Chapter 9: Mechanisms of
Learning
Unit 4 – AOS 1
Learning
Pages 422-451
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Study Design Content
• behaviours not dependent on learning including
reflex action, fixed action patterns and behaviours
due to physical growth and development
(maturation)
• mechanisms of learning:
– areas of the brain and neural pathways involved in
learning, synapse formation, role of
neurotransmitters
– developmental plasticity and adaptive plasticity of
the brain: changes to the brain in response to
learning and experience; timing of experiences
– use of imaging technologies in identification of
localised changes in the brain due to learning
specific tasks
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Defining Learning

Learning is such an integral part of daily living
that without the ability to learn, people would
be unable to live independently and would need
constant care in order to survive.

Learning can be defined as a relatively
permanent change in behaviour that occurs as a
result of experience.
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Defining Learning

It is an ongoing process which continues
throughout the lifespan, enabling us to adapt and
cope with an ever-changing world.

Learning can occur intentionally or
unintentionally.

Learning can also occur actively or passively.
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Defining Learning

The notion of change is an important part of
the definition of learning because something
must be different about the organism after learning
has taken place.

The change in behaviour may be immediate
(ie changing your golf swing after a coach
suggests an improvement).
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Defining Learning

The change also may be delayed and actually
occur some time after learning has taken place
(ie changing your golf swing the next time you
play golf after watching an instructional video).

Consequently, learning refers to a change in
behaviour potential as well as behaviour which
is observed to take place.
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Defining Learning

Learned behaviour is
also defined as being
relatively
permanent because
it cannot simply be
present at one
moment and then
disappear the next.
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Behaviour not
Dependent on Learning

Although learning accounts for most of the
behaviour of people and animals, not all
behaviour has to be learned.

Reflexes, fixed-action patterns and
maturation also account for certain
behaviours.
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Reflex Actions

Automatic or involuntary behaviour which
does not require prior experience and is
basically the same each time is called a reflex.

We are born with a large number of reflexes,
with each one allowing us to deal with certain
stimuli that are important for our protection
and survival.
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Reflex Actions

Some reflex actions that we have include:

The suckling reflex
The gripping reflex
Blinking
The knee jerk reflex
The Babinski reflex
Peripheral vision reflex
Gagging reflex
Fainting

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Fixed Action Patterns

A fixed-action pattern of behaviour occurs when
different members of the same species produce and
identical response to the same specific
environmental stimuli.

This type of behaviour is also referred to as
species-specific behaviour.
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Fixed Action Patterns

The mechanisms that controls the behaviours
are ‘fixed’ in that they are genetically
programmed into the animals nervous system
and appear to be unable to be changed as a
result of learning.

The term ‘fixed-action’ is used to describe
behaviour that is inherited by every individual
member of a species.
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Fixed Action Patterns

Fixed-action behaviour can also be sex-specific.

Sex-specific behaviours are linked to courtship, sexual
behaviour and nesting by male and/or female members
of the species.

Fixed-action patterns differ from reflexes in that they
are more complex consisting of a sequence of
responses.
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Maturation

Other unlearned behaviour is the result of
maturation.

Maturation is a developmental process leading
towards maturity based on the orderly
sequence of changes that occur in the nervous
system and other bodily structures controlled
by genetic inheritance.

Learning Activity 9.1 – Learned versus nonlearned behaviour, pg. 426

Learning Activity 9.2 – Review questions, pg.
427
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Neural Basis of Learning

When neurons communicate with each other, they do so by
sending a neurotransmitter comprising of electrochemical
messages across a tiny space between the neurons

The gap between the axon terminal of one neuron (which
releases the neurotransmitter) and the dendrite of another
(which receives the transmitter is known as the synaptic
gap

The synapse contains three components;
◦ The synaptic gap
◦ The axon terminal of the presynaptic neuron
◦ The dendrite of the postsynaptic neuron

The synapse is the site of communication between adjacent
neurons and the act of sending neurotransmitter across the
synaptic gap can actually change the synapse
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Neural Basis of Learning
A – Presynaptic Neuron
B – Postsynaptic Neuron
2 – Neurotransmitter
4 – Synapse
Direction of
neural impulse
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Neurotransmitters

The site of chemical communication between neurons is, as we
know, the synapse

This small gap between the pre and post synaptic neurons is where
electrical energy is converted into chemical energy to allow the
impulse to continue

When a neural impulse reaches the axon terminal in the
presynaptic neuron, neurotransmitters (a chemical substance
that enables communication between neurons) are released into
the synapse from the axon terminal

Each type of neurotransmitter has a distinctly different shape and
role – there are believed to be over 100 different
neurotransmitters

Two of these are believed to involved in learning – glutamate and
dopamine
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Neural Basis of Learning

Dendrites can grow longer and ‘sprout’ new
branches while others can be ‘pruned’ away
if not used – everyday we form and lose
millions of synaptic connections

The ability of the brain to change is
commonly referred to as plasticity, a
property that makes learning and memory
possible and assists us to adapt to life’s every
changing circumstances
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Areas of the Brain and Neural
Pathways involved in Learning

Like memory, many areas of the brain are
involved in learning although some areas
seem to be more actively involved in certain
types of learning

Learning can involve the formation and
strengthening of neural connections at the
synapse – for example learning to play the
piano will form new neural connections
while regularly playing the piano will
strengthen those connections
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Areas of the Brain and Neural
Pathways involved in Learning

According to Hebb (1949), when a
neurotransmitter is repeatedly sent across the
synaptic gap, the presynaptic and postsynaptic
neurons are repeatedly activated at the same
time

This has the effect of changing the chemistry at a
synapse, leading to a strengthening of the
connections between neurons at a synapse

When the connection is strengthened, this makes
the neurons more likely to fire together – when
the connection is disused, it weakens and the
neurons become less likely to fire together
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Areas of the Brain and Neural
Pathways involved in Learning

The synaptic changes that take place within a neuron during
learning are believed to have long-term potentiation

Long-term potentiation refers to the long-lasting
strengthening of the synaptic connections of neurons,
resulting in the enhanced or more effective functioning of the
neurons whenever they are activated

The effect of LTP is to improve the ability of two neurons to
communicate together

Evidence of LTP – Morris and others (1982), Tsien (2000)
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Learning Activity 9.4 – Review questions, pg. 433
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Plasticity and Effects of Experience
on the Brain

Plasticity refers to the ability of the brain’s neural structure
or function to be changed by experience throughout a
lifespan (plasticity meaning flexible or pliable)

Some areas of the brain such as the sensory and motor
cortices are more plastic than others but it is unclear
whether all brain structures have this plasticity

The brain of a developing individual has a much higher level
of plasticity than that of an adult – this is one reason why
children can learn much more quickly than an adult, a new
language for example

Effect of the environment on learning - Research by
Roseweiz and others (1960s)
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Developmental Plasticity and
Adaptive Plasticity

Some psychologists distinguish between
various types of plasticity

Developmental plasticity – occurs as
the brain develops according to its
genetics

Adaptive plasticity – most apparent in
recovery from brain trauma or injury
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Developmental Plasticity

Refers to changes in the brain’s neural structure in
response to experience during its growth and
development

This type of plasticity is predetermined by our genes
but can also be influenced by our environment

After birth a significant developmental change occurs
where the infant brain forms far more synaptic
connections than it will ever use in a process known
as synaptogenesis (the forming of new synapses)

Synaptogenesis during an early age is believed to
allow an infant to respond to the constant stream of
new environmental input
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Developmental Plasticity

Following the development of
all these new neural
connections, the brain
undertakes a process of
eliminating these synaptic
connections in a process
known as synaptic pruning

Synaptic pruning occurs in
different rates in different
areas of the brain but the
number of synapses in an
adult brain is 40% less than
that of a three-year old brain
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Developmental Plasticity

The timing of experiences is also important in the
plasticity of the brain

These periods are called sensitive periods

A sensitive period is a specific period of time in
development where an organism is more responsive
to certain environmental stimuli or experiences

An example is in cats, monkeys and humans; if after
birth one eye is kept closed or does not function
properly due to an abnormality, that eye will be
forever blind – this change responsible for the loss of
vision occurs in the visual cortex
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Adaptive Plasticity

Adaptive plasticity refers to changes occurring in
the brain’s neural structure to enable adjustment to
experience, to compensate for lost function and/or to
maximise remaining functions in the event of brain
damage

Generally adaptive plasticity allows the brain to
compensate for damage by reorganising its structure

At a neuronal level, two processes for recovery are
rerouting and sprouting
◦ Rerouting involves an undamaged neuron which has lost an
active connection with a neuron may seek a new
connection with an active neuron
◦ Sprouting is the growth of new bushier nerve fibres with
more branches to make new connections
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Adaptive Plasticity

Through adaptive plasticity, functions that are assigned to particular
areas of the brain can sometimes be reassigned to other
undamaged parts of the brain to compensate for changing input
from the external environment

Areas of the somatosensory cortex for example, can be reassigned
to receive input from other areas of the body in the event of
damage or in response to the environment

The brain does not only demonstrate adaptive plasticity in
response to damage – it also can be due to the environment

Neuroimaging studies show that in violinists, the area of the
somatosensory cortex that represents the fingers of the left hand
(requiring fine finger control) is larger than the area the represents
the right hand (using the bow)
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Imagery in Learning

Using neuroimagery techniques, it is possible to
demonstrate the plasticity of the brain and brain
areas

When MRI scans of London cab drivers (who find
new routes daily) are compared with London bus
drivers (who follow a fixed route), they show that
the rear part of the hippocampus of taxi drivers,
which is involved in spatial awareness and
memory, is significantly larger.

Learning Activity 9.1 – Review questions, pg.
445
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