Neuroimaging studies of auditory perception and attention

我们的听觉环境通常是由无数的声音组成的，然而关于声音“对象”是如何在大脑中表现出来的，以及在嘈杂的环境中如何将注意力部署到特定的声音对象上的研究却很少。确定在复杂的听觉场景中注意力是如何分配的，既有实践上的原因，也有理论上的原因。在实践方面，这些信息可以指导培训方案的发展，以帮助有注意力问题的个人。在理论方面，它可以深入了解调节听觉感知、注意和认知的神经机制。拟议的研究计划将行为技术与事件相关脑电位（ERPs）的头皮记录相结合，并围绕两个截然不同但相互交织的主题发展：(1)使用变化检测范式评估记忆中并发声音对象的表征；(2)评估在嘈杂环境中注意力的部署。我们将研究听者在听觉场景中发现显著变化的惊人失败（即变化性耳聋）。这种变化耳聋可能是由于未能正确地在记忆中编码各种声音对象和/或在比较不同场景时出现问题。我们将通过比较与编码和保留过程相关的神经活动来检验这些假设。此外，我们将研究变化性盲和变化性聋的神经活动的异同。通过要求参与者指出听觉场景是否由预定义的目标声音（在不同位置同时发生的其他声音中）组成，将调查听觉场景中的注意力部署。我们预计，听觉注意力的部署将以目标位置对侧的神经活动增强为特征，并且当注意力被定向到声音身份（例如，说话人的声音）时，这种神经活动将与将注意力分配到位置（例如，说话人的位置）时有所不同。我们将利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描述。

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.