Prefrontal Cortex: Cognition, Emotion, Behavior

Question 1

What structures are int he prefrontal cortex

Answer 1

Medial prefrontal cortex
Dorsolateral prefrontal cortex
Orbitofrontal

Question 2

What structures are in the medial prefrontal cortex

Answer 2

• superior frontal gyri

- cingulate gyrus

Question 3

What structures are int he dorsolateral prefrontal cortex

Answer 3

• superior frontal gyri
• middle frontal gyri
• inferior frontal gyri

Question 4

What structure is in the orbitofrontal

Answer 4

Orbital gyri

Gyrus rectus

Question 5

What does the prefrontal cortex serve

Answer 5

Many “higher functions” due to convergence of input from many cerebral regions

Question 6

Maintaining focus and effort on one task, related to level of alertness

Answer 6

Sustained attention

Question 7

What kind of attention is dependent on prefrontal/orbitofrontal cortex and other subcortical and brainstem regions

Answer 7

Sustained attention

Question 8

Ability to tune-out irrelevant stimuli and to enhance detection and processing of relevant stimuli

Answer 8

Selective attention

Question 9

What kind of attention is dependent on the prefrontal/orbitofrotnal cortex and input from the parietal lobe

Answer 9

Selective attention

Question 10

Examples of selective attention

Answer 10

• Visual: where’s Waldo? Or finding family member in a crowd.
• Auditory: listening to a friends voive while tuning out a nearby strangers. Listening to one of several instruments during a song

Question 11

Switching focus of selective attention between different types of stimuli

Answer 11

Attentions “set-shifting”

Question 12

Examples of attentional set shifting

Answer 12

Color vs shape of visual object, adult vs child voices in convo, listening to prosody vs semantic aspects of speech.

Question 13

What is the prefrontal/orbtiofrontal cortex mainly used for

Answer 13

Attentions

Question 14

Selective attention for visual spatial attention, what lobe?

Answer 14

Superior parietal lobule regulates activity in primary or secondary visual cortex
Top down

Question 15

Selective attention and visual object information

Answer 15

Similar top down regulation occurs: temporal visual association cortex regulates primary or secondary visual cortex

Question 16

Selective attention for other types of sensory information

Answer 16

Not well understood, but general principal is sensory association cortex projected to primary sensory cortex and acts to filter our irrelevant info

Question 17

What is a common test for selective attention or “set shifting”?

Answer 17

Stroop test

Question 18

What is the stroop test

Answer 18

Tests selective attention or “set shifting” by having a color and meaning of word mismatched

Question 19

What is the set shifting in stroops test dependent on

Answer 19

Dorsolateral prefrontal cortex and anteiror cingulate gyrus cortex

Question 20

Damage to dorsolateral prefrontal cortex and the anterior cingulate cortex

Answer 20

Impairs both maintaining focus on a set and set shifting

Question 21

Areas of brain responsible for set shifting

Answer 21

Dorsolateral prefontal cortex and anteiror cingulate cortex

Question 22

What does switching response criteria in set shifting depend on

Answer 22

Orbitofrontal cortex

Question 23

Damage to the orbitofrontal cortex and set shifting

Answer 23

Impairs set shifting but patient may still be able to maintain focus on initial set

Question 24

Ability to hold information in mind during use for seconds to hours

Answer 24

Short term or working memory

Question 25

Accuracy of recall in short term or working memory

Answer 25

Accuracy of recalled information decreases as delay length increases: delay-dependent memory

Question 26

What is short term memory mediated by

Answer 26

Prefrontal cortex, mainly dorsolateral prefrontal cortex

Question 27

Spatial working memory localization

Answer 27

Dorsal to inferior frontal sulcus

Question 28

Object working memory localization

Answer 28

Ventral to inferior frontal sulcus

Question 29

Lab test for working memory (short term)

Answer 29

Delayed non-match to sample test Basically a matching game

Question 30

N-test

Answer 30

Stream of one letter or number appearing at a time, changing every 1-2 seconds, subject responds by noting if current letter or number matches 2 samples ago (2-back) or is a mismatch -difficulty can be increases

Question 31

Maintaining focus and effort on one task

Answer 31

Sustained attention

Question 32

What is the cause of sustained attention

Answer 32

NT through diffuse projections though out cerebral cortex and lambic regions, especially to prefrontal cortex. Prefrontal cortex is a major target of ascending NT projections systems, whose cell bodies are in brainstem nuclei or deep subcortical regions in cerebrum

Question 33

What NT promotes alertness, sustained attention, and selective attention

Answer 33

Locus coeruleus, a major ascending noradrenergic (NE) system

Question 34

Promotes selective attention to relevant stimuli, especially rewarding stimuli

Answer 34

Ventral Tegmental area, a major ascending dopaminergic system with widespread projections throughout the prefrontal cortex and lambic regions

Question 35

Where is the ventral tegmental area

Answer 35

In the substantia nigria

Question 36

Conventional medication of ADD

Answer 36

Ritalin and adderol, they increase action of NE and dopamine

Question 37

Cholinergic (acetylcholine) neurons

Answer 37

Form multiple subcortical regions have widespread projections targeting cerebral cortex, lambic regions. Enhance both sustained and selective attention

Question 38

Emotional/motivational/behavioral functions

Answer 38

- motivational level toward specific/all tasks/goals - impulse control and delayed gratification - social interactions - emotional stability and self regulation - prefrontal regulation of fear/stress

Question 39

Cognitive/executive functions

Answer 39

Decision making

Question 40

Assessing whether stimuli are rewarding or aversive, or predict danger or reward, consequences of decisions

Answer 40

Decision making

Question 41

Phineas gage

Answer 41

- Rail road stake in head - alert and normal during exam immediately after accident - head injury not fully closed till several months later - 1 month later falls into coma, awakes next day unable to raise head from bed - couple days later: long term memory intact, but impaired at size estimations and counting. Acts childishly and wants to go to childhood home - reports being pain free and goes home - cant keep work

Question 42

Major changes noted in Phineas Gage

Answer 42

- loss of motivation at work, becomes unreliable - profane and socially inappropriate - emotionally volatile or agitated

Question 43

Frontal love release phenomenon

Answer 43

- Behavior is diminished and inappropriate, including towards medical professionals - infantile reflexes (grasping finger, suckling)

Question 44

Utilization behavior, aka environmental dependency

Answer 44

Inappropriate use of objects when they suddenly become available, answering questions that are being directed to someone else

Question 45

A patient repeatedly says the same words, or the same motor responses, or the same choices in a cognitive test, despite these responses now being inappropriate.

Answer 45

Preservation

Question 46

An impairment in attentional set shifting (failing to shift) is a _________ error

Answer 46

Perseverative error

Question 47

Patient does not spontaneously produce speech and may be verbally unresponsive to questioning/examination. This deficit is a motivational deficit, not a problem in the language system (not aphasia)

Answer 47

Akinetic mutism

Question 48

Term derives from lack of ebullient mood/attitude (flat emotion). Lack of spontaneous behavior of any kind, delayed motor/verbal responses. Could contribute to a dx of major depression

Answer 48

Abulia

Question 49

Extreme forms of abulia and akinetic mutism

Answer 49

Can present as a catatonic state

Question 50

Vascular territory of prefrontal/orbitofronalt cortex

Answer 50

Branches of ACA

Question 51

Vascular territories of orbitofrontal cortex

Answer 51

Medially: MCA Laterally: ACA

Question 52

When does the prefrontal cortex develop

Answer 52

Not until 20s

Question 53

What is the last brain region to fully develop

Answer 53

Prefrontal cortex

Question 54

How does the prefrontal cortex mature

Answer 54

Over production of synapses followed by pruning

Question 55

Behavioral implications of a developing prefrontal cortex

Answer 55

Gradual maturation of executive and emotional functions: risk/reward assessment, delayed gratification, impulse control, resisting peer pressure

Question 56

Disorders involving impaired prefrontal development

Answer 56

Autism | Schizophrenia

Question 57

Disorders involving impaired but treatable prefrontal function

Answer 57

- schizophrenia - depression - PTSD - drug addiction