6/4- Higher Cortical Function II

Question 1

Is language controlled by both hemispheres equally or unequally? If unequally, which is more important?

Answer 1

The left hemisphere is mostly in charge of language.

Question 2

It was found that patients with language deficits (aphasias) had damage to ____?

Answer 2

It was found that patients with language deficits (aphasias) had damage to the left hemisphere

Question 3

Where is Broca’s area?

Answer 3

Small area in left inferior prefrontal cortex

(nearish primary motor cortex and articulation areas)

Question 4

What is Broca’s aphasia?

Answer 4

Problem with speech production: expressive aphasia

• Normal comprehension, speech is meaningful… but awkward (comprehension fine; output damaged)
• Can’t express self, either verbally, written, or via sign language

Question 5

What artery supplies Broca’s area?

Answer 5

Middle cerebral artery (posterior)

• Could also result from tumors or strokes

Question 6

How does Broca’s aphasia affect the mouth/articulatory systems?

Answer 6

It doesn’t.

Nothing is wrong with the mouth or articulatory systems; it is NOT apraxia

Question 7

Where is Wernicke’s area?

Answer 7

Just posterior to primary auditory cortex

(superior temporal gyrus)

Question 8

What is Wernicke’s aphasia?

Answer 8

Receptive aphasia

• Reduced language comprehension (can’t understand others or self)
• Reduced ability to produce intelligible speech
• Speech sounds normal but has no meaning: ‘word salad’, jargon, neologisms, logorrhea, uninhibited output
• “Lost in a fog of sounds, words, and references that mean nothing”
• Can’t name objects
• Affects all language (NOT an apraxia), written output is also impaired, and a deaf pt makes gibberish sign language
• Pts who recover report that while aphasic, they found the speech of others to be unintelligible and, despite being cognizant of that fact that they were speaking, they could neither stop themselves nor understand their own words (can still detect intonation, sarcasm, humor, but not meaning)

Question 9

T/F: Broca’s affects all language

T/F: Wernicke’s affects all language

Answer 9

True: Broca’s affects all language

True: Wernicke’s affects all language

Question 10

Which patient suffers more: Broca’s or Wernicke’s aphasia?

Answer 10

• Broca’s patient realizes impairment and suffers from it; often depressed
• Wernicke’s aphasics usually do not understand why people aren’t understanding them

Question 11

Affected areas of brain in Broca’s vs. Wernicke’s aphasia (picture)

Answer 11

Question 12

What connects Wernicke’s and Broca’s area?

Answer 12

Arcuate fasciculus

Question 13

What is conduction aphasia? What would you observe?

Answer 13

The arcuate fasciculus connects Wernicke’s and Broca’s areas

• Comprehension and speech normal, but unable to repeat

Question 14

What is global aphasia? What causes it?

Answer 14

All the disability of Broca’s, Wernicke’s, and conduction aphasias combined:

• Cannot speak
• Cannot comprehend
• Cannot repeat

Typically caused by infarct of middle cerebral artery

Question 15

What is alexia?

Answer 15

Inability to read

Question 16

What is agraphia?

Answer 16

Inability to write

Question 17

Damage where causes inability to read or write (alexia/agraphia)?

Answer 17

Left angular gyrus (nearer visual system)

Goes to Broca’s area still for comprehension

Question 18

Picture comparing language input for heard/read words and pathway to output

Answer 18

Question 19

How is hemisphere dominance determined?

Answer 19

Wada test (sodium amytal)

• Anesthetize one hemisphere with barbiturates in carotid and check for language function

Functional brain imaging

• Use fMRI to see which half is active when doing a language test

Question 20

Which hemisphere is normally dominant? How does this change for right vs. left-handed people?

Answer 20

Left- hemisphere is dominant in almost all right-handers and most left-handers

Question 21

What is the right hemisphere in charge of language-wise?

Answer 21

Understanding musicality; also inflection and sarcasm…

Question 22

What does the frontal cortex control?

Damage results in what?

Answer 22

• Intentionality, purposefulness, complex decision making
• Damage -> loss of self, mind, judgment, social interaction, executive control
• Leadership/executive control (only necessary when an organization reaches a certain size and complexity; provides balance and decides when to grant autonomy) (as opposed to damage of posterior brain where damage leads to loss of sensation or movement functionality)

Question 23

What are the three divisions of the frontal lobe?

Where are they located?

Answer 23

Primary motor cortex (precentral gyrus)

Premotor cortex (anterior to primary cortex)

Prefrontal cortex

Question 24

What does a lesion to the primary motor cortex cause?

Answer 24

Weakness and paralysis of contralateral muscles

Question 25

What does a lesion to the premotor cortex cause?

Answer 25

Difficulty in producing coordinated movements

Question 26

What does a lesion to the prefrontal cortex?

Answer 26

Impaired ability to execute plans

Question 27

What can cause damage to frontal lobes?

Answer 27

- Congenital - Stress - TBI - Anterior cerebral artery stroke - Frontotemporal degeneration (e.g. Pick's disease)

Question 28

What are symptoms of people with frontal lobe damage?

Answer 28

- Cognition disintegrates and ultimately collapses with frontal lobe damage, like a leaderless army - Superficial appearance of normality - Inability to coordinate mental functions taking unseen goals into account - Disinhibition and lack of behavioral control (impulsive, quick to anger, rude comments) - Stimulus-bound - Emotional impairments (reduced ability to recognize others' emotional states; irritable, aggressive, alteration of patient's moods and emotions) - Difficulty planning and organizing their lives - Impaired working memory (delayed response task impairments)

Question 29

Are these decisions impeded by frontal dysfunction: **1)** If I have $100 in my pocket and loan you $30, how much do I have left? **2)** Should I dress as a hippie, zombie, or a superhero for Halloween?

Answer 29

Only **2)** is impeded

Question 30

What are the main parts of the prefrontal cortex (PFC)?

Answer 30

- Dorsolateral - Ventromedial/orbitofrontal

Question 31

What is the **dorsolateral PFC** in charge of?

Answer 31

"Cold" system - Working memory - Holding and manipulating objects - Impersonal problems

Question 32

What is the **ventromedial/orbitofrontal PFC** in charge of?

Answer 32

"Hot" system - Decision making affected - Moral judgments affected Orbitofrontal - Required for putting aside attractive things to further a longer term strategy (e.g. suppressing urge to grab/eat food; children have a hard time with such suppression in part due to slow maturation of frontal lobe) **Ventromedial** - Connection, meaning - Decision-making

Question 33

What is seen with people with **dorsolateral** PFC damage?

Answer 33

Damage -\> undermines ability to monitor own performance and to learn from mistakes Dorsolateral syndrome -\> "inertia" - Pt cannot stop - e.g. Wisconsin card sorting task: unable to change ways, even when old ways fail to bring reward

Question 34

What is seen with people with **orbitofrontal** PFC damage?

Answer 34

Damage -\> environmental dependency syndrome - When confronted by some cue that affords something, they cannot resist - e.g. see a hammer and nail, cannot help but use it or crawl into bed if sheets are turned down

Question 35

What part of the brain was damaged in Phineas Gage? How did this affect him?

Answer 35

Orbitofrontal PFC - He became unable to follow through with plans

Question 36

What is Orbitofrontal Syndrome?

Answer 36

**Emotional disinhibition:** - Oscillate between euphoria and rage - No foresight into the consequence of their actions - "Not immoral, but amoral" **Sexual aggression** - Men with orbito-frontal damage often have changes in sexual behavior (e.g. from loveable/gentle to sexual, over-forceful pest who won't take no for an answer) **Shoplifting** **Irresponsible with money** **"Immature" personality** - Selfish, boastful, puerile, profane, sexually explicit - Like a drunken adolescent Formerly "**pseudopsychopathic**" syndrome

Question 37

Where is the ventromedial PFC compared to the orbitofrontal?

Answer 37

Ventromedial is just superior to orbitofrontal

Question 38

What is the ventromedial PFC in charge of?

Answer 38

- Connection, meaning - Decision making

Question 39

Lowered activity in the ventromedial PFC causes what? Higher activity?

Answer 39

Lower -\> depression (events are fragmented, making all meaningless) Higher -\> mania, paranoia (have in common increased connectivity between everything)

Question 40

What does this patient have? - Left frontal lobe shrunken, right missing - Monstrous social behavior - Complete absence of anxiety, incapacity for insight, inability to learn from punishment - “an unawareness of his total life situation involving todays and tomorrows” - In and out of prisons and psychiatric hospitals - “a very simplified human organism with only rudimentary mechanisms for social adjustment”

Answer 40

(Patient J.P.) Widespread prefrontal cortex (PFC) damage

Question 41

What does this patient have? - "The case of the sudden pedophile" - 40 yo man, normal sexual appetite - Increasing interest in pedophilia

Answer 41

Massive frontal lobe tumor - When tumor was removed, sexual behavior returned to normal

Question 42

What does this picture show? What symptoms are expected?

Answer 42

Frontotemporal lobar degeneration Three clinical syndromes: **- Frontotemporal dementia** **- Semantic dementia** **- Progressive nonfluent aphasia**

Question 43

Frontotemporal lobe degeneration is the ___ most common cause of dementia in people \> 65 yo? In people younger than 65 yo, FTLD is the ___ MCC of dementai?

Answer 43

Frontotemporal lobe degeneration is the **4th** most common cause of dementia in those **over 65**, and the **2nd** most common cause in people **under 65**

Question 44

What is seen in frontotemporal dementia?

Answer 44

- **Disinhibition + diminished emotional concern for consequences** - Sociopathic behavior in 57% of FTLD pts (unsolicited sexual acts, traffic violations, physical assaults, other unacceptable behaviors) - Aware of their behavior and knew it was wrong but could not prevent impulsive acting - Claimed subsequent remorse, but did not act on it or show concern for the consequences

Question 45

In the eyes of the law, responsibility parallels \_\_\_\_\_\_?

Answer 45

In the eyes of the law, responsibility parallels **volitional control** (Can get in trouble from vomiting in public [but not if food poisoning], crashing a car [but not if epileptic seizure], shouting profanities [but not in Tourette's])