Mechanisms of Attention in the Human Visual Cortex

描述：（由申请人提供）我们通常看到的视觉场景是 被许多不同的物体弄得乱七八糟。注意力机制需要 选择相关，过滤掉不相关的信息。在非人 单细胞记录研究表明，在灵长类动物中， 视觉皮层对注意刺激的神经反应与相同的 在无人看管的情况下进行刺激。注意力增强神经元功能的机制 活动似乎是神经元增益的增加。几个因素 确定注意力反应增强，包括刺激显著性， 多个刺激对神经表征的竞争程度， 选择的性质（如果是特征或空间），以及对 单独的.在人类的视觉皮层中，我们先前的研究使用功能性的 磁共振成像（fMRI）显示，注意力增强了神经元的功能。 视觉刺激的活动，特别是在存在干扰刺激的情况下， 甚至在没有任何视觉刺激的情况下。但 注意力增强神经反应增益的机制， 决定响应调制的因素尚不清楚。长期 本申请的目的是确定这些基本的注意力 机制运作在人类视觉皮层与假设来自 用功能磁共振成像研究猴子生理学。功能磁共振成像和行为研究的目的是：1） 确定注意力对刺激对比度的影响; 2）确定 特征和空间注意机制的关系; 3）确定 在没有视觉刺激的情况下基线活动增加的性质。 注意力选择通常会在注意力缺陷的患者中出现福尔斯， 常见于主要的神经系统疾病和精神疾病。因此，我们认为， 因此，提高我们对健康人视觉注意力的认识是很重要的， 主题，以促进我们的病理生理学的理解， 关注，并最终为患者开发更有效的治疗方法， 注意力缺陷

DESCRIPTION: (provided by applicant) The visual scenes we typically view are cluttered with many different objects. Attentional mechanisms are required to select relevant and to filter out irrelevant information. In non-human primates, single-cell recording studies have shown that attention enhances neural responses in visual cortex to attended stimuli as compared to the same stimuli when unattended. The mechanism by which attention enhances neural activity appears to be an increase in the neuron's gain. Several factors determine attentional response enhancement, including stimulus salience, the degree of competition among multiple stimuli for neural representation, the nature of the selection (if featural or spatial), and the expectations of the individual. In the human visual cortex, our previous studies using functional magnetic resonance imaging (fMRI) have shown that attention enhances neural activity to visual stimuli, particularly in the presence of distracter stimuli, and even in the absence of any visual stimulation whatsoever. However, the mechanism by which attention enhances the gain of neural responses and the factors that determine the response modulation are not clear. The long-term objective of this application is to determine these basic attentional mechanisms operating in the human visual cortex with hypotheses derived from monkey physiology using fMRI. fMRI and behavioral studies are proposed to: 1) Determine the effects of attention on stimulus contrast; 2) Determine the relation of mechanisms for featural and spatial attention; and 3) Determine the nature of increases in baseline activity in the absence of visual stimulation. Attentional selection often falls in patients with attentional deficits, which are common in major neurologic disorders and psychiatric diseases. Therefore, it will be important to advance our knowledge of visual attention in healthy subjects in order to advance our understanding of the pathophysiology of attention and ultimately, to develop more efficient treatment for patients with attentional deficits.