The amplitude of N 1peakof whole-nerve AP was measured in cats using a tone-burst probe with tonal maskers in a forward-masking paradigm. Experiments examined the effects of masker level, frequency, and duration (Tm), as well as interstimulus interval (Δt). Results are consistent with the interpretation that amplitude of N1reflectsactivity of a limited group of fibers with CF near the probe frequency. For single fibers, decrement in discharge rate (relative to an unmasked condition) is dependent upon rate to the masker [Smith, Neurophys. 40 (1977)]. For the AP, decrement in probe-elicited amplitude should reflect the rate to the masker in those fibers excited by the probe. Thus measurements of N1decrement versus masker frequency and level are similar to single unit rate versus level functions. Since decrement in N1reflects amount of adaptation, increasing Tmdecreases probe response. N1amplitude as a function of Tmthus resembles PST histograms of nerve fibers. Finally, plots of N1, amplitude as a function of Δt are interpreted as a measure of recovery from adaptation.
ASJC Scopus subject areas
- Arts and Humanities (miscellaneous)
- Acoustics and Ultrasonics