auditory system (e3)

Question 1

what is a major part of the inner ear?

Answer 1

the cochlea

Question 2

what is the importance of the cochlea?

Answer 2

contains auditory receptors: hair cells that move with vibrations, which will open potassium channels; positively charged potassium ions flow into the cell and this electrical signal will result in the release of neurotransmitters

Question 3

what is the relay center for sensory info?

Answer 3

the thalamus

Question 4

what is the auditory pathway?

Answer 4

• axons leave the cochlea to the medulla
• next synapse occurs in the inferior colliculus (midbrain)
• next synapse occurs in the medial geniculate nucleus of the thalamus
• last stop is the auditory cortex (A1)

Question 5

where is the tonotopic map?

Answer 5

the primary auditory cortex (A1)

Question 6

what is the tonotopic map?

Answer 6

cells in the primary auditory cortex have a preferred tone; neurons located to the left respond more to low frequencies - to the right is high frequencies

Question 7

how does the tonotopic map develop?

Answer 7

it develops with experience in the critical period

Question 8

dr. knight and pasley

Answer 8

• intracranial EEG with electrodes on the AI
• told them words and detected them based on the brain “speaking” (similar to Pink Floyd)

Question 9

where do both the what and where pathways start?

Answer 9

the primary auditory cortex (A1 - superior temporal cortex)

Question 10

the “what” pathway (ventral)

Answer 10

• starts in A1
• involves the superior temporal gyrus
• ends in anterior (inferior) temporal sulcus
• object recognition

Question 11

the “where” pathway (dorsal)

Answer 11

• starts in A1
• ends in posterior temporal cortex and parietal cortex
• object localization (directing movements with respect to auditory information)

Question 12

other connections; from STG to ITG to superior temporal sulcus

Answer 12

polymodal pathway probably underlies stimulus categorization

Question 13

temporal lobes

Answer 13

• superior temporal gyrus
• middle temporal gyrus
• inferior temporal gyrus
• insula
• medial temporal region

Question 14

superior temporal gyrus

Answer 14

auditory ventral stream

Question 15

middle temporal gyrus

Answer 15

auditory and visual processes

Question 16

inferior temporal gyrus

Answer 16

visual ventral stream (together with fusiform gyrus)

Question 17

insula

Answer 17

helps with interoception (awareness of ones body)

Question 18

medial temporal region

Answer 18

amygdala and hippocampus

Question 19

function of the ventral pathway in the temporal lobe

Answer 19

object recognition and developing object categories

Question 20

function of superior temporal sulcus

Answer 20

• cross-modal matching (auditory and visual information)
• biological motion perception and social cognition (to develop hypotheses about other people’s intentions)

Question 21

function of amygdala

Answer 21

affective responses to sensory input (fear conditioning)

Question 22

function of hippocampus

Answer 22

spatial navigation

Question 23

amusia (Heschl’s gyrus)

Answer 23

• impairment to make pitch discriminations
• much larger Heschl’s gyrus in musicians

Question 24

auditory hallucinations

Answer 24

spontaneous activity in the auditory regions

Question 25

Wernicke’s aphasia

Answer 25

disturbed word recognition, the extreme form being “word deafness”, an inability to recognize words despite hearing of pure tones

Question 26

anterograde amnesia

Answer 26

bilateral removal of the medial temporal lobes

Question 27

problems with conscious recall of information

Answer 27

inferotemporal cortex (left: verbal / right: visual)

Question 28

temporal-lobe personality (Geschwind syndrome)

Answer 28

pedantic speech, egocentricity, preservation in discussions of personal problems, paranoia, prone to aggressive outbursts
- epilepsy or damage of temporal lobe