Cognitive navigation based on nonuniform Gabor space sampling, unsupervised growing networks, and reinforcement learning

IEEE Trans Neural Netw. 2004 May;15(3):639-52. doi: 10.1109/TNN.2004.826221.

Abstract

We study spatial learning and navigation for autonomous agents. A state space representation is constructed by unsupervised Hebbian learning during exploration. As a result of learning, a representation of the continuous two-dimensional (2-D) manifold in the high-dimensional input space is found. The representation consists of a population of localized overlapping place fields covering the 2-D space densely and uniformly. This space coding is comparable to the representation provided by hippocampal place cells in rats. Place fields are learned by extracting spatio-temporal properties of the environment from sensory inputs. The visual scene is modeled using the responses of modified Gabor filters placed at the nodes of a sparse Log-polar graph. Visual sensory aliasing is eliminated by taking into account self-motion signals via path integration. This solves the hidden state problem and provides a suitable representation for applying reinforcement learning in continuous space for action selection. A temporal-difference prediction scheme is used to learn sensorimotor mappings to perform goal-oriented navigation. Population vector coding is employed to interpret ensemble neural activity. The model is validated on a mobile Khepera miniature robot.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cognition*
  • Learning*
  • Neural Networks, Computer*
  • Reinforcement, Psychology*