Understanding the brain mechanisms that regulate attention to auditory memory

人类的口头交流受到我们“听到”说话者的能力的限制，即使有其他噪音存在，无论是其他人说话还是其他声音来源（例如音乐，机械发动机的声音）。要做到这一点，通常需要在脑海中回想起一个人刚刚说过的话，回想那些在短期记忆中仍然可以访问的话语。也就是说，刚刚听到的声音，但不再存在，成为我们注意的对象。我们知道，选择性注意力会影响我们记忆的内容，而且我们更容易理解一个熟悉的说话人，而不是一个不熟悉的说话人。然而，我们并不完全了解大脑的机制，使我们能够在短期记忆中注意到声音，也不知道现有的记忆是如何影响这种注意力的。这个研究项目的目的是：(i)描述允许人们将注意力集中在听觉记忆上的神经结构；（ii）确定当听者对刚刚听到的声音的时间、内容或地点进行反思时，大脑的处理过程是如何不同的；（iii）研究对记忆的关注如何增强对退化言语的处理；（iv）描述长时记忆如何引导注意力；(v)确定在不利听力条件下，长期记忆中的信息如何与正在进行的感知加工相结合。所有的研究都以健康的年轻人为研究对象，并将行为、计算和脑成像技术仔细结合起来，以绘制出参与这些过程的时间过程和大脑区域。使用所谓的延迟匹配样本范式研究了自上而下对短期记忆的注意。在这类任务中，在刺激阵列呈现后，会出现一个（复古）提示，告诉参与者要在记忆中保持哪个项目（内部定向注意）。我们预测，对记忆的关注将涉及一个广泛分布的大脑区域神经网络，包括听觉皮层和集中注意力的重要区域。注意和听觉长期记忆之间的相互作用是研究使用的学习范式设计，以创建两种听觉刺激之间的强关联。我们预计，现有的情境记忆会通过重新激活原本参与学习的大脑区域来影响注意力和优化感知。研究结果将使我们能够通过考虑到从我们的内部和外部世界关注事件的适当和不断变化的平衡，来推进注意力模型。确定注意力是如何分配到听觉记忆上的，可以指导训练方案的发展，以提高一生中正常人群的注意力，也可以提高脑损伤、医疗条件和/或学习障碍人群的注意力，这些都会影响他们的记忆力。**

Human oral communication is constrained by our ability to “hear” a speaker even in the presence of other noise, whether that be other people talking or other sound sources (e.g., music, mechanical engine sounds). Doing this often requires a sort of replay of what a person just said by going back in one's mind to those spoken words still accessible in short-term memory. That is, the sounds just heard, but no longer present, become the object of our attention. We know that selective attention influences what we remember, and that it is easier to understand a familiar talker than an unfamiliar one. However, we do not fully understand the brain mechanisms that allow us to attend to sounds in short-term memory nor do we know how existing memories bias that attention. The aims of this research program are to: (i) characterize the neural architecture that allows people to focus their attention to auditory memory; (ii) determine how brain processes differ when listeners are reflecting on the when, what, or where of the sound just heard; (iii) examine how attention to memory enhances processing of degraded speech; (iv) characterize how long-term memory steers attention; and (v) identify how information in long term memory is integrated with ongoing perceptual processing in adverse listening conditions. All studies include healthy young adults and implement a careful combination of behavioral, computational, and brain imaging techniques in order to map out the time course and brain areas involved in these processes. Top-down attention to short-term memory is studied using what is called a delayed match-to-sample paradigm. In such tasks, a (retro)cue telling participants which item(s) to maintain in memory (internally oriented attention) appears after the stimulus array is presented. We predict that attention to memory will engage a widely distributed neural network of brain regions that include the auditory cortex and regions important for focusing attention. The interplay between attention and auditory long-term memory is investigated using a learning paradigm designed to create a strong association between two auditory stimuli. We anticipate that existing contextual memories will bias attention and optimize perception by re-activating brain areas originally involved during learning. The results will allow us to advance models of attention by taking into account the proper and changing balance of attending to events from our internal and external worlds. Determining how attention is allocated to auditory memory can guide the development of training regimens to improve attention in normal populations across the life span and also in people within brain damage, medical conditions and/or learning disabilities which affect their ability to attend to memory.**