Matthias and Ingmar’s paper is out in Nature Communications!

Homing, or determining the straight path back to “home” after a winding outbound journey, is a critical but error-prone computation.

What are the main causes of human homing error, and how do they change with age?

We put humans into immersive VR, measured homing errors along winding paths, and modeled the time-resolved process of error accumulation with a Langevin-type diffusion equation.

We found that forgetful integration, biases in velocity estimation or integration, and reporting or readout errors do not limit homing ability; rather, the bottleneck is an accumulation of unbiased random error.

The random error accumulates with movement but not time, suggesting it is related to velocity sensing rather than integration.

Aging humans do worse; their diminished performance is not from new sources of error but an increase in the unbiased error already limiting young subjects.