User:Gwestheimer/Hyperacuity

Hyperacuity is the term used when a sensory performance is better than expected from the limits of its underlying anatomical apparatus. The most prominent example of a hyperacuity and the one for which the word was coined, is vernier acuity in vision where a misalignment of two abutting lines can be detected with a precision up to ten times better than the optical resolving power of the eye and the spacing of the anatomical receptors cells (retinal cones), for which the term visual acuity is reserved. Similar phenomena occur in color vision where many more hues can be discriminated that the three normally present color cones, in hearing where pitch discrimination in the acoustic sound spectrum transcends the spacing of the cochlear hair cells, and in touch for detection of minute mechanical deformations by the sense cells in the skin.

The fundamental difference between hyperacuity and the traditional concept of acuity is that in a hyperacuity the task is not to resolve whether there are one or two stimuli but instead, given the frank presence of stimuli, to identify their precise location in their perceptual realm. Hence the neural mechanisms by which the two kinds of task are achieved are distinct.