DevFly: Bio-Inspired Development of Binary Connections for Locality Preserving Sparse Codes

Tianqi Wei, Rana Alkhoury Maroun, Qinghai Guo, Barbara Webb

Keywords: bioinspired, neurodevelopment, mushroom body, locality-sensitive hash, sparse coding

TL;DR: A bio-inspired developmental method to build new connections in a network used for locality sensitive hashing.

Abstract: Neural circuits undergo developmental processes which can be influenced by experience. Here we explore a bio-inspired development process to form the connections in a network used for locality sensitive hashing. The network is a simplified model of the insect mushroom body, which has sparse connections from the input layer to a second layer of higher dimension, forming a sparse code. In previous versions of this model, connectivity between the layers is random. We investigate whether the performance of the hash, evaluated in nearest neighbour query tasks, can be improved by process of developing the connections, in which the strongest input dimensions in successive samples are wired to each successive coding dimension. Experiments show that the accuracy of searching for nearest neighbours is improved, although performance is dependent on the parameter values and datasets used. Our approach is also much faster than alternative methods that have been proposed for training the connections in this model. Importantly, the development process does not impact connections built at an earlier stage, which should provide stable coding results for simultaneous learning in a downstream network.