Attentional Mechanisms in Multisensory Environments

描述（由申请人提供）：我们生活在一个多感官的世界，这需要我们持续地、动态地、有效地处理来自各个感官模式的刺激。为了成功地做到这一点，我们需要将相应的非感觉刺激成分整合在一起，以感知连贯的多感觉物体，同时适当地分离出并发的非对应刺激。在这项资助的下一个阶段，我们提出了一套新的研究，以继续我们对注意力和相关认知因素在复杂的多感官环境中促进有效功能的机制的程序化调查。在

DESCRIPTION (provided by applicant): We live in a multisensory world, which requires us to continually, dynamically, and effectively process stimuli from across the sensory modalities. To do so successfully, we need to integrate corresponding unisensory stimulus components together to perceive coherent multisensory objects, while also appropriately segregating out concurrent non-corresponding stimuli. In the next period of this grant, we propose a new set of studies to continue our programmatic investigation of the mechanisms by which attention and related cognitive factors facilitate effective functioning in complex multisensory environments. In particular, we will investigate three fundamental facets of these mechanisms. First, we will study the influence of the top-down cognitive factors of spatial attention and reward prospect on multisensory (auditory/visual) integration and segregation processes. Second, we will examine the commonality across the auditory and visual modalities of the mechanisms underlying rapid attentional target-search processes in complex stimulus environments, including the cross- modality coupling of such attentional processes. Third, we will investigate the multisensory integration and segregation processes when input from one particular modality is relevant, but there is conflicting concurrent input from a second modality; we will also compare these crossmodal processes to those invoked in response to conflicting input from within the same modality. As before, we will use a combination of behavioral measures, oscillatory electroencephalography (EEG), event-related potentials (ERPs), and functional MRI (fMRI) to perform these studies, with the aim to delineate the timing, sequence, and location of underlying neural processes. Additionally, we will acquire EEG and fMRI measures of brain activity simultaneously for several of the proposed experiments using our new MR- compatible EEG system purchased via a supplement from this project. Such an approach will enable us to perform trial-to-trial covariational analyses on the EEG and fMRI data patterns, providing powerful new ways to link the high-temporal-resolution EEG signals to the associated cortical generators measured in the fMRI. Moreover, the simultaneous recording will also allow us to examine the modulating influence on the cortical EEG of the subcortical brain regions involved in attention, reward, and multisensory integration but whose influence cannot be assessed with EEG alone. Thus, these experiments will delineate with unprecedented precision the neural mechanisms by which attention and related cognitive functions enable successful navigation of our complex multisensory world. PUBLIC HEALTH RELEVANCE: A number of neurological and psychiatric disorders, including attention-deficit disorder, Alzheimer's disease, and autism, have adverse effects on attentional and multisensory-integration capabilities. Moreover, traumatic brain injury (e.g., following concussions) and or stroke can also result in dramatic impairments in sensory processing and attention (e.g., poor attentional focus, hemispatial neglect). Given that individuals with disordered brain function need to interact and cope in a multisensory world, the proposed studies of multi- sensory attentional mechanisms will provide important and fundamental knowledge for better understanding these deficits and developing effective treatments.