Toward A Brain-Based Theory of Beauty (Ishizu & Zeki, 2011)

Tomohiro Ishizu and Semir Zeki recently published a paper entitled “Toward A Brain-Based Theory of Beauty” in the open access journal PLoS ONE. Their main objective was to determine whether there are common neural mechanisms underlying the appreciation of beauty in visual and auditory stimuli. In order to do so, they asked 21 volunteers to rate 30 paintings and 30 musical fragments, presented for 16 seconds, on a 1 to 9 beauty scale while their brain activity was being scanned by means of functional magnetic resonance imaging (fMRI). Stimuli receiving ratings between 1 and 3 were classified as ugly, those between 4 and 6 were classified as indifferent, and those between 7 and 9 were classified as beautiful.

Their results revealed that rating the beauty of painting and music was related with activity in several brain areas. However, there was a single common region that was more active while people viewed or listened to stimuli they regarded as beautiful than the rest. This brain region was located in the medial orbitofrontal cortex (mOFC). Their analysis showed that neural activity in this region increased, almost linearly, with the beauty scores awarded to paintings and musical fragments. This relation is clearly visible in their figure 2, shown here:

The authors aimed to ascertain whether the mOFC region involved in judging the beauty of paintings and music excerpts was actually the same, so they performed a conjunction analysis. As shown in the next figure, their analysis revealed a specific region of the mOFC (in yellow) that is more active while engaging with stimuli, whether visual or auditory, regarded by the participants as beautiful. The authors refer to it as subdivision A1 of the mOFC.

Ishizu and Zeki (2011) have addressed the important and pressing issue of differences and similarities in the neural underpinnings of the experience of the beauty of stimuli belonging to different sensory modalities. They should also be commended for attempting to bridge the scientific and humanistic approaches to aesthetics. The authors discuss their results in light of the work of philosophers and art theorists. Specifically, they build upon Edmund Burke’s physiological perspective by proposing that “all works that appear beautiful to a subject have a single brain-based characteristic, which is that they have as a correlate of experiencing them a change in strength of activity within the mOFC and, more specifically, within field A1 in it” (Ishizu & Zeki, 2011, p. 8). I fear, however, that few humanists will be sympathetic to their reductionist brain-based theory of beauty.

Also, even though later in the paper Ishizu and Zeki (2011) “broaden [their] neurobiological definition of beauty given above to include not only activation of mOFC but also its co-activation with sensory areas that feed it” (Ishizu & Zeki, 2011, p. 9), I get the impression from reading their work that the authors regard mOFC subdivision A1 as a sort of beauty detector, downplaying the role of other brain regions and assigning it a very specific role in the experience of beauty. Previous neuroimaging studies, however, have demonstrated that a number of other brain regions are involved in the appreciation of beauty (Nadal & Pearce, 2011). Moreover, the important role of cognitive processes related with perception, memory, emotion, expectations and decision-making is widely recognized today. In fact, the interaction among these processes is the essence of psychological and neuroscientific models of beauty appreciation (Chatterjee, 2004; Leder et al., 2004).

From this interactionist perspective, the experience of beauty cannot be equated with increases in the activity of any given brain region. Rather, it is viewed as the result of the interaction among brain regions related with processes perception, memory, reward, and so on. Ishizu and Zeki’s (2011) significant contribution has shown that some of these regions are involved in the appreciation of the beauty of both paintings and music. The kind of brain-based theory of beauty that we need today, however, is one that can clarify how beauty emerges from the activity of a network of broadly distributed brain regions, and how certain personal and environmental factors modulate activity in those regions and the mutual interactions among them.

Chatterjee A. 2004. Prospects for a Cognitive Neuroscience of Visual Aesthetics. Bulletin of Psychology of the Arts 4:55-60.

Ishizu, T. & Zeki, S. (2011) Toward A Brain-Based Theory of Beauty. PLoS ONE, 6: e21852.  doi:10.1371/journal.pone.0021852.  [pdf]

Leder H, Belke B, Oeberst A, Augustin D. 2004. A model of aesthetic appreciation and aesthetic judgments. British Journal of Psychology 95:489-508.

Nadal, M., & Pearce, M. T. (2011). The Copenhagen Neuroaesthetics conference: Prospects and pitfalls for an emerging field. Brain and Cognition, 76, 172–183. [pdf]