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Nengo Cognitive Robot: Biologically Plausible Agent with Curiosity

A neurally-inspired agent built in Nengo/NEF that navigates a colored grid world, learns transition statistics, and exhibits curiosity-driven exploration.

Architecture

Perception Pipeline (Biologically Inspired Vision)

  • RGB input with Gaussian noise (σ=0.01)
  • Opponent color transformation (red-green, blue-yellow, luminance)
  • 4D cortical color space
  • Cosine similarity classification (threshold 0.4)

Memory Systems

  • Short-term: Leaky integrator (0.9 decay) for previous color
  • Transition detection: Outer product → 25-dimensional space
  • Long-term: Integrators (0.99 recurrence) for red-origin transitions

Behavior

  • Reflexive: Wall avoidance from 3 proximity sensors
  • Cognitive: Curiosity bias toward less-familiar color transitions
    • Familiarity = count_red→X / total_red_transitions
    • Bias = -0.6 × familiarity (soft repulsion)
  • Arbitration: Priority scaling based on wall distance (emergency > moderate > open)

Results

  • Stable color recognition under moderate noise
  • Accurate transition counting for red-origin sequences
  • Observable exploration diversification in open environments

Technologies

  • Nengo / NEF
  • Python
  • Neural population coding
  • Dynamical systems

Future Work

  • Hopfield networks for context-sensitive memory
  • Predictive processing / prediction error signals
  • Multi-modal integration
  • Long-term adaptation via synaptic plasticity

Author

Chiara Benini