Chapter 3 - Sensation and Perception Flashcards
Sensory Receptors
- Specialized forms of neurons. Stimulated by different kinds of energy rather than by neurotransmitters.
Sense Organs
- Eyes, ears, nose, skin, and taste buds.
Subliminal stimuli
- Stimuli below level of conscious awareness.
- Just strong enough to activate sensory receptors, not strong enough for conscious awareness.
- Limin: “Threshold”
- Sublimin: “Below threshold”
Subliminal perception
- Process by which subliminal stimuli act upon unconscious mind, influencing behavior.
- Signal detection theory.
Microsaccades
- a type of a fixational eye movement that are small, jerk-like eye motions that are associated with fixed vision.
Brightness
- Determined by amplitude of wave - how high or low with actually is.
- Higher wave, brighter the light.
- Low waves are dimmer.
Color
- Determined by the length of wave.
- Long wavelength are found at red end of visible spectrum.
- Shorter wavelengths are found at blue end.
Saturation
- purity of color people see -mixing black or grey lessens the saturation.
Cornea
- Clear membrane that covers surface of eye, protects eye, focuses most of light coming into eye.
- Fixed curvature - abnormal = astigmatism
Aqueous humor
- Visual layer below cornea, clear watery fluid - continually replenished.
- Supplies nourishment of eye.
Pupil
- hole through which light from visual image enters interior of eye.
Iris
- Round muscle (colored part of eye) where pupil is located.
- Can change size of pupil, let’s more or less light in eye.
- Increase - Dilate
- Decrease - Constriction
- Helps focus the image.
Lens
- Another clear structure behind Iris, suspended by muscles.
- Finishes focusing process begun by cornea.
Visual accommodation (Presbyopia)
- Change and thickness of lens as eye focuses on object faraway or close
Vitreous humor
- Jelly-like fluid that also nourishes eye and gives shape.
Nearsightedness (Myopia)
- Shape of eyes causes focal point to fall short of retina.
Farsightedness (Hyperopia)
- Focus point is behind retina.
Retina
- Final stop for light and eyes.
- Contains three layers: Ganglion cells, bipolar cells, and photoreceptors (rods and cones) that respond to various light waves.
Rods (low light)
- Visual sensory receptors found at back of retina.
- Responsible for non-color sensitivity to low levels of light.
Cones (Color-Needs bright light)
- Visual sensory receptors found at back of retina.
- Responsible for color vision and sharpness of vision.
Blind spot
- area in retina where axons of three layers of retinal cells exit eye to form optic nerve: Insensitive to light = no rods/cones.
Dark adaptation
- Recovery of eyes sensitivity to visual stimuli in darkness after exposure to bright lights.
- Night blindness.
Light adaptation
- Recovery of eyes sensitivity to visual stimuli in light after exposure to darkness.
Trichromatic theory
- Theory of color vision that proposes three types of cones: Red, blue, and green.
Opponent-Process theory
- Theory of color vision that proposes four primary colors with cones arranged in pairs: Red and green, blue and yellow.
Afterimages
- images that occur when visual sensation persists for brief time even after original stimulus is removed.
Lateral geniculate nucleus (LNG) of thalamus
- Processing of color vision and afterimage.
Monochrome colorblindness
-Condition in which persons eyes either have no cones or have cones that aren’t working.
Red-green colorblindness
- Either red or green cones are not working.
Sex-linked inheritance
- Gene for color-deficient vision is recessive.
Wavelengths
-Interpreted as frequency or pitch (high, medium, or low)
Amplitude
- Interpreted as volume (how soft or loud sound is).
Purity
- Interpreted as Timbre (richness in tone of sound).
Hertz (Hz)
- Cycles or waves per second.
- Measurement of frequency.
Decibal
- unit of measure for loudness.
Auditory Canal
- Short tunnel that runs from pinna (outer ear) to eardrum. (Tympanic membrane)
Eardrum
- thin section of skin that tightly covers opening into middle part of ear.
- When sound waves hit eardrum, it vibrates and causes three tiny bones in middle ear to vibrate.
- Hammar (Malleus), Anvil (incus), and Stirrup (Stapes).