Download 8.7 Learning and Memory

8.6 Learning and Memory
Topic 8 Specification
• 14 Describe how animals, including humans,
can learn by habituation.
• 16 Discuss the moral and ethical issues
relating to the use of animals in medical
research from two ethical standpoints.
Where are memories stored?
– Read page 244
– Q 8.51• parietal lobe , temporal lobe,
hippocampus
– Q 8.52• involved in forming new long-term
memory but NOT involved in recalling
long-term memory
How are memories stored?
– Read page 244-247
– How are memories created?
• Pattern of connections - which other neurons is
each neuron is connected to.
• Strength of the synapse
Events at the Synapse
Habituation – get used to it!
• Wearing socks
• Birdsong
• Noisy computer
• the diminishing of an innate response to a
frequently repeated stimulus
•
https://www.youtube.com/watch?v=dlilZh60qdA
Habituation
A type of learning, if you are exposed repeatedly to
the same stimulus after a while you are neither aware
of it nor respond to it.
What is the advantage of habituation?
• Animals can ignore unimportant stimuli so that
limited sensory, attention and memory resources
can be concentrated on more threatening or
rewarding stimuli.
Habituation in Sea Slugs
– Why was the sea slug used to study the change in
synapse strength?
• No fundamental difference between nerve cells and
synapses in humans and slugs
• Only 20,000 neurons in the sea slug so simpler to
study than the human.
• Large accessible neurones
– Q 8.53
Habituation in sea slugs
– https://www.youtube.com/watch?v=yLa-cXg8BwM
– Identify the stages in the reflex arc when
water is sprayed at the syphon and then the
gill is withdrawn
Habituation
– Describe in your own words how habituation is
achieved.
• Ca2+ ion channels become less responsive so
they don’t open and less or no Ca ions diffuse
into the neuron.
• Less neurotransmitter is released
• Less depolarisation in the post-synaptic
neurone
• May not reach the threshold so no action
potential is triggered in the motor neurone
– Activity 8.17
Activity 8.17
Compare habituation and
sensitisation in terms of• The effect on sensitivity to stimuli.
• What happens at the synapse.
Compare habituation and
sensitisation in terms of• After repeated stimuli habituation decreases the
awareness and response to that stimulus.
Sensitisation will result in an increase in awareness
to all stimuli.
• Two neurons are involved in habituation- the Ca2+
channels in the pre-synaptic neuron become less
responsive- less Ca uptake.
• In sensitisation three neurones are involvedSerotonin released by neurones from the receptor of
the first stimulus increase the uptake of Ca in the
pre-synaptic neuron of other sensory neurons.
Habituation vs Long term memory
– Memories are created either by changing
the pattern of connection or by changing
the strength of the synapses. Which is
habituation an example of?
• Changing the strength of the synapse
– How are long term memories created?
• Increase in the number of synaptic
connections
Activity 8.16 Can snails become
habituated to a stimulus?
• https://www.youtube.com/watch?v=MslbUpxC1-A
• Use this movie to collect and present data as
stated in steps 1-6
• Questions 1-6
• Going Further: Introduce Statistical test and
null hypothesis- Statistics and the Unit 6 exam
slide show, with Unit 3 and 6 booklet
The ethics of animal research
• Who would not accept any experimentation
on animals?
• Do you believe some experimentation on
animals is acceptable? Why? Any research?
Any animal?
• What is a utilitarian approach to the use of
animals?
• https://www.beep.ac.uk/content/425.0.html
Ethics of using animals in medical
research
Reasons for using animals in medical
research
Reasons against using animals in
medical research
Animals which are tested on are
provided with good food, water,
veterinary treatment (better than in
the wild) and the ability to express
normal behaviour
The welfare of animals is threatenedthey may experience pain, or may not
be able to express normal behaviour
Although animals are used and may die
in animal testing this is by far
outweighed by the good that comes
form the testing- cures, treatment of
disease reducing the suffering of many
people- utilitarian argument
They have a right to freedomnot being incarcerated for animal
testing
Animals are not able to give
consent- they have a right to do
this