Unit 4: Sensation and Perception

Question 1

Sensation

Answer 1

o Stimulation of sense organs (receptors in eyes, nose, skin, mouth)

Question 2

Transduction

Answer 2

o Sensory receptors convert sensory stimulation into neural impulses

Question 3

Perception

Answer 3

o Organization and interpretation of sensory info

Question 4

Absolute threshold

Answer 4

o The minimal intensity needed to just barely detect a stimulus (usually identification on 50% of trials).
o Seeing a candle flame at 30 miles away on a clear, dark night
o Hearing the tick of a watch 20 feet away in a quiet room
o Tasting a 1 teaspoon of sugar in 2 gallons of water

Question 5

Just noticeable difference (JND)

Answer 5

o Minimal change in a stimulus that can just barely be detected

Question 6

Sensory Adaptation

Answer 6

o A gradual decline in sensitivity to a constant stimulus.

o Allows you to focus on new or changing stimuli

Question 7

Synethesia

Answer 7

o Hearing involves the detection of sound waves or changes in air pressure unfolding over time.
o Sound waves involve qualities of:
       o Frequency (pitch: how high or low a sound is);
       o Amplitude (loudness: a sound’s intensity);
       o Timbre (sound quality or richness in the tone of the sound)

Question 8

The Ear

Answer 8

o Outer ear—Sound waves are collected
o Middle ear—Sound waves are amplified
o Inner ear—Sound waves are transduced into neural messages

Question 9

Psychological Properties of Sound

Answer 9

o Noise can affect stress, learning, aggression, and other aspects of psychology

Question 10

Smell (Olfaction)

Answer 10

o The cilia, tiny hairlike cells that project into the nasal cavity, are the receptors for the sense of smell. The neural signals then go to the olfactory bulbs under the frontal lobes.

Question 11

Taste (Gustation)

Answer 11

o The tongue is covered with tiny bumps, called papillae (clusters of taste buds or taste receptor cells).
o different areas on the tongue are slightly more sensitive to different tastes
o nerve impulses sent to the parietal lobe for taste perception
o 5 tastes

Question 12

Somesthetic Senses

Answer 12

o How we experience the sensations of touch, pressure, temperature, and pain.
o Skin senses (touch, pressure, temperature, pain)
o Kinesthetic sense (location of body parts in relation to one another)
o Vestibular senses (movement, body position)

Question 13

The Physiology of Pain

Answer 13

o When excessive amounts of temperature or pressure are applied to the touch receptors on the surface of your skin (organs, bones, muscles), a neurotransmitter called substance P is released, triggering a pain signal.
o Gate-Control Theory: When neurotransmitter P is released into the spinal cord, it activates other pain receptors by opening “gates” in the spinal column and sending the message to the brain.
o Analgesics:
o Block the release of substance P or interfere with the brain’s interpretation of pain signals.
o Acupuncture:
o Needles stimulate the body to increase the release of endorphins (which block substance P)

Question 14

Vision

Answer 14

o The wavelengths that people can see are only a small part of the whole electromagnetic spectrum

Question 15

Anatomy of the Human Eye

Answer 15

o Specialized organs of the eye evolved to detect light.
o Rods:
o Function in dim light
o Detect black and white vision, but not colors
o Necessary for peripheral and twilight vision
o Cones:
o Near center of retina (fovea)
o Function in bright or day light
o Detect fine detail
o Enable color perception

Question 16

The Neural Connections of the Visual System

Answer 16

o Info in right visual field stimulate left half of retinas and travel to the left occipital lobe
o Info in left visual field stimulate right half of retinas and travel to the right occipital lobe

Question 17

Color Vision: Dual-Process Theory of Color Vision

Answer 17

o Trichromatic theory:

         o All color perception derives from three types of cones in the retina: red, green, and blue.
         o Firing rate of cones, and the combination of cones firing, determines color that is seen.

o Opponent-process theory:

         o Assumes 4 primary colors of red, green, blue, and yellow
         o Colors are arranged in pairs, and when one member of a pair is activated, the other is not 
         o Afterimages occur when a visual sensation persists for a brief time even after the original stimulus is removed

Question 18

Color Blindness

Answer 18

o Provides some support for trichromatic theory
o About 8% of males and 1% of females affected
o Missing or damaged cones
o Most people with color blindness have two type of cones working and can see many colors

Question 19

The afterimage

Answer 19

o Can be explained by opponent–process theory and sensory adaptation. Staring at one color makes your visual receptors less sensitive to that color and you see the opposing color in the color pair.

Question 20

Naive Realism

Answer 20

o The brain “makes a copy” of sensory info

Question 21

Constructive Perception

Answer 21

o The brain actively constructs our perception and makes its “best guess”

Question 22

Inattentional Blindness

Answer 22

o Failure to perceive objects that are not the focus of attention

Question 23

Gestalt School of Thought

Answer 23

o People perceive things as wholes (not as separate elements)
o Ex: When you listen to music you hear whole melodies not separate notes
o Gestalt:
o An organized whole
o Combine pieces of information into meaningful wholes

Question 24

Grouping Principles

Answer 24

o Proximity: group things that are nearby
o Similarity: group things that are similar
o Continuity: perceive continuous patterns
o Closure: fill in gaps

Question 25

Perceiving Depth and Distance

Answer 25

o Binocular Cues – information from both eyes that allows us to judge depth and distance
o Retinal disparity
o Comparing images from 2 eyes
o Convergence
o Muscles of 2 eyes move inward for near objects

o Monocular cues – information from a single eye that allows us to judge depth and distance
o object size
o interposition
o linear perspective

Question 26

Visual Cliff

Answer 26

o Used to test depth perception in infants

o Babies develop depth perception at about the time they begin to crawl

Question 27

Perceptual Constancy

Answer 27

o Perceive objects as unchanging despite changes in retinal image
o Color of object
o Shape of object
o Size of object

Question 28

Change Blindness

Answer 28

o When people fail to detect changes to the visual details of a scene
Optical Illusions
o misinterpretation of visual stimulus

Question 29

Expectancy Effects

Answer 29

o Our expectations affect our perceptions