aesthetics

Emotion, consciousness, aesthetics and subjective value assessments

Neuroaesthetics Eds: Martin Skrov & Oshin Vartanian

INTRODUCTION: The parts of the this book dealt with here emphasise the role of the orbitofrontal and other brains regions connected with emotional processing in the creation of aesthetic preferences. In these studies, aesthetic preference does not appear to be the result of the rational processing of abstract rules, but of a value assessment based on feeling. This is similar to the subjective value assessments in response to other stimuli, and as with these, it is hard to find place for a system of algorithms, calculation or other abstract rule that could produce the resulting assessment.

Chapter 4: The Arts are more than Aesthetics - Steven Brown and Ellen Dissanayake

In discussing the neuroscientific basis of aesthetic appreciation, the authors understand emotions as being responses to events in the environment that are appraised as being either good or bad. They see the concept of emotion as referring to three factors, valence, intensity and focus.

Valence refers to the fact that most emotions are primarily positive or negative. Intensity refers to the spectrum between say mere frustration and outright rage. The valence process as to whether something is emotionally positive or negative is seen as a mixture of perception of the external environment and perception of the internal state including visceral responses. Other researchers suggest that most of the processing for perception is unconscious, and that the conscious part of the processing of the aesthetic value is to a good extent at the emotional level.

With regard to focus, the authors largely reject Basic Emotion Theory (BET) as used in traditional psychology since the 19^th century. This theory worked in terms of a small number of emotions with a particular concentration on fear. Instead the authors view the valence reaction as being focused on the outcome of actions, the actions of other agents and the attractiveness of objects or events. The last category relates to aesthetic reaction, the understanding of which is seen by the authors as based on emotion.

The orbitofrontal area tends to relate to the prediction of reward, whereas the nucleus accumbens in the basal ganglia plus the dopamine and opiate systems relate to the actual delivery of reward. However, the orbitofrontal projects strongly to the basal ganglia which in turn project to the dopamine nuclei. It is possibly significant that the dorsolateral and orbitofrontal cortices are some of the brain regions that has expanded most in the evolution from the monkey to the human brain. No new areas as such have evolved between macaque monkeys and humans.

Chapter 6

Evolution of art and aesthetic expression

Marcos Nadal et al

The anterior cingulate has also been demonstrated to be active during the exercise of aesthetic preference. A type of neurons called spindle neurons is only found in the anterior cingulate cortex of great apes and humans. The highest proportion of such neurons is found in humans, who also have these neurons in clusters of three to six. Amongst great apes only bonobos have such clusters, and these also had a higher proportion of such neurons than the other apes. The greatest concentration of such cells is in the ventral part of the anterior cingulate, which is associated with emotional activity. Studies suggested that these neurons might allow emotional information to influence motor activity, vocalisation and autonomic functions.

Neuroimaging studies suggest that there is no single centre for aesthetic preferences. Apart from the orbitofrontal frontal, the caudate nucleus in the basal ganglia, the anterior cingulate and parts of the temporal lobe are involved, while presumably via feedback from the frontal areas, the primary visual processing area in the occipital cortex is also involved.

Chapter 13

Conscious experience of pleasure in art

Oshin Vartanian

The authors see the ventral portion of the human brain and notable the amygdala and the central and lateral parts of the orbitofrontal as involved in emotional processing. The amygdala tends to have a fixed response to inputs, while the orbitofrontal responds more to the context and a third brain region, the anterior insula cortex, responds more to internal body signals. The three together are suggested to create a value-based representation of a stimulus. This is seen a suitable basis for handling aesthetic preference.

Studies showed that reports of aesthetic preference are correlated to activation in the caudate nucleus and part of the cingulate cortex. Cognitive processing of the aesthetic input does not necessarily have to be complete for an aesthetic rating to be arrived at. Judgements can be based on emotion rather than abstract rules. With artistic stimuli, pictures already rated by others as beautiful resulted in particular stimulation of the orbitofrontal, and this was especially the case when beautiful paintings dealt with unattractive subject matter. When subjects rated the attractiveness of faces areas including the junction of the temporal and frontal lobe, the orbitofrontal and the caudate nucleus were involved.