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，比如拿起响起的电话，需要将不同感官的特征归因于相同的特征 对象和心理物理研究表明，包括灵长类和啮齿动物在内的各种物种， 在面对噪音时，以最佳方式组合不同感官的信息。大脑是如何完成这些壮举的 还有待进一步了解。 初级感觉皮质区，代表皮层信息处理的第一阶段，有 长期以来一直被认为是单感官的。然而，一种新兴的另一种观点认为，即使是初级感觉 大脑皮层区域参与多感觉整合。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质区域，理论研究表明 相互连接的感觉区域对于执行某些多感觉计算可能是有用的。 然而，到目前为止，经验性文献忽略了学习在多感官整合中的作用 主要感觉皮质区，理论研究表明这可能是关键。这项提议的目标是 确定学习对初级感觉皮层区域多感觉相互作用的影响。我们将首先测试 假设仅仅是交叉感觉统计的经验就能改变小学学生的多感官反应 感觉皮质区域。为了验证这一假设，将使用双光子钙成像来记录神经 清醒儿童初级躯体感觉皮层对一组体感和听觉刺激的反应 老鼠。然后，一个听觉刺激将在几个过程中与一个胡须刺激重复配对 几天后，将再次记录对全部刺激的反应。特别是，重复配对 可以使对配对音调的S1响应更接近于对配对胡须的S1响应 刺激。我们还将测试这样一种假设，即不同感觉模式的刺激重复配对具有 配对刺激预测时对初级感觉皮层区域多感觉活动的增强效应 奖励。 这些实验将扩大我们对大脑如何执行多感觉整合的理解 并有助于对主要感觉区域的传统观点进行重大修订，如离散的、平行的 每个模块负责单个感觉通道，而不是扩展我们对主要功能的理解 整个大脑的感觉区域可以密切协调，将某些计算作为一个整体来执行。

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.