10. Motor Control and Disorders Flashcards
Disrupting primary motor cortex regions in the left hemisphere with TMS will affect motor function on which side of the body?
The right
Primary motor cortex is involved in which of these: preparing actions, higher level planning, sensory-motor links, execution?
Execution of movement
This structure is located on the postcentral gyrus
Primary somatosensory cortex
The primary output of M1 is to:
The spinal cord
M1 recieves input from:
premotor areas, somatosensory cortex, SMA
Hemiplegia is the paralysis of one side: true or false?
true
Hemiparesis is weakness of one side: true or false?
true
Vector coding relies on:
Neurons in M1 having preferred directions of movement they respond to and averaging these across neuronal populations
Why is it important that somatosensory cortex inputs to M1?
- proprioception to aid movement
- pain sensation to move limbs away
The eyes are controlled separately to the body by this region
the Frontal Eye Fields
These types of eye movement are fast, short, and happen constantly
Saccades
This type of eye movement is slow and involves actively tracking a stimulus
Smooth Pursuit
Which is responsible for externally generated action: lateral premotor cortex or SMA?
Lateral premotor cortex
Premotor region involved in internally generated action and complex or learnt sequences
SMA
What changes occur in the activity of the PFC, M1, premotor cortex and SMA when a sequence goes from effortful to automatic
decreased activation in all regions except for SMA, which increases
Blocking the SMA only interferes with complex sequences and not simple. This shows that:
SMA is not involved in simple sequences
This brain region is involved in choosing whether we want to perform an action, attending to difficult actions, and goals/intentions
the prefrontal cortices
Prefrontal lesions: what is perseveration?
continuing an action when no longer relevant or desired
Prefrontal lesions: what is utilisation behaviour?
acting on an object inappropriately eg grasping someone else’s glasses
What is disinhibition following prefrontal lesions?
- doing an action when you dont want to
- performing inappropriate behaviours or actions that go against social rules
The antisaccade task assesses frontal lobe damage, in particular which symptom of prefrontal lesions?
Disinhibition
Which type of apraxia results in being unable to follow steps in a routine action?
Frontal Apraxia
The norman and shallice model proposes we can select a schema/goal via contention scheduling. This may be impaired in prefrontal lesions and cause:
perseveration and utilisation behaviour
What is apraxia?
An inability to performed skilled, meaningful action
Ideomotor apraxia: subjects can recognise action performed by another but not mime it or execute it. This is caused by damage to:
the Parietal cortex
True or false: those with ideomotor apraxia can perform sequences of actions and those with frontal apraxia cannot
True
Cerebellar patients tend to have this form of tremor during the finger-to-nose test (action, resting, essential)?
Action tremor
How will cerebellar patients perform in a random saccade test?
struggle to move eye to the target
What are the subcortical motor areas (2)?
Cerebellum and basal ganglia
What is micrographia in Parkinson’s?
writing becomes smaller and fainter due to fatigue
What is the underlying pathology of parkinson’s?
Death of dopamine releasing cells in the Substantia Nigra Pars Compacta
The 3 cardinal motor symptoms of parkinson’s:
bradykinesia, resting tremor, rigid muscles
The basal ganglia is related to the SMA, this means parkinson’s patients often struggle with:
- internally generated movement
- complex sequences and bimanual coordination
The parietal cortex is the site of:
Sensory-motor links
Frontal apraxics can do each individual aspect of sequence but not whole sequence: T or F?
True
What is optic ataxia and what is optic apraxia?
- ataxia: reach and grasp deficit: parietal cortex damage
- not being able to move eyes voluntarily and horizontally
