Figure 5.

Cooperative features for spectral motion selectivity. a, A set of downward and upward FM sweeps with varying velocities was presented to an IC neuron with its spiking response displayed below each sweep. b, Using the most informative features and their nonlinearity extracted from responses to natural stimuli we were able to predict the response of the neuron to only a single sweep velocity of around −150 octaves/s (oct/s) in the downward direction. c, f, Both features were tilted in the downward direction and had a BV of ∼150 oct/s. d, Both features also had a 1D symmetric nonlinearity and their combined 2D nonlinearity suggests their summation. e, Fitting a Gabor function to a smoothed cross-section perpendicular to the BV of the first (black) and second (blue) features revealed that they are offset in phase by 87°. This shows that spectral motion selectivity in this IC neuron could be described by a functional model similar to the energy model previously described in the processing of visual motion.