Mechanisms of Perception

Question 1

Primary sensory cortex

Answer 1

input mainly from thalamic relay nuclei

-lowest level of processing

Question 2

Secondary sensory cortex

Answer 2

input mainly from primary and secondary cortex

Question 3

Association sensory cortex

Answer 3

input from more than one sensory system, usually secondary

Question 4

Disruption of lower levels of the cortex lead to loss of _______

Answer 4

sense perception

Question 5

Disruption of higher levels of the cortex lead to ________

Answer 5

complex deficits (man who mistook wife for hat)

Question 6

Where is the primary visual cortex located (V1)

Answer 6

posterior occipital lobe

Question 7

Scotoma

Answer 7

area of blindness resulting from damage to visual cortex

-may not be detected due to completion

Question 8

Blindsight

Answer 8

ability to respond to a visual stimulus even with no conscious awareness due to scotoma
-may be because some connections still exist in V1

Question 9

Agnosia

Answer 9

failure of recognition

Question 10

Visual agnosia

Answer 10

ability to see but not recognize

Question 11

Prosopagnosia

Answer 11

inability to recognize and differentiate faces

-bilateral damage to ventral stream

Question 12

Fusiform face area

Answer 12

activity is increased during facial recognition but not recognition of other objects

Question 13

Frequency

Answer 13

number of complete wavelengths that pass a point in a given time

Question 14

Pitch

Answer 14

tones highness or lowness which depends on frequency

Question 15

Middle ear

Answer 15

between eardrum and cochlea containing ossicles that concentrate the vibrations of the eardrum on the ovals window

Question 16

Inner ear

Answer 16

cochlea, semicircular canals, vestibular sacs

Question 17

Tympanic membrane

Answer 17

eardrum

Question 18

Cochlea

Answer 18

contains organ of Corti, hair cells, auditory receptors and is highly sensitive

Question 19

Oval window

Answer 19

on cochlea where stapes presses

Question 20

Superior olivary complex

Answer 20

group of nuclei in medulla which code for spatial location

Question 21

Lateral lemniscus

Answer 21

band of fibres that carry auditory info through medulla and pons to inferior colliculus

Question 22

Inferior colliculus

Answer 22

involved in sensory reflexes (startle to unexpected noise)

Question 23

Phase difference

Answer 23

• difference in arrival times of sound waves at each eardrum
• detected by medial superior olivary complex
• it is difficult to determine whether sound is directly in front or behind

Question 24

Conductive deafness

Answer 24

ossicle damage

Question 25

Nerve deafness

Answer 25

cochlea or auditory nerve damage | -major cause is a loss of hair cells

Question 26

Divisions of exteroreceptive system

Answer 26

touch (mechanical) temp (thermal) pain (nociceptive)

Question 27

Free nerve endings

Answer 27

temp and pain | -no specialized structures

Question 28

Pacinian corpuscles

Answer 28

adapt rapidly, large and deep | -sudden displacements of skin

Question 29

Merkels disks

Answer 29

gradual skin indentation

Question 30

Ruffini endings

Answer 30

gradual skin stretch

Question 31

Stereognosis

Answer 31

identifying objects by touch (manipulate object so pattern of stimulation changes)

Question 32

Dermatome

Answer 32

area of the body innervated by the L and R dorsal roots of a given segment of spinal cord

Question 33

Ascending somatosensory pathways

Answer 33

- dorsal column medial lemniscus system | - anterolateral system

Question 34

Dorsal medical lemniscus system

Answer 34

-touch and proprioception

Question 35

Anterolateral system

Answer 35

- pain and temp | - 3 tracts: spinothalmic, spinoreticular, spinotectal

Question 36

Asterognosia

Answer 36

inability to recognize objects by touch

Question 37

Asomatognosia

Answer 37

failure to recognize parts of ones own body - unilateral L side of body - damage to R temporal and posterior parietal lobe - accompanied by anosognosia (can't recognize ones symptoms)

Question 38

Descending pain control states pain can be suppressed by ______ and ______ factors

Answer 38

cognitive and emotional

Question 39

Discoveries supporting descending pain control

Answer 39

- electrical stim of PAG has pain blocking effects - PAG and other areas have opiate receptors for pain relief drugs such as morphine - existence of endogenous opiates- endorphins

Question 40

What is the only sensory system whose pathway reaches the cerebral cortex without passing through thalamus

Answer 40

olfaction

Question 41

How is the olfactory system organized

Answer 41

chemotopically | -according to map of odors

Question 42

Metabotropic mediated tastes

Answer 42

sweet umami bitter (receptor causes ion channel to open)

Question 43

Ionotropic mediated tastes

Answer 43

salty sour (don't have receptors and therefore act on ion channels)

Question 44

Anosmia

Answer 44

inability to smell | -blow to the head which damages olfactory nerves

Question 45

Ageusia

Answer 45

inability to taste - damage to ear on same side of the body can cause limited ageusia - rare due to multiple taste pathways

Question 46

Exogenous attention

Answer 46

bottom up - external events - drawn to table since cat knocked lamp off it

Question 47

Endogenous attention

Answer 47

top up - internal cognitive processes - focused on table since you are trying to find keys

Question 48

Change blindness

Answer 48

no memory of which that is not attended to | -doesn't occur without brief intervals since memory isn't needed

Question 49

Cocktail phenomenon

Answer 49

indicates there is processing of info not attended to | -unconsciously monitoring contents of one convo while consciously listening to another

Question 50

Simultanagnosia

Answer 50

difficulty attending to more than one visual object at once | -damage to dorsal stream (localizing objects)

Question 51

Visual neglect

Answer 51

receive info from L side but neglect it since there is damage to L side structures