Chapter 3: Spatial Vision - From Spots to Stripes Flashcards
contrast
The difference in luminance between an object and the background, or between lighter and darker parts of the same object.
acuity
The smallest spatial detail taht can be resolved at 100% contrast.
cycle
For a grating, a pair consisting of one dark bar and one bright bar.
visual angle
The angle subtended by an object at the retina.
sine wave grating
A grating with a sinusoidal luminance profile as shown in Figure 3.4a
spatial frequency
The number of grating cycles (i.e., dark and bright bars) in a given unit of space.
cycles per degree
The number of grating cycles per degree of visual angle.
contrast sensitivity function (CSF)
A function describing how the sensitivity to contrast (defined as the reciprocal of the contrast threshold) depends on the spatial frequency (size) of the stimulus.
contrast threshold
The smallest amount of contrast required to detect a pattern.
lateral geniculate nucleus (LGN)
A structure in the thalamus, part of the midbrain, that receives input from the retinal ganglion cells and has input and output connections to the visual cortex.
magnocellular layer
Either of the bottom two neuron-containing layers of the lateral geniculate nucleus, the cells of which are physically larger than those in the top four layers.
parvocellular layer
Any of the top four neuron-containing layers of the lateral geniculate nucleus, the cells of which are physically smaller than those in the bottom two layers.
koniocellular cell
A neuron located between the magnocellular and parvocellular layers of the lateral geniculate nucleus. This layer is known as the koniocellular layer.
contralateral
Referring to the opposite side of the body (or brain).
ipsilateral
Referring to the same side of the body (or brain).