PSYC314 Lecture Notes - Lecture 12: Lateral Geniculate Nucleus, Choroid Plexus, Parvocellular Cell
22 May 2018
School
Department
Course
Professor
Vision II 4/3
Quiz 13
1. What is the simplest visual feature ganglion cells in your retina respond to?
a. Triangles
b. Red light
c. Square shapes
d. On center/off surround receptive fields
2. What are the 3 properties of light that give light its, ‘color’ characteristic?
a. Particle nature of light
b. Different types of photons
c. Saturation, hue, brightness
d. Brightness, hue, quality
3. The outermost covering of the eye is the
a. Choroid plexus
b. Sclera
c. Cornea
d. Retina
4. Three kinds of cells in your retina are
a. Bipolar cells, hair cells, parvocellular cells
b. Pyramidal cells, granule cells, ganglion cells
c. Ganglion cells, bipolar cells, photoreceptors
d. Photoreceptors, granule cells, pyramidal cells
5. Photoreceptors are
a. Inhibited with light stimulation
b. Excited with light stimulation
c. Inhibited in the absence of light
d. Responsive to ultraviolet light only
Review
● Light is refracted onto fovea of your retina
● There it hits cones, which is critical for seeing color and visual acuity
● Via surround inhibition ganglion cells have on center/off surround receptive fields
● Ganglion cells communicate receptive fields to neurons in the lateral geniculate body
Lateral Geniculate Body: 3 Types of Layers
● Magnocellular layer
○ Layers 1 & 2
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○ Passes information about orientation to striate cortex
● Parvocellular layer
○ Layers 3-6
○ Passes color information onto striate cortex
● Koniocellular sublayer
○ In between each layer of the lateral geniculate
○ Passes color information onto striate cortex
Striate Cortex Receives Contralateral Input
● Contralateral:
○ Input from the left half of visual space is processed in the right half of the visual
cortex (V1) and input from the right half of visual space is processed in the left
half of the visual cortex (V1)
○ However, each half of the visual cortex receives input from both eyes
○ All input from the lateral geniculate (LG) enters layer 4 of the striate cortex
Convergence of Visual Information in the Striate Cortex
● Information from many ganglion cells converge onto a few neurons in visual cortex
● V1 neurons respond best to lines in different orientations
Types of Striate Orientation Neurons
● Simple neuron (featured in video of cat)
○ Responds to line in a central region, otherwise inhibited
● Complex neuron
○ Responds to line in a particular orientation irrespective of where the line is in the
receptive field
○ Responds to movement of line within the receptive field
● Hypercomplex neuron
○ Responds to edges of lines
Organization of the Striate Cortex
● Orientation columns
○ Column of neurons that tend to respond to lines in a specific orientation
● Ocular columns
○ Column of neurons that tend to respond to visual input from eye
● Blobs
○ Cytochrome oxidase (CO) rich neurons interspersed among the columns
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Light is refracted onto fovea of your retina. There it hits cones, which is critical for seeing color and visual acuity. Via surround inhibition ganglion cells have on center/off surround receptive fields. Ganglion cells communicate receptive fields to neurons in the lateral geniculate body. Passes information about orientation to striate cortex. In between each layer of the lateral geniculate. Input from the left half of visual space is processed in the right half of the visual cortex (v1) and input from the right half of visual space is processed in the left half of the visual cortex (v1) However, each half of the visual cortex receives input from both eyes. All input from the lateral geniculate (lg) enters layer 4 of the striate cortex. Convergence of visual information in the striate cortex. Information from many ganglion cells converge onto a few neurons in visual cortex. V1 neurons respond best to lines in different orientations.
