L5: FRONTAL LOBES & VOLUNTARY BEHAVIOUR

Question 1

describe the cerebral cortex

Answer 1

symmetrical cortical surface with separate wrinkled sheets, comprised mostly of the frontal lobe

Question 2

how are the frontal and parietal lobes divided?

Answer 2

lateral fissure

Question 3

what is the M1

Answer 3

primary motor cortex which occupies the pre central gyrus

Question 4

what is the property of substantial proportions of the frontal lobe?

Answer 4

motor functions

Question 5

how is the primary motor cortex function determined?

Answer 5

direct electrical stimulation of brain surface when head was opened for surgery

Question 6

what is the result of damage to primary motor cortex?

Answer 6

problems coordinating and controlling muscles in voluntary movement (tight musculature)

Question 7

what is the result of damage to rostral motor areas?

Answer 7

effects on planning, selecting and initiating acts

Question 8

define voluntary behaviour

Answer 8

brought about by an act of will

Question 9

define involuntary behaviour

Answer 9

doesn’t occur as part of an intended act

Question 10

how can we learn involuntary behaviours?

Answer 10

• pavlovian condiitoning
• habitual actions

Question 11

what is anarchic hand syndrome?

Answer 11

non intended actions of the affected limb
- may be purposeful and not random

Question 12

what causes anarchic hand syndrome?

Answer 12

supplementary motor area in frontal lobe is damaged with immediately neighbouring tissue also affected
- damage is restricted to one hemisphere

Question 13

what does damage to frontal eye fields affect?

Answer 13

ability to produce saccades voluntarily

Question 14

describe unilateral damage to SMA (supplementary motor areas)

Answer 14

• damage to 1 SMA
• symptoms associated with contralateral upper limb
• no abnormal sensory experiences
• abnormal action execution
• denies responsibility

Question 15

define alien hand syndrome

Answer 15

anarchic hand syndrome accompanied by delusions of ownership

Question 16

describe bilateral damage to SMA

Answer 16

• damage to both SMA
• utilisation behaviour - spontaneous performance of object appropriate action when the person sees an object
• normal execution but missing intnetion
• acknowledge responsibility

Question 17

what happens when supplementary motor areas are damaged?

Answer 17

sensory messages activate the circuits involved in production of actions appropriate for things that are sensed - inhibition has been eliminated

Question 18

what part of the brain did Phineas Gage lose?

Answer 18

almost all prefrontal cortex of left hemisphere

Question 19

describe prefrontal lobotomy

Answer 19

• cuts through white matter fibres
• severs connections to and from the prefrontal cortex

Question 20

describe a transorbital lobotomy

Answer 20

• can be done at home
• white matter tract fibres severed
• damage to grey matter in orbitofrontal cortex and superior, medial & temporal regions of PFC

Question 21

disadvantages of transorbital lobotomy

Answer 21

• practitioner cannot see
• brains are all slightly different so some grey matter would be lesioned
• tool would penetrate orbitofrontal cortex

Question 22

damage caused by transorbital lobotomy

Answer 22

• personality changes to withdrawn & compliant (but reduces depression and anxiety)
• impairments in ability to control impulses / urge to satisfy desire, planning, concentration and holding info in working memory