Focused Questions Section 2

Question 1

What are the three levels of the sensory cortex?

Answer 1

primary sensory cortex
secondary sensory cortex
association cortex

Question 2

The primary sensory cortex receives input mostly from

Answer 2

thalamic relay nuclei

Question 3

The secondary sensory cortex receives input mostly from

Answer 3

the primary cortex or other secondary sensory cortex areas of the same system

Question 4

The association cortex receives input from

Answer 4

more than one sensory system

Question 5

How do we characterize the interaction between each level of the sensory cortex?

Answer 5

hierarchical organization, functional segregation, and parallel processing

Question 6

What is hierarchical organization?

Answer 6

organization based on the specificity and complexity of function

Question 7

What is functional segregation?

Answer 7

each of the three levels of the cerebral cortex in each sensory system contains functionally distinct areas for different types of analysis

Question 8

What is parallel processing?

Answer 8

the simultaneous analysis of a signal in different ways

Question 9

Sensory systems can be considered ___ systems

Answer 9

parallel

Question 10

Which system is responsible for the perception of sound?

Answer 10

the auditory system

Question 11

List the physical dimensions of sound and their correspondent perceptual dimension

Answer 11

amplitude –> loudness
frequency –> pitch
complexity –> timbre

Question 12

The combination of the individual dimensions of sound results in

Answer 12

the formation of a complex sound wave

Question 13

In what order are sound waves/vibrations passed through the mechanisms of the ear? (8)

Answer 13

auditory canal - tympanic membrane - ossicles (stapes) - oval window - cochlea fluid - organ of Corti - hair cells - auditory nerve

Question 14

Similar to the somatotopic organization of the somatosensory system, the auditory system can be described as _______

Answer 14

tonotopic

Question 15

Neurons in both the auditory cortex and the cochlea are ________

Answer 15

cochlea; frequency specific

Question 16

What area is recognized for its responsibility in multisensory integration?

Answer 16

posterior parietal

Question 17

The vestibular system explains balance in a way that it processes

Answer 17

info about the direction and intensity of head movements

Question 18

What is the order of processing sound from the ear to the primary auditory cortex?

Answer 18

axons of olivary neurons - inferior colliculi - medial geniculate nuclei of thalamus - primary auditory cortex

Question 19

What system is responsible for the localization of sound in space?

Answer 19

the subcortical auditory system

Question 20

In what ways do the lateral and medial superior olives differ in the way they allow you to localize sound?

Answer 20

the lateral olives detect differences in the amplitude of sound from two ears; the medial superior olives detect differences in times of arrival

Question 21

What is the location of the primary auditory cortex?

Answer 21

the temporal lobe

Question 22

Describe the organization of the auditory cortex

Answer 22

the primary auditory cortex is organized in functional columns and organized tonotopically

Question 23

Each area of primary and secondary auditory cortex appears to be organized on the basis of ___

Answer 23

frequency

Question 24

What are the two main cortical streams of auditory analysis and what is the difference between the two?

Answer 24

the anterior auditory pathway is more involved in identifying sounds (what); the posterior auditory pathway is more involved in locating sounds (where)

Question 25

The primary auditory cortex is located within the superior _____ gyrus and is thought to be essential for _______

Answer 25

Temporal; detection of temporal patterns of sound

Question 26

Severe hearing problems typically result from damage to which parts of the ear

Answer 26

the inner ear, the middle ear, or the nerves leading from them

Question 27

If only part of the cochlea is damaged an individual may experience

Answer 27

nerve deafness for some frequencies but not others

Question 28

What three subsystems compose the somatosensory system?

Answer 28

exteroceptive - senses stimuli applied to the skin proprioceptive - monitors position of the body interoceptive - conditions within the body

Question 29

What are free nerve endings?

Answer 29

they are the simplest cutaneous receptors that are sensitive to temperature changes and pain

Question 30

What are Pacinian corpuscles and what do they do?

Answer 30

they are the largest and deepest cutaneous receptors; they adapt rapidly and react to only sudden displacements of the skin

Question 31

What is the difference between Merkel's and Ruffini receptors?

Answer 31

they are both slow adapting; Merkel's receptors respond to gradual skin indentation while Ruffini respond to skin stretch

Question 32

A person with the inability to recognize and discriminate objects by touch would be said to have

Answer 32

asterognosis

Question 33

What is the main difference in functioning of the two major somatosensory pathways?

Answer 33

the dorsal-column medial-lemniscus handles touch and proprioception; the anterolateral system handles pain and temperature

Question 34

The organization of the somatosensory system can be best described as

Answer 34

somatotopic - organized according to a map of the body

Question 35

What is the main result of damage to the primary somatosensory cortex?

Answer 35

typically mild disability in detecting light touch and reduced ability to identify objects by touch

Question 36

The minimal impairment in functioning following damage to the S1 cortex is explained by

Answer 36

the numerous parallel pathways in the somatosensory system

Question 37

What is asomatognosia and what causes it?

Answer 37

the inability to recognize parts of one's own body; typically on the left side as a result of damage in the right temporal and posterior parietal lobe

Question 38

How can we explain the Rubber-Hand Illusion?

Answer 38

(not 100% sure) thought to be due to the roles of the association cortex in the posterior parietal and frontal lobes as well as the bimodal neurons (visual + somatosensory)

Question 39

What three aspects of pain explain the paradox of pain perception?

Answer 39

the adaptiveness of pain lack of clear cortical representation descending (down-regulation) pain control

Question 40

Which areas do we typically see activated with the introduction of painful stimuli?

Answer 40

thamalus, S1, S2, insula, and anterior cingulate

Question 41

The anterior cingulate is not responsible for the perception of pain itself, however, is typically associated with

Answer 41

expectation of pain, emotional reaction, and adaptive response to minimize pain

Question 42

Which brain areas are associated with the effective suppression of pain through cognitive and emotional factors?

Answer 42

the periaqueductal gray (PAG) - produce analgesic (pain blocking) effect endogenous opioids (endorphins)

Question 43

What underlies the phenomenon of Phantom Limb Pain?

Answer 43

best explained by neuropathic pain - severe, chronic pain in the absence of recognizable pain stimulus; the mechanism is unknown