Role of Supramarginal Gyrus in the Integration of Visual Features Across Eye Movements

被称为眼跳的快速眼球运动不断增强视力，导致在短暂的稳定注视期间频繁的时空中断。跨视跳视觉特征整合(TSI)是视觉感知的基础，是理解视觉系统中不同信号之间相互作用的理想模型系统。在我们之前由NSERC资助的工作中，我们确定了一个有助于TSI的皮质区域网络，包括额叶和顶叶眼场、背外侧前额叶皮质和早期视觉皮质。但到目前为止，跨眼跳特征存储和整合发生的关键部位(S)仍然难以捉摸。 最近，使用fMRIa(适应)范式，我们在紧邻人类顶叶眼场的边缘上回(SMG)中发现了一个区域，似乎直接参与了跨眼跳的物体定向整合。SMG位于顶下小叶，位于顶上皮质和颞叶之间，因为它与复杂的视觉行为有关，并且已经参与了背侧流(空间/感觉运动)和腹侧流(特征/物体)视觉信号的整合。 在这一令人振奋的发现及其更广泛的影响的推动下，我们的目标是通过跨学科的方法重点关注SMG在TSI网络中的关键作用。我们将使用1)空间更新和特征整合的状态空间模型来为我们的心理物理和生理实验生成模拟预测，2)fMRIa适配协议以确认SMG在不同类型的特征整合、参照系和眼睛运动类型的整合中的作用，3)扩散张量成像以了解其与跨扫视整合所涉及的大脑其他区域的联系，4)功能磁共振引导的经颅磁刺激(TMS)以定位SMG信号在视觉空间整合中的因果作用，5)脑磁图(MEG)以调查SMG与其他TSI部位的时间和同步，和6)动物神经生理学，以探索SMG在被训练执行类似TSI任务的猴子中的详细细胞反应。 建立SMG在TSI中的具体机制和作用将为理解主动视觉提供重要的进展。但更进一步，我们对SMG区的战略关注可能会回答神经科学中的一个基本问题：展示顶下小叶在整合认知和行为的背侧和腹侧流信号中的关键作用。这一主题(TSI)在从交通运输到机器人等领域的人机交互和计算机视觉方面有许多应用。最后，我们独特多样的技术组合将为学生和博士后研究员提供强大的培训场地。

Vision is constantly augmented by rapid eye movements called saccades, resulting in frequent spatiotemporal interruptions between brief periods of stable fixation. Trans-saccadic integration of visual features (TSI) is thus fundamental to visual perception, and forms an ideal model system for understanding interactions between different signals in the visual system. In our previous NSERC-funded work we identified a network of cortical areas that contribute to TSI, including the frontal and parietal eye fields, dorsolateral prefrontal cortex, and early visual cortex. But until now, the key site(s) where trans-saccadic feature storage and integration occurs has remained elusive. Recently, using an fMRIa (adaptation) paradigm we identified an area in the supramarginal gyrus (SMG), immediately adjacent to the human parietal eye fields, that appears to be directly involved in the integration of object orientation across saccades. The SMG located in the inferior parietal lobule and couched between the superior parietal and temporal cortices is intriguing because it is associated with complex visual behaviors and has already been implicated in the integration of dorsal stream' (spatial/sensorimotor) and ventral stream' (feature/object) visual signals. Motivated by this exciting finding and its broader implications, we aim to focus on the key role of SMG in the TSI network through a trans-disciplinary approach. We will use 1) state-space models of spatial updating and feature integration to generate simulated predictions for our psychophysical and physiological experiments, 2) fMRIa adaptation protocols to confirm SMG's role in integration for different types of feature integration, frames of reference, and types of eye movement, 3) diffusion tensor imaging to understand its connections with other areas of the brain involved in trans-saccadic integration, 4) fMRI-guided Trans-cranial magnetic stimulation (TMS) to localize the causal role of SMG signals for visuospatial integration, 5) magnetoencephalography (MEG) to investigate the timing and synchrony of SMG with other TSI sites, and 6) animal neurophysiology to explore the detailed cellular responses of SMG in monkeys trained to perform similar TSI tasks. Establishing the specific mechanism and role of SMG in TSI will provide an important advance for understanding active vision. But further, our strategic focus on area SMG could answer a fundamental question in neuroscience: demonstration of a key role of the inferior parietal lobule in the integration of dorsal and ventral stream signals for cognition and behavior. This topic (TSI) has numerous applications for human-computer interaction and computer vision, in areas ranging from transportation to robotics. Finally, our uniquely diverse combination of techniques will provide a powerful training ground for students and post-doctoral fellows.