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]

Do you know why you prefer the music you prefer?

A study in press at the Journal of Personality and Social Psychology, carried out by Peter J. Rentfrow, Lewis R. Goldberg and Daniel J. Levitin suggests that our preferences for music are related with 5 different underlying factors.

Like with other art forms, we engage with music at many different levels. On the one hand, music emerges from a complex interaction of acoustic properties and auditory processes, but on the other it conveys emotions and has strong social connotations. One of the aims of researchers interested in musical preferences is to determine how people’s preferences for music are related with those levels. Some preferences might be influenced by music’s purely physical properties, like loudness, tempo, and so on, the emotion it conveys, or its social implications.

Rentfrow and colleagues’ objective was to characterize the underlying structure of affective reactions to music excerpts. To achieve this aim they performed four experiments. First, they assessed the preferences of a sample of Internet users for fragments of commercially released but unfamiliar pieces of music. Second, they repeated this process with a sub-sample of participants using new unreleased pieces of music. Third, they assessed the preference of a sample of university students for a subset of the new music pieces. Finally, the musical fragments were coded on a number of attributes that could be used to characterize each of the underlying preference factors.

The results of their first three experiments converge on the existence of 5 main factors underlying musical preference determined both by social connotations and particular auditory features: (i) Mellow, which comprises smooth and relaxing music; (ii) Unpretentious, including mostly singer-song writer music; (iii) Sophisticated, including music perceived as complex, intelligent and inspiring; (iv) Intense, with loud, energetic and forceful music; (v) Contemporary, which comprises rhythmic and percussive music.

Their fourth study revealed that each factor is characterized by a unique set of attributes that distinguishes it from the rest. Specifically, excerpts with high loading on the Mellow factor were perceived as slow, quiet, undistorted, romantic, relaxing, unaggressive, sad, simple and interesting. Unpretentious music is rated as undistorted, instrumental, loud, electric, not fast, somewhat romantic, relaxing, sad, unaggressive, not complicated, and not intelligent. Sophisticated includes mostly instrumental, not electric, not percussive, not distorted, not loud, intelligent, inspiring, complex, relaxing, romantic and unaggressive music. Intense music was perceived as distorted, electric, loud, percussive, dense, aggressive, not relaxing, not romantic, not intelligent, and not inspiring. Music with high loadings on the Contemporary factor was rated as percussive, electric, and not sad.

If one of neuroaesthetics’ aims is to clarify the biological underpinnings of people’s liking and preference for music, these results are of relevance for at least two reasons. First, researchers should probably take these factors into account when designing future studies. Second, it would interesting to ascertain the neurobiological concomitants of such factors, and to determine whether there are any differences among the neural correlates of the aesthetic experience of people whose preferences clearly differ across those factors.

Rentfrow, P. J., Goldberg, L. R., & Levitin, D. J. (2011, February 7). The Structure of Musical Preferences: A Five-Factor Model. Journal of Personality and Social Psychology. Advance online publication. doi: 10.1037/a0022406

Music for relaxation or relaxation for music?

Many people feel that music has powerful effects on their mood and emotions. The fact that lullabies exist attests to music’s capacity to soothe. Adults too use music to relax: they play music to focus before an exam or to cool down after a stressful day. If music is beneficial for relaxation, could relaxation be beneficial for music? A recent study by Oshin Vartanian (DRDC Toronto) and Peter Suedfeld (University of British Columbia) adds to the growing evidence that relaxation and music might be mutually beneficial.

The study aimed to test whether a particular form of relaxation could enhance certain aspects of jazz improvisation. Prior evidence had shown that floating in a virtually stimulus-less environment (floatation version of the restricted environmental stimulation technique-REST) enhances perceptual and motor skills as well as creativity in sports and sciences. This disconnection from external stimulation reduces stress and induces a state of relaxed alertness and concentration. Could the same technique also lead to improvements in the perceptual-motor and creative aspects involved in jazz improvisation?

To answer this question Vartanian and Suedfeld asked 8 students enrolled in a jazz improvisation course to undergo one floatation session, which lasted an hour, each week for 4 weeks. Five other students acted as control group. All the participants individually performed five minute long freely conceived improvisations a week before and a week after the floatation sessions. These performances were recorded and then rated by an expert for improvisation, creativity, expressiveness, technical ability, and overall quality.

The results revealed that the initial performances of both groups of students did not differ on any of the assessment dimensions. However, the participants that completed the four floating sessions scored higher on technical ability than the control students on the post-treatment performance. No significant differences were found between both groups on any of the other measures. This result was confirmed by an independent measure of progress throughout the course.

Hence, flotation REST can improve the technical aspects inherent to musical improvisation. Contrary to the authors’ initial expectations, however, the same technique did not lead to better creativity scores. This might have been because these sessions have only short-term benefits on creativity, which faded before assessment. Alternatively, creativity in performing arts might not be expressed in the same ways as it is in other fields.

Clearly these results warrant further studies to test the effects of flotation REST on other musical abilities, as well as on other performing arts, and to clarify the neural mechanisms responsible for these improvements.