Mulholland Pádraig J, Redmond Tony, Garway-Heath David F, Zlatkova Margarita B, Anderson Roger S
National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom Vision Science Research Group, School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, United Kingdom.
School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom.
Invest Ophthalmol Vis Sci. 2014 Dec 16;56(1):431-7. doi: 10.1167/iovs.14-15304.
To estimate the critical duration of temporal summation for achromatic Goldmann III stimuli under the conditions of standard automated perimetry (SAP) and quantify response variability for short-duration stimuli.
Contrast thresholds were gathered using the method of constant stimuli for seven circular (0.48° diameter) incremental stimuli of varying duration (sum-of-frames equivalent: 8.3-198.3 ms), at an eccentricity of 8.8° along the four principal meridians of the visual field in two healthy, psychophysically experienced observers. Stimuli were presented on a high-resolution cathode ray tube display with a background luminance of 10 cd/m(2). Psychometric functions were fitted using a probit model and nonparametric local-linear analysis. The critical duration was estimated using iterative two-phase regression analysis, the results also being compared with values produced using previously published methods of analysis.
The median critical duration estimated using iterative two-phase regression analysis was 27.7 ms (IQR 22.5-29.8). A slight steepening of the psychometric function slope (lower variability) was observed for longer stimulus durations, using both probit and local-linear analysis techniques, but this was not statistically significant.
Critical duration estimates in this study are substantially shorter than those previously reported for a Goldmann III stimulus, under the conditions of SAP. Further work is required to firmly establish the relationship between measurement variability and the degree of local temporal and spatial summation.
在标准自动视野计（SAP）条件下，估计消色差Goldmann III刺激的时间总和临界持续时间，并量化短持续时间刺激的反应变异性。
在两名健康的、有心理物理学经验的观察者中，沿着视野的四个主要子午线，在8.8°的偏心率处，使用恒定刺激法收集七个不同持续时间（帧总和等效：8.3 - 198.3毫秒）的圆形（直径0.48°）递增刺激的对比度阈值。刺激在背景亮度为10 cd/m²的高分辨率阴极射线管显示器上呈现。使用概率模型和非参数局部线性分析拟合心理测量函数。使用迭代两阶段回归分析估计临界持续时间，结果还与使用先前发表的分析方法得出的值进行比较。
使用迭代两阶段回归分析估计的中位临界持续时间为27.7毫秒（四分位距22.5 - 29.8）。使用概率和局部线性分析技术，在较长刺激持续时间下观察到心理测量函数斜率略有变陡（变异性降低），但这在统计学上不显著。
在SAP条件下，本研究中的临界持续时间估计值明显短于先前报道的Goldmann III刺激的估计值。需要进一步开展工作，以牢固确立测量变异性与局部时间和空间总和程度之间的关系。
