CCC- Dysexecutive syndrome

Question 1

What does the primary motor cortex do?

Answer 1

Production of skilled movements

Question 2

What does the premotor cortex do?

Answer 2

Organization of more complex actions

Question 3

What does the prefrontal cortex do?

Answer 3

Controlled behaviour

Question 4

What does the dorsolateral prefrontal cortex do?

Answer 4

inhibition, planning, working memory

Question 5

What does the ventrolateral prefrontal cortex do?

Answer 5

Emotional control/regulation

Question 6

Role of the prefrontal cortex in cognition

What do the frontal lobes mediate?

Answer 6

Mediate “higher” cognitive functions, and the co-ordination and strategic use of other cognitive resources

These are commonly referred to as “executive functions”

Question 7

What are some examples of executive functions?

Answer 7

Organizing, planning, prioritizing
Making decisions, thinking strategically
Deploying attention, focusing, following a plan
Monitoring performance, actions
Multi-tasking, task switching, inhibition
Problem-solving, abstract thinking, integration of knowledge
Working memory, prospective memory, future thinking
Regulating emotions, appropriateness to the context

Question 8

What causes disexecutive syndrome?

Answer 8

Damage to the frontal lobes- (damaging executive functions)

Question 9

What are the common reasons for prefrontal damage?

Answer 9

Traumatic brain injury (TBI)- (e.g. car crash)
Stroke or rupture of aneurysm of anterior communicating/cerebral artery
Tumor (e.g., meningioma)

Question 10

What happened to Phineas Gage?

Answer 10

1848: 25 years old, railroad construction foreman
An accident caused penetrating head injury – a metal bar went up through his eye and skull
A few hours later he was able to speak to the doctors
Two weeks later his memory for familiar people and recent events was intact
Survival for another 11.5 years
Haemorrhage and infections damaged particularly the ventromedial prefrontal cortex

Question 11

What was Phineas Gage like after the injury?

Answer 11

He could perform normal actions in day to day life

Personality changed in bad way

Couldn’t keep a job/ kept losing them- wouldn’t go back to life like it was before.

Cognitive and behavioural changes- considered unpopular & weird.

Question 12

What area of the brain was damaged for Phineas Gage?

Answer 12

Ventromedial prefrontal cortex

Question 13

What is Utilisation behaviour?

Answer 13

The tendency to grasp common objects when presented, and perform the function commonly associated with the object.
Indicates lack of appropriateness to the context, impulsivity.

Individuals with prefrontal damage find it difficult to resist the impulse to use the objects in front of them, even when these actions are not appropriate to the situation.

Question 14

What are examples of executive dis-functions?

Answer 14

Inability to organize and plan
Distractibility
Inability to inhibit prepotent responses, impulsivity
Inability to switch/shift focus
Inability to solve complex problems, think in abstract ways
Inability to make farsighted decisions
Inability to envision future situations
Inability to respond the context appropriately

Question 15

What is a way of testing executive functions?

Answer 15

Wisconsin Card Sorting Test (WCST)
Tests: set-shifting, rule abstraction, flexible thinking

3 possible ways of categorising stimuli: number, colour, shape

Task: learn what is the correct rule to categorise stimuli based on feedback

Question 16

Wisconsin Card Sorting Test (WCST)

How did individuals with prefrontal damage do on the task?
What is the behaviour referred to as?

Answer 16

Individuals with prefrontal damage get “stuck”, carrying on sorting by a rule even if told it was wrong.

This behaviour is referred to as perseveration (Milner, 1963)

Question 17

What other test other than the Wisconsin Card Sorting Test (WCST) can be used to test executive functions?

How do individuals find this test?

Answer 17

Stroop test!

Individuals with prefrontal damage cannot inhibit the more prepotent, automatic response of reading the words, despite knowing their task it to name the colour of the ink the word is written with.

Question 18

What does the Hayling test do?

Answer 18

Tests: response inhibition and strategy generation

A series of sentences are read with the last word missing
“The captain wanted to stay with the sinking…”
“He posted the letter without a…”
Part A: complete the sentence with an appropriate word – “ship”/ “stamp”
Part B: complete the sentence with an unrelated word – e.g., “chair”/ “blue”

Question 19

How do individuals do in the Hayling test?

Answer 19

Individuals with prefrontal damage cannot inhibit the automatic response of completing the sentence with the obvious word.

They also cannot generate a strategy to find unrelated words
(e.g., listing words belonging to a certain category).

Question 20

Testing Executive functions

What are the pros/ cons/ discussion

Answer 20

Some individuals will perform well on tests of general IQ, attention and even traditional tests of executive function but…

They are disorganised in their daily life – e.g., poor at making a plan and sticking to it

Most lab-based tests are very structured vs real life situations are not well structured

Tests need to be open-ended, require multi-tasking and planning

Ecologically valid tests predict functioning in “the real world”

Question 21

What is the Multiple Errands Test?

Answer 21

Shallice & Burgess, 1991
Tests: planning, strategy thinking, problem-solving

6 simple tasks (e.g., buy a brown loaf, buy a packet of throat pastilles)
A seventh task requires the subject to be at a certain place 15 minutes after starting
An eighth task requires to obtain four sets of information and write them on a postcard (i.e., the name of the shop in the street likely to have the most expensive item; the price of a pound of tomatoes; the name of the coldest place in Britain yesterday; the rate of the exchange of the French franc yesterday).

Takes place in the real world (in a small shopping precinct near the hospital previously unknown to the patients)
Requires to obey various rules
Only go into each shop once
Only use a watch to assist you
Stay within a certain area
Spend as little money and time as possible

Question 22

How did healthy controls do in the Multiple Errands Test?

How did the individuals with pre-frontal damage do?

Answer 22

They managed to do all the tasks in the right amount of time- went to post office when tasks completed & didnt spend much money.

Went back and fourth to shops- didn’t do stuff in right order- behaviour was disorganised- cant plan schedule & stick to plan- found hard to focus attention on the list of tasks they had to do- didn’t stay within the boundaries.

Question 23

The Multiple Errands Test

What errors were typically made by patients with prefrontal damage?

Answer 23

Plan formulation or modification
Going to Post Office before all relevant information obtained (Cases 1-3)
Failure to look at watch at start (Case 3)
Generation of inappropriate criteria

Marker creation or triggering
Going out of bounds (Cases 2, 3)
Attempt not to pay for item in shop (Case l, 2)
Looking in irrelevant shops (Cases 1, 2)

Evaluation and goal articulation
Posting postcard without all information (Cases 2, 3)
Failure to keep a check of money (Cases 2, 3)
Thinking finished when had not (Case 1)

Question 24

What is a theory which explains Prefrontal Damage?

Answer 24

Supervisory attentional system (SAS)
Norman & Shallice, 1986

Question 25

What does the theory, Supervisory attentional system say about behaviour?

Answer 25

Action is either automatic or under attentional control

Automatic (e.g., making a cup of tea):
Can be executed without awareness or deliberate attention
Attention can be automatically drawn to an object

Controlled (e.g., learning to drive a car):
Involve planning or decision making
Involve troubleshooting
Involve novel sequences of actions
Are dangerous or technically difficult
Require the inhibition of habitual/overlearned responses

Question 26

Supervisory attentional system (SAS)
Norman & Shallice, 1986

What is the main point of the model?

Answer 26

We don’t need to use deliberate attention for most of our actions- because when we receive stimuli from the perceptual environment- because we have contention scheduling (an automatic system)- allowing us to use the schemas that we have about how to perform actions in an automatic way.

Question 27

Problems with SAS result in executive dysfunction.
How?

Answer 27

Perseveration: once activated, schemas persist in absence of any SAS input

Distractibility: when no single schema is dominant, the SAS would normally inhibit responses

Question 28

What is wrong with the SAS model?

Answer 28

The model does not easily address more complex planning / decision making / multitasking situations

Question 29

EVR / Elliot: “A modern day Gage”
Damasio & Eslinger, 1985

What happened to him?

Answer 29

Age 32 - Father of two, active in local community, promoted to senior position in accountancy firm, “role model” for siblings

Age 35 - after brief period of visual disturbances and personality change, large tumour removed from ventromedial frontal cortex

WAIS-R IQ – 125, above average performance on all subtests an intelligence battery and traditional tests of frontal lobe function

BUT…
Spent family savings
Continually fired from increasingly unskilled jobs
Wife divorced him
Remarried against advice, divorced 2 years later
Could spend entire days “getting ready for work” & then not actually going to work.
Deciding where to dine out could take hours

Question 30

Somatic Marker hypothesis

Damasio 1996

What is this?

Answer 30

Ventromedial prefrontal cortex acts as a repository of dispositionally recorded linkages (memory) between factual knowledge and bioregulatory states -> necessary to learn the association between a given situation and certain emotional states

Ventromedial prefrontal cortex is involved in the reactivation of signals related to previous situations (via the amygdala) -> memories guide the emotional reaction to new situations

Signals related to previous emotional states act as “markers” -> they mark a new situation as good or bad based on the “match” with similar situations that elicited similar emotional reactions, a “gut reaction”

Somatic markers boost attention/inhibition and facilitate logical reasoning in new situations, by improving decision making (easier to reject/endorse actions)

Question 31

The Iowa Gambling Task
Bechara, Damasio, Anderson, 1994

What is this?

Answer 31

Decks A + B contain frequent high rewards,
but occasional high punishments
Decks C + D contain low rewards, and low punishments

Normally people can do this well- start with AB- then change to CD

Question 32

The Lowa Gambling task

What were the results?

Answer 32

Individuals with prefrontal damage do not learn to associate desks A and B with losses and keep choosing cards from “bad” decks

Question 33

The Lowa Gambling task

When they measured skin conductance of participants- what were the results?

Answer 33

Controls build up large anticipatory skin conductance responses (SCRs) to “bad” decks A and B

Individuals with prefrontal damage do not show this effect, they fail to activate the somatic marker the signals the potential loss in controls

Question 34

The delay discounting task
Kirby & Herrnstein, 1995

What were the results?

Answer 34

Individuals with prefrontal damage tend to increase their preference for small-immediate over larger-delayed rewards, showing steeper discount of future rewards compared to controls

Question 35

What is dis-executive syndrome?