Evaluating the contributions of age-related changes in sensory acuity and cognitive control on the speed and accuracy of visual search.

识别和定位场景中与任务相关的对象的能力是功能视觉的关键组成部分。在心理学和人类神经科学中，这种能力是通过视觉搜索任务来研究的，视觉搜索任务衡量的是在可变数量的非目标(分心)刺激中检测目标的速度和准确性。衰老与感觉和认知过程的变化有关，这可能会影响搜索的效率。尽管如此，支持与年龄相关的视觉搜索效率变化的经验证据是喜忧参半的。相互矛盾的发现反映了不同的样本和不同的方法，用于调查与年龄相关的感觉和认知成分的变化。事实上，研究与年龄相关的感觉敏锐度变化的研究很少测试与竞争性视觉输入、短期记忆或眼跳的计划和执行相关的认知机制。实验也很少滴定呈现给老年人和年轻人的刺激，以消除前者可能因感觉退化而导致的表现差异。由于这些原因，本项目将试图通过使用不同的心理物理技术来测量对比度、空间频率和对视野中刺激的颜色敏感性来量化与年龄相关的感觉敏锐度的变化。此外，由于该项目的目的是测量与年龄相关的知觉过程的减少以及影响视觉采样和感觉信息的维持和评估的认知过程的自上而下的调制的贡献，本项目的目的是将同时的眼睛跟踪和脑电(EEG)结合起来，以获得在搜索过程中调制目标表征、引导、选择和识别的神经反应的准确测量。最后，这个项目将尝试整合与任务相关的瞳孔大小变化和脑电功率谱的瞳孔测量学记录，以对比年轻和老年观察者的认知努力和持续注意力，以应对显示器、任务指令和先前经验的知觉辨别能力的变化

he ability to identify and locate task-relevant objects in the scene is a key component of functional vision. In psychology and human neuroscience, this ability has been investigated using visual search tasks, which measure the speed and accuracy of detection for a target among a variable number of non-target (distractor) stimuli. Ageing is associated with changes in sensory and cognitive processes, which are likely to impact the efficiency of search. Despite this, empirical evidence to support age-related changes in the efficiency of visual search is mixed. Contradictory findings reflect heterogenous samples and different measures used to investigate age-related changes in sensory and cognitive components. Indeed, studies investigating age-related changes in sensory acuity rarely test cognitive mechanisms associated with the evaluation of competing visual input, short-term memory or the planning and execution of saccades. Experiments also rarely titrate the stimuli presented to old and young participants so to eliminate differences in performance that may have been caused by sensory degradation in the former. For these reasons, the present project will attempt to quantify age-related changes in sensory acuity by employing different psychophysical techniques to measure contrast, spatial frequency, and chromatic sensitivity for stimuli across the visual field. Additionally, since the objective is to measure both the contributions of age-related reductions in perceptual processes and the top-down modulation of cognitive processes that influence visual sampling and the maintenance and evaluation of sensory information, the present project aims to combine simultaneous eye tracking and electroencephalogram (EEG) to obtain accurate measures of the neural responses that modulate target representation, guidance, selection and identification during search. Lastly, this project will attempt to integrate pupillometric recordings of task-related changes in pupil size and EEG power spectrum to contrast cognitive effort and sustained attention in young an older observers in response to changes in the perceptual discriminability of displays, task instructions and prior experience