Encoding and modulation of vibration representations in human neocortex

项目摘要/摘要 触摸包括对振动的精致敏感度。这种敏感性是我们感知能力的基础 通过手持工具的纹理和感觉。振动传递的大部分信息都携带在它们的 光谱含量。因此，振动知觉很可能涉及类似于 支持听证的进程。尽管外周躯体感觉中的振动的神经编码 系统已经建立，对中枢神经系统中的振动表现知之甚少。在这 项目，我们将扩展我们对振动处理的皮质基础的研究，并确定如何 人类的振动频率表征受到选择性注意和多感官环境的影响 大脑。 我们对大脑皮层反应如何与知觉相关的理解是建立在对如何 感觉信息在神经群体中被选择性地编码。事实上，在不知道逻辑的情况下 感觉信号在大脑中被表示和转换，很难理解感觉是如何 反应是由注意状态或多感官环境决定的。尽管关于神经调节的知识已经很多了 对于视觉和听觉刺激特征，对体感调节机制知之甚少， 尤其是关于振动的频率内容。我们最近发现了 人脑振动频率的体感调谐。这项建议是建立在对 躯体感觉调谐，以测试皮质处理层次支持 振动频率信息的编码和细化。我们将解决一些基本问题 使用人类行为、功能神经成像和建模的问题。在目标1中，我们将确定如何 选择性注意影响体素水平活动中的频率表征。在目标2中，我们将确定如何 听觉频率信息--已知的人类触觉频率感知的偏差--是整合的 具有体素级别活动中的振动频率信息。在目标3中，我们将测试更复杂的刺激以识别 大脑对振动做出反应的区域，包括频率变化(扫描)，并确定大脑皮质 响应反映了对时变频率信号的调谐。 总的来说，这些实验将促进我们对人脑如何支持振动的理解 感知和触觉如何与听觉相结合，以实现多感官认知。我们的发现可能会让 诊断和治疗涉及躯体感觉缺陷的感觉、认知和精神障碍，如 与脑损伤、自闭症、精神分裂症和与年龄相关的认知障碍的个体一样，包括 阿尔茨海默氏症。

PROJECT SUMMARY/ABSTRACT Touch comprises an exquisite sensitivity to vibrations. This sensitivity underlies our ability to perceive textures and sense through handheld tools. Much of the information conveyed by vibrations is carried in their spectral content. Thus, vibration perception likely involves cortical processing that is analogous to the processes that support hearing. Although the neural encoding of vibrations in the peripheral somatosensory system is established, far less is known about vibration representations in the central nervous system. In this project, we will extend on our investigations of the cortical basis of vibration processing and determine on how vibration frequency representations are impacted by selective attention and multisensory context in the human brain. Our understanding of how cortical responses relate to perception is predicated on knowledge of how sensory information is selectively encoded in neural populations. Indeed, without knowing the logic of how sensory signals are represented and transformed across the brain, it is difficult to understand how sensory responses are shaped by attention state or multisensory context. Although much is known about neural tuning for visual and auditory stimulus features, relatively little is known about somatosensory tuning mechanisms, particularly with respect to the frequency content of vibrations. We recently uncovered evidence for somatosensory tuning for vibration frequency in the human brain. This proposal builds on the observation of somatosensory tuning to test the overarching hypothesis that a cortical processing hierarchy supports the encoding and elaboration of vibration frequency information. We will address a number of fundamental questions using human behavior, functional neuroimaging, and modeling. In Aim 1, we will establish how selective attention impacts frequency representations in voxel-level activity. In Aim 2, we will establish how auditory frequency information – which is known to bias tactile frequency perception in humans – is integrated with vibration frequency information in voxel-level activity. In Aim 3, we will test more complex stimuli to identify brain regions that respond to vibration comprising frequency changes (sweeps) and establish whether cortical responses reflect tuning for time varying frequency signals. Collectively, these experiments will advance our understanding of how the human brain supports vibration perception and how touch is combined with audition for multisensory cognition. Our findings may inform the diagnosis and treatment of sensory, cognitive, and psychiatric disorders involving somatosensory deficits, such as in individuals with brain damage, autism, schizophrenia, and age-related cognitive impairments including Alzheimer’s disease.