Sparse Codes for Speech Predict Spectrotemporal Receptive Fields in the Inferior Colliculus
An overcomplete sparse coding model trained on spectrograms of speech predicts Inferior Colliculus (IC) and auditory thalamus (ventral division of the medial geniculate body; MGBv) spectro-temporal receptive fields (STRFs) consisting of localized checkerboard patterns containing roughly four to nine distinct subfields. (a) Example STRFs of localized checkerboard patterns from two Gerbil IC neurons , one cat IC neuron , and one cat MGBv neuron  (top to bottom). Data courtesy of N.A. Lesica (top two cells) and M.A. Escabí (bottom two cells). (b) Elements from the four-times overcomplete, L0-sparse, spectrogram-trained dictionary with similar checkerboard patterns as the neurons in panel a.