Model comparisons to receptive fields from auditory midbrain and cortex.

<p>on spectrograms of speech predicts several classes of broadband spectro-temporal receptive field (STRF) shapes found in Inferior Colliculus (IC) and primary auditory cortex (A1). (<b>a,b</b>) An example broadband OFF-type STRF from cat IC <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002594#pcbi.1002594-Escab1" target="_blank">[34]</a> (top; data courtesy of M.A. Escabí) and an example broadband ON-type subthreshold STRF from rat A1 <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002594#pcbi.1002594-Machens1" target="_blank">[35]</a> (bottom; data courtesy of M. Wehr) shown in panel <b>a</b> resemble example elements from a four-times overcomplete, L0-sparse, spectrogram-trained dictionary shown in panel <b>b</b>. (<b>c</b>) STRFs from a bat IC neuron <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002594#pcbi.1002594-Andoni1" target="_blank">[32]</a> (top; data courtesy of S. Andoni) and a cat A1 neuron <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002594#pcbi.1002594-Escab1" target="_blank">[34]</a> (bottom; data courtesy of M.A. Escabí) each consist of a primary excitatory subfield that is modulated in frequency over time, flanked by similarly angled suppressive subfields. (<b>d</b>) Example STRFs from four elements taken from the same dictionary as in panels <b>b</b> exhibit similar patterns as the neuronal STRFs in panel <b>c</b>.