Chapter 6: More Vision Flashcards Preview

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Flashcards in Chapter 6: More Vision Deck (34)
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1
Q

Law of Specific Nerve Energies

A

Johannes Muller; regardless of the type of stimulus, activity in the nerve always leads to the same psychological experience.

2
Q

Photons

A

packets of energy with oscillating electromagnetic fields that travel through space at 3.0e8 m/s. Brightness of a light source depends on how many photons it emits

3
Q

Wavelength

A

based on the frequency of electromagnetic oscillation taking into account the speed of light. Color of a light source depends on wavelengths of the photons

4
Q

Electromagnetic Spectrum

A

light makes up small portion; x-rays to radio waves

5
Q

Choroid Coat

A

found behind retina; heavily pigmented to absorb scatteredlight; provides oxygen and nutrients for parts of retina; maintains photoreceptors

6
Q

Cornea

A

main refractive surface of the eye; bends the light; fluid filled

7
Q

Lens

A

Does bend light; provides visual accommodation; siscilary muscles contract and pull the ligament and make lens thinner, relax to make it more round

8
Q

Visual accommodation

A

provides fine focus by changing thickeness

9
Q

Presbyopia

A

condition in which the lens lose resiliency with age

10
Q

Iris

A

radial muscle tissue which constricts or expands the size of the pupil. Determines eye color

11
Q

Humors

A

provide structural and functional support for the eye

12
Q

Aqueous Humor (fluid)

A

in anterior chamber. Behind the cornea, in front of the lens

13
Q

Vitreous humor

A

in posterior chamber. located behind the lens; helps eye maintain shape (thicker)

14
Q

Retina

A

contains the visual photoreceptors and neurons that process and transmit visual information to the brain

15
Q

Fovea

A

indentation in the retina, contains only cones (point of central focus)

16
Q

Macula

A

has a lot of cones, surrounds the fovea

17
Q

Photoreceptors

A

hyperpolarize in response to light (depolarize in response to dark), and synapse with horizontal cells and bipolar cells (RODS AND CONES)

18
Q

Horizontal cells

A

have large dendritic trees that make inhibitory contaact with many nearby photoreceptors; responsible for phenomena of lateral inhibition (no action potentials)

19
Q

Bipolar Cells

A

each stimulated by a group of surrounding photoreceptors forming a receptive field. synapse with ganglion cells (no action potentials)

20
Q

ganglion cells

A

each stimulated by a group of surrounding bipolar cells forming a receptive field; convergence of input through the visual pathway; axons form optic nerve

21
Q

amacrine cells

A

modulate the output of bipolar cells

22
Q

Trichromatic Theory of Color Vision

A

color vision is based on ratio of responses from 3 different types of cones that have peak absorption of light at different wavelengths

23
Q

Opponent Process Theory of Color Vision

A

the way the information is organized in the visual system appears to be based on two opponent processes: Red vs. Green; Yellow vs. Blue

24
Q

Psychological evidence

A

no reddish-green or blueish-yellow color perceptions

25
Q

Electrophysiological evidence

A

Some bipolar cells, ganglion cells, LGN cells, and cortical cells have center-surround receptive fields that are organized in opponent process way

26
Q

Retinex THeory

A

suggests the cortex compares information from various parts of the retina to determine the brightness and color for each area. Better explains color constancy

27
Q

magnocellular pathway

A

named after the large cell bodies of the retinal ganglion cells and LGN cells of the pathway

28
Q

Parvocellular pathway

A

named after the small cel bodies of the retinal ganglion cells and LGN cells of the pathway

29
Q

Parvocellular ganglion cells

A

have small cell bodies, small receptive fields, are dense and near fovea

30
Q

Magnocellular ganglion cells

A

large cell bodies, large receptive field, and are uniformly distributed in the retina

31
Q

koniocellular ganglion cells

A

small cell bodies, mixed receptive field size, and are distributed uniformly throughout retina

32
Q

simple cells

A

small receptive fields, bar or edge shaped, excitatory and inhibitory zones, spots of light can produce weak excitatory or inhibitory responses

33
Q

complex cells

A

larger receptive fields, no clear cut inhibitory zones, spots of light are relatively ineffective, responds to bars of light of a specific orientation anywhere in receptive field

34
Q

occular dominance

A

cells in particular column respond best to input from left eye and from right eye