Mechanisms of Attention in the Human Visual Cortex

描述：(申请人提供)我们通常看到的视觉场景有 杂乱地堆满了许多不同的物体。注意力机制需要被用来 选择相关并过滤掉不相关的信息。在非人类中 灵长类动物的单细胞记录研究表明，注意力增强 视皮层对注意刺激的神经反应与相同刺激的比较 无人看管时的刺激。注意力增强神经的机制 活动似乎是神经元增益的增加。几个因素 确定注意反应增强，包括刺激显著、 多个刺激之间对神经表征的竞争程度， 选择的性质(如果是特征的或空间的)，以及 个人的。在人类的视皮层中，我们之前的研究使用功能 磁共振成像(Fmri)显示注意力增强了神经。 对视觉刺激的活动，特别是在存在分心刺激的情况下， 甚至在没有任何视觉刺激的情况下也是如此。然而， 注意力增强神经反应的机制和 决定反应调制的因素尚不清楚。长期的 此应用程序的目标是确定这些基本注意力 在人类视皮层中工作的机制，其假说源自 使用功能磁共振成像的猴子生理学。功能磁共振成像和行为研究建议：1) 确定注意对刺激对比度的影响；2)确定 特征注意和空间注意的机制之间的关系；以及3)决定 在没有视觉刺激的情况下基线活动增加的性质。 注意力选择通常落在注意缺陷患者身上，这 在严重的神经疾病和精神疾病中很常见。因此， 提高我们对健康人视觉注意的认识将是很重要的 为了增进我们对心绞痛的病理生理学的理解 关注并最终开发出更有效的治疗方法 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.