BMB 1 - The Prefrontal Cortex; Classical Cortical Syndromes

Question 1

True/False.

The prefrontal cortex accomplishes a series of both low-order and high-order functions.

Answer 1

True.

Question 2

What types of largely unconscious, low-order functions does the pre-frontal cortex orchestrate?

Answer 2

Automatic, routine, obligatory kinda stuff

(e.g. brushing your teeth)

Question 3

What types of conscious, high-order functions does the pre-frontal cortex orchestrate?

Answer 3

New, controlled, strategic, voluntary kinda stuff

(e.g. a new task, making a decision, etc.)

Question 4

Which portion of the prefrontal cortex is largely involved in regulating cognitive processes?

Answer 4

The dorsolateral prefrontal cortex

Question 5

Which portion of the prefrontal cortex is largely involved in regulating behavior (especially in determining the appropriateness of one’s behavior)?

Answer 5

The orbitofrontal cortex

Question 6

Where does active memory occur (as in, visualize your car or hear the noise of a cow within your mind)?

Answer 6

The dorsolateral prefrontal cortex

+

task-specific posterior areas

Question 7

Which types of memory does the prefrontal cortex manage?

Answer 7

Active memory (i.e. “the mind’s eye”);

working memory (manipulation of the representation in “the mind’s eye”)

Question 8

Which portion of the cerebral cortex is most involved in agency and choice?

Answer 8

The prefrontal cortex

Question 9

Which portion of the cerebral cortex is most involved in discriminating between reality, memory, and imagination?

Answer 9

The prefrontal cortex

Question 10

Which portion of the cerebral cortex is most involved in conscious experience?

Answer 10

The prefrontal cortex

Question 11

The _________ prefrontal cortex (DLPFC) is the key region for keeping information “on-line.”

Answer 11

The dorsolateral prefrontal cortex (DLPFC) is the key region for keeping information “on-line.”

Question 12

fMRI in patients with psychosis is associated with deficits in which three specific areas of the cerebral cortex?

Answer 12

(1) Anterior cingulate cortex
(2) Superior temporal gyrus
(3) Medial temporal cortex

Question 13

The inability to separate reality from imagination in patients with schizophrenia is largely due to defects in what portion of the brain?

Answer 13

The prefrontal cortex

Question 14

Deficits of ________ memory is the primary deficit in schizophrenia.

Answer 14

Deficits of working memory is the primary deficit in schizophrenia.

Question 15

It is largely a lesion in what portion of the brain that leads to a disconnect in a schizophrenic patient’s ability to distinguish auditory hallucinations from auditory reality?

Answer 15

The dorsolateral prefrontal cortex

Question 16

When does the theory of mind first appear in child development (theory of mind being the capacity to understand the mental state of others as separate and distinct from one’s own)?

(E.g. at what age would a child begin to look where you point with your finger instead of just at your finger?)

Answer 16

6 months

Question 17

What term refers to the absence (extremely rare) of language ability in an individual?

Answer 17

Aphasia

Question 18

What term refers to the a partial deficiency of language ability in an individual?

Answer 18

Dysphasia

Question 19

What term refers to the absence of ability to read but with intact writing ability?

Answer 19

Alexia

Question 20

What term refers to the loss of ability to understand non-spoken, non-written aspects of language like pitch, cadence and intonation (the lyrical, rhythmic aspects of language)?

Answer 20

Aprosodia

Question 21

True/False.

Language ability is typically found in the dominant hemisphere, which is also typically ipsilateral to the patient’s dominant hand.

Answer 21

False.

Language ability is typically found in the dominant hemisphere, which is also typically contralateral to the patient’s dominant hand (although, a significant number of left-handed individuals are left hemisphere -dominant).

Question 22

Most brains have language ability wired in the _______ (right/left) hemisphere.

Answer 22

Most brains have language ability wired in the left hemisphere.

Question 23

Which model of aphasia is more accurate than the Wernicke-comprehension / Broca-motor model?

Answer 23

The Distributed Network Model - there is a broader network of fibers that are involved with language production and consequently, aphasias. I.e., a singular part of the brain is not responsible for all of language.

Question 24

_______ aphasia is an inability to produce speech.

Answer 24

Broca’s aphasia is an inability to produce speech.

Question 25

\_\_\_\_\_\_\_ aphasia is an inability to comprehend speech.

Answer 25

**_Wernicke's_** aphasia is an inability to comprehend speech.

Question 26

\_\_\_\_\_\_\_ aphasia is an inability to repeat speech.

Answer 26

**_Conduction_** aphasia is an inability to repeat speech.

Question 27

Where is Broca's area?

Answer 27

The inferior frontal gyrus

Question 28

Where is Wernicke's area?

Answer 28

The superior temporal gyrus

Question 29

What is the structure that connects the inferior frontal gyrus (Broca's area) and the superior temporal gyrus (Wernicke's area)?

Answer 29

The arcuate fasciculus

Question 30

Which aphasia is more likely to be ego dystonic and frustrating to a patient, Broca's or Wernicke's?

Answer 30

Broca's

Question 31

Lesions in the inferior frontal gyrus will lead to a(n) ______ inability to speak. Lesions in the superior temoral gyrus will lead to an inability to ______ speak. Lesions in the arcuate fasciculus will lead to an inability to ______ speech.

Answer 31

Lesions in the inferior frontal gyrus will lead to a **_motor_** inability to speak. Lesions in the superior temoral gyrus will lead to a inability to **_comprehend_** speech. Lesions in the arcuate fasciculus will lead to an inability to **_repeat_** speech.

Question 32

Aphasic patients will be more likely to eventually recover if they have which form of aphasia?

Answer 32

**Broca's** (due to frustration as a motivating factor)

Question 33

Apraxia occurs due to a lesion in which portion(s) of the brain?

Answer 33

The **dominant parietal lobe** | (typically lefthand)

Question 34

**True/False**. Apraxia is often associated with aphasia and is basically a loss of strength and/or coordination.

Answer 34

**False**. Apraxia is often associated with aphasia and is ***a loss of ability to perform specialized tasks (e.g. making a sandwhich, dressing oneself, making coffee, driving a car, etc.)***.

Question 35

Aprosodia is a result of damage to what portion(s) of the brain?

Answer 35

The **non-dominant frontal operculum**

Question 36

\_\_\_\_\_\_\_\_\_ is a disorder of attention and a failure to respond to objects on one side of the body (the patient is typically unaware they have a deficit).

Answer 36

**_Neglect_** is a disorder of attention and a failure to respond to objects on one side of the body (the patient is typically unaware they have a deficit).

Question 37

Very generally, what portion of the brain is damaged in patients with neglect?

Answer 37

The non-dominant hemisphere

Question 38

The ________ stream is the visual pathway involved in determining **where** an object is (spatial processing). The ________ stream is the visual pathway involved in determining **what**​ an object is (object identification).

Answer 38

The **_dorsal_** stream is the visual pathway involved in determining **where** an object is (spatial processing). The **_ventral_** stream is the visual pathway involved in determining **what**​ an object is (object identification).

Question 39

The dorsal stream is the visual pathway involved in determining _______ an object is. The ventral stream is the visual pathway involved in determining \_\_\_\_\_\_\_​ an object is.

Answer 39

The **dorsal** stream is the visual pathway involved in determining **_where_** an object is (***spatial processing***). The **ventral** stream is the visual pathway involved in determining **_what_**​ an object is (***object identification***).

Question 40

Agnosia generally refers to inability to do what?

Answer 40

The **inability** to **recognize** **objects** by use of the senses

Question 41

What term refers to the specific type of agnosia in which one is unable to recognize faces?

Answer 41

Prosopagnosia

Question 42

Object agnosia, prosopagnosia, and alexia are all disorders that involve a defect in which neural stream from the primary visual cortex?

Answer 42

**Ventral**

Question 43

A defect in the ventral stream of visual cortical processing can lead to _________ syndrome.

Answer 43

A defect in the ventral stream of visual cortical processing can lead to **_Balint_** syndrome.

Question 44

Describe the three features of Balint syndrome (a defect in the ventral stream of visual cortical processing).

Answer 44

1. **Simultanagnosia**: Loss of ability to perceive holistic gestalt of what senses are presenting: i.e., cannot take in a lot of competing information from the environment (see examples in image). 2. **Optic apraxia**: Inability to control eye movements voluntarily. 3. **Optic ataxia**: Failure of vision to guide complex voluntary movement, such as reaching for an object.

Question 45

Make the diagnosis:

Answer 45

Broca's aphasia

Question 46

A 63 y/o right-handed woman presented with several months of gradually worsening problems with completing tasks at home and at work. Despite normal strength and preserved fine finger motion, on exam she was unable to pantomime tool use with either hand, often using her fingers as if they were the tool themselves. Brain imaging revealed a meningioma with mass effect and edema on the left parietal lobe. ## Footnote **What is the diagnosis secondary to her meningioma?**

Answer 46

Apraxia

Question 47

A 68 y/o right-handed male with hypercholesterolemia and atrial fibrillation presented with inability to recognize his wife. He thought she sounded and acted like his wife, but could not distinguish her from other women by sight. He was unable to recognize faces of famous people. Brain MRI showed infarct of left frontal lobe and another left temporal-occipital area and acute infarct right temporal-occipital area. ## Footnote **What is the diagnosis secondary to his stroke?**

Answer 47

Prosopagnosia

Question 48

A 57 y/o RH man with h/o hypertension and hypercholesterolemia presented with problems with vision saying “things just don’t look right” and difficulty reading. His neuro exam was significant for difficulty moving eyes on command although EOMI. He could not identify more than one object at a time. He had difficulty reaching out to targets but could touch his nose bilaterally with his eyes closed. He could read single letters but not words. Brain MRI revealed old, previously unknown infarction in the left parietal lobe and an acute hemorrhage deep in the right parietal and occipital region. ## Footnote **What is the diagnosis secondary to his stroke?**

Answer 48

Balint Syndrome