sensation and perception

Question 1

sensation

Answer 1

the stimulus detection process by which our sense organs respond to and translate environmental stimuli into nerve impulses that are sent to the brain.

Question 2

perception

Answer 2

making “sense” of what our senses tell us; it is the active process of organizing this stimulus input and giving it meaning.

Question 3

sensory transduction

Answer 3

the process whereby the characteristics of a stimulus are converted into nerve impulses.

Question 4

psychophysics

Answer 4

studies that relationship between the physical characteristics stimuli and sensory capabilities.

Question 5

absolute threshold

Answer 5

the lowest intensity at which a stimulus can be detected 50 percent of the time.

Question 6

decision criterion

Answer 6

how certain someone must be that a stimulus is present before they will say they can detect it.

Question 7

signal detection theory

Answer 7

an account of sensory perception that is concerned with the factors that influence humans´ judgements about sensory stimuli.

Question 8

difference threshold

Answer 8

defined as the smalest difference between two stimuli that someone or som people can perceive 50 percent of the time.

Question 9

Weber’s law

Answer 9

states that the difference threshold, or JND, is directly proportional to the magnitude of the stimulus with which the comparison is being made.

Question 10

sensory adaption

Answer 10

the diminishing sensitivity ti an unchanging stimulus.

Question 11

sensory transduction

Answer 11

the process whereby the characteristics of a stimulus are converted into nerve impulses.

Question 12

lens

Answer 12

an elastic structure in the eye that becomes thinner to focus on distant objects and thicker to focus on nearby objects.

Question 13

retina

Answer 13

multilayered light-sensitive tissue at the rear of the fluid-filled eyeball.

Question 14

rods

Answer 14

function best in dim light, and are primarily black-and white brightness receptors.

Question 15

cones

Answer 15

color receptors, which function best in bright illumination.

Question 16

fovea

Answer 16

small area in the centre of the retina that contains no rods but many densely packed cones.

Question 17

optic nerve

Answer 17

ganglion cells, whose axons are collected into a bundle to form the optic nerve.

Question 18

visual acuity

Answer 18

ability to see fine detail.

Question 19

photo-pigments

Answer 19

rods and cones translate light waves into nerve impulses through the action of protein molecules called photo-pigments.

Question 20

dark adaption

Answer 20

the progressive improvement in brightness sensitivity that occurs over time under conditions of low illumination.

Question 21

young-helmholtz trichromatic theory

Answer 21

states that there are three types of color receptor in the retina.

Question 22

Hering’s opponent process theory.

Answer 22

states that each of the three cone types responds to two different wavelengths.

Question 23

dual-process theory

Answer 23

combines the trichromatic and opponent-process theories to account for the color transduction process.

Question 24

feature detectors

Answer 24

fire selectively in response to visual stimuli that have specific characteristics.

Question 25

frequency

Answer 25

the number of sound waves, or cycles, per second.

Question 26

hertz (Hz)

Answer 26

the measure of cycles per second; 1 hertz equals 1 cycle per second.

Question 27

amplitude

Answer 27

the vertical size of the sound waves- the depth between the peaks and the troughs in the sound wave.

Question 28

decibels (dB)

Answer 28

measure of the physical pressures that occur at the eardrum.

Question 29

cochlea

Answer 29

coiled, snail-shaped tube about 3.5 cm in length.

Question 30

basilar membrane

Answer 30

sheet of tissue that runs the length of the cochlea.

Question 31

organ of Corti

Answer 31

contains thousands of tiny hair cells that are the actual sound receptors.

Question 32

frequency theory of pitch perception

Answer 32

holds that nerve impulses sent to the brain match the frequency of the sound wave.

Question 33

place theory of pitch perception

Answer 33

suggests that the specific point in the cochlea where the fluid wave peaks and most strongly bends the hair cells serves as a frequency coding cue.

Question 34

conductive hearing loss

Answer 34

involves problems with the mechanical system that transmits sound waves to the cochlea.

Question 35

sensorineural hearing loss

Answer 35

caused by damaged receptors within the inner ear or damage to the auditory nerve itself.

Question 36

gustation

Answer 36

sense of taste

Question 37

olfaction

Answer 37

sense of smell

Question 38

anosmia

Answer 38

loss of olfaction, the sense of smell.

Question 39

taste buds

Answer 39

small bodies containing taste receptor cells concentrated along the tip, edges and back surface of the tongue.

Question 40

olfactory bulb

Answer 40

forebrain structure immediately above the nasal cavity.

Question 41

pheromones

Answer 41

chemical signals found in natural body scents.

Question 42

orthonasal olfaction

Answer 42

the sense of smell that comes from odors inhaled up the nostrils from in front of us; orthonasal olfaction is involved in sensing odors in our surroundings and deciding whether or not to ingest something.

Question 43

retronasal olfaction

Answer 43

the sense of odors that come from the mouth; retronasal olfaction is heavily involved in the perception of flavor while we are eating and drinking.

Question 44

cutaneous touch

Answer 44

the sense of touch arising from events on the skin surface (including temperature and pressure)

Question 45

proprioception

Answer 45

sensory input that provide us with information about the layout and movements of our body and limbs.

Question 46

interoceptive touch

Answer 46

the sense of touch arising from receptors inside the body, typically in blood vessels and organs.

Question 47

haptics

Answer 47

the active use of touch and movement to explore objects and surfaces within reach.

Question 48

vestibular system

Answer 48

apparatus in the cochlea that contributes especially to the sense of bodily movement, and orientation with respect to gravity; the vestibular sense plays a crucial role in maintaining balance.

Question 49

synaesthesia

Answer 49

literally, “mixing of the senses”

Question 50

bottom-up processing

Answer 50

individual elements of a stimulus are analyzed and then combined to form a unified perception.

Question 51

top-down processing

Answer 51

sensory information is interpreted in light of existing knowledge, concepts, ideas and expectations.

Question 52

figure-ground relations

Answer 52

our tendency to organize stimuli into a central or foreground figure and a background.

Question 53

gestalt laws of perceptual organization

Answer 53

similarity, proximity, close and continuity.

Question 54

perceptual schema

Answer 54

a mental representation or image containing the critical and distinctive features of a person, object, event or other perceptual phenomenon.

Question 55

bayesian inference

Answer 55

a statical method for making predictions about what will happen based on information about prior occurrences; it has been used as a basis for explaining how humans perceive the world.

Question 56

perceptual constancies

Answer 56

allow us to recognize familiar stimuli under varying conditions.

Question 57

binocular disparity

Answer 57

each eye sees a slightly different image.

Question 58

convergence

Answer 58

produced by feedback from the muscles that turn your eyes inwards to view a close object.

Question 59

stroboscopic movement

Answer 59

illusory movement produced when a light is briefly flashed in darkness and then, a few milliseconds later, another light is flashed nearby.

Question 60

critical periods

Answer 60

periods during which certain kinds of experience must occur if perceptual abilities and the brain mechanisms that underlie them are to develop normally.