Modeling Sensory Integration and Attention in Postural Control of Older Adults

描述（由申请人提供）：这份授予R01AG029546的竞争性修订申请是为了响应NOT-OD-09-058: NIH宣布竞争性修订申请的恢复法案资金的可用性而提交的。这一修订建议在我们正在进行的研究中增加光学脑成像，这将使我们能够在年轻人和老年人执行当前平衡和信息处理（IP）任务时可视化和量化大脑皮层活动。在我们目前的研究中加入这一神经成像目标不需要改变实验方案。跌倒是老年人受伤和死亡的主要原因，是由感觉、运动和认知丧失的复杂相互作用造成的。研究表明，老年人需要更多的认知资源（即注意力）来保持平衡，与年轻人相比，环境变化改变了身体方向和运动的感觉信息，对老年人的平衡有更大的影响。目前，尚不清楚年轻人和老年人之间的姿势控制差异在多大程度上是由于感觉统合的差异造成的。此外，老年人的注意力和感觉统合的相互作用尚未得到充分的研究和发展。我们目前的研究是通过涉及适度平衡扰动和IP任务的双任务实验来提供对这些问题的见解，然后从中获得的数据适合于姿势控制模型。我们研究的一个中心假设是，需要注意力的信息处理任务同时伴有适度的姿势挑战，会转移老年人对平衡控制的注意力，这可以通过我们模型中的时间延迟和其他生理相关参数来量化。当受试者进行双任务实验时，我们建议使用一种便携式、非侵入性光学成像系统来测量大脑皮层的激活，这将使我们能够更好地解决姿势控制中平衡和注意力之间干扰的认知基础。我们的假设是，这种干扰将表现为来自前额叶中部和前额叶背外侧的激活区域的更大募集，并显示运动前和运动区域的激活减弱。我们预计这种效应会受到IP任务难度的调节，并且这种效应在老年受试者中会更大。

DESCRIPTION (provided by applicant): This competitive revision application to grant R01AG029546 is submitted in response to NOT-OD-09-058: NIH Announces the Availability of Recovery Act Funds for Competitive Revision Applications. This revision proposes to add optical brain imaging to our ongoing study that will enable us to visualize and quantify cortical brain activity while young and elderly adults perform our current balance and information processing (IP) tasks. No change in experimental protocol is required to add this neuroimaging aim to our current study. Falls are a leading cause of injury and death among the elderly, resulting from a complex interaction of sensory, motor and cognitive loss. Older adults have been shown to require increased cognitive resources (i.e. attention) for balance, and environmental changes that alter sensory information about body orientation and motion have a greater impact on balance of older adults compared to young adults. Currently, it is not known to what extent differences in postural control between young and older adults are due to differences in sensory integration. Moreover, the interaction of attention and sensory integration in older adults has not been fully studied or developed. Our current research is providing insights into these issues through dual-task experiments involving moderate balance perturbations and IP tasks, the data from which is then fit to a postural control model. A central hypothesis of our research is that attention-requiring information processing tasks concurrent with moderate postural challenges will divert attention away from balance control in older adults, which can be quantified by time delay and other physiologically relevant parameters in our model. The proposed addition of neuroimaging using a portable, non-invasive optical imaging system to measure cortical brain activation while subjects perform the dual task experiments, will allow us to better address the cognitive basis of interference in postural control between balance and attention. Our hypothesis is that this interference will manifest as a larger recruitment of activation areas from the midfrontal and dorsolateral prefrontal brain regions and show diminished activation in the premotor and motor regions. We expect that this effect will be modulated by IP task difficulty and that this effect will be greater in older subjects. PUBLIC HEALTH RELEVANCE: The proposed research is relevant to public health in that falls are a significant problem in older adults compared to young adults. Environmental changes that alter sensory orientation information tend to have a greater destabilizing effect on older adults, and older adults appear to require greater attentional resources for balance control. Our research will provide new insights into the interaction of balance and attention through cortical brain imaging while subjects perform balance and attention tasks simultaneously.