The Golden Beauty: Brain Response to Classical and Renaissance Sculptures

Citation: Di Dio C, Macaluso E, Rizzolatti G ( The Golden Beauty: Brain Response to Classical and Renaissance Sculptures Cinzia Di Dio 0 1 Emiliano Macaluso 0 1 Giacomo Rizzolatti 0 1 0 Academic Editor: Aldo Rustichini, University of Minnesota , United States of America 1 1 Dipartimento di Neuroscienze, Universita` di Parma , Parma, Italy, 2 Fondazione Santa Lucia , Neuroimaging Laboratory , Rome , Italy Is there an objective, biological basis for the experience of beauty in art? Or is aesthetic experience entirely subjective? Using fMRI technique, we addressed this question by presenting viewers, nave to art criticism, with images of masterpieces of Classical and Renaissance sculpture. Employing proportion as the independent variable, we produced two sets of stimuli: one composed of images of original sculptures; the other of a modified version of the same images. The stimuli were presented in three conditions: observation, aesthetic judgment, and proportion judgment. In the observation condition, the viewers were required to observe the images with the same mind-set as if they were in a museum. In the other two conditions they were required to give an aesthetic or proportion judgment on the same images. Two types of analyses were carried out: one which contrasted brain response to the canonical and the modified sculptures, and one which contrasted beautiful vs. ugly sculptures as judged by each volunteer. The most striking result was that the observation of original sculptures, relative to the modified ones, produced activation of the right insula as well as of some lateral and medial cortical areas (lateral occipital gyrus, precuneus and prefrontal areas). The activation of the insula was particularly strong during the observation condition. Most interestingly, when volunteers were required to give an overt aesthetic judgment, the images judged as beautiful selectively activated the right amygdala, relative to those judged as ugly. We conclude that, in observers nave to art criticism, the sense of beauty is mediated by two non-mutually exclusive processes: one based on a joint activation of sets of cortical neurons, triggered by parameters intrinsic to the stimuli, and the insula (objective beauty); the other based on the activation of the amygdala, driven by one's own emotional experiences (subjective beauty). - INTRODUCTION One of the most debated issues in aesthetics is whether beauty may be defined by some objective parameters or whether it merely depends on subjective factors. The first perspective goes back to Platos objectivist view of aesthetic perception, in which beauty is regarded as a property of an object that produces a pleasurable experience in any suitable viewer. This stance may be rephrased in biological terms by stating that human beings are endowed with species-specific mechanisms that resonate in response to certain parameters present in works of art. The alternative stance is that the viewers evaluation of art is fully subjective. It is determined by experience and personal values (see [1,2]). Although it is commonly accepted that subjective criteria play a major role in ones aesthetic experience (see [3]), it is also reasonable to accept that there exist specific biologically-based principles which may facilitate the perception of beauty in the beholder. After all, new artists typically first master the ability to represent standard principles of beauty, such as symmetry and proportion, and only then eventually bend these rules to represent their overall vision of the world (see [4]). In the present study we investigated the aesthetic effect of objective parameters in the works of art by studying brain activations (fMRI) in viewers nave to art criticism who observed images of sculptures selected from masterpieces of Classical and Renaissance art that are commonly accepted as normative Western representations of beauty. An important feature that characterized the present study distinguishing it from others that also have attempted to clarify the neural correlates of aesthetic perception [58] was the use of two sets of stimuli that were identical in every aspects but one: proportion. More specifically, a parameter that is considered to represent the ideal beauty, namely the golden ratio (1:0.618; for reviews see [9,10]), was modified to create a degraded aesthetic value of the same stimuli in a controlled fashion (Figure 1). Stimulus manipulation was very contained and in no cases were the modified sculptures judged as deformed representations of the human body, as assessed in postscanning debriefing. Another important feature of the present study was that the same stimuli were presented in experimental conditions that varied in the instructions given to the participants. In one condition-observation (O)viewers were asked to observe the sculptures as if they were in a museum, without any explicit request to judge them. By inducing a simply enjoy contextual frame and without having the volunteers perform any specific cognitive task, we meant to elicit a most spontaneous/unbiased brain response to the artworks. In a second-aesthetic judgment (AJ)- and third -proportion judgment (PJ)- condition, on the other hand, the viewers had to judge the stimuli on the basis of their aesthetic or proportion quality, respectively. Therefore, in both these conditions the participants were involved in an additional cognitive evaluation of the stimuli. Whereas the aesthetic Funding: This study was supported by a grant from Italian Ministero Universita` Ricerca to G Rizzolatti. Funders had no role in the design and conduct of the study, in the collection, analysis, or interpretation of the data, and in the preparation, review, or approval of the manuscript. Figure 1. Example of canonical and modified stimuli. The original image (Doryphoros by Polykleitos) is shown at the centre of the figure. This sculpture obeys to canonical proportion (golden ratio = 1:1.618). Two modified versions of the same sculpture are presented on its left and right sides. The left image was modified by creating a short legs:long trunk relation (ratio = 1:0.74); the right image by creating the opposite relation pattern (ratio = 1:0.36). All images were used in behavioral testing. The central image (judged-as-beautiful on 100%) and left one (judged-as-ugly on 64%) were employed in the fMRI study. doi:10.1371/journal.pone.0001201.g001 judgment condition allowed us to determine brain activations in response to the volunteers subjective evaluation of the stimuli, the PJ condition was used to observe brain response during a task of overt proportion evaluation. In order to assess both objective and subjective aesthetic values, two types of analysis were carried out. In the first one, aimed at establishing the neural responses to objective beauty parameters, we contrasted brain activations during the presentation of the canonical sculptures vs. their modified counterparts. The underlying (...truncated)