PERCEIVED TARGET-MASKER SEPARATION UNMASKS RESPONSES OF LATERAL AMYGDALA TO THE EMOTIONALLY CONDITIONED TARGET SOUNDS IN AWAKE RATS

摘要: In a (simulated) reverberant environment, both human listeners and laboratory rats are able to perceptually integrate the direct wave of sound source with reflections source, leading fused image as coming from location around (the precedence effect). This perceptual grouping effect produces perceived spatial separation between sources facilitates selective attention target source. However, neural correlates unmasking effects have not been reported in literature. The lateral nucleus amygdala (LA) is critical for processing ecologically salient sensory signals (e.g., threatening sounds) mediating auditory fear conditioning. LA neuronal responses increase if conditioned. study investigated whether awake fusion-induced fear-conditioned noise masker enhances target. results show that frequency-following (FFRs, i.e., sustained potentials based on phase-locked firing neuron populations periodical waveforms) recorded tone-complex, which was masked by wideband noise, were enhanced after tone-complex became More importantly, but pseudo-conditioned elicited further larger FFRs when it separated than co-located masker. suggest there exists correlate significant sounds high degree stimulus specificity.