Physio Psych Exam 2

Sensory Receptors

Specialized Neurons that detect a particular category of physical events

Process of Sensing

Energy → Action Potentials → Nervous System → Perception

Receptor Potentials

Electrical changes in sensation

Sensory Transduction

Energy getting converted into a nervous system response

Photoreceptors

Detects the presence of light stimuli, visual light is a narrow band of the spectrum of electromagnetic radiation

Hue

Determined by wavelength, dimension of color perception, ROYGBIV

Brightness

Intensity of electromagnetic radiation, dimension of color perception

Saturation

Relative purity of the light being perceived, dimension of color perception

Fully Saturated

If all radiation is of one wavelength

Anatomy of the Eye

The extraocular muscles allow for movement of the eyes

Vergence

Cooperative movements, keeps eyes fixated on target

Saccade

Rapid, jerky movements to scan scene

Persuit

Allows for smooth movement

Sclera

Tough outer layer of eye

Conjunctiva

Mucous membrane lining the eyelid attaching to the eye

Retina

Inner lining of eye

Fovea

Central region of retina

Cornea

Outer layer at front of eye, 1st thing light enters and provides 2/3 of the focusing power

Lens

Contributes 1/3 of the focusing power, allows for accommodation by activation of the ciliary muscles, cataracts can be treated with the replacement of the lens

Optic Disk

The blind spot, exit point of the retina for the optic nerve to leave

Photoreceptor Layer

1st layer of the retina, Rods and Cones, outer segment contains lamellae

Rods

120 Million Rods, sensitive to low levels of light, only monochrome

Cones

6 Million cones, hue information, sensitive to moderate to high levels of light

Lamellae

Contains photopigments which consist of opsin and retinal

Bipolar Cell Layer

The interconnector layer relaying information, 3 layers: bipolar, horizontal, amacrine

Retina Layers

Ganglion cell: recieves info from bipolar cells

Lateral Geniculate Nucleus (LGN)

In the thalamus, processes visual info, 6 layers of nuerons

Magnocellular Layers

Inner 2 layers of LGN, transmits info regarding perception, movement, depth, and brightness differences

Parvocellular Layers

Outer 4 layers of LGN, transmits info regarding color perception and fine details

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