Prefrontal Cortex and Executive Function

Question 1

Functions of the frontal lobe include

Answer 1

motor control, language function (esp Broca’s), higher level cognition/executive functioning

Question 2

How can the frontal lobe be divided?

Answer 2

cytoarchitecture (layers of cortex); thalamic connections (less common); functional properties (primary, secondary, association areas)

Question 3

Broadmann’s area 45

Answer 3

Broca’s

Question 4

Functional distinctions of the frontal lobe are

Answer 4

motor, premotor, and prefrontal cortex

Question 5

The prefrontal cortex is associated with

Answer 5

Language and executive higher order cognitive function

Question 6

Lobotomy

Answer 6

removal of tissue

Question 7

Locotomy

Answer 7

severing of connections (Walter Freeman frontal locotomies)

Question 8

What were the effects of frontal locotomies?

Answer 8

some people were made calmer and more timid, others had the opposite effect - all changed the personality of the patient eg desire to do things, engagement with environment, capacity to reason through problems, to initiate tasks

Question 9

Luria’s functional system attributes the anterior unit to what functions?

Answer 9

Planning, executing, and verifying behaviour - ie, executive function

Question 10

What is executive function?

Answer 10

umbrella term encompassing a huge number of different cognitive domains; planning, executing, and verifying behaviour, thinking skills, social functioning, interrelated processes of goal directed and purposeful behaviour

Question 11

The dorsolateral prefrontal cortex is responsible for

Answer 11

traditional executive functions: working memory, response selection (and strategy changing), planning and organising, hypothesis generation, flexibly maintaining or shifting set ideas, insight, capacity for moral judgement (right from wrong)

Question 12

The dorsolateral prefrontal cortex is supplied largely by what artery?

Answer 12

MCA

Question 13

Working memory tasks assess

Answer 13

capacity to keep information in the mind and use it

Question 14

Working memory tasks ask the patient to

Answer 14

take something and manipulate it eg remember numbers and repeat them backwards

Question 15

The medial prefrontal cortex is responsible for

Answer 15

emotional and motivational interface - role in emotional tone or the way emotion is expressed

Question 16

Medial PFC lesions present with

Answer 16

akinetic mutism (extreme) - functional capacity to move, talk, do, and speak are intact but they lack the motivation or initiation to do anything; apathy, lack of engagement, lack of initiative, lack of self-awareness or capacity to understand own emotions or attribute emotions to others

Question 17

The medial PFC is largely supplied by which artery?

Answer 17

ACA

Question 18

How do medial PFC lesions affect self-awareness?

Answer 18

lack of ability to attribute mental state and/or emotions to themselves or others

Question 19

What is emotional intelligence?

Answer 19

Ability to understand and use emotions appropriately in day-to-day life

Question 20

What is the orbitofrontal prefrontal cortex responsible for?

Answer 20

highly connected to limbic areas (emotions); inhibition (emotional, cognitive, social); impulsivity

Question 21

Orbitofrontal prefrontal cortex lesions present with

Answer 21

impulsivity and disinhibition - emotional (crying randomly, laugh inappropriately, greater emotional responses than normal for the situation), cognitive (not stopping a task when they should), or socially (say things they think out loud)

Question 22

The orbitofrontal prefrontal cortex is supplied by which artery?

Answer 22

ACA and MCA

Question 23

The frontal lobe is the _____ area of the brain to develop. and one of the ____ to degenerate in ageing

Answer 23

last; first

Question 24

Because the frontal lobe develops last, what is true of executive functioning?

Answer 24

executive functions are amongst the last abilities to reach maturity (have genetic and environmental factors) with lower order functions developing first and higher order (eg shifting and reasoning) later

Question 25

What is the idea of a dynamic process of development?

Answer 25

Neural proliferation and pruning based on experiences/stimuli in early life

Question 26

T/F executive dysfunction and frontal lobe dysfunction are interchangeable terms

Answer 26

F, should not be used interchangeably as executive dysfunction is not a unitary disorder and you don't have to lesion the PFC to get executive dysfunction (ie connections to/from or cerebellar lesions can result in ED)

Question 27

General, the prefrontal cortex acts as

Answer 27

a coordinator of executive functioning

Question 28

T/F lesions that cause executive dysfunction occur only in the frontal lobe

Answer 28

F; can occur in connections, thalamic connections, subcortical or cerebellar lesions can all give rise to executive dysfunction in addition to frontal lesions

Question 29

What are positive symptoms of executive dysfunction?

Answer 29

more of something: distractability; social disinhibition; emotional instability; perseveration; impulsivity; hypergraphia

Question 30

What are negative symptoms of executive dysfunction?

Answer 30

less of something: lack of concern; restricted emotion; deficient empathy; failure to complete tasks; lack of initiation

Question 31

Formal neuropsychological tests tend to be most sensitive to which lesions?

Answer 31

DLPFC lesions

Question 32

Medial and orbitofrontal lesions are assessed by

Answer 32

difficult to do formally; clinical judgement and hx taking usually from patient AND someone who knows them

Question 33

Examples of neuropsychological tests of DLPFC lesions

Answer 33

tower of london - balls (planning, impulsivity, inhibition, learning from mistakes, adapting); stroop test - compatible/incompatible coloured words (inhibition); rey complex figure test - copying image (planning, visuospatial)