Spatial and Temporal Visual Attention in Infants with Fragile X Syndrome

描述（由申请人提供）：脆性X综合征（FXS）是遗传性智力低下的主要原因，其特征是与大脑顶叶相关的视觉处理能力的特定缺陷。为了了解FXS在大龄儿童和成人中的分子机制以及认知和行为后果，已经进行了大量的研究工作，但该疾病的早期发展仍有待研究。本研究的总体目标是通过分离FXS婴儿的视觉注意的空间和时间方面，并将其与心理年龄匹配的正常发育婴儿的观察结果进行比较，进一步了解这种视觉缺陷。这将通过心理物理来确定个体时空对比检测阈值，作为低水平、注意前处理的测量，以及空间拥挤和闪烁相位检测指标的阈值，分别用于空间和时间视觉注意限制。视觉注意的差异已被用作后期一般智力功能的早期指标和发展结果的预测指标，因此，从本研究计划中获得的知识对于设计针对年幼FXS儿童的行为干预和基于教育的治疗方法至关重要。鉴于我们对FMRP在发育过程中正常突触形成、成熟和可塑性中的作用的理解，以及文献记录了生命前3年对大脑发育和行为轨迹的影响，我们预计最具影响力的干预措施是在生命早期神经连接快速增殖和修剪的时期提供的。此外，随着FXS的新生儿筛查可能在不久的将来开始，研究导致早期认知功能缺陷的基本视觉过程的紧迫性就更大了。随着更多的婴儿在12个月前被诊断出来，早期干预设计将依赖于研究结果，如本文提出的研究结果，为此类治疗框架提供信息，并最终促进FXS患者的最佳长期发展。这项研究对FXS儿童和整个社会都有未来的意义。

DESCRIPTION (provided by applicant): Fragile X Syndrome (FXS) is the leading cause of inherited mental retardation, and has been characterized by specific deficits in visual processing abilities associated with the parietal lobe of the brain. Significant research efforts have been made toward understanding the molecular mechanisms and cognitive and behavioral consequences of FXS in older children and adults, but much of the early development of the disorder remains to be examined. The overarching goal of the current proposal is to further understand this visual deficit by disentangling the spatial from the temporal aspects of visual attention in infants with FXS, and comparing them to those observed in mental age-matched typically developing infants. This will be accomplished by psychophysically determining individual spatiotemporal contrast detection thresholds as a measure of low-level, pre-attentive processing, and thresholds for spatial crowding and flicker phase detection indicators of the spatial and the temporal visual attention limit, respectively. Differences in visual attention have been used as an early indicator of later general intellectual function and a predictor of developmental outcome, and thus, the knowledge gained from this research proposal will be vital for the design of behavioral interventions and education-based treatments specific to young children with FXS. Given our understanding of the role of FMRP in normal synaptic formation, maturation, and plasticity during development, and the literature documenting the implications of the first 3 years of life on brain development and behavioral trajectories, it is expected that the most influential interventions are those provided early in life during the period of rapid proliferation and pruning of neural connections. Additionally, with the likelihood that newborn screening for FXS will begin in the near future, there is an even greater urgency to study basic visual processes that lead to early deficits in cognitive functioning. With a greater number of infants diagnosed before the age of 12 months, early intervention design will rely on results from studies such as the one proposed here to inform the framework of such therapies and ultimately promote optimal long-term development in individuals with FXS. This research has future implications for children with FXS and society as a whole.