Action Flashcards
Briefly describe how simple motor behaviours are generated via reflex arcs.
- Input and output are quick
- No conscious involvement of the brain
- Purpose?
- Protective functions: reduce damage
- Postural stability: stand up and stand
completely still
- This is done by the extrapyramidal –
tracts, unconsciously and automatically
Briefly describe the differences between the extrapyramidal tracts and the pyramidal tract (no detail on the various types of extrapyramidal tracts)
- The corticospinal or pyramidal tract is made
up of descending fibres that originate in the
cortex and project monosynaptically to the
spinal cord. - Extrapyramidal tracts are neural pathways
that project from the subcortex to the spinal
cord. - Extrapyramidal tracts are involved in subconscious activity (posture)
Describe in more detail how more specific behavioural goals are accomplished; include the role of the primary motor cortex, the premotor areas (SMA and PMC) and the posterior parietal lobe.
- SMA: supplementary motor area, internally
guided actions - PMC: premotor cortex, externally guided
actions - Posterior parietal cortex, function?
- Representation of space and body in space
- Somatosensory cortex! S1, S2
- The where pathway of vision
- Lesions: ideational apraxia, the loss of
ability to conceptualize, plan, and execute
the complex sequences of motor actions
Briefly discuss the symptoms and neural substrate of hemiplegia.
- Hemiplegia: the loss of voluntary
movements on the
contralateral side of the body - Lesions to M1 or the corticospinal tract
result in hemiplegia, the loss of the ability
to produce voluntary movement.
Discuss in somewhat more detail the symptoms and neural substrate of apraxia.
- Apraxia is a disorder in which the patient
has difficulty producing coordinated, goal-
directed movement, despite having normal
strength and control of the individual
effectors. - Ideomotor apraxia
- problems with translating intentions into
movements - damage to SMA for internal processes
(food, sleep), Premotor Cortex for
reaction to environment
- problems with translating intentions into
- Ideational apraxia
- problems to conceptualize and execute
complex sequences of motor actions - damage to the parietal cortex
- problems to conceptualize and execute
Explain in detail the concept of population vectors (study the text in the chapter, not the explanation in the glossary).
- Population vector
- The sum of the preferred directions of
individual neurons within a group that
represents the activity across that group
- The sum of the preferred directions of
Explain briefly what a brain-machine (computer) interface is and how population vectors are applied in brain-machine interface control.
- Brain-machine (computer) interface
- A device that uses the interpretation of
neuronal signals to perform desired
operations with a mechanical device
outside the body - For instance, signals recorded from
neurons of EEG can be used to move a
prosthetic arm
- A device that uses the interpretation of
- Population vectors reflect the aggregate
activity across the cells, providing a better
correlation with behaviour than that
obtained from the analysis of individual
neurons - For example, the population vector
calculated from neurons in the motor
cortex can predict the direction of a limb
movement
Describe brain areas involved in the internal and external loop.
Explain the concept of sensorimotor integration and the brain’s mirror neuron system.
- Same cells activate while doing something
oneself and seeing others doing it - empathy, integration into society
- Monkey see, monkey do
- Mirror neurons (MNs)
- A neuron that shows similar responses
when an animal is either performing an
action or observing that action produced
by another organism - For instance, a mirror neuron responds
when you pick up a pencil and when you
watch someone else pick up a pencil - Mirror neurons are hypothesized to
provide a strong link between perception
and action, perhaps providing an
important basis for the development of
conceptual knowledge.
- A neuron that shows similar responses
Describe the roles of the spino, vestibulo and cerebrocerebellum (neocerebellum) in motor behaviour. Describe the main areas providing the input to and receiving output from cerebellar structures. Know the location of the 3 substructures of the cerebellum.
- Spinocerebellum to the spine
- Vestibulocerebellum (eye movement and
balance) - Cerebocerebellum (motor planning)
- Location creatable in notion
Describe the symptoms and the underlying pathology of the motor disorders cerebellar ataxia and Parkinson’s disease
- Hyperkinesia
- Damage to the neocerebellum
- Parkinson’s is reduction of dopamine
production in substantia nigra - is connected to problems in initiation and
inhabitation of
motor movement
Explain the role of the basal ganglia in motor behaviour, know the brain areas of the basal ganglia and the location of the caudate nucleus, putamen, globus pallidus, thalamus and the substantia nigra.
- Basal ganglia
- A collection of five subcortical nuclei: the
caudate, putamen, globus pallidus,
subthalamic nucleus, and substantia nigra - The basal ganglia are involved in motor
control and learning - Reciprocal neuronal loops project from
cortical areas to the basal ganglia and
back to the cortex - Two prominent basal ganglia disorders
are Parkinson’s disease and Huntington’s
disease
- A collection of five subcortical nuclei: the
Explain the concept of deep brain stimulation.
- electrical stimulation of brain structures
via an implanted electrode - Stimulation of the subthalamic nucleus
- used as a treatment for Parkinson’s
disease - electrical impulses that regulate
abnormal impulses
