Reply to Grossberg

In response to comments by Grossberg, we discuss some topics related to neural models. We consider some experimental evidence from neurophysiology and neuroanatomy that bears on the simplifying assumptions that must be made when nervous system models are developed. A simple numerical example of a neural model with feedback is presented and discussed. As we tried to point out in our recent article (Anderson, Silverstein, Ritz, & Jones, 1977), the approximations we made there were oversimplifications of the complex reality of the nervous system—made so we could discuss only a few aspects of a very difficult problem. In Anderson et al. (1977), we considered a model that is partially linear. Whatever their theoretical shortcomings, linear systems approximate some aspects of neuron behavior surprisingly well. Clearly, many aspects of nervous system operation cannot be explained with linear models. We made the suggestion that a linear model, combined with a simple nonlinearity, gives rise to an interesting, relatively understandable nonlinear model with some intriguing applications to psychology. Grossberg (1978) obviously disagrees with some of our approximations. Below we make some comments that may clarify the biological basis of our model, and we also make a few remarks about the model itself. Cell Properties