Cortical Asymmetry

Question 1

where is the Broca’s area

Answer 1

• left frontal lobe just above the lateral sulcus

Question 2

where is the primary motor cortex

Answer 2

• Primary motor cortex is located inside the precentral gyrus

Question 3

What did Broadmann do

Answer 3

• Broadmann using a stain for neuronal cell bodies showed that there were subtle differences in neurone type and density in different parts of the cortex
• He divided the cortex into 50 anatomically different areas, this was the start of the science of cytoarchitectonics

Question 4

what Brodmann area is the primary motor cortex

Answer 4

area 4

Question 5

what Brodmann area is the visual cortex

Answer 5

area 17 18,19

Question 6

what are the Brodmann area of the somatosensory cortex

Answer 6

the somatosensory (touch) cortex includes areas 1,2 & 3.

Question 7

what are the brodmann area of the auditory cortex

Answer 7

areas 41 and 42

Question 8

what is the association cortex

Answer 8

• this is the large part of the cortex that is outside of specific areas and tend not to have any function

Question 9

what hemisphere is language controlled by

Answer 9

left

Question 10

what does Brocas area do

Answer 10

• language vocalisation, it is controlled by specialised cortical areas in the left hemispheres

Question 11

What brodmann area is Broca’s area

Answer 11

44 & 45. (the areas are sometimes known as pars opercularis and pars triangularis of the frontal lobe)

Question 12

what is the fold underneath Brocas area called

Answer 12

Insula

Question 13

what is the role of the insula

Answer 13

• modern MRI have shown that the insula is active during speech production therefore it may be part of the speech production cortex

Question 14

what is the opercular Cortex

Answer 14

• This is the cortex on the upper and lower lips of the laterl fissure, this cortex is thicker in the left hemisphere this is thought to correlate with language production

Question 15

where is Wernickes area

Answer 15

it is adjacent to the primary auditory cortex which is also on the temporal lobe

Question 16

what does Wernickes area do

Answer 16

• does language perception

- it has shown that the area that is involved in speech recognition

Question 17

where is speech heard

Answer 17

• it is heard on the auditory cortex on both the left and right sides of the brain

Question 18

what type of aphasia does damage to Brocas result in

Answer 18

expressive aphasia

Question 19

what type of aphasia does damage to Wernickes area result in

Answer 19

receptive Aphasia

Question 20

describe expressive aphasia

Answer 20

• Halting speech
• Repetitive
• Disordered grammar
• Disordered syntax
• Disordered word order
• Sense behind words
• Patients with expressive aphasia use single words: they find it difficult to link words together into grammatical sentences

Question 21

describe receptive aphasia

Answer 21

• Fluent speech
• No repetition
• Good syntax
• Grammar ok
• Meaningless
• Inappropriate words
• Patients with receptive aphasia speak fluently but in an almost meaningless way

Question 22

what is the tract that connects Borcas and Wernickes area

Answer 22

Broca & Wernicke’s areas are joined by a bundle of cortico-cortical association fibres called the arcuate fasciculus

Question 23

what does damage to the arcuate fascicles result in

Answer 23

Damage to arcuate fasciculus produces conduction aphasia.

Question 24

describe conduction aphasia

Answer 24

• Patients with Conduction Aphasia show an impaired ability to repeat back heard or written words.
• Speech output is characterized by word-finding difficulties
• also have difficulty reading aloud but they may have good comprehension

Question 25

describe how The Wernicke Geschwind model works

Answer 25

- hear a noise - this is coded in the auditory cortex - When we wish to speak the word concepts are formed in Wernicke’s area, stored in some kind of buffer memory and then sent via the arcuate fasciculus to Broca’s area. - Here they are converted into motor programs which are then sent to the motor cortex of the mouth, lips and tongue. - When we speak we hear our own voice. The sounds produce patterns of neuronal activity in the auditory cortex. - These patterns are decoded into perceived words or fractions of words in Wernicke’s area. = The input signals (perceived words) are compared with the output in the buffer to see if our physical speech sounds matched what we wanted to say.

Question 26

what happens when you are deaf

Answer 26

Without this feedback (The Wernicke Geschwind model) of your own heard speech learning to speak is difficult this is why deaf children find speech more difficult to learn

Question 27

what is the blood supply to the Broca and Wernickes area

Answer 27

Both broca and Wernicke’s areas are supplied by branches of the middle cerebral artery

Question 28

what will a stroke to the proximal part of the middle cerebral artery do

Answer 28

- will affect both broca and Wernicke areas producing global or total aphasia

Question 29

can the Borcas area be on the right or left side of the brain

Answer 29

both - it is estimated that between 70% to 95% of humans have a left-hemisphere language specialization. - 5% to 30% of humans have anomalous patterns of specialization. - These might include: (a) having a right-hemisphere language specialization or (b) having bilateral specialization.

Question 30

what is the right hemisphere involved of in speech

Answer 30

- They are involved in rhythm, volume, intonation and emphasis of speech

Question 31

what does intonation mean

Answer 31

- Intontion – same words but different out tonight – going out tonight and going out to night

Question 32

what does a lesion of the right hemisphere region in Brocas equivalent do

Answer 32

- lesion of these right hemisphere regions in brocas equvialnet may produce robotic, monotonous speech. This is known as aprosodia.

Question 33

what does a lesion of the right hemisphere region in wernickes equivalent do

Answer 33

- If you have a lesion in werkinces area on the right hand side then you cannot tell if someone changes emphasis

Question 34

what is Aspordia

Answer 34

a robotic monotonous speech

Question 35

What does the left prefrontal lobe do

Answer 35

- enable you to focus your attention on particular objects or problems, and block out distracting inputs. - They facilitates analytical and logical skills, in particular use of language and mathematics to solve problem

Question 36

what does the right prefrontal lobe do

Answer 36

- maintain broad overall vigilance on all sensory inputs so that if something important occurs you can switch your attention and concentrate on the new inputs. - The right hemisphere is important for survival as it can override the left hemisphere and make you pay attention to the immediate environment.