This is the second volume in a series intended to give clear expositions of the applications of the new techniques developed to understand nonlinear phenomena in the life sciences. The first paper by West, Mackey and Chen is methodological in nature and reviews how to distinguish between noise in biomedical data sets and irregularities generated by deterministic dynamical equations. The second paper by Hock, Schoner, Balz, Eastman and Voss addresses the problem of pattern formation and pattern change in the vision system. The premise of this research is that our understanding of visual pattern formation can be furthered using the theoretical concepts and associated experimental methods borrowed from nonlinear dynamics, stochastic processes and the theory of pattern formation. The authors emphasize the experimental correspondence between quantifiable perceptual phenomena and certain features of nonlinear dynamical systems theory. The paper by Chay focuses on modelling strategies for biological phenomena that manifest strong nonlinear behaviour. Biological rhythms and electrical bursting phenomena are discussed in detail, and certain apparently random processes are shown to be describable by chaos. The final paper is an attempt by Nicolis and Katsikas to use nonlinear dynamics systems theory to develop a general theory of linguistics. The concepts of information and pattern recognition are used in concert with that of a dynamic attractor to argue for the general properties of a cognitive processor.