Contextual modulation of neural responses in the bat auditory cortex

动物利用声音信息作为宣传生理状态、社会环境情景和定向的手段。本研究的目的是研究“环境”信息如何调节食果蝙蝠听觉皮层中声音信号的处理。我们将上下文定义为附加的听觉或非听觉感官信息的集合，这些信息可能会影响特定声音刺激的处理。该建议被细分为两个工作包（w1和w2）。在w1中，我们将研究听觉环境如何调节回声定位和痛苦发声的加工，通过将这两种发声类型的混合物呈现给动物并评估对意外刺激的反应。这种方法是基于这样一个事实，即遇险和回声定位信号在其光谱组成上有很大的不同。w1中获得的结果将揭示预测编码等现象如何影响自然发声的编码。在第二个工作包（w2）中，我们将使用所谓的驻留-入侵者范式研究成对蝙蝠在社会互动中的听觉处理。在这种情况下，“情境线索”将通过考虑诸如所研究蝙蝠之间的距离和动物之间先前相互作用的性质（即安抚与攻击）等变量来量化。本文所列出的实验将为哺乳动物听觉皮层中情境依赖信息编码的神经元机制提供重要数据。

Animals use acoustic information as a mean of advertising physiological states, socio-contextual scenarios and for orientation. The aim of this proposal is to study how “context” information modulates the processing of acoustic signals in the auditory cortex of the fruit eating bat Carollia perspicillata. We define context as the assembly of additional auditory or nonauditory sensory information that could potentially affect the processing of specific sound stimuli. The proposal is subdivided into two work-packages (w1 and w2). In w1, we will study how auditory context modulates the processing of echolocation and distress vocalizations, by presenting mixtures of those two vocalization types to the animals and evaluating the responses to the unexpected stimulus. This approach is based on the fact that distress and echolocation signals differ largely in their spectral composition. The results obtained in w1 will shed light into how phenomena such as predictive coding influence the encoding of natural vocalizations. In the second work-package (w2), we will study auditory processing during social interactions in pairs of bats using the so-called resident-intruder paradigm. In this situation, “contextual cues” will be quantified by taking into account variables such as the distance between the bats studied and the nature of previous interactions (i.e. appeasing vs. aggressive) between the animals. The experiments listed in this proposal will provide important data on the neuronal mechanisms for context-dependent information coding in the auditory cortex of mammals.