Contrary to traditional assumptions in the behavioral sciences, the behavior of natural systems does not, as a rule, vary randomly over time, but instead tends to obey power-law or fractal scaling. Fractal scaling in time-evolving behavior refers to a scale invariant pattern of variation wherein smaller fluctuations are nested within larger fluctuations in a self-similar fashion. Ample research has confirmed that fractal scaling characterizes many different human time series, including a variety of neurological, physiological perceptual-motor, and cognitive behaviours. Of recent interest has been the discovery that when two or more individuals interact, the fractal structure of behaviour tends to become strongly correlated. This phenomenon, called complexity matching, has been found between interacting individuals engaged in many joint action tasks, such as coordinated finger tapping, treadmill walking, and conversational interaction. CM has also been shown to occur between participants and computer-generated stimuli, as well as between two different effectors of the same participant. The study of CM in human behavior is still in its infancy, however, and there is little agreement on the nature of the coordinative processes that promote its occurrence. Accordingly, the aim of this project is to better understand when, how, and why CM emerges between interacting individuals and the implications of CM with regards to understanding how coupled complex systems (including human and non-human agents) exchange information and mutually-adapt to ongoing environmental events.
Washburn, A., Kallen, R. W., Shockley, K., & Richardson, M. J. (2015). Harmony from Chaos: Anticipatory Synchronization and Complexity Matching in Aperiodic Interpersonal Coordination. Journal of Experimental Psychology: Human Perception and Performance. DOI:10.1037/xhp0000080
Washburn, A. Coey, C. A., Romero, V. Malone, M. L., & Richardson, M. J. (2015). Interaction of Intention and Environmental Constraints on the Fractal Dynamics of Human Performance. Cognitive Processing. DOI:10.1007/s10339-015-0652-6.
Coey, C. A., Washburn, A., & Richardson, M. J. (2014). Recurrence Quantification as an Analysis of Temporal Coordination with Complex Signals. In N. Marwan, M. Riley, A. Giuliani, and C. L. Webber (Eds.), Translational Recurrences: From Mathematical Theory to Real-World Applications (pp. 173-186). Springer International Publishing