Adaptive allocation of attention during perception, working memory, and decision

描述(申请人提供)：人类感官系统不断受到远远超过其处理能力的输入的轰炸。因此，注意力机制已经进化，以至于可用容量仅用于编码环境中最突出和行为相关的刺激。反过来，最重要的刺激支配着知觉，并拥有访问记忆存储和神经机制的特权，这些机制控制着如何最好地与外部物体互动的决定。在这个方案中，我们将使用视觉系统作为一个模型来理解基本的大脑行为过程，这些过程涉及选择性注意影响知觉、工作记忆和感觉运动决策的计算。此外，我们将开发和使用新的方法，使用功能磁共振成像来非侵入性地研究注意力调制和感觉系统的信息编码能力，这与NIMH的战略目标一致，即开发新的工具和方法来了解神经细胞群体如何在脑区内和脑区之间协同工作。传统观点认为，注意力的作用是放大重要刺激引起的神经反应，从而使刺激更容易被察觉。这一总体框架是直观的，三十多年来一直成功地指导着实证研究。然而，最近的理论研究表明，注意力不应该简单地增加调节到相关刺激的神经元的增益。相反，注意力应该以一种更动态的方式调节感觉神经元的活动，以便最大限度地增加成功完成特定感知任务的可能性。通常，这违反直觉地要求增强对不在视野中的物理存在的刺激最敏感的神经元的活动，因为这些神经元携带更多关于类似物品之间非常困难的区分的信息(例如，当放射科医生在低质量的X射线图像中搜索癌变肿块时)。最近的实证研究支持这一总体框架，并进一步提出了一个有趣的可能性，即注意最佳程度的个体差异可以预测在困难歧视上的总体表现，以及通过实践(学习)改善困难歧视的能力。在这里，我们将对这一新的理论观点进行批判性的评估，我们还将探索不同个体的注意力差异如何影响短期记忆的精确度和简单决策过程的效率。总而言之，我们的目标是对注意机制的运行提供见解，以便我们能够更准确地描述系统应该如何理想地运行。反过来，这将极大地提高我们隔离注意力处理的特定方面的能力，这些方面有时会出错，从而在临床环境中实现更有针对性的诊断和干预。 与公共健康相关：无论是在教室里听老师讲课，还是在路上开车，注意环境中重要感官刺激的能力对成功和生存都至关重要。在目前的研究方案中，我们将使用视觉系统作为模型，以更好地了解注意力如何选择性地改变感觉神经元的活动，以促进更有效的感知、记忆和决策。这些知识将有助于开发对常见注意力障碍--如注意力缺陷障碍--的更客观测试，以便诊断可以更精确地进行，干预可以更早开始。

DESCRIPTION (provided by applicant): Human sensory systems are continuously bombarded with far more input than they can process. As a result, attentional mechanisms have evolved so that available capacity is dedicated to encoding only the most salient and behaviorally relevant stimuli in the environment. In turn, the most important stimuli dominate perceptual awareness and have privileged access to memory stores and to the neural mechanisms that control decisions about how to best interact with external objects. In this proposal, we will use the visual system as a model to understand the basic brain-behavior processes involved in selective attention influence perception, working memory, and the computation of sensorimotor decisions. In addition, we will develop and employ new methods that use fMRI to non-invasively study attentional modulations and the information encoding capacity of sensory systems, in line with the strategic aim of the NIMH to develop novel tools and methodologies for understanding how populations of neural cells work together within and between brain regions. Traditional accounts hold that attention operates to magnify the neural response evoked by important stimuli, which makes a stimulus easier to perceive. This general framework is intuitive, and has been successfully guiding empirical studies for more than three decades. However, recent theoretical work suggests that attention should not simply increase the gain of neurons tuned to a relevant stimulus. Instead, attention should modulate the activity of sensory neurons in a more dynamic manner in order to maximize the probability that a specific perceptual task will be successfully completed. Often times, this counterintuitively requires enhancing the activity of neurons that are most responsive to stimuli that are not physically present in the visual field, because these neurons carry more information about very difficult discriminations between similar items (e.g. when a radiologist searches for a cancerous mass in a low-quality x-ray image). Recent empirical studies support this general framework, and further raise the intriguing possibility that individual differences in the optimality of attention can predict overall performance on difficult discriminations as well as the ability to improve on difficult discriminations with practice (learning). Here, we will critically evaluate this new theoretical perspective, and we will also explore how differences in attention across individuals can influence the precision of short-term memory and the efficiency of simple decision making processes. Collectively, our goal is to provide insights into the operation of attentional mechanisms so that we can more precisely characterize how the system should ideally operate. In turn, this should dramatically improve our ability to isolate specific aspects of attentional processing that can sometimes go awry, thereby enabling more targeted diagnoses and interventions in clinical settings. PUBLIC HEALTH RELEVANCE: Whether listening to a teacher in a classroom or driving a car down the road, the ability to pay attention to important sensory stimuli in the environment is critical to success and survival. In the present research proposal, we will use the visual system as a model to better understand how attention selectively changes the activity of sensory neurons to promote more efficient perception, memory, and decision making. This knowledge will aid in the development of more objective tests for common disorders of attention - such as attention deficit disorder - so that diagnosis can proceed with greater precision and interventions can be started earlier.