MDL: A system for fast simulation of large layered neural networks

Abstract

The Model Development Language (or MDL) is a simulation language and system which uses an assignment statement notation tailored for 2-dimensional layered neural networks. The key features are: (1) Operations occur on 2-dimensional arrays which correspond to the layout of many brain structures. (2) A spatial convolution operation models spatial summation occurring in dendritic trees. (3) Arbitrary time invariant expressions and differential equations may be specified by simple assignment statements. (4) Numerical methods are automatically taken care of in the MDL environment rather than in the user's specification of the model. These features allow high level modeling using leaky integrator model neurons and modeling of detailed biophysical properties, such as the Hodgkin-Huxley equations and voltage clamp experiments. Conciseness of the language allows specification of a moderately complex retina model in only one or two pages of code. The parallel structure of the language allows highly optimized implementation on parallel or vector processing computers. Use of the language is illustrated through two ex amples.