Department of Psychiatry and Biobehavioral Sciences, Jane and Terry Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles (UCLA), Los Angeles, CA, USA.
German Center for Neurodegenerative Diseases (DZNE), Aging & Cognition Research Group, Magdeburg, Germany.
Nat Commun. 2020 May 26;11(1):2626. doi: 10.1038/s41467-020-15805-9.
Path integration plays a vital role in navigation: it enables the continuous tracking of one's position in space by integrating self-motion cues. Path integration abilities vary widely across individuals, and tend to deteriorate in old age. The specific causes of path integration errors, however, remain poorly characterized. Here, we combine tests of path integration performance in participants of different ages with an analysis based on the Langevin equation for diffusive dynamics, which allows us to decompose errors into distinct causes that can corrupt path integration computations. We show that, across age groups, the dominant error source is unbiased noise that accumulates with travel distance not elapsed time, suggesting that the noise originates in the velocity input rather than within the integrator. Age-related declines are primarily traced to a growth in this noise. These findings shed light on the contributors to path integration error and the mechanisms underlying age-related navigational deficits.
它通过整合自我运动线索，使个体能够持续跟踪其在空间中的位置。个体之间的路径整合能力差异很大，并且随着年龄的增长而逐渐恶化。然而，路径整合错误的确切原因仍未得到很好的描述。在这里，我们将不同年龄段参与者的路径整合表现测试与基于扩散动力学 Langevin 方程的分析相结合，这使我们能够将错误分解为可能破坏路径整合计算的不同原因。我们表明，在不同年龄组中，主要的误差源是无偏噪声，该噪声随行程距离而累积，而不是随经过的时间累积，这表明噪声源来自于速度输入而不是积分器内部。与年龄相关的下降主要归因于这种噪声的增加。这些发现揭示了路径整合误差的贡献因素以及与年龄相关的导航缺陷的机制。
