29 Prefrontal Cortex

Question 1

Generally speaking, where is the prefrontal cortex located?

Answer 1

anterior to the motor cortex

Question 2

Name the sulcus that divides the premotor and prefrontal cortices.

Answer 2

pre central sulcus

Question 3

What two sulci border the inferior frontal gyrus (vmPFC)?

Answer 3

the pre central sulcus and the inferior frontal gyrus

Question 4

Patient “tan” was suffering from prefrontal brain damage due to syphyilis suffered damaged to which area important for speech?

Answer 4

Broca’s aphasia

Question 5

Which sulci border on either side of the superior frontal gyrus (dlPFC)?

Answer 5

superior frontal sucli

Question 6

What gyrus lies between the superior and inferior frontal sulci?

Answer 6

the middle frontal gyrus (dlPRC)

Question 7

Where is the orbitofrontal cortex located (vmPFC)?

Answer 7

prefrontal cortex located just above the orbits

Question 8

The gyrus rectus lies between which two sulci?

Answer 8

olfactory sulci

Question 9

How does the prefrontal cortex in humans compare with other species?

Answer 9

in humans the prefrontal cortex is much more developed than other species and accounts for a lost ⅓ of the brain mass NOTE: prefrontal cortex is also the last area to fully mature (mid or late 20’s)

Question 10

Name the two subdivisions of the prefrontal cortex

Answer 10

dorsolateral PFC and the ventromedial PFC

Question 11

Dorsolateral PFC has connections with these areas for the functions of planning behavior and movement

Answer 11

premotor area and frontal eye fields

Question 12

Dorsolateral PFC has connections with this are for the functions of working memory, focused attention, sensor/spatial processing

Answer 12

lateral parietal cortex

Question 13

Ventralmedial PFC has connections with the hypothalamus and brainstem for what purpose?

Answer 13

regulation of autonomic, visceral responses

Question 14

Connections between vmPFC and the ventral striatum are important for this function.

Answer 14

reward and decision-making

Question 15

Connection between the amygdala and the vmPFC participate in these emotions.

Answer 15

fear, threat, arousal

Question 16

What area does the vmPFC connect with to produce self-reflection and rumination (undirected thoughts)

Answer 16

medial parietal cortex

Question 17

Name the white mater tracts that are important to eh dorsolateral and ventromedial PFC respectively.

Answer 17

superior longitudinal fasciculus and the uncinate fasciculus

Question 18

Which vessels supply the vmPFC and the dlPFC respectively?

Answer 18

ACA and MCA

Question 19

What are the main functions of the dorsolateral PFC?

Answer 19

acts as working memory, executive function of cognitive control (ie. strop test), task switching

Question 20

What are the main functions of the ventro medial PFC?

Answer 20

reasoning of risk and reward in the long term (value computation) as well as personality (emotional regulation) and empathy (social cognition) and moral judgement as well as introspection (intelligence is unrelated)

Question 21

What have lobotomies taught us about the prefrontal cortex?

Answer 21

the vmPFC has huge impacts on affect, unintended lobotomies have been shown to cure depression

Question 22

What is currently a practice to treat severe depression involving the PFC?

Answer 22

deep brain stimulation (reversible and localized)

Question 23

Name common PFC pathologies.

Answer 23

frontotemporal dementia, ischemic stroke (of either ACA or MCA), subarachonid hemorrhage (ie. aneurysm), tumor (meningioma is common near PFC) or dramatic brain injury (shearing on the orbital plate along with initial impact