Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia.
Invest Ophthalmol Vis Sci. 2013 Mar 19;54(3):2004-10. doi: 10.1167/iovs.12-11326.
We examined factors influencing perceptual stability in observers with fusion maldevelopment nystagmus syndrome (FMNS). In addition, we also investigated the effect of visual demand, task-related physiologic stress, and motivation on the nystagmus waveform.
Perception of oscillopsia during daily activities was assessed via a questionnaire. Perception of oscillopsia in the laboratory was assessed using central and peripheral (10°) light emitting diodes (LEDs) in front of a background display of random, fixed-contrast shapes. Task-induced stress was achieved via a time restricted acuity task with or without concurrent mental arithmetic challenge, and motivation varied using a reward-penalty paradigm. The experiments have been previously described elsewhere.
Six out of nine subjects reported experiencing oscillopsia in certain daily activities. in the laboratory, the percentages of trials with perceptions of motion of the led and background were as follows: neither, 60% to 70%; background only, 20% to 30%; both, 5% to 15%, and LED only, 5% to 15%. Over all trials, six of nine experienced oscillopsia for both the low- and high-contrast image respectively (i.e., three subjects never experienced oscillopsia). The background was frequently seen moving for both images regardless of contrast and/or condition. Trials with and without oscillopsia did not differ when comparing foveation. In the second experiment, task-related physiologic stress and motivation were reflected in an increase in heart rate; nystagmus waveform intensity increased and foveation decreased. The magnitude of changes in heart rate was uncorrelated with changes in waveform parameters for all experiments, however.
Preliminary results suggest that the FMNS group does perceive spatially inhomogeneous oscillopsia, similar to infantile nystagmus syndrome (INS), in certain visual environments. In investigating the effect of stress and motivation on FMNS, a new, if tentative, finding suggests that task-induced stress and/or motivation may have a negative impact on the nystagmus. Taken together, our findings provide an insight into the particular environments and tasks that are likely to present particular challenges to persons with FMNS.
我们研究了影响融合发育性眼球震颤（FMNS）患者知觉稳定性的因素。此外，我们还研究了视觉需求、与任务相关的生理应激和动机对眼球震颤波形的影响。
通过问卷评估日常活动中视差感的感知。通过在随机固定对比度形状的背景显示前的中央和外围（10°）发光二极管（LED），在实验室中评估对 LED 和背景运动的感知。通过限时视力任务和/或同时进行心算挑战来实现任务诱导的应激，通过奖励-惩罚范式来改变动机。这些实验已在其他地方进行了描述。
9 名受试者中有 6 名报告在某些日常活动中出现视差感。在实验室中，以下是 LED 和背景运动感知试验的百分比：均无，60%至 70%；只有背景，20%至 30%；两者均有，5%至 15%；只有 LED，5%至 15%。在所有试验中，9 名受试者中有 6 名分别对低对比度和高对比度图像都有视差感（即，3 名受试者从未经历过视差感）。无论对比度和/或条件如何，背景经常被视为运动。在注视方面，有和没有视差感的试验没有差异。在第二个实验中，与任务相关的生理应激和动机反映在心率增加；眼球震颤波形强度增加，注视减少。然而，所有实验中，心率变化的幅度与波形参数变化之间没有相关性。
初步结果表明，FMNS 组确实在某些视觉环境中感知到空间不均匀的视差感，类似于婴儿性眼球震颤（INS）。在研究 FMNS 中应激和动机的影响时，一个新的、如果是暂定的发现表明，任务诱导的应激和/或动机可能对眼球震颤产生负面影响。总的来说，我们的发现为了解 FMNS 患者可能面临特定挑战的特定环境和任务提供了一些启示。
