Modulation-frequency-specific adaptation in awake auditory cortex.

摘要: Amplitude modulations are fundamental features of natural signals, including human speech and nonhuman primate vocalizations. Because signals frequently occur in the context other competing we used a forward-masking paradigm to investigate how modulation prior signal affects cortical responses subsequent modulated sounds. Psychophysical “modulation masking,” which presentation “masker” elevates threshold for detecting stimulus, has been interpreted as evidence central filterbank modeled accordingly. Whether tuning is compatible with such models remains unknown. By recording pairs sinusoidally amplitude (SAM) tones auditory cortex awake squirrel monkeys, show that SAM masker elicited persistent tuned suppression firing rate signals. Population averages these effects adaptation broadly channels. In contrast, had little effect on synchrony representation second stimuli did not match observed rate. Our results suggest that, although temporal more robust changes stimulus than representations based average rate, this fully exploited psychophysical masking closely mirrors physiological given feature neuron's pathway appears sufficient engender context-sensitive adaptation.