A B S T R A C T
The author reviews visual perception studies showing that fractal patterns possess an aesthetic quality based on their visual complexity. Specifically, people display an aesthetic preference for patterns with mid-range fractal dimensions, irrespective of the method used to generate them. The author builds upon these studies by presenting preliminary research indicating that mid-range fractals also affect the observer’s physiological condition. The potential for incorporating these fractals into art and architecture
as a novel approach to reducing stress is also discussed.
Introduction
In art school I was told that Monet’s water lilies calm the observer, while van Gogh’s sunflowers electrify. To what extent, however, do paintings really affect the observer’s physical condition? The foundations of this question date back to 1890, when the connection between psychological states and physiological states was first considered [1]. However, the health trends of modern society cause this question to take on new urgency.
Stress is woven deep into our daily experiences. One in four people in the U.S.A. suffers from stress, and the associated annual cost to society is estimated to be $300 billion [2]. Consequently, researchers are searching for effective ways to reduce stress. One hope lies in adapting the interior and exterior of buildings to create environments that are more “in tune” with physiological responses to visual stimuli. Such projects offer the potential for interdisciplinary collaborations among scientists, artists and architects.
There are several characteristics of artworks that might be engineered to induce a desirable physiological response. These include subject matter, color and compositional form. I will focus on the latter characteristic. Furthermore, given the prevalence of natural landscapes in art and the popularity of windows that offer views of nature’s scenery, a useful starting point lies in the investigation of art composed from nature’s patterns.
For this reason, I will focus on fractal patterns. A diverse range of natural objects are fractal, including mountains, clouds, rivers and trees [3,4]. Furthermore, computers have led to the popularity of mathematically generated fractals. Fractals have also assumed a rapidly expanding role as an art form. This has been emphasized by my own discovery of fractal patterns in the works of Jackson Pollock [5,6]. Owing to fractals’ growing impact on cultures around the world and their prevalence in nature, they constitute a central feature of our daily visual experiences. How, then, do we respond to their visual characteristics? In this article, I address this issue by analyzing the results of an experiment performed by the National Aeronautics and Space Administration (NASA), in which skin conductance measurements were used to measure people’s physiological responses to natural images [7,8]. My fractal analysis of these images provides a preliminary demonstration that certain forms of fractal patterns might be used to reduce physiological stress.
Over the past 30 years, the visual appeal of fractals has been celebrated frequently [9–12], culminating in the dramatic identification of them as “the new aesthetic” [13]. The discovery that this aesthetic quality might be accompanied by a positive response in the observer’s physiology lends considerable support to previous proposals for fractal art and fractal architecture [14–18]. I therefore consider the artistic and architectural challenges of incorporating fractal imagery into buildings to affect people’s perceptual and physiological responses...
CONCLUSIONS
Although preliminary, the results discussed above have enormous potential —the motivation of this article is therefore to trigger further investigations. In particular, it is important to extend the physiological measurements beyond electro-dermal responses to include cardiovascular, eye-tracking and pupillography responses. In addition, future experiments should narrow the precise fractal character of the patterns that maximize the responses by considering additional parameters such as lacunarity and the full spectrum of dimensions obtained
from a multi-fractal analysis [63].
These experiments could provide a fascinating insight into the impact that fractal art and architecture might have on an observer’s perceptual and physiological responses. Stress reduction is of enormous benefit to society, and this novel approach of using fractals might prove particularly useful for therapeutic environments such as hospitals or in situations where people are deprived of nature’s fractals—for example, in windowless rooms or research stations in the Antarctic and in outer space. NASA’s motivation for conducting the experiments was to explore methods of maintaining low stress for astronauts, an aim that has become topical with the recent calls for manned missions to Mars.
The challenges of incorporating fractals into the interiors and exteriors of buildings will require an interplay between scientific, artistic and social considerations. In particular, the manner in which people are exposed to the patterns should be unobtrusive. Certainly, a future world where we are required to stare at fractal images for an allotted daily period conjures up unappealing visions of Orwell’s 1984! Fortuitously, the experiments described here indicate that the responses can be induced without prolonged exposure to fractals. The perception studies showed that observation periods of less than 10 seconds were sufficient to trigger aesthetic appeal. Furthermore, the participants in the NASA experiments were not instructed to look directly at the fractals, which were located on a far wall. This suggests that the fractals could be incorporated into the background environment. A swift glance at a painting on a corridor wall might be sufficient to induce the desired effect. Also, research into the fractal dynamics of music indicates that this subtle visual exposure might be integrated with sonic fractals [64].
Could a common set of fractal images be used for everyone? Although the majority of participants in the perception experiments preferred mid-range fractals [65], there is some evidence that creative people prefer the greater complexity of high-D patterns [66], raising the question of whether fractal images will have to be tuned to individual preferences. Furthermore, to prevent saturation of the relaxation effect, the fractal images would have to be varied over time, perhaps through the use of electronic screens or evolving lighting conditions. If these challenges seem daunting, it is worth stressing that we may already be using this approach to stress reduction without knowing it. Take, for example, staring into the flickering flames of a fire or looking up at tree branches swaying in the wind. The patterns in both cases vary with time while preserving their fractal qualities. The combination of their fractal content, along with other factors such as color and subjective associations, almost certainly reduce our stress.
The prevalence of artificial fractals suggests the possibility that we have been making use of fractal stress reduction throughout history. We expect our findings to apply to a range of fractal patterns appearing in art, architecture and archaeology, spanning five centuries! One example, shown in Fig. 7, is the skyline of the temple of Borobodur built in Java during the 8th century. Other examples include the Nasca lines in Peru (pre–7th century) [67], Gothic cathedrals (12th century) [68], the Ryoanji Rock Garden in Japan (15th century) [69], Leonardo’s sketch The Deluge (1500) [70], Hokusai’s woodcut print The Great Wave (1846) [71], Eiffel’s tower in Paris (1889) [72]