Ripple Analysis in Ferret Primary Auditory Cortex. 1. Response Characteristics of Single Units to Sinusoidally Rippled Spectra
Abstract
We compared the response properties of single units to tones and sinusoidally rippled spectral stimuli in the primary auditory cortex (Al) of the barbiturate-anesthetized ferret. Using two-tone stimuli, we determined the response area of each cell and parameterized it in terms of best frequency (BF), the bandwidth of the excitatory responses at 20dB above threshold (BW20), and an asymmetry index measuring the balance of inhibition and excitation around the BF. Using frequency-modulated (FM) tones, we also determined a directional sensitivity index for the cell. Using broadband stimuli (1-20 kHz) with sinusoidally modulated spectral envelopes (ripples), we measured the response magnitude of each cell as a function of ripple frequency (omega) and ripple phase (phi), and then reconstructed the magnitude and phase of a ripple transfer function. Most cells (approximately 90%) were tuned to a specific ripple frequency, denoted as a characteristic ripple frequency (omegao) Most cells also exhibited a linear ripple phase as a function of omega.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1994
- Accession Number
- ADA452778
Entities
People
- H. Versnel
- N. Kowalski
- S. A. Shamma
Organizations
- University of Maryland