Sources of path integration error in young and aging humans
Matthias Stangl, Ingmar Kanitscheider, Martin Riemer, Ila Fiete, Thomas Wolbers
Received Date: 20th December 18
Path integration is a vital function in navigation: it enables the continuous tracking of one's position in space by integrating self-motion cues, and it serves as a building block for cognitive maps. Path integration abilities are known to vary widely across individuals, and they tend to deteriorate in old age. The specific causes of path integration errors, however, remain poorly characterized. Here, we combined tests of path integration performance in subjects of different ages with a novel analysis based on the Langevin equation for diffusive dynamics, which allowed us to decompose errors into distinct causes – including noise, leaky integration, additive biases, multiplicative gain and reporting errors – that can corrupt path integration computations. Across age groups, the dominant errors were due to noise and a systematic bias in speed estimation. Noise-driven errors accumulated with travel distance not elapsed time, suggesting that the dominant noise originates in the velocity input rather than within the integrator. In addition, age-related declines were traced primarily to a growth in this unbiased noise. Together, these findings shed light on the contributors to path integration error and the mechanisms underlying age-related navigational deficits.
Read in full at bioRxiv.
This is an abstract of a preprint hosted on an independent third party site. It has not been peer reviewed but is currently under consideration at Nature Communications.