照明环境与LCD显示界面背景饱和度的交互效应对视觉绩效的影响

摘 要 采用E-prime编排认知实验研究照明环境与TFT-LCD视觉显示终端界面背景饱和度的交互效应对视觉绩效的影响。依据字母视力表设计原理制作认知材料,以认知速度与准确率为视觉绩效评价指标。结果发现,照度与饱和度的交互效应对视觉绩效存在显著影响,色温与饱和度的交互效应仅对准确率存在显著影响,三因素交互作用对准确率存在显著影响。结果表明,不同照度、色温下,通过调节显示终端界面背景饱和度可改善视觉绩效。     

Visual contribution to human standing balance during support surface tilts

Visual position and velocity cues improve human standing balance, reducing sway responses to external disturbances and sway variability. Previous work suggested that human balancing is based on sensory estimates of external disturbances and their compensation using feedback mechanisms (Disturbance Estimation and Compensation, DEC model). This study investigates the visual effects on sway responses to pseudo-random support surface tilts, assuming that improvements result from lowering the velocity threshold in a tilt estimate and the position threshold in an estimate of the gravity disturbance. Center of mass (COM) sway was measured with four different tilt amplitudes, separating the effect of visual cues across the conditions ‘Eyes closed’ (no visual cues), ‘4 Hz stroboscopic illumination’ (visual position cues), and ‘continuous illumination’ (visual position and velocity cues). In a model based approach, parameters of disturbance estimators were identified. The model reproduced experimental results and showed a specific reduction of the position and velocity threshold when adding visual position and velocity cues, respectively. Sway variability was analyzed to explore a hypothesized relation between estimator thresholds and internal noise. Results suggest that adding the visual cues reduces the contribution of vestibular noise, thereby reducing sway variability and allowing for lower thresholds, which improves the disturbance compensation.