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

识别和定位场景中任务相关对象的能力是功能性视觉的关键组成部分。在心理学和人类神经科学中，这种能力已经使用视觉搜索任务进行了研究，该任务测量了在可变数量的非目标（干扰物）刺激中检测目标的速度和准确性。衰老与感官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，支持视觉搜索效率与年龄相关变化的经验证据是混合的。矛盾的结果反映了异质性样本和不同的措施，用于调查与年龄相关的感觉和认知成分的变化。事实上，调查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、短期记忆或扫视的规划和执行的评估相关的认知机制。实验也很少滴定老年和年轻参与者的刺激，以消除可能由前者的感官退化引起的表现差异。由于这些原因，本项目将试图量化与年龄相关的变化，通过采用不同的心理物理学技术来测量对比度，空间频率和色敏感度的刺激在整个视野中的感觉敏锐度。此外，由于目标是测量感知过程中与年龄相关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调制的贡献，因此本项目旨在将联合收割机同时结合眼跟踪和脑电图（EEG）以获得调节目标表征，引导，搜索过程中的选择和识别。最后，本研究将尝试整合瞳孔测量记录的瞳孔大小和脑电功率谱的任务相关变化，以对比年轻和老年观察者对显示器、任务指令和先前经验的感知辨别能力变化的认知努力和持续注意力

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