6/4- Higher Cortical Function II Flashcards Preview

Term 5: Neuro > 6/4- Higher Cortical Function II > Flashcards

Flashcards in 6/4- Higher Cortical Function II Deck (45):

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

The left hemisphere is mostly in charge of language.


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

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


Where is Broca's area?

Small area in left inferior prefrontal cortex

(nearish primary motor cortex and articulation areas) 


What is Broca's aphasia?

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


What artery supplies Broca's area?

Middle cerebral artery (posterior)

- Could also result from tumors or strokes


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

It doesn't.

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


Where is Wernicke's area?

Just posterior to primary auditory cortex

(superior temporal gyrus)


What is Wernicke's aphasia?

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)


T/F: Broca's affects all language

T/F: Wernicke's affects all language

True: Broca's affects all language

True: Wernicke's affects all language


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

- Broca's patient realizes impairment and suffers from it; often depressed

- Wernicke's aphasics usually do not understand why people aren't understanding them


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


What connects Wernicke's and Broca's area?

Arcuate fasciculus


What is conduction aphasia? What would you observe?

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

- Comprehension and speech normal, but unable to repeat 


What is global aphasia? What causes it?

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


What is alexia?

Inability to read


What is agraphia?

Inability to write


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

Left angular gyrus (nearer visual system)

Goes to Broca's area still for comprehension


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


How is hemisphere dominance determined?

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


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

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


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

Understanding musicality; also inflection and sarcasm...


What does the frontal cortex control?

Damage results in what?

- 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)


What are the three divisions of the frontal lobe?

Where are they located?

Primary motor cortex (precentral gyrus)

Premotor cortex (anterior to primary cortex)

Prefrontal cortex 


What does a lesion to the primary motor cortex cause?

Weakness and paralysis of contralateral muscles


What does a lesion to the premotor cortex cause?

Difficulty in producing coordinated movements


What does a lesion to the prefrontal cortex?

Impaired ability to execute plans


What can cause damage to frontal lobes?

- Congenital

- Stress


- Anterior cerebral artery stroke

- Frontotemporal degeneration (e.g. Pick's disease)


What are symptoms of people with frontal lobe damage?

- 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)


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?

Only 2) is impeded


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

- Dorsolateral

- Ventromedial/orbitofrontal


What is the dorsolateral PFC in charge of?

"Cold" system

- Working memory

 - Holding and manipulating objects

- Impersonal problems


What is the ventromedial/orbitofrontal PFC in charge of?

"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)


- Connection, meaning

- Decision-making 


What is seen with people with dorsolateral PFC damage?

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


What is seen with people with orbitofrontal PFC damage?

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


What part of the brain was damaged in Phineas Gage?

How did this affect him?

Orbitofrontal PFC

- He became unable to follow through with plans


What is Orbitofrontal Syndrome?

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)


Irresponsible with money

"Immature" personality

 - Selfish, boastful, puerile, profane, sexually explicit

- Like a drunken adolescent

Formerly "pseudopsychopathic" syndrome


Where is the ventromedial PFC compared to the orbitofrontal?

Ventromedial is just superior to orbitofrontal


What is the ventromedial PFC in charge of?

- Connection, meaning

- Decision making


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

Lower -> depression (events are fragmented, making all meaningless)

Higher -> mania, paranoia (have in common increased connectivity between everything)


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”

(Patient J.P.)

Widespread prefrontal cortex (PFC) damage


What does this patient have?

- "The case of the sudden pedophile"

- 40 yo man, normal sexual appetite

- Increasing interest in pedophilia

Massive frontal lobe tumor

- When tumor was removed, sexual behavior returned to normal


What does this picture show?

What symptoms are expected? 

Frontotemporal lobar degeneration

Three clinical syndromes:

- Frontotemporal dementia

- Semantic dementia

- Progressive nonfluent aphasia


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?

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


What is seen in frontotemporal dementia?

- 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


In the eyes of the law, responsibility parallels ______?

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])