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LGN and V4 have distinct layers for each eye.

The distinct layers for each eye in LGN and V4 only arise after the initial projections from the retina are made, but, in higher mammals, before birth.

Most neurons in the visual cortex (except v4) are binocular.

Usually, input from one eye is dominant, however.

The distribution of monocular dominance in visual cortex neurons is drastically affected by monocular stimulus deprivation during early development.

Neural responses in LGN to short and medium-to-long wavelengths of light are antagonistic in rodents and cats (in certain cells).

Buzás et al. found blue-ON-type cells in the cat LGN, but no blue-OFF cells.

Blue-ON-type cells in primate and cat LGN have large receptive fields

LGN is the earliest stage in the visual pathway receiving feedback (the retina does not).

The superficial SC projects retinotopically to LGN.

The same regions in LGN receiving projections from the superficial SC project to the cortex.

The ventral lateral geniculate nucleus projects to the deep SC.

The lateral geniculate nucleus (lgn) is described as some sort of waystation.

The lateral geniculate nucleus (lgn) receives visual, auditory and higher cognitive input. According to Winston, 80% of lgn input is non-visual.

There's a retinotopic, polysynaptic pathway from the SC through LGN.

Benevenuto and Fallon found projections from the SC mostly to midbrain and thalamus structures. They did not study projections to cortical regions. In detail, they found projections to:

Midbrain:

  • inferior colliculus
  • pretectum

Thalamus:

  • ventral lgn
  • dorsal lgn
  • suprageniculate nucleus
  • intralaminar nuclei
  • parafascicular nucleus
  • parts of dorsomedial nucleus
  • suprageniculate nucleus
  • certain pulvinar nuclei
  • lateral posterior nucleus
  • reunions nucleus
  • ventral posterior inferior nucleus
  • ventral posterior lateral nuclei
  • ventral lateral nucleus
  • limitans nucleus

Hypothalamus

  • dorsomedial nucleus

Other

  • Fields of Forel (subthalamic)
  • zona incerta
  • accessory optic tract (in midbrain)

Color opponency and center-surround oppenency arise first in LGN.

The receptive fields of LGN cells can be described as either an excitatory area inside an inhibitory area or the reverse.

Difference-of-Gaussians filters are parsimonious candidates for modeling the receptive fields of striate cortex cells, because the kind of differences of Gaussians used in striate cortex (differences of Gaussians with different peak locations) can themselves be computed linearly from differences of Gaussians which model receptive fields of LGN cells (where the peaks coincide), which provide the input to the striate cortex.

LGN cells respond whitened---ie. efficiently---to natural images, but they respond non-white to white noise, eg. They are thus well-adapted to natural images from the efficient coding point of view.

LGN has six layers.

LGN is retinotopically organized.

LGN receives more feedback projections from V1 than forward connections from the retina.