Biological level of analysis
Physiology and behaviour
© Hodder & Stoughton 2013
Activity
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Alf is an experienced taxi driver whose job
involves ferrying passengers around
London every day in his cab.
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Alf never gets lost and he knows the
location of all 25,000 streets and every
possible route within 6 miles of the centre
of London.
•
Before becoming a taxi driver he spent
over 3 years ‘doing the knowledge’, which
involves learning all possible destinations
and routes off by heart.
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He had to pass a strict examination of ‘the
knowledge’ before he was granted his taxi
driver’s licence.
1. Alf evidently has an incredible
memory of London’s streets and
routes, but is this because he has
a different type of brain than
most people?
2. Maybe learning all the
destinations and routes changed
the physical structure of his brain
in some way, but consider how
could we test if this was so?
© Hodder & Stoughton 2013
Neural plasticity
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Neural plasticity is the ability of the nervous
system, especially the brain, to alter the
number of neurons and/or connections
between them in response to environmental
influences.
The development of sophisticated scanning
techniques has allowed researchers to see
evidence of neurogenesis, where new
neurons grow in certain brain areas.
This has especially been seen in regions of
the hippocampus, a brain area associated
with memory, which suggests that memories
are encoded in brain structure through the
production of new neurons.
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Woollett & Maguire (2011) compared 79
trainee male taxi drivers with 31 male
controls.
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Participants did not differ in terms of
memory ability or IQ.
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Participants had MRI brain scans (as did the
controls) before training began and 3-4 years
later after their taxi driver’s qualification test.
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The MRI scans showed that the number of
hippocampal neurons had increased in those
passing their test, but not in the controls or
those who failed.
How can we relate the concept of neural plasticity and the findings of Woollett &
Maguire’s study to Alf’s incredible memory ability?
© Hodder & Stoughton 2013
Command words:
The language of the learning outcomes
Learning outcome: Discuss two effects of the environment on
physiological processes
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Exam questions will require candidates to describe and evaluate how external environmental
experiences influence internal biological functioning.
•
This could be achieved by outlining the physiological effects of environmental influence, such
as neural plasticity where the structure of the nervous system changes in response to
environmental experience.
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Evaluation could centre on the degree of research support, practical applications and relevant
methodological considerations.
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Additional evaluation could come from an appraisal of related theoretical considerations,
such as the ethics of research methods that involve brain scanning, as well as issues like the
nature versus nurture debate, which centres on the degree to which behaviour is a result of
innate biological factors, learned environmental experiences or, as is more relevant here, an
interaction of the two.
© Hodder & Stoughton 2013
Functions of two hormones
Oxytocin
Testosterone
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A hormone manufactured in the
hypothalamus and released from the
pituitary gland, which is involved in
reproductive and maternal behaviour.
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A hormone released from the testes of
males, but also found in females, which is
important in determining male sexual
characteristics and behaviour.
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Oxytocin influences milk production in new
mothers, stimulates uterine contractions
during birth and influences sexual behaviour,
including orgasms, in males and females.
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Testosterone released in early embryonic
development is associated with
masculinization of the brain.
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Testosterone levels are related to aggression
in animals, but its influence is less clear on
human aggression.
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Recently testosterone has been linked with
autism, due to its effects on the developing
brain in infancy.
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Oxytocin is important in mother-child
bonding and adult pair-bonding, which
suggests it has an ‘affiliation’ purpose.
Females have higher levels, which may why
they generally tend to be more sociable and
nurturing in nature.
© Hodder & Stoughton 2013
Command words:
The language of the learning outcomes
Learning outcome: Using one or more examples, explain
functions of two hormones in human behaviour
• Exam questions will require candidates to use relevant examples to give a
detailed account of the purposes hormones fulfil in human functioning.
Differentiation between candidates will occur through the amount of
accurate detail supplied.
• Evaluation could generally centre on what research studies inform about
the functions of selected hormones, as well as practical applications and
relevant ethical and methodological considerations, such as a
consideration of the degree to which the findings of testosterone research
performed on animals is generalizable to humans.
© Hodder & Stoughton 2013
Nature vs Nurture
The nature versus nurture debate concerns the
extent to which behaviour, such as aggression,
results from nature via innate biological forces, or
nurture via environmental influences. An
alternative point of view sees behaviour as an
interaction of biological and environmental factors.
Consider the case of Brad described below.
1.
What possible reasons can you think of
for Brad’s aggressive behaviour?
2.
How can his high levels of aggression be
related to the nature versus nurture
debate?
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Brad comes from a deprived area, where crime and unemployment are high and life is tough.
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Brad has a reputation for aggression. He was expelled from two schools for acts of violence, has
been arrested by the police on several occasions for fighting and has only recently been released
from a prison sentence for beating someone up following an argument over a car-parking space.
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Last week Brad was sacked from his job for punching his boss after being told off for being late for
work.
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Brad has several brothers and sisters who have a reputation for aggression and both his father and
grandfather have been sent to prison for acts of violence.
© Hodder & Stoughton 2013