1. Introduction



1.1 Narrative Background

It was originally my intent to study the perception of time as a function of the fractal nature of stimuli, using auditory or musical stimuli, when Elliot Middleton informed me of a program by Julien Clinton Sprott that generated visual strange attractors, which I immediately downloaded from Sprott’s website, and was immersed in a world of beautiful images. We realized that by switching to these visual stimuli we could have a set of images whose fractal dimension was already computed by his program. I had been using his earlier book (Sprott, 1993) with the newly established Chaos Society of Silliman University, and so was familiar with his approach to dynamics, and with his research on aesthetics as a function of fractal dimension (Aks & Sprott, 1996). I later visited him while he adapted his programs to more general psychophysical explorations. While mainly interested in time perception, I had decided to use aesthetic judgments as well, mainly to attenuate the importance on time for my participants. Then I had the idea to add complexity judgments, thinking at the time that there were no precedents for that, which was true for such images, but in fact, I learned later, has a large history in psychophysical research. At any rate, he adapted his programs for me to be flexible to meet the changing needs of future experimental designs. When some undergraduate students at Silliman asked me for an idea for a research project using chaos for an experimental psychology course they were taking, the opportunity for them to do this exploratory study presented itself. About the same time, while giving lectures at a conference in Moscow in 2000 (Sulis & Tromifova, 2001), I shared Sprott’s computer program with Olga Mitina who subsequently did a nice study with it adding the investigation of personality factors (Mitina & Abraham, 2003). Thus began our collaboration.



1.2 Research Background

Nonlinear dynamical systems have recently been explored in cognitive and perceptual systems by the foundational programs of Freeman, (2006; Skarda & Freeman, 1987), Gregson (1996, 2006), Heath, (2000), Kelso and Engstrøm (2006), Turvey (2005), and Ward (2001), among many others. For a brief earlier history, see Abraham (1997a).

Perceptual/neural organizational features of attending complex stimuli may affect both the estimation of complexity and aesthetics, but also, there is the possibility that they could also affect the perception of time. There is likely a nonlinear interaction between the complexity of stimuli and experiencing time and aesthetics. Studies of both the perception of time and of aesthetics have centered on cognitive and biological factors (Anderson & Mandell, 1996; Eisler, A., 2003; Eisler, H.; Eisler, Eisler, & Montgomery, 1996). Many factors of stimuli, cognition, and biology have been investigated. One of the features of stimuli which make both biological and cognitive demands for time estimation is the amount of perceptual/cognitive effort involved, such as can vary with complexity of stimuli (Cupchik & Gebotys, 1988; Stoyanova & Yakimoff et al., 1987). The same could likely be said for aesthetic judgments (Aks & Sprott, 1996, 2003; Mureika, Cupchik, & Dyer, 2004; Sprott, 1993, 2003; Taylor, Spehar, Wise, et al., 2005).

To investigate the possibility of a relationship between complexity and judgments of time and aesthetics it was decided to use abstract stimuli. Chaotic attractors were used for this purpose as they are easy to generate along with objective measurements of their complexity (Aks & Sprott, 1996; Sprott, 1993a,b, 2003). Also, they are relatively free of prior associations. Chaotic attractors as stimuli can be created by integration of three coupled differential equations that produce abstract computer images in two spatial dimensions with the third dimension being represented by color coding, which adds to their aesthetic potential. To check on the assumption that mathematical complexity has a relationship to perceived complexity, it was decided to add an estimate of complexity to the ratings obtained from the participants.

While complexity of stimuli was the principal independent variable, demographic factors as well, namely age and culture (Eisler, Eisler, & Montgomery, 1994; H. Eisler, 1996) were also varied. Therefore, both children and adults, and both urbanized students of Silliman University and rural cultural minority visitors (Ati and Sulod) to a specialized education program to our campus served as participants.

And to enrich the dependent variable side of the experiment, in addition to scales of aesthetics and complexity, and estimates of stimulus duration, some narrative explorations of the features upon which the participants might have been basing their judgments were also attempted.