plasticity and functional recovery

Question 1

Josie is twelve. Last year she was involved in a serious road accident and suffered head
injuries that caused problems with speech and understanding language. Now, a year later,
Josie has recovered most of her language abilities.

Using your knowledge of plasticity and functional recovery of the brain after trauma,
explain Josie’s recovery.

Answer 1

• When the brain is still maturing recovery from trauma is more likely. Josie is young.

• Transfer of functions to undamaged areas (‘neural reorganisation’) which can
explain her recovery.

• Growth of new neurons and/or connections to compensate for damaged areas
(‘neural regeneration’) which can explain her recovery.

• Plasticity allows the brain to cope better with ‘indirect’ effects of brain damage eg
swelling, haemorrhage following road accident.

Question 2

Lotta worries that because of her grandmother’s age she will not be able to make
any recovery.
Using your knowledge of plasticity and functional recovery of the brain after trauma,
explain why Lotta might be wrong.
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Answer 2

Lotta’s grandmother might still be capable of functional
reorganisation/plasticity

• functional compensation by other undamaged areas
• although she is older her brain might still be able to form new connections
(axons and dendrites) between neurons
• neuronal loss may be compensated for by regeneration (axon sprouting)
• denervation supersensitivity to reduce the severity/extent of Lotta’s
grandmother’s impairment
• plasticity allows the brain to cope better with ‘indirect’ effects of brain damage
resulting from inadequate blood supply following a stroke
• references to increased brain stimulation of the opposite hemisphere,
physiotherapy, etc to enhance Lotta’s grandmother’s recovery
• reference to relevant studies on plasticity, eg suggesting women recover
quicker than men would be an effective way to illustrate key points, if directly
linked to Lotta’s grandmother’s recovery.

Question 3

Outline one difference between the EEG and ERPs

Answer 3

EEG is a recording of general brain
activity usually linked to states such as sleep and arousal, whilst ERPs are elicited
by specific stimuli presented to the participant.

Question 4

Outline and evaluate one or more ways of studying the brain.

Answer 4

• fMRI – uses magnetic field and radio waves to monitor blood flow; it measures the
change in the energy released by haemoglobin, reflecting activity of the brain
(oxygen consumption) to give a moving picture of the brain; activity in regions of
interest can be compared during a base line task and during a specific activity

• EEGs – electrodes are put on the scalp and detect neuronal activity directly below
where they are placed; differing numbers of electrodes can be used depending on
focus of the research

• ERPs – electrodes are put on the scalp and detect neuronal activity (directly below
where they are placed) in response to a stimulus introduced by the researcher

• post-mortem examinations – the brain is examined after death to try and correlate
structural abnormalities/damage to behaviour.

Question 5

Briefly outline how excitation and inhibition are involved in synaptic transmission

Answer 5

• Neurotransmitters can be excitatory or inhibitory (most can be both but GABA is
purely inhibitory).
• If the neurotransmitter is excitatory then the post synaptic neuron is more likely to fire an impulse

• If the neurotransmitter is inhibitory then the post synaptic neuron is less likely to fire
an impulse.
• The excitatory and inhibitory influences are summed, if the net effect on the post
synaptic neuron is inhibitory, the neuron will be less likely to ‘fire’ and if the net effect
is excitatory, the neuron will be more likely to fire.

Question 6

Jeremy is digging in the garden. He feels the spade hit a rock and stops digging
immediately.
Explain how sensory, relay and motor neurons would function in this situation.

Answer 6

• Sensory neurons send information from the senses to the brain – here receptors in
Jeremy’s hand would sense the jolt of the spade hitting the rock and send that
information via the peripheral nervous system to his brain/CNS.

• Relay neurons connect with other neurons, mostly found in the brain/CNS - here
they would be involved in analysis of the sensation, what it means, deciding about
how to respond to it, thus acting between the sensory and motor neurons.

• Motor neurons send messages via long axons from the brain to the muscles or
effectors – here the message from the brain instructs Jeremy’s arm muscles to stop
working and stop the digging action.