Understanding the brain mechanisms that regulate attention to auditory memory

人类口头交流受到我们即使在存在其他噪声的情况下也能“听到”说话者的能力的限制，无论是其他人说话还是其他声源（例如，音乐、机械发动机声音）。要做到这一点，通常需要对一个人刚才所说的话进行某种重放，即在脑海中回想那些在短期记忆中仍然可以理解的口语。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的记忆，而且熟悉的谈话者比不熟悉的谈话者更容易理解。然而，我们并不完全了解让我们在短期记忆中注意声音的大脑机制，也不知道现有记忆如何使这种注意力偏向。这项研究计划的目的是：（i）表征神经结构，使人们能够将注意力集中在听觉记忆上;（ii）确定当听众反映刚刚听到的声音的时间，内容或地点时，大脑过程如何不同;（iii）检查对记忆的注意力如何增强对退化语音的处理;（iv）表征长期记忆如何引导注意力;（iv）确定长期记忆如何引导注意力。以及（v）识别长期记忆中的信息如何与不利的听力条件下正在进行的感知处理相结合。所有研究都包括健康的年轻人，并实施了行为，计算和大脑成像技术的精心组合，以绘制出这些过程中涉及的时间过程和大脑区域。自上而下的短期记忆的注意力研究使用所谓的延迟匹配到样本的范例。在这样的任务中，一个（回溯）线索告诉参与者哪些项目（S）保持在记忆中（内部导向的注意力）出现在刺激阵列呈现之后。我们预测，对记忆的注意力将参与一个广泛分布的大脑区域神经网络，包括听觉皮层和对集中注意力很重要的区域。注意和听觉长期记忆之间的相互作用进行了研究，使用的学习范式，旨在创建一个强大的两个听觉刺激之间的关联。我们预计，现有的上下文记忆将通过重新激活最初参与学习的大脑区域来使注意力偏向并优化感知。这些结果将使我们能够通过考虑我们内部和外部世界的事件的适当和不断变化的平衡来推进注意力模型。确定注意力如何分配给听觉记忆可以指导训练方案的制定，以提高正常人群在整个生命周期中的注意力，以及脑损伤，医疗条件和/或学习障碍影响他们注意记忆能力的人。

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.**