Neurobiological Substrates of Visual-Somatosensory Integration in Aging

 描述(由申请人提供)：一个迅速发展的认知神经科学领域，称为多感觉整合(MSI)，研究同时处理感觉信息的复杂性。MSI主要是在三种主要感觉(即视觉、听觉和躯体感觉系统)的组合中进行研究的，这三种感觉通常被称为：听觉-躯体感觉(AS)、听觉-视觉(AV)和视觉-躯体感觉(VS)组合。成功整合多个感官通道中的并发信息对于在真实世界中发挥作用、完成日常生活活动和行动能力至关重要。到目前为止，只有很少的研究调查了老年人的多感官加工，并且主要集中在房室相互作用上。将MSI与现实世界活动联系起来的人仍然很少。我们实验室进行的一项研究结果显示，与年轻人相比，老年人在处理并发信息和信息时表现出明显更大的反应时间优势；这两种感觉模式显然在日常步态和平衡中发挥着重要作用。此外，我们最新的工作表明，与MSI效应较小的老年人相比，多感觉效应较大(即，较差)的个体表现出更差的静态平衡，报告更多的跌倒，并支持较少参与体育活动。这些结果支持VS整合测量的行为可能反映了与年龄有关的生理衰退的单一感觉加工的概念。VS信息处理在老年人中的促进作用具有重大的公共健康影响，因为单感觉视觉和躯体感觉障碍与功能衰退、摔倒风险增加、步态速度减慢、 以及更差的生活质量。此外，MSI的作用被归因于衰老过程中神经元结构的基本退行性变化；然而，这种推测性的解释尚未得到经验验证。此外，VS整合在衰老中的功能和结构神经相关性尚未建立--确定VS整合在衰老中的神经生物学底物以及这种增强与老年人各种运动结果的关联将是至关重要的，有朝一日将有助于确定引入结合VS增强策略的认知和身体补救计划的机会，以努力保持功能独立。

 DESCRIPTION (provided by applicant): A rapidly growing field of cognitive neuroscience referred to as multisensory integration (MSI) investigates the complexities of processing simultaneous sensory information. Primarily, MSI has been investigated in pairings of the three "major" senses (i.e., visual, auditory, and somatosensory systems), which are typically referred to as: auditory-somatosensory (AS), auditory-visual (AV), and visual-somatosensory (VS) combinations. Successful integration of concurrent information across multiple sensory modalities is crucial for functioning in the real world, completion of activities of daily living, nd mobility. To date, only few studies have investigated multisensory processing in older adults and have predominately focused on AV interactions. Fewer still have related MSI to real world activities. Results from a study conducted in our laboratory revealed that compared to younger adults, older adults demonstrated a significantly larger reaction time benefit when processing concurrent VS information; two sensory modalities that clearly play an important role in everyday gait and balance. Further, our most recent work indicates differential patterns of multisensory processing in aging where individuals with larger (i.e., worse) VS multisensory effects manifested worse static balance, reported more falls, and endorsed less engagement in physical activities compared to elders with smaller MSI effects. These results provide support for the notion that VS integration measured behaviorally might reflect age-related physiological declines in unisensory processing. The facilitative benefit of VS information processing in older adults has major public health implications since unisensory visual and somatosensory impairments have been linked to functional decline, increased risks of falls, slower gait velocity, and poorer quality of life. Additionally, the effect of MSI has been attributed to basic degenerative changes in neuronal architecture during the aging process; however, this speculative interpretation has yet to be empirically tested. Furthermore, the functional and structural neural correlates of VS integration in aging have not been established - determining the neurobiological substrates of VS integration in aging and the association of such enhancement with various motor outcomes in older adults would be paramount to one day help identify opportunities to introduce cognitive and physical remediation programs that incorporate VS enhancement strategies in an effort to maintain functional independence.