Hyperacuity edit

 
Ewald Hering's model of how a Vernier acuity stimulus is coded by a receptor array. Receptors marked c signal a different position code along the horizontal direction from either the position a code or the position b code.[1]

Hering has done seminal work on what we now[2] call hyperacuity, i.e., a spatial resolution in certain visual tasks that exceeds visual acuity by about an order of magnitude. In his famous 1899 treatise "On the Limits of Visual Acuity"[1] he summarizes empirical data published 1863 by Alfred Wilhelm Volkmann and points out that the resulting spatial resolution goes well below the size of receptor cells in the central retina. In an explanatory model, Hering superimposes a Vernier acuity stimulus – i.e. a disalignment among two line segments – onto an idealized receptor array. He argued that, by a mechanism of integration across small eye movements, the location information signalled by the involved receptors is coded to a much higher precision than would be possible by a single receptor, an explanation that is still holds up today.[3][4]

Add reference to Volkmann: [5] [6]

  1. ^ a b Strasburger, Hans; Huber, Jörg; Rose, David (2018). "Ewald Hering (1899) On the Limits of Visual Acuity: A Translation and Commentary. With a Supplement on Alfred Volkmann (1863) Physiological Investigations in the Field of Optics". i-Perception. 9 (3): 1–14.
  2. ^ following G. Westheimer
  3. ^ JIang, H.; Cottaris, N.; Golden, J.; Brainard, D.; Farrell, J. E.; Wandell, B. A. (2017). "Simulating retinal encoding: Factors influencing Vernier acuity". Human Vision and Electronic Imaging. 2017: 177–181.
  4. ^ Rucci, M.; Lovin, R.; Poletti, M.; Santini, F. (2007). "Miniature eye movements enhance fine spatial detail" (PDF). Nature. 447: 851–854.
  5. ^ Strasburger, Hans; Rose, David (2018). "Alfred Volkmann (1863). Physiological Investigations in the Field of Optics (Physiologische Untersuchungen im Gebiete der Optik). Supplement to Strasburger, Huber, Rose (2018). "Ewald Hering (1899) On the Limits of Visual Acuity". i-Perception. 9 (3): 1–14.
  6. ^ Volkmann, Alfred (1863). Physiological Investigations in the Field of Optics (Physiologische Untersuchungen im Gebiete der Optik). Leipzig: Breitkopf und Härtel.