Frontal Lobe Damage And Executive Dysfunction

Front 1

The frontal lobes constitute ___% of the neocortex.

Back 1

20%

Front 2

All regions anterior to the _______ sulcus make up the frontal lobes.

Back 2

central sulcus

Front 3

Area 4 of the frontal lobes is the ________ area.

Back 3

motor area

Front 4

Areas 6 and 8 of the frontal lobes are the _______ areas.

Back 4

premotor areas

Front 5

What is lateral area 6?

Back 5

Premotor cortex (44 Broca’s)

Front 6

What is medial area 6?

Back 6

Supplementary motor cortex (SMA)

Front 7

What is area 8?

Back 7

frontal eye field

Front 8

What is area 8A?

Back 8

supplementary eye field

Front 9

The PREFRONTAL CORTEX is an area of the frontal lobe that receives input from the ________________ of the thalamus.

Back 9

dorsomedial nucleus

Front 10

What are three divisions of the prefrontal cortex?

Back 10

Dorsolateral Prefrontal Cortex (working memory)

Inferior Frontal Cortex
-Also called Orbitofrontal cortex

Medial Frontal Cortex
-Sometimes considered part of the cingulate

Front 11

What are some hypothesized frontal lobe functions?

Back 11

PLANNING in advance and selection from OPTIONS.

PERSISTENCE and ignoring distracting stimuli.

MEMORY for what you have already done, and the order in which you have done it.

EXECUTIVE Functions ("cognitive control"; working memory and voluntary attention

Responds to both internal, external, and context cues
-Social context

Front 12

Describe some executive functions.

Back 12

-planning and decision making.
-error correction and troubleshooting.
-responses are not well-learned or contain novel sequences of actions.
-dangerous or technically difficult situations (Mental Workload).
-overcoming of a strong habitual response and resisting temptation. Perseveration.

Front 13

What does the Wisconsin Card Sorting Task test?

Back 13

whether a person can change rules or if he/she "perseverates" on original rule even after it has changed. (Changes after 10 correct trials)

suggests Disconnection between thought
and action

Front 14

Do those who perseverate on the WCST know they are following the wrong rule?

Back 14

They may. The notes say that they "Even continue when they
'know' they are not following
the rule."

Front 15

What is Environmental Dependency Syndrome? Highly comorbid with what disorder?

Back 15

Such patients cannot help but do what the environmental cues are telling them to do. “Environmental cues” trigger perseveration. Also relates to pre-morbid functioning (comorbid with OCD).

Front 16

A more complex WCST-like task tests for abstraction difficulties in patients with frontal lobe damage. What happens with such patients on these tasks?

Back 16

They can sort according to a rule, but cannot tell you what rule they are using (or that another person is using). They also cannot change the rule even when asked to.


Deficit in conceptualization.

Front 17

PFC, novelty oddball, and p3a/p3b?

Back 17

Cognitive flexibility. Dealing wit novel situations. PFC seems to be implicated in these.

P3a decreases after PFC damage
P3a correlates with grey matter volume in PFC
Source analysis of P3a suggests PFC

Front 18

What is the Sequencing: Recency Judgment Task?

Back 18

Two types of trials: recognition and a recency.

.. check slide 11 (Mar 15th lecture)

Front 19

On the Sequencing: Recency Judgment Task, do Right-PFC damage do poorly on recency or recognition or both?

Back 19

Right PFC damage is specifically associated with doing poorly on the temporal aspects (recency).

Front 20

On the Sequencing: Recency Judgment Task, do temporal damage do poorly on recency or recognition or both?

Back 20

Temporal damage do poorly on recognition & recency.Temporal lobe damage deficits on this task is not surprising (could have agnosias, can’t hear you, etc.).

Front 21

What type of patients do poorly on the Six-item Self-ordered Pointing task? And what are two possible reasons they may do poorly?

Back 21

Left PFC damage disrupts performance. This task involves sequencing and working memory.. areas implicated in the PFC (working memory a function of the DLPFC).

Front 22

What type of patients do poorly on the Tower of London task? What is the purpose of this task?

Back 22

It is used to assess strategies used to sequence action.

More evidence for active sequencing relating to left PFC. They have problems with efficiency (in the set amount of moves), or effectiveness (can they even do it at all)?

Front 23

On the WCST task involving extra dimensions, most frontal lobe patients can both recognize and tell the difference between simple, compound, and intradimensional shapes. However, they have troubles with the extradimensional shapes (in recognition & in telling the difference). What type of problem is this?

Back 23

They’re having figure-ground issues.

[How are the intradimensional that diff. from the extradimensional?]

Front 24

What is the Advance Information Paradigm?

Back 24

Either given advance information (a cue) or not given one... Usually people will have a faster RT in responding (yes or no?) to the target when given the cue ms beforehand.

Front 25

How do frontal lobe patients perform on this task? What are two reasons for their performance?

Back 25

Frontal Lobe patients have
difficulty using advance
Information

i.e. cannot employ advance info
for strategy formation

Alternative hypothesis: cannot
maintain image in working memory

Perseveration?

The frontal lobe patients’ performance does not go up, even with the advanced information. Could be due to them perseverating their previous strategy. Could be an inability to use working memory.

Front 26

Summary of Task Effects.

Back 26

WCST
-Perseveration

Abstraction

Novelty – P3a & novelty oddball

Sequencing
-Passive & Active
-Strategy – Tower of London

Conceptual shifting

Advance information


Cases: (1) Accountant with bilateral orbitofrontal cortex legion. Can’t control himself, constantly remembering numbers, feels naïve. Has judgment problems, though knows that they’re immoral or illegal.

(2) Dorsolateral damage (?).

Front 27

What is a "Blunder Blip" as mentioned in the notes? Where might it be generated?

Back 27

Error Related Negativity (ERN)

Blunder blip peaks after people make a mistake… well before we have the awareness that we actually made the mistake. Occurs ~100 ms after error
has been made


"Generated in Anterior Cingulate Cortex (ACC)?" (in medial surface of frontal lobe)
If lesion in ACC, you don’t see a ERN.

Front 28

Does a blunder blip change depending whether a person is in a condition where they are asked to be accurate or where they are asked to be fast? What if a person has a lesion near the PFC? If you lesion near the PFC, you get ERN to both response types.

Back 28

Yes. Huge blip when they are making errors when they are supposed to be accurate. No spike when you tell them to go fast.

Front 29

Response inhibition. Go/Nogo task ??? Slide 18

Back 29

Inferior frontal = orbitofrontal. 80% of the time there will be red, and push the red button. Then 20% of the time, it’s green, and they need to inhibit the response (NOGO). ACC activation is basically the same in both conditions. The difference comes in the inferior frontal (oribitofrontal)… helps in response inhibition.