Zusammenfassung
A computer model of the auditory periphery is used to study the involvement
of auditory-nerve (AN) adaptation in forward-masking effects. An
existing model is shown to simulate published AN recovery functions
both qualitatively and quantitatively after appropriate parameter
adjustments. It also simulates published data showing only small
threshold shifts when a psychophysical forward-masking paradigm is
applied to AN responses. The model is extended to simulate a simple
but physiologically plausible mechanism for making threshold decisions
based on coincidental firing of a number of AN fibers. When this
is used, much larger threshold shifts are observed of a size consistent
with published psychophysical observations. The problem of how stimulus-driven
firing can be distinguished from spontaneous activity near threshold
is also addressed by the same decision mechanism. Overall, the modeling
results suggest that poststimulatory reductions in AN activity can
make a substantial contribution to the raised thresholds observed
in many psychophysical studies of forward masking.
Nutzer