A high- temporal resolution, high brightness 3D projector to study visual perception, attention & eye movements

运动感知对于许多日常活动至关重要，例如在拥挤的环境中行走，练习运动，穿过忙碌的街道，驾驶和看电视。然而，随着年龄的增长，这种视觉功能受到很大影响，这会影响老年人完成基本日常任务的能力，从而逐渐影响他们的自主性。重要的是要确定这种与年龄相关的视力下降的根本原因，以制定干预措施，以优化老年人的自主性。然而，年龄相关的视力下降可能不是由于运动知觉本身。我们最近发现，健康老年人的光感受器检测到的光量大约是年轻人的10倍。假定运动感知很大程度上取决于亮度强度（即，取决于光感受器吸收的光量），与年龄相关的运动感知下降的很大一部分可能是由于光感受器对光的检测较低。中和不同光检测水平的影响的有效方法是以高亮度呈现刺激，使得视觉性能最佳。因此，将获得的新设备（即，高亮度、高时间分辨率3D投影仪）将使我们能够以高亮度显示移动刺激，从而优化视觉性能，并且光感受器吸收的光量对视觉性能的影响可以忽略不计。目前研究计划的主要目标是调查健康老龄化中与年龄相关的变化的潜在机制。我们将研究1）光感受器检测到的光量的减少在多大程度上解释了这些变化，以及2）通过以高亮度呈现测试视觉刺激，从而中和这种与年龄相关的可见性效应，考虑到这种降低的可见性，不同的视觉功能如何变化。为了从一个新的角度来解决这些问题，一个独特的实验装置将通过结合两个基础设施，使探测视觉系统在升高的时间频率使用非侵入性的实验范例。第一个是用于心理物理学的实时投影仪设计（PROPixx/HB），具有高时间分辨率（1440 Hz）和高亮度，使我们能够在高亮度下以高时间精度呈现视觉刺激。第二件设备是一个高分辨率的视频为基础的眼动跟踪设置，允许高的时间和空间记录精度的眼球运动。所要求的基础设施将创建一个独特的心理物理实验设置。高时间分辨率、高亮度显示屏与尖端的眼动仪相结合，将能够前所未有地探测视觉系统，并为衰老对运动感知的影响提供新的见解。

Motion perception is crucial for many daily activities such as walking in a crowded environment, practicing a sport, crossing a busy street, driving and watching TV. However, this visual function is considerably affected with aging, which can affect the ability of older adults to accomplish basic daily tasks, and thereby gradually affect their autonomy. It is important to identify the underlying causes of this age-related visual decline in order to develop interventions to optimise the autonomy of older adults. However, age-related visual declines might not be due to motion perception per se. We have recently found that the amount of light detected by the photoreceptors of healthy older adults is approximately 10 times less than young adults. Given that motion perception largely depends on luminance intensity (i.e., on the amount of light absorbed by photoreceptors), a large component of age-related decline in motion perception may be due to a lower detection of light by photoreceptors. An efficient method to neutralize the impact of different levels of light detection is to present the stimulus at a brightness so high that visual performance is optimal. Thus, the new equipment that will be acquired (i.e., high brightness, high temporal resolution 3D projector) will enable us to display moving stimuli at high brightness so that visual performance is optimised and the amount of light absorbed by photoreceptors has a negligible impact on visual performance. The main objective of the current research program is to investigate the underlying mechanisms involved in age-related changes in healthy aging. We will investigate 1) to what extent reduction in the amount of light detected by photoreceptors accounts for these changes and 2) how different visual functions change taking this lowered visibility into consideration by presenting testing visual stimuli at high brightness, thus neutralizing this age-related visibility effect. To address these topics from a new perspective, a unique experimental setup will be acquired by combining two pieces of infrastructure enabling to probe the visual system at elevated temporal frequencies using non-invasive experimental paradigms. The first is a real-time projector design for psychophysics (PROPixx/HB) with a high temporal resolution (1440 Hz) and high brightness, allowing us to present visual stimuli with high temporal precision at high brightness. The second piece of equipment is a high-resolution video-based eye tracking setup that allows high temporal and spatial recording precision of eye movements. The requested infrastructure will create a unique psychophysical experimental setup. The high temporal resolution, high brightness display combined with a cutting-edge eye tracker will enable to probe the visual system like never before and provide new insights on the impact of aging on motion perception.