Strogatz 9627189 Many populations of biological oscillators can exhibit remarkable collective behavior. Despite differences in their individual natural frequencies, the oscillators spontaneously synchronize to a common frequency. Examples include chorusing crickets, fireflies that flash in unison, and synchronous firing of cardiac pacemaker cells. The investigator and his colleagues study the principles underlying these self-synchronizing systems, using analytical, computational, and experimental methods. The mathematical investigations concern the dynamics and stability of mutual synchronization, analyzed with techniques from perturbation theory, nonlinear dynamics, and statistical mechanics. The experimental aspects of the project deal with the chorusing behavior of the snowy tree cricket, regarded as a model experimental system for studying mutual synchronization. The experiments quantify psychophysical aspects of individual male responses as they relate to chorusing, and then extend to the behavior of larger groups, based on empirical measures of auditory perception, physiology, and signal propagation. The goal is to understand mutual synchronization in this biological system, and to test the results quantitatively against the predictions of mathematical models. This study provides the first detailed experimental investigation of mutual synchronization in a biological system. Although the synchronized chirping of crickets is the phenomenon being studied, the goals of the project are much broader. How does synchrony emerge in a group of dissimilar oscillators? This issue arises throughout all of science and technology, in such problems as the synchronization of arrays of lasers to achieve greater collective power, or the synchronization of pacemaker cells in the heart to produce a coherent beat. Theories of such self-synchronizing systems have been considered mathematically for almost thirty years, but they have never been checked experime ntally against any real biological system. This study is the first step in that direction. Benefits are expected not only for our understanding of biological synchronization, but also for spin-offs to technological applications involving arrays of oscillators, such as superconducting Josephson junctions and lasers.
