{
  "id": 9767927,
  "title": "Retinal curl as a functional signal for heading estimation beyond the focus of expansion",
  "url": "https://urgent.news/2026/09/25/retinal-curl-as-a-functional-signal-for-heading-estimation-beyond-the",
  "topic": "science",
  "section": "Science",
  "published": "2026-09-25T00:00:00.000Z",
  "source": {
    "name": "eLife",
    "slug": "elife",
    "url": "https://elifesciences.org/articles/110770"
  },
  "original_language": "en",
  "account": "Current models of how humans determine direction suggest the need to return to the Focus of Expansion (FoE), accounting for any eye movement-induced rotation. However, researchers propose a different explanation: the visual system uses the mean retinal curl from fixations as a substitute signal for direction, eliminating the need to explicitly find the FoE. In a study, stationary participants viewed simulated walking paths on a large screen while focusing on points on the projected ground texture at different distances from the center. This behavior naturally creates varying levels of retinal curl. Participants were asked to report their perceived direction in 3D scene coordinates continuously. To determine the role of retinal curl, the researchers conducted an experiment where they used a real-time technique that preserved the constant movement across the field of view while altering the curl component of the foveal area. They manipulated the curl to be either left unchanged, canceled, or overly canceled. In normal circumstances (unchanged retinal curl), participants showed consistent heading biases going in the opposite direction of their gaze. Significantly, when the expected curl was canceled, these biases disappeared, but when the curl was excessively canceled, the biases reversed, clearly identifying retinal curl as the key factor driving perceptual bias. To explain these results, the researchers built a straightforward feedback controller and a ring-attractor neural network that included gaze-contingent inhibition and a 'straight-ahead' prior. The study implies that the brain makes use of the geometry of gaze stabilization to simplify navigation, treating retinal curl as a functional signal instead of noise to be filtered out.",
  "summary": "Prevailing models aiming at explaining heading assume that humans need to recover the Focus of Expansion (FoE) while accounting for eye-movement-induced rotation. We propose an alternative: the visual system utilizes mean retinal curl from fixations as a surrogate signal for heading, rendering the explicit recovery of the FoE unnecessary. Stationary participants viewed simulated walking paths on…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}