Department of Human Factors Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
Sci Rep. 2020 May 29;10(1):8783. doi: 10.1038/s41598-020-65568-y.
We examined the effect of aging on the integration of position and motion signals, which is essential for tracking visual objects, using the motion-induced position shift (MIPS) phenomenon. We first measured the MIPS and bias in speed perception at three eccentricities. Both young and older adults showed the increasing MIPS and decreasing perceived speed as the eccentricity increased, which is consistent with previous literature. More importantly, we found that the mean MIPS was 2.87 times larger in older adults, and the response variability in position tasks showed a larger difference between age groups compared with the difference in speed tasks. We then measured the MIPS across stimulus durations. Temporal changes in the MIPS showed similar patterns in young and older adults in that the MIPS initially peaked at around 60 ms and approached an asymptote. We further analyzed the changes in response variability across stimulus durations to estimate sensory noise and propagation noise separately and found that only sensory noise was significantly larger in older adults. The overall results suggest that the increased MIPS in older adults is due to the increased dependency on predictive motion signals to compensate for the relatively imprecise position signals, which in turn implies that older adults would depend more on the motion signals to track objects.
我们使用运动诱发位置偏移（MIPS）现象研究了年龄对位置和运动信号整合的影响，这对于跟踪视觉物体至关重要。我们首先在三个偏心率处测量了 MIPS 和速度感知偏差。年轻和老年成年人都表现出随着偏心率增加 MIPS 增加和感知速度降低的趋势，这与之前的文献一致。更重要的是，我们发现老年成年人的平均 MIPS 大 2.87 倍，并且位置任务的响应变异性在年龄组之间的差异比速度任务更大。然后我们测量了跨刺激持续时间的 MIPS。MIPS 的时间变化在年轻和老年成年人中表现出相似的模式，即在大约 60 毫秒处初始达到峰值并接近渐近线。我们进一步分析了跨刺激持续时间的响应变异性变化，以分别估计感觉噪声和传播噪声，发现只有感觉噪声在老年成年人中明显更大。总体结果表明，老年成年人中 MIPS 的增加是由于对预测运动信号的依赖性增加，以补偿相对不精确的位置信号，这反过来意味着老年成年人将更多地依赖运动信号来跟踪物体。
