Effects of learning on multi-sensory integration in primary sensory cortical areas

摘要 整合来自不同感官的信息对于导航我们周围的世界至关重要。许多 日常任务，比如伸手去拿一个正在响的电话，需要将不同感官的特征归因于同一个感官。 心理物理学研究表明，包括灵长类和啮齿类在内的各种物种， 最佳的联合收割机信息从不同的感官面对噪音。大脑如何实现这些壮举 还有待了解。 初级感觉皮层区代表皮层信息处理的第一阶段， 一直被认为是单感官的然而，一种新兴的替代观点认为，即使是初级感觉， 皮质区参与多感觉整合。最近的研究表明，多种多感官 相互作用甚至发生在初级感觉皮层区域，理论研究表明， 相互连接的感觉区域可用于执行某些多感觉计算。 然而，迄今为止，经验文献忽视了学习在多感觉整合中的作用， 初级感觉皮层区域，理论研究表明这可能是关键的。本提案的目的是 确定学习对初级感觉皮质区多感觉相互作用的影响。我们将首先测试 假设仅仅是跨感觉统计学的经验改变了小学生的多感觉反应， 感觉皮质区为了验证这一假设，将使用双光子钙成像来记录神经元的钙离子浓度。 清醒时初级体感皮层（S1）对一组体感和听觉刺激的反应 小鼠然后，一个听觉刺激将与一个触须刺激在几个时间段内重复配对。 天，之后将再次记录对整个刺激面板的反应。特别是重复配对 可能导致对成对音调的S1响应更接近于对成对须音的S1响应 刺激。我们还将检验这一假设，即不同感觉形式的刺激的重复配对具有一种 当成对刺激预测时，初级感觉皮层区多感觉活动的增强效应 奖励 这些实验将扩展我们对大脑如何执行多感觉整合的理解 并有助于对初级感觉区域的传统观点进行重大修订， 每个模块负责一个单一的感觉模态，而不是扩大我们的理解， 整个大脑的感觉区域可以紧密协调，作为一个整体来执行某些计算。

ABSTRACT Integrating information from different senses is critical to navigating the world around us. Many everyday tasks, like reaching for a ringing phone, require attributing features from different senses to the same object, and psychophysical studies show that a variety of species, including both primates and rodents, optimally combine information from different senses in the face of noise. How the brain achieves these feats remains to be understood. Primary sensory cortical areas, which represent the first stage of cortical information processing, have long been considered uni-sensory. An emerging alternative view, however, holds that even primary sensory cortical areas participate in multi-sensory integration. Recent work has shown that a variety of multi-sensory interactions occur even in primary sensory cortical areas, and theoretical studies suggest that networks of reciprocally-connected sensory areas may be useful for performing certain multi-sensory computations. The empirical literature, however, has thus far ignored the role of learning in multi-sensory integration in primary sensory cortical areas, which theoretical studies suggest may be critical. The goal of this proposal is to determine the effect of learning on multi-sensory interactions in primary sensory cortical areas. We will first test the hypothesis that mere experience of cross-sensory statistics modifies multi-sensory responses in primary sensory cortical areas. To test this hypothesis, 2-photon calcium imaging will be used to record neural responses to a panel of somatosensory and auditory stimuli in primary somatosensory cortex (S1) of awake mice. One auditory stimulus will then be repeatedly paired with one whisker stimulus over the course of several days, after which responses to the full panel of stimuli will be recorded again. In particular, repeated pairing may cause S1 responses to the paired tone to more closely resemble S1 responses to the paired whisker stimulus. We will also test the hypothesis that repeated pairing of stimuli of different sensory modalities has an enhanced effect on multi-sensory activty in primary sensory cortical areas when the paired stimuli predict reward. These experiments will expand our understanding of how the brain performs multi-sensory integration and contribute to a significant revision of the traditional view of primary sensory areas as as discrete, parallel modules responsible for a single sense modality each, instead expanding our understanding of how primary sensory areas across the brain can coordinate closely to perform certain computations as a whole.