Supramodal human brain networks for temporal frequency processing

项目总结/摘要 时间频率是一个基本的感觉领域，对我们如何交流至关重要（例如， 通过听觉进行语音处理）和与我们环境中的对象进行交互（通过触摸进行纹理处理）。我们 听觉和触觉冗余地发出时间频率信号， 一下这种重叠使得听觉和触觉能够交互，这可能是有益的，因为信息 通过组合跨独立的感官线索提供的信息比由单个感官线索提供的信息更准确。 感觉线索尽管有这样的背景，但我们并不清楚 听觉和触觉频率处理机制。神经基质的先前研究 支持听觉和触觉传统上集中在单一的感觉形态上。在这里，我们将测试 假设共同的大脑区域和神经机制，称为超模态，支持听觉和 触觉频率处理我们将开发一个感觉神经元如何联合收割机 听觉和触觉频率信息，以及这些神经元如何通过适应而改变。我们将 将模型的预测与人类心理物理实验中获得的行为数据进行比较。使用 血氧水平依赖性功能磁共振成像（BOLD fMRI）和感觉适应， 我们将定位大脑区域，其反应模式与神经适应一致，我们将使用 这种测试大脑区域是否代表（即，适应）听觉和触觉频率 信息.使用fMRI和多变量模式分析（MVPA），我们将识别哪些大脑区域 可以解码听觉和触觉频率信息。我们将决定各地区是否支持 两种感觉的可解码频率表示。我们的初步建模，心理物理学，和成像 结果表明，大脑外侧裂周皮质的多个区域，包括经典定义为单峰的区域， 对听觉和触觉刺激都有频率选择性反应。这种模式表明， 外侧裂周区可以作为用于频率处理的超模态网络。我们假设注意力 对振动频率的响应增强了该频率网络中的功能连通性。我们会调查 通过结合经颅磁共振技术研究体感皮层和听觉皮层之间的功能连接 刺激（TMS）与功能磁共振成像（在并行TMS-功能磁共振成像实验）和行为（在心理物理 实验）。根据我们的假设，我们预测，经颅磁刺激引起的神经变化， 当受试者注意到振动频率时，皮层应该传播到听觉皮层。该传播 应该调节听觉皮层活动和听觉感知。这些预测结果将支持 经典定义的躯体感觉和听觉区域合作处理时间频率的概念 信息是一个超模态网络。超模态网络可能支持其他基本感觉 像形状和动作处理这样的操作。

PROJECT SUMMARY/ABSTRACT Temporal frequency is a fundamental sensory domain that is critically important to how we communicate (e.g., speech processing by audition) and interact with objects in our environment (texture processing by touch). Our auditory and tactile senses redundantly signal temporal frequencies spanning tens to hundreds of cycles per second. This overlap enables audition and touch to interact, which can be beneficial because the information available by combining across independent sensory cues is more accurate than that provided by a single sensory cue. Despite this background, we do not have a clear understanding of the relationship between auditory and tactile frequency processing mechanisms. Previous investigations of the neural substrates supporting audition and touch have traditionally focused on a single sensory modality. Here we will test the hypothesis that common brain regions and neural mechanisms, termed supramodal, support auditory and tactile frequency processing. We will develop a computational model of how sensory neurons may combine auditory and tactile frequency information and how these neurons may be changed by adaptation. We will compare the model's predictions to behavioral data acquired in human psychophysical experiments. Using blood oxygen-level dependent functional magnetic resonance imaging (BOLD fMRI) and sensory adaptation, we will localize brain regions whose response patterns are consistent with neural adaptation, and we will use this approach to test whether brain regions represent (i.e., adapt to) both auditory and tactile frequency information. Using fMRI and multivariate pattern analysis (MVPA), we will identify the brain regions from which auditory and tactile frequency information can be decoded. We will determine whether regions support decodable frequency representations for both senses. Our preliminary modeling, psychophysics, and imaging results suggest that multiple regions in perisylvian cortex, including areas classically defined as unimodal, display frequency-selective responses to both auditory and tactile stimulation. This pattern suggests that perisylvian areas may serve as a supramodal network for frequency processing. We hypothesize that attention to vibration frequency enhances the functional connectivity in this frequency network. We will causally probe functional connectivity between somatosensory cortex and auditory cortex by combining transcranial magnetic stimulation (TMS) with fMRI (in concurrent TMS-fMRI experiments) and behavior (in psychophysical experiments). According to our hypothesis, we predict that neural changes caused by TMS of somatosensory cortex should propagate to auditory cortex when subjects attend to vibration frequency. This propagation should modulate auditory cortex activity and auditory perception. These predicted results would support the notion that classically defined somatosensory and auditory areas collaborate to process temporal frequency information as a supramodal network. Supramodal networks may support other fundamental sensory operations like shape and motion processing.