Week 10 Lecture Flashcards
What did Charles Sherrington quote in 1953 about cognitive decision making?
life’s goal is an act, not a thought
What are 3 key aspects of the motor systems?
- hierarchical and parallel organisation
- sensory input guides output
- nature and locus of control change to learning (conscious to automatic)
What are physical actions performed by
muscles
Muscles act under what?
tensions
Alpha motor neurons + muscle fibres equal what?
Motor unit
How is muscle activity measured?
using electromyography (EMG)
What are golgi tendon organs
- embedded in tendons
- tendons connect to muscle to bone
- GTOs detect muscle tension
What are muscle spindles?
- embedded in muscle tissue
- detect changes in muscle length (stretch receptors)
- have their own muscle control system
What are simple reflexed controlled by?
circuits in the spinal cord
What impacts directly onto motor neurons and act to counteract muscle stretch?
sensory afferents (muscle spindles) synapse
What is the stretch reflex?
monosynaptic
Is withdrawal reflex monosynaptic?
no
What does monosynaptic mean
serves to maintain limb stability
Action is mediated by multiple descending pathways, which are what 2 tracts?
pyramidal and extrapyramidal
Damage to the basal ganglia would result in what?
difficulty in learned movements
What is the neocerebellum?
newest part (outer layers) involved in motor planning
What is vestibulocerebellum?
involved in balance, significantly affected by alcohol
What are the 3 divisions of the cerebellum?
- neocerebellum
- spinocerebellum
- vestibulocerebellum
What are the secondary motor areas involved in?
planning on movement, rhythmic coordination, higher order coordination, anything which involved two limbs
Is sensory feedback required for action? (severed dorsal route)
no, sensory feedback is not required for action.
What is the theory of endpoint control?
the hypothesis that movements are planned based on the final goal of movement (not planning how to get there).
What are some questions which are asked in the neural coding of movements?
What are the neurons coding? muscle activation? direction? position?
If a monkey are using different grips and therefore different muscles, what is the correlation between each grip?
muscle activation is important for coding, regarding what that muscle is.
Can we use robots to pick up neural signals from the brain to control their movements?
yes, observed in rat experiments, thinking about something can activate neural activity which can move the robotic arm
Basal ganglia are important for movement and mediating what?
response competition; the most active response “wins”, gets released
the output neurons of the basal ganglia to the thalamus are what?
inhibitory
The direct pathway from the striatum inhibits the basal ganglud. Therefore:
there is less (inhibitory) output into the thalamus, this means it is the greatest driver to the cotex
The indirect pathway excites the basal ganglia, therefore:
the basal ganglia has a greater inhibitory output onto the thalamus, and less cortical drive
Parkinson’s disease has what affect to the basal ganglia?
loss of dopamine production, affecting the direct pathway; less drive to thalamus and lack of movement
How does Huntington’s disease affect the basal ganglia?
reduced activity in the indirect pathway, increased cortical excitation/movement
What is one way to help Parkinson’s disease?
deep brain stimulation
