Multisensory integration and attention

描述(由申请人提供)：来自人类行为、心理物理学、事件相关电位和功能磁共振成像以及动物单个单元研究的融合证据突出了感觉模式之间相互作用的重要性。然而，关于早期多感官刺激如何汇聚仍存在争议。一种观点认为，感觉流只有在被单峰皮层处理后才会汇聚到多峰皮层。这一观点不排除反馈到单峰皮质区域的可能性，但与早期单峰皮质直接受到多感觉刺激影响的观点相反。虽然有证据表明多感觉刺激影响早期感觉皮质，但还没有证据表明对特定通道的注意直接调节人类多感觉相互作用的时间和空间范围。这个项目的目标是描绘神经基础和注意力对多感觉整合的影响。我们预测，当注意力被引导到感觉通道时，单通道刺激将在早期潜伏期得到增强，这与跨通道注意调节皮层早期感觉加工的观点一致。此外，我们预测，同步的听觉和视觉多感觉刺激将在反映早期感觉加工的潜伏期引起更大的神经反应，头皮分布和来源定位分析将表明这种调制发生在皮质加工的早期。最后，我们预测，对不同感觉通道的关注将导致对所关注通道的多感觉活动进一步增强。

DESCRIPTION (provided by applicant): Convergent evidence from behavior, psychophysics, ERP, and fMRI in humans, as well as single unit studies in animals highlights the importance of interactions across sensory modalities. However, there is still controversy about how early multisensory stimuli converge. One view holds that sensory streams converge in polymodal cortices only after being processed by unimodal cortices. This view does not exclude the possibility of feedback to unimodal cortical areas but is in contrast to the view that early unimodal cortices are affected by multisensory stimuli directly. While there is evidence that multisensory stimuli affect early sensory cortices, it has not been demonstrated that attention to a specific modality modulates the timing and spatial extent of multisensory interactions directly in humans. The goal of this project is to delineate the neural underpinnings and influence of attention on multisensory integration. We predict that when attention is directed to a sensory modality, unimodal stimuli will be enhanced at early latencies consistent with the view that intermodal attention modulates early sensory processing in the cortex. Furthermore, we predict that synchronous auditory and visual multisensory stimuli will elicit larger neural responses at latencies reflecting early sensory processing and that scalp distributions and source localization analyses will indicate that this modulation is occurring early in cortical processing. Finally, we predict that attention to different sensory modalities will result in further enhanced multisensory activity to the attended modality.