Neuroimaging studies of auditory perception and attention

我们的听觉环境通常由无数的声音组成，但很少有人研究声音“对象”在大脑中的表现方式，以及在嘈杂的环境中如何将注意力集中在特定的声音对象上。 确定如何在复杂的听觉场景中分配注意力，是感兴趣的实际和理论的原因。 在实践方面，这些信息可以指导训练方案的制定，以帮助有注意力问题的人。 在理论方面，它可以提供深入了解的神经机制介导的听觉知觉，注意力和认知。 拟议的研究计划结合了行为技术与事件相关脑电位（ERP）的头皮记录，并围绕两个不同但交错的主题开发：（1）使用变化检测范式评估记忆中并发声音对象的表示，（2）评估在嘈杂环境中的注意力部署。 我们将研究令人惊讶的失败，听众发现显着的变化，在听觉场景（即，变聋）。 这种变化耳聋可能是由于未能在存储器中正确编码各种声音对象和/或比较各种场景时出现问题而发生的。 我们将通过比较与编码和记忆过程相关的神经活动来检验这些假设。 此外，我们将研究变化盲视和变化聋视神经活动的相似性和差异。 通过要求参与者指出听觉场景是否由预定义的目标声音（以及在不同位置同时发生的其他声音）组成，来研究听觉场景期间的注意力部署。 我们预计，听觉注意力的部署将以目标位置对侧的增强的神经活动为特征，并且当注意力指向声音身份时，这种神经活动将有所不同（例如，讲话者的声音）与分配给位置的注意力（即，说话人的位置）。 我们将使用从这些研究中获得的知识来完善我们目前基于对象的听觉注意解释。

Our auditory environment is often comprised of a myriad of sounds and yet there has been a paucity of work investigating how sound "objects" are represented in the brain and how attention is deployed to a particular sound object within a noisy environment. Determining how attention is allocated in complex auditory scenes is of interest for both practical and theoretical reasons. On the practical side, this information can guide the development of training regimens to help individuals with attention problems. On the theoretical side, it can provide insight into the neural mechanisms mediating auditory perception, attention, and cognition. The proposed research program combines behavioural techniques with scalp-recording of event-related brain potentials (ERPs) and is developed around two distinct but interleaved themes: (1) assessing the representation of concurrent sound objects in memory using a change detection paradigm, and (2) assessing the deployment of attention within a noisy environment. We will examine the surprising failure of listeners to detect salient changes in auditory scenes (i.e., change deafness). This change deafness may occur because of a failure to properly encode various sound objects in memory and/or a problem in comparing various scenes. We will examine these hypotheses by comparing the neural activity associated with the encoding and retention processes. In addition, we will examine the similarities and differences in neural activity for change blindness and change deafness. The deployment of attention during auditory scenes will be investigated by asking participants to indicate whether an auditory scene is comprised of a predefined target sound (among other sounds occurring simultaneously at various locations). We anticipate that the deployment of auditory attention will be characterized by enhanced neural activity contralateral to the target location and that this neural activity will differ when attention is directed to sound identity (e.g., talker's voice) compared to attention allocated to location (i.e., talker's location). We will use the knowledge gained from these studies to refine our current object-based account of auditory attention.