Fahle M, Henke-Fahle S
Department of Neuroophthalmology, University Eye Clinic, Schleichstrasse, Tubingen, Germany.
Invest Ophthalmol Vis Sci. 1996 Apr;37(5):869-77.
Normal observers and patients with apparent disease usually are tacitly expected to yield homogeneous thresholds in clinical tests of visual perception. The authors tested this assumption.
Through training of 70 observers, performance and improvement of performance were tested for different hyperacuity tasks using psychophysical tests.
Although the assumption of homogeneous results might be true for many tasks limited by the physical properties of the eye, such as two-point resolution, the authors find a relatively wide variation of performance, especially in untrained observers, for tasks that require more elaborate processing in the visual cortex. Observers vary widely both in their baseline performance and in the extent and speed of learning for tasks such as vernier discrimination and stereoscopic depth perception. On average, speed of learning is inversely correlated to baseline performance, that is better initial performance usually is associated with slower improvement.
This finding indicates that retesting of unusually high (pathologic) thresholds in clinical tests of visual perception might improve discrimination between patients whose performance is poor because of lack of familiarity with the task and who improve with training and patients who improve far less if their poor performance results from pathologic conditions.
在视觉感知的临床试验中，通常默认正常观察者和患有明显疾病的患者会产生一致的阈值。作者对这一假设进行了测试。
通过对70名观察者进行训练，使用心理物理学测试对不同超敏锐度任务的表现及表现的改善情况进行测试。
尽管对于许多受眼睛物理特性限制的任务（如两点分辨力）而言，结果一致的假设可能成立，但作者发现，对于需要在视觉皮层进行更精细处理的任务，表现存在较大差异，尤其是在未经训练的观察者中。在诸如游标辨别和立体深度感知等任务中，观察者的基线表现、学习程度和学习速度差异很大。平均而言，学习速度与基线表现呈负相关，即初始表现越好，通常改善越慢。
这一发现表明，在视觉感知的临床试验中，对异常高（病理性）阈值进行重新测试，可能有助于区分因不熟悉任务而表现不佳但经训练可改善的患者，以及因病理状况导致表现不佳且改善甚微的患者。
