AP Psychology Chapter 4: Sensation and Perception

Transduction

a process during which signals are transferred into neural impulses

Sensory Adaptation

decreased responsiveness to stimuli due to constant stimulation eg. socks on feet

Sensory Habituation

our perception of sensations is partially due to how focused we are on them

Sensation

activation of our senses

Perception

the process of understanding sensations

Energy Senses

Vision (light), hearing (sound waves), and touch (pressure).

Chemical Senses

smell and taste

Vision

the dominent sense in human beings, gather information using their surroundings more than any other sense

Cornea

the protective covering that light first enters through, helps focus light

Pupil

light travels through it, the shutter of a camera

Lens

curved and flexible in order to focus light

Retina

a screen in the back of the eye on which inverted images are projected

Feature Detectors

nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement

Optic Nerve

the nerve that carries neural impulses from the eye to the brain

Occipital Lobe

the lobe in which the visual cortex is, the point that sensation ends and perception begins

Visible Light

Electromagnetic radiation that can be seen with the unaided eye

Rods

respond to black and white, outnumber 20:1

Fovea

an indentation in the center of the retina that has the highest concentration of cones

Blind Spot

the spot where the optic nerve leaves the retina and has no cones or rods

Trichromatic Theory

oldest and most simple theory, we have three cones that detect blue red and green

Color Blindness

cannot see certain colors

Afterimages

if you stare at one color for a while then look at a blank space, you will see color, stare at green, it will be red, yellow blue

Opponent-Process Theory

state that sensory receptorsare arranged in retina are in pairs of red/green, yellow/blue, black/white

Hearing

auditory senses, waves are created in the air

Sound Waves

created by vibrations which travel through the air and collect in our ears

Amplitude

the height of the wave and determines the loudness, measured in decibels

Frequency

refers to the length of the waves and determines pitch, measured in megahertz

Cochlea

the snail-shaped tube (in the inner ear coiled around the modiolus) where sound vibrations are converted into nerve impulses by the Organ of Corti

Frequency Theory

theory that we sense pitch because the hair cells fire at different rates

Conduction Deafness

occurs when some goes wrong with the system of conducting the sound to the cochlea

Touch

sense is activated when the skin is indented, pierced, or experiences a change in temperature

Taste/Gustation

chemical sense involved in food

Smell/Olfaction

depends on chemicals emitted by substance

Vestibular Sense

the sense that tells how our body is oriented in space

Kinesthetic Sense

the sense that gives us feedback about the position and orientation of specific body parts

Absolute Threshold

the smallest amount of stimulus we can detect

Subliminal Messages

stimuli below our absolute threshold

Difference Threshold

is the smallest amount of change needed in a stimulus before we can detect a change

Weber's Law

states that the change needed is proportional to the original intensity of the stimulus

Signal Detection Theory

this theory investigates the effects of the distractions and interference we experience while perceiving the world

Top-down Processing

perceive by filling in gaps in what we sense, less accurate but quicker than bottom-up

Perceptual Set

a predisposition to perceive something in a certain way

Bottom-up Processing

we use only the features of the object itself to build a complete perception, automatic process, takes longer but more accurate than top-down

Gestalt Rules

we normally perceive images as groups, not as isolated elements, innate and inevitable

Proximity

objects that close together are more likely to be perceived as belonging to the same group

Similarity

objects that are similar in appearance are more likely to be perceived as belonging to the same group

Continuity

objects that form a continuous form are more likely to be perceived as belonging in the same group

Closure

objects that make a recognizable image are more likely to be perceived as belonging in te same group even if it contains caps

Constancy

our ability to maintain a constant perception of an object despites changes in light, angle, etc.

Size Constancy

objects closer to our eyes will produce bigger images on our retinas, but we take distance into account

Shape Constancy

objects viewed from dfferent angles will produce different shapes, but we know the shape of an object remains constant

Brightness Constancy

objects as being a constant color even as the light reflected off of them changes

Depth Cues

Perceptual features that impart information about distance and three-dimentional space

Light Intensity

how much energy a light contains, how bright the object is

Light Wavelength

determines the particular hue, longer than visible light infrared, microwaves, radio waves, shorter, UV and X

Color Spectum

longest to shortest wavelength: red orange yellow green blue indigo violet

Iris

the muscles that control the pupil, dilate it to let more light in, make it smaller to let less light in

Accommodation

light that centers the pupil is focused by the lens

Cones

respond to color

Left Hemisphere

impulses from the left side of the retina go here

Right Hemisphere

impulses from the right side of the retina go here

Optic Chiasm

the spot where the nerves cross each other

Outer Ear/Pinna

sound waves collected here

Auditory/Ear Canal

waves travel through here to eardrum

Ear Drum/Tympanic Membrane

a thin membrane that vibrates as the sound wave hits it

Hammer/Anvil/Stirrup

three bones as the ossicles, vibration transmitted to the oval window

Oval Window

membrane similar to the eardrum, attached to the cochlea

Organ of Corti

neurons activated by movement of hair cells, fires, impulses then transmitted to the brain via auditory nerve

Monocular Cues

depth cues that do not depend on having two eyes

Binocular Cues

cues that depend on having two eyes

Linear Perspective

to draw train tracks, you would draw two lines that converge at the top of the paper

Relative Size Cue

draw things closer to the viewer as bigger

Interposition Cue

objects that block the view to other objects must be closer

Texture Gradient

we know that we can see details in texture close to us but no far away

Shadowing

by shadowing part of your picture, you can imply where the light source is thus implying depth and position of objects

Convergence

as an object gets closer to our face, our eyes must move toward each other to keep focused on the object