Cover image

Cover: The background image shows multiple exposures of an American cockroach, Periplaneta americana, running along an angled wall using its antenna to guide its locomotion. The upper inset shows a neuromechanical model that governs this sensory feedback behavior. The lower inset shows a Nyquist plot of the cockroach's open-loop transfer function, which reveals that the cockroach antenna must encode both distance and rate-of-convergence to the wall for stability. This hypothesis was tested by N. J. Cowan, J. Lee and R. J. Full (pp. 1617-1629).