perception of contemporary art are discussed.

Faces and their aesthetic appreciation are a core element of social interaction. Although studies have been made on facial processing when looking at faces with different perspectives, a direct comparison of faces from the left to the right perspective is missing. Portraits in classical Western art indicate a preference for the left compared to the right perspective, but the neural underpinnings of such an asymmetry still have to be clarified. Using functional magnetic resonance imaging, this study focuses on the processing of three-quarter faces seen from different perspectives. Seventeen participants were asked to passively look at photographs of six male and six female faces with neutral expression; the photographs were taken from the left, right, and frontal perspectives while keeping their focus on the eyes. The results showed that specific brain areas were involved in processing the three-quarter faces in either symmetric or asymmetric ways. Viewing left and right three-quarter faces resulted in two mirror-like activations in the striate cortex corresponding to the symmetric layout of the left and right perspectives. Viewing the left face resulted additionally in an enhanced activation also in the left extrastriate cortex. The right perspective of male faces elicited a lower activation compared to other perspectives in face-selective areas of the brain. Our findings suggest that the preference of the left three-quarter face emerges already in the early visual pathway presumably prior to facial identification, emotional processing, and aesthetic appreciation. Our observations may have general importance in disentangling different neural components and processing stages in the spatiotemporal characteristics of artistic expressions.

Preferring life to death is deeply rooted in our biology. With this study, we explored two questions: (1) Can this inclination be transposed to aesthetics so that a living being is valued as more beautiful than a non-living being? and (2) Are there any differences in the visual exploration of portrayals of a living compared to a dead human? In particular, are there any specific facial features representing the vitality status of a living or dead subject? By answering both questions, young adults’ eye gazing was analyzed while they observed, aesthetically judged, and judged the vitality status of faces extracted from paintings representing a sleeping or dead subject. The aesthetic preference for the stimuli as a function of vitality (living and dead) was assessed both during the eye-tracking study and during a follow-up priming behavioral experiment. The analysis of the responses given during the aesthetic judgment (AJ) task in the eye-tracking study revealed preference for the sleeping compared to the dead subjects, supporting proclivity to attribute greater aesthetic value to living beings. This evidence was substantially confirmed by the follow-up priming behavioral study, which further showed a significant effect of explicit vitality labeling on the aesthetic evaluation of the portrayals of sleeping subjects. As far as the visual exploration of the stimuli is concerned, the main eye-tracking results revealed great attention to the eye region of both sleeping and dead subjects, which was particularly enhanced for the sleeping compared to the dead subjects. For the latter stimuli, focused attention was also found in the mouth region. These results are discussed in light of different theoretical proposals, including the “embodied” theory of aesthetic perception based on the existence of mirror systems.

The original left-front perspective of portraits by Rembrandt was detected by Chinese students with a higher recognition rate as compared to the right-front perspective or the mirror reversals of both perspectives. Oculomotor patterns indicated that the eye regions provided essential information for such implicit detection.

Empirical evidence shows that the often-made positive correlation between human physical and moral beauty is tenuous. In this study, we aimed to learn whether facial and moral beauty can be psychophysically separated. Participants (n = 95) provided beauty and goodness (i.e., trustworthiness) ratings for pictures of faces, after which they were presented with a fictitious peer rating for the same face and asked to re-rate the face. We used the difference between the initial and final ratings to quantify the degree of resistance to external influence. We found that judgments of facial beauty were more resistant to external influence than judgments of facial “goodness”; in addition, there was significantly higher agreement within beauty ratings than within goodness ratings. These findings are discussed in light of our Bayesian–Laplacian classification of priors, from which we conclude that moral beauty relies more upon acquired “artifactual” priors and facial beauty more on inherited biological priors.

We addressed the question of the extent to which external information is capable of modifying aesthetic ratings given to two different categories of stimuli — images of faces (which belong to the biological category) and those of abstract paintings with no recognizable objects (which sit in the artifactual category). A total of 51 participants of different national origins rated the beauty of both sets of stimuli, indicating the certainty of their rating; they then re-rated them after being exposed to the opinions of others on their aesthetic status. Of these 51 participants, 42 who met our criteria were selected to complete the experiment. The results showed that individuals were less prone to modifying their ratings of stimuli belonging to the biological category compared to those falling into the artifactual category. We discuss this finding in light of our theoretical Bayesian–Laplacian model and on the evidence given by previous empirical research.

We have previously suggested a distinction in the brain processes governing biological and artifactual stimuli. One of the best examples of the biological category consists of human faces, the perception of which appears to be determined by inherited mechanisms or ones rapidly acquired after birth. In extending this work, we inquire here whether there is a higher memorability for images of human faces and whether memorability declines with increasing departure from human faces; if so, the implication would add to the growing evidence of differences in the processing of biological versus artifactual stimuli. To do so, we used images and memorability scores from a large dataset of 58,741 images to compare the relative memorability of the following image categories: real human faces versus buildings, and extending this to a comparison of real human faces with five image categories that differ in their grade of resemblance to a real human face. Our findings show that, in general, when we compare the biological category of faces to the artifactual category of buildings, the former is more memorable. Furthermore, there is a gradient in which the more an image resembles a real human face, the more memorable it is. Thus, the previously identified differences in biological and artifactual images extend to the field of memory.

The existence of discrete time windows has triggered the search for permanence and continuity for artists (including poets) in multiple cultures throughout history. In this chapter, we argue that there exists a 3-s window in the temporal structure of poems as well as in the aesthetic appreciation of poetry by reviewing previous literature on the temporal aspects of poems. This 3-s window can also be considered to be a general temporal machinery underlying human behavior, including language production and perception in general. The reafference principle has provided us with a unique frame for understanding cognitive processes. However, “time” was absent in the original two-stage reafference principle. Therefore, we propose a three-stage cycling model of language perception, taking into account time and time windows. We also inspect the possible neural implementations of the three stages: the generation, maintenance, and comparison of predictions (as well as the integration of predictions into the representational context). These three stages are embedded in a temporal window of ∼3 s and are repeated in a cycling mode, resulting in the representational context being continuously updated. Thus, it is possible that “semantics” could be carried forward across different time windows, being a “glue” linking the discrete time windows and thus achieving the subjective feeling of temporal continuity. Candidates of such “semantic glue” could include semantic and syntactic structures as well as identity and emotion.

We studied the effect of time windows of a few seconds on the aesthetic appreciation of poems. Both Chinese and German subjects rated traditional Chinese poetic verses more beautiful in a time window of approximately 3 s, irrespective of understanding the poetic content. This observation suggests a common temporal preference for poetry appreciation across a different language background.

Movie shots of singular scenes have a preferential duration of 2 to 3 s regardless of producers, movie types, and cultural environments. This observation suggests that the temporal structure of movies matches a neural mechanism of information processing in the time domain.

“Seeing with the mind’s eye” and “hearing with the mind’s ear” are two common indicators of musical imagery, and they can be referred to as “visual” and “auditory” musical imagery. However, a question remains open, that is, whether visual and auditory imagery of the same musical composition share the same neural mechanisms. Moreover, how can neural mechanisms guarantee the temporal flow of “musical imagery”? To answer these questions, we report here a preliminary single case study using functional magnetic resonance imaging with an eminent composer who imagined one of his compositions in two states of mind as compared to his resting-state activity. In the visual imagery condition, he imagined visually the score of his composition in a continuous way. In the auditory imagery condition, he imagined auditorily the same musical composition with pauses. In spite of the modality and temporal differences, the two types of mental imagery showed similar temporal durations for the same musical composition. However, different patterns of neural activation were observed for visual and auditory imagery with one important exception, that is, a common activation pattern was observed in the left medial temporal gyrus in both visual and auditory imagery. We speculate that the left medial temporal gyrus may play an important role in the creation of apparent temporal continuity in musical imagery and perhaps even in conscious information processing in general.