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Updated: Aug 18, 2026

Functional Imaging of Auditory Cortex in Adult Cats using High-field fMRI
Published on: February 19, 2014
Sensitivity of cat primary auditory cortex (AI) neurons to the direction and rate of frequency modulation
Abstract:
Responses of 65 single auditory cortex (AI) neurons to frequency-modulated (FM) sweeps with different rates and direction of frequency change were examined quantitatively. Most units responded differentially depending on the characteristics of the FM sweep stimulus. Sixty-five percent of the units encountered responded at least twice as well for one direction of the FM sweep as for the other direction. Of these direction selective neurons, 67% preferred downward-directed FM sweeps (i.e. changing from high to low frequencies) while only 33% preferred upward-directed FM sweeps. The preference for downward-directed FM sweeps was especially clear in EI cells. In addition, cortical neurons often displayed sensitivity to the rate of frequency modulation (speed sensitivity).
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