Chapter 10: Principles of Neocortical Function Flashcards
What is Brain Plasticity
- the brains considerable capacity for change in response to experience, drugs, hormones or injury
Levels of function
- subcortical structures can mediate complex behaviours
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Who is patient A.R
- 11 year old boy who developed seizures on only the right side of his body, and eventually turned so bad he could not talk and was so weak due to damage to CNS
- had rasmussen encephalitis a chronic brain infection that leads to loss of function in one brain hemisphere
- he received a hemispherectomy , showed remarkable improvement though was illiterate
Why do animals begin by grooming the head and then work their way down?
- many levels of nervous system participate in producing the elements of the organization of grooming behaviours
- hierarchical organization holds virtually every behaviour in which we engage
What behaviours is the spinal cord involved in?
- reflexes
- responds to appropriate sensory stimulation by stretching, withdrawal, support, scratching, paw shaking
- the spinal cord is the lowest CNS level
What behaviours is the Low Decerebrate (hindbrain) involved in?
- Postural support
- performs units of movement when stimulated (licking, hissing, chewing)
- elements of sleep walking behaviour
- postural reflexes
- exaggerated standing
What behaviours is the high decerebrate (midbrain) involved in?
- spontaneous movement
- simple visual and auditory stimulation
- performs automatic behaviours such as grooming
- when stimulated performs subsets of voluntary movements like standing, walking, jumping
What behaviours if the diencephalic (hypothalamus and thalamus) involved in
- affect and motivation
- voluntary movements occur spontaneously and excessively but are aimless
- well-integrated but poorly directed behaviours
What behaviours is the Decorticate (basal ganglia) involved in
- self - maintenance
- links voluntary movements and automatic movements sufficiently well for self-maintenance in a simple environment
- eating and drinking
What behaviours is the typical (cortex) involved in
- control and intention
- performs sequences of voluntary movements in organized patterns
- responds to patterns of sensory stimulation
- cognitive maps for responding to the relationships between objects , events and things
- adds emotional value
What happens with injury to the spinal cord or spinal cord transection
- paraplegia and quadriplegia
- inability to move voluntarily because the brain cannot communicate with spinal neurons
- limb approach to tactile stimuli and limb withdrawal is another reflex of the spinal cord
- stepping responses and walking are an automatic reflex of spinal cord provided that body weight is supported
What happens the the hindbrain and the spinal cord remain connected after an injury but both are disconnected from the rest of the brain
- low decerebrate injury
- difficulty maintaining consciousness becuase many essential inputs to the brain regions above the injury are disconnected leaving forebrain in the dark
- body stiffness and narcolepsy (loss of all body tone)
- persistent vegetative state (PVS)
- they can swallow, smile, cough
What happens with a high decerebration
- diencephalon from midbrain or pons, extensor
- visual and auditory stimuli in tact but difficulty coordinating movements
- automatic movements in tact
- voluntary movements are difficult
- similar to new born ?
what are the symptoms of a diencephalic animal
- olfactory system intact, hypothalamus and thalamus intact
What is sham rage
- diencephalic cats showed sham rage
- for sham rage to occur, a least the posterior part of the hypothalamus must be in tact
- people with hypothalamic lesions have similar rage reactions
- hyperactivity
- does not have forebrain control?
