Learning spatial hearing via innate mechanisms
Fig 3
Student error follows Teacher bias.
Top plot: tuning curves of 32 lateral superior olive (LSO) neurons for different sound source locations, color-coded by their estimated bias (code shown in the vertical line segments below). While most neurons exhibit small biases near the true midline, several show larger deviations, demonstrating natural variability for different Teachers with the same innate circuit connectivity. Bottom plot: the estimated Teacher bias matches the trained DNN Student test error (measured here as signed error, positive for clockwise direction difference, negative for counter-clockwise). Four out of 96 cases failed to converge within the allowed training period due to extremely noisy Teacher signals that slows down Student learning. Right hand plots: learned maps for four representative cases (a-d). Each point on the inner circle represents the true angle on the horizontal plane, while corresponding points on the outer circle show the angle predicted by the Student model. Connecting lines are color-coded by true angle. Case b (LSO neuron no.24 in [31]) shows the ideal radius-aligned lines, indicating accurate learning. Cases a and c (neurons no.1 and no.32) demonstrate systematic clockwise or counter-clockwise bias respectively, illustrating shifted Student maps bootstrapped from biased Teachers—similar to shifted auditory maps learned with visual prism adaptation. Case d is one of the 4 unconverged cases due to high variance in LSO Teacher signal.