Frontal Lobe Dysfunction Flashcards
Who was Phineas Gage?
A man who suffered a severe injury to his frontal lobe at the age of 25
An iron tamping rod went through below his left eye and out at teh top of his head
What was the first impression peoeple had of Gage after the accident?
Alive & Perfectly Fine
How was his wound treated?
1) Positioned Gage so would would drain
2) Removed as many bone fragments as possible
3) Kept would clear and free of infection
What aspects of Gages injury worked in his favor?
1) Healthy 25 year old man
2) Pointed shape and smoothness of iron
3) Enterance at skull of base, served as drainage point
What basic misconception did Gage’s case help disprove?
In the early 19th century the common belief was that even the slightest brain injury always led to death
Gage helped prove that you can lose a lot of brain tissue and still live
What did Pierre Flourens argue?
Effect of ablations depended on the amount of tissue removed, not the location
Sensorimotor processes are localized up to the brain stem.
- Dorsal roots = sensory
- ventral roots = motor
- cortex could not be localized
Hemispheres seat of general psychological processes
How did holists/dualists use Gage’s case to support their arguement? (add potentially)
- Little of Gage’s function was impaired
- Supported the unity of the soul in hemispheres
- Still allowed for localization at levels below hemisphere
What did Ferrier’s research in electrical stimulation reveal?
- Electrical stimulation led to an upwatd expansion of localization
- Found extensice, precise localization in hemispheres
**However nothing happenedwhen frontal lobes were stimulated **
What did David Ferrier conclude from stimulating the frontal cortex?
Frontal lobes actually inhibit other areas
- Linked attention with inhibition
- Essentially put attention in frontal lobes becuase no other function could be found there
Frontal lobes constitute the organic basis of all the higher intellectual faculties
What was Gages behaviour like 20 years after the accident?
He was described as a child in his intellectual capacity/manifestations & having the animal passions of a strong man
What were the two conclusions made based on the lack sensory-motor systems at the frontal lobes?
The two conflicting views of frontal lobe function
1) The Silent Areas
2) The Seat of the Highest Faculties
How did Gage’s case support phrenologists?
The rod disrupted the function of the neighboorhood of Benevolence and the front part of Veneration.
Benevolence = the quality of being well meaning; kindness.
Veneration = respect or awe inspired by the dignity, wisdom, dedication, or talent of a person
What was Hebb’s (1945) view on Frontal Lobe Function?
- Patients with frontal love damage showed no appreciable change in IQ scores
What was Goldsten’s (1944) view on Frontal Lobe Function?
Argued that IQ tests are not sensitive to higher level intellectual deficits
- Tap concrete knowledge and rountine cognitive skills
- Don’t tap planning and decision-making under novel situations, goal directed behaviour
Scientists did not agree with Goldstein’s arguement. Name one practice that this disagreement lead to?
Used the fact that intelligence was not alteres as justification for frontal lobotomies
What patients answers to Luria et al.’s questions that specifically tested frontal lobe dysfunction reveal?
It appears as if patients were running routine procedures without any thought
Describe patient EVR
What part of his brain was damaged?
What were his impairments?
Damage
- Large orbitofrontal meningioma removed (bilateral damage to frontal lobes)
Impairment
- Supervisory organization of his activities was very impaired
What attentional system is associated with frintal lobes?
Supervisory attentional system
What dies samage to the supervisory attentional system result in?
Reliance on contention scheduling alone (“stimulus bound”)
What behaviours are expected with CS running in isolation without SAS
1) Behavioural Rgidity
2) Distractibility
What test is administered to asses behavioral rigidity
Wisconsin Card Sorting Task
- They are unable to adapt to new rules within the test
Stuck-in-set perseverations
What test is administered to assess Distractibility?
Describe an example of this task
Test 1
Utilization behaviour task
- Glass is brought within reach of patient, patient grasps it. Bottle of water is brought within reach of patient, patient pours water into glass.
This behaviour persists even when patients are told not to grasp or use object once attention is breifly diverted.
Test 2
Event-Related Potential (ERP) Study
- Systematic change occurs when exposed to stimulus ex. DOG
- In healthy patients: Waves show that they can process/attend to target tones AND supress irrelevant tones
- Patients can not
What occurs when the SAS is damaged?
Behavioural Rigidity
- They fall into routine behavior
- Engaging in un moderated stimulus driven response
What is the primary purpose of SAS?
- Producing response to novelty that is planned rather than a response that is routine or impulsive
- Need to engage in some form of problem-solving behavior
What aspect of the Maze Learning & Tower of London tasks are frontal lobe patients impaired in?
Problem-solving
Planning
What aspect of the maze learning & WAIS Blocks tasks are posterior patients impaired in?
Visuospatial
How did Frontal patients perform on cognitive estimation tasks?
Frontal patients made significantly more bizarre or extreme answers
What behaviours are expected given the impairement of SAS functioning?
- Impaired ability to generate a non-routine response to novelty
- Impaired planning
- Impaired error checking our monitoring
deficits in language, memory, emotion, personality
