Chapter 2-sensation & perception

Question 1

sensation

Answer 1

transduction, conversion of physical, electromagnetic, auditory, and other info from environment into electrical signals to the CNS

Question 2

perception

Answer 2

processing of sensory info

Question 3

difference threshold

Answer 3

minimum difference in magnitude between 2 stimuli that is required to detect the difference

Question 4

Weber’s law

Answer 4

there is a constant ratio between the change in stimulus magnitude needed to produce a difference threshold and the magnitude of the original stimulus; for larger magnitude stimulus, the actual difference must be larger to perceive that difference

Question 5

signal detection theory

Answer 5

internal (psychological) and external (environmental) context influences the perception of the same stimuli

Question 6

Response Bias

Answer 6

tendency to systematically respond to a stimulus a particular way due to nonsensory factors.

Question 7

signal detection experiment

Answer 7

consists of many trials where stimulus may or may not be presented; catch trials: signal presented; noise trials: signal not presented (think of white noise); after each trial participant asked if signal was presented; 4 outcomes: hits (correctly perceived the signal), miss (fails to perceive signal), false alarms, and correct negatives (correctly identifies that no signal was given

Question 8

adaption

Answer 8

decrease in stimulus perception over time

Question 9

retina

Answer 9

back of the eye, converts incoming photons of light into electrical signals

Question 10

duplexity/duplicity theory of vision

Answer 10

retina contains 2 kinds of photoreceptors, rods and cones

Question 11

cones

Answer 11

color perception, fine details; come in three different forms for long, medium, short wavelenghs

Question 12

rods

Answer 12

more functional in reduced illumination, contain rhodopsin, better for night vision and peripheral

Question 13

fovea

Answer 13

central retina where best visual acuity, contains only cones

Question 14

visual pathway

Answer 14

photoreceptors-bipolar cells-ganglion cells-optic nerve-hemidecussation-LGN of thalamus-visual cortex

Question 15

amacrine and horizontal cells

Answer 15

receive input from multiple retinal cells before passing on info to ganglion cells

Question 16

parallel processing

Answer 16

ability to simultaneously analyze and combine info on color, shape, and motion. Feature detection: have cells that specialize in color, shape, motion

Question 17

parvocellular cells

Answer 17

ability to see shape and distinguish object from background, color, fine detail, low temperal resolution (only can see stationary or slowly moving objects)

Question 18

magnocellular

Answer 18

detect motion, high temporal resolution, blurry but moving image of object

Question 19

vestibular sense

Answer 19

rotational and linear acceleration of the ear

Question 20

pinna/auricle

Answer 20

outside part of ear, channels sound waves to external auditory canal

Question 21

external canal

Answer 21

directs sound to tympanic membrane (eardrum)

Question 22

tympanic membrane

Answer 22

vibrates in phase with incoming sound waves; sound wave frequency determines rate of vibration; louder sounds-greater intensity, greater amplitude; divides outer ear from middle ear

Question 23

middle ear

Answer 23

contains three small bones: ossicles- transmit and amplify vibrations from ear drum to inner ear; malleus (hammer) attached to tympanic membrane acts on incus (anvil), which acts on stapes (stirrup); middle ear attached to Eustachian tube-helps equalize pressure

Question 24

inner ear

Answer 24

sits within bony labyrinth which includes cochlea, vestibule, and semicircular canals; structures are filled with membranous labyrinth, bathed in potassium rich fuild called endolymph and perilymph (cushions inner ear structures and transmits vibrations)

Question 25

Cochlea

Answer 25

contains organ of Corti, the actual hearing apparatus, which sits on basilar membrane; organ composed of lots of hair cells

Question 26

Hair cells

Answer 26

receive vibrations through perilymph, convert physical stimuli into electrical signals, which are carried by auditory (vestibulocochlear) nerve; long tufts of stereocilia which sway from vibrations-swaying opens ion channels-receptor potential; which hair cells are vibrating tells brain info on pitch

Question 27

auditory pathway

Answer 27

hair cells-auditory nerve-medial geniculate nucleus-auditory cortex

Question 28

olfactory chemoreceptors

Answer 28

chemical stimuli binds chemoreceptors in olfactory epithelium in nasal cavity to cause a signal

Question 29

olfactory pathway

Answer 29

odor molecules inhaled in nasal passages-olfactory nerve-signal to olfactory bulb

Question 30

two-point threshold

Answer 30

minimum distance necessary between two points of stimulation on skin such that the points will be felt as two separate stimuli

Question 31

physiological zero

Answer 31

normal temperature of skin; object feels cold when less than physiological zero

Question 32

nociceptors

Answer 32

pain receptors

Question 33

gate theory of pain

Answer 33

other touch signals can inhibit perception of pain

Question 34

kinesthetic sense

Answer 34

proprioception; ability to tell where your body is in space

Question 35

bottom-up processing

Answer 35

object recognition by parallel processing and feature detection, combine individual sensory stimuli to create cohesive image; happens quickly, body reacts before brain, takes in different sensory stimuli, tells brain what to do

Question 36

top-town processing

Answer 36

driven by memories and expectations that allow the brain the recognize the whole object and then recognize components, like looking at an object for the first time; perception is driven by brain, which applies what it knows and what it expects to see, when given specific context, brain expects certain stimuli

Question 37

perceptual organization

Answer 37

ability to use both top-down and bottom-up processes together to form complete picture

Question 38

Gestalt principles

Answer 38

ways for brain to infer missing parts of an incomplete picture

Question 39

law of proximity

Answer 39

elements close to each other tend to be perceived as a unit

Question 40

law of similarity

Answer 40

objects that are similar tend to be grouped together

Question 41

law of good continuation

Answer 41

elements that appear to follow in the same pathway tend to be grouped together, tendency to perceive continuous patterns in stimuli

Question 42

law of closure

Answer 42

when a space is enclosed by a contour, it tends to be perceived as a complete figure

Question 43

law of pragnanz

Answer 43

gestalt principles altogether; perceptual organization will always be as regular, simple, and symmetric as possible