Bodis-Wollner, "Foveal vision
is impaired in Parkinson's disease," Parkinsonism and Related Disorders, vol.
The emphasis on foveal vision
is known as cortical magnification or M-scaling, (9-10) a concept that is demonstrated in Figure 1, where a physically small area of retina (the fovea) is represented on a much greater scale within the primary visual cortex.
All stimuli were presented foveally, bearing in mind that the diameter of foveal vision
is limited to approximately 5 degrees of visual angle.
Since, currently it is an all or nothing consideration of cones and foveal vision
, on the surface, it sounds like a good thing.
The hypothesis that, due to visual saliency, the smiling mouth radiates to adjacent facial regions implies, first, that the smile would be particularly resistant to visual acuity degradation when it appears outside of foveal vision
(e.g., when the viewer is looking at the eyes of a smiling face).
Panchuk and Vickers (2009) suggested that determining the extent to which participants picked-up peripheral target information was not possible because the eye-tracking technology is limited to measuring foveal vision
. The general superiority of expert's peripheral perception is well assumed (for an overview, see Williams at al., 1999), but to our knowledge nothing is known about the role of peripheral information pick-up during the quiet eye period.
Excessive tension of those muscles perpetuates an elongated shape of the eyeballs, interfering with natural focal length and disturbing optimal foveal vision
, a very common characteristic of the myopic eye.
An eye fixation encompasses a high-acuity foveal vision
area of about 2[degrees] (Wandell, 1995).
In the peripheral scene condition, viewers need to widen the scope of spatial attention to incorporate in it both the foveal letter and the peripheral scene, but this is not needed when the letter and the picture appear superimposed at fixation (i.e., in foveal vision
These inequalities are propagated further along the visual system, with relatively larger regions of lateral geniculate nucleus (LGN) and visual cortex being devoted to foveal vision
than to peripheral vision which is named cortical magnification or scaling factor (Connolly & Van Essen, 1984; Daniel & Whitteridge, 1961; Hubel & Wiesel, 1974; for a review see Battista, Kalloniatis, & Metha, 2005).