AS Module -PSYA2
Biological Psychology
Stress
The Biological Approach
• Views psychology from the physical perspective
of the body
• Argues understanding
physiological processes
can help us see how our thinking, emotions and
behaviour are controlled.
Physiological processes = an explanation based
on the biological (parts) or neurobiological
(chemical factors) functioning of the body.
Biological Approach and Stress
• Unit will focus on:
• Biological events or processes that cause feelings and
behaviours associated with stress.
•
The negative consequences or stress.
• Biological factors that affect severity and response to
stress.
• How biological factors interact with psychological ones.
• Clip – http://live.kerboodle.com
Lesson Objectives – Period1
By the end of the lesson you will be able to:
• Define the term stress AO1
• Describe and evaluate some of the methods used
in measuring stress (Biological perspective) A02
• Identify the causes and effects of stress now
and 200,000 years ago (Evolutionary
perspective).
How would you define stress?
Is it the same for
everyone?
Define the term stress AO1
• Stress is the
biological and
psychological
responses
experienced on
encountering a threat
that we feel we do
not have the
resources to deal
with.
• (stimulus definition)
What is an example of a
threat?
Feeling too hot?
Having a lot of work to
do?
Being stuck in traffic?
Are these always
stressful?
• Its important to note
that Stress is the
response to a threat
we feel we cannot
cope with.
• In some situations,
feeling hot, having a
lot of work to do or
being stuck in traffic
may not be stressful if
we feel we are able to
cope.
• However when they
have the potential to
elicit a stress
response, they are
known as Stressors
• Stressors = Internal
or external factors
that are threatening
and have the potential
to cause a stress
response
Give an
example of an
internal and
external factor
Starter Task
• Now we have considered what stress
is…..
• I would like you to think about your
behaviour in the last few months and fill
out the questionnaire.
• We will then work out your scores.
Female
Mean Score
Male
Mean Score
Are there individual differences? Were more males more or less stressed than
females?
Evaluation of questionnaire
• Is this a valid way of measuring stress?
•
•
•
•
•
What are the flaws?
Subjective – open to interpretation
Time dependent
Requires honesty
Not actually measuring stress / stress response
• What could be an alternative methods?
Biological/physiological ways of
measuring stress
• Blood pressure (BP)
 Inflated arm band
• Breathing Tubes
around chest
• Heart rate (HR)
Stress increase heart
rate
 ECGelectrocardiogram.
• Sweating - GSR
 Hormone levels
 Blood/urine
Stress increases BP, get blood
pumping to muscles for energy
and oxygen for F/F.
Stress increases breath rate, take
in more oxygen for F/F.
Therefore heart rate increases to
pump the oxygenated blood
around the body.
Measure increased electrical
activity in the heart.
Stressed Changes in GSR – sweat
and electrical resistance of skin
Increases in adrenaline
Stress response and Evolutionary
origins
• Evolution = process by
which traits are shaped by
natural selection.
• Biological processes of stress
response would have
prepared our ancestors by:
• The stress response has
been shaped by this process.
• Immediate changes –
breathing faster, heart
beating faster, pupils dilate
(wider), increased muscle
tension and greater strength.
• Walter Cannon identified it as
the ‘fight or flight
response’, an animal that
didn’t respond in this way is
less likely to survive and
reproduce.
• These changes are caused
by the sympathetic pathway
of the autonomic nervous
system (sANS).
http://www.youtube.com/watch?v=sPS7GnromGo
Stanford uni – psychological states, damage.
Modern Challenges
• AS examinations
• Uncertainty of new
relationships
• The never-ending lack of
money
• Most modern day
stressors are social and
mental
• Is the fight or flight
response suited to
modern day living?
• Costs – uses calories,
interferes with activities of
finding food, forming
alliances and mating.
• Chronic stress –
weakens the bodies
ability to defend itself to
infection.
• But ancestrally the
benefits outweighed the
costs.
• Now = mainly costs.
• Chronic = persisting for a
long time
Task
• Complete the table –
Causes of
stress
today
Causes of
stress
200,000
years ago
Effects of
stress on
the body
GAS – Theory of stress response
1930’S Hans Selye
Experimenting on rats – observed that the rats
showed distinctive physiological changes due to
daily injections and other noxious agents (over a
few months).
Changes included development of stomach ulcers
(a stress symptom)
Selye reported the injections were harmless – thus
the process was causing stress.
Conclusion: physiological reaction was due to the
unpleasant stimulus
(stressor) and was causing
a stress response.
Changes, e.g. stomach ulcer, due to prolonged
stressor in a situation of low control – does this
occur in our society?
This is where stress is problematic and can lead to
similar and worse physiological changes
Selye’s General Adaptation Syndrome –
universal response to stressors
General: same response to all
stimulus
3 Stage response:
Stage 1: Alarm = stress response –
stressor has been detected and a
response made to alarm. Adrenaline
is produced leading to fight or flight
activity.
Stage 2: Resistance =
Apparent coping, if stress
continues it is necessary to find
some means of coping and
resist collapse. In this stage the
body is adapting to the
demands of the environment, but
at the same time resources are
being used up. Thus = apparent
coping because in reality things
are deteriorating.
Adaptation: because actually was an
adaptive response
Syndrome: because there were
several symptoms in the stress
response.
Stage 3: Exhaustion = breakdown, onset of
stress-related illness. Eventually the body can no
longer maintain normal functioning.
Initial physiological changes may appear, e.g.
sweating, increased heart rate. The adrenal
gland (produces adrenaline) may be damaged
due to over activity and the immune system
may unable to cope due to the production of
proteins being needed elsewhere = ulcers,
depression, cardiovascular problems etc.
Critique of GAS
+ Influential
on the
relationship
between stress
and illness.
+ Led to a vast
amount of
research.
+ Supports stress
does affect
body's systems
and may lead to
illness.
+/-
focus on physiological factors as research
on animals, humans have the ability
to think and therefore can elicit more
control over situations, e.g. driving test
can practice relaxation techniques to
reduce physiological activity.
-
GAS does not include cognitive
influences.
-
Does not include individual
differences
-
Recent research has shown resources
do not become depleted even under
extreme stress – current view is
exhaustion leads to increased cortisol
that leads to stress related illness rather
than deleted resources (Sheriden and
Radmacher 1992).
Plenary
•
Stress is…………..
•
A stressor is………. They can be ………. Or
………………. E.g. are
………………and……………..
•
In response to stress the physiological
changes are ………………
•
We can measure stress by………………..
• Homework: Use the information sheets to fill out the boxes relating to Selyes
General Adaptation Syndrome (1936).
Lesson Objective – P3
By the end of the lesson you will be able to:
• Research and present definitions of stress
• Discuss Cox’s transactional definition of stress
• Improving independent enquiry and team work
skills through research and presentation
In 3’s – 5 groups – upto 5 minutes.
Task – Research and present
definitions of stress
• In 3’s research and
present definitions of
stress
• 20 minutes to research
and put the presentation
together
• Presentation be upto 5
minutes – only has to be
short.
•
Must Include:
•
•
Definition of stress
Physiological changes that occur
•
Must also include:
•
Biological reasons why this
occurs (sj)
Or
Theory or explanation e.g.
Evolutionary theory,
Hans Selyes response definition,
•
•
•
•
Response definition or Stimulus
definition?
• What is an example for each?
• Do you think the stress response is either
or?
• Cox developed the transactional model of
stress…….
Cox’ s Transactional Definition of
stress
• Cox (1975) = stress involves
external stimuli,
the physiological response
to these stimuli,
and psychological
processes that mediate
between stimulus and
response.
• The psychological
processes
involve differences between
individuals in their perception
of the environmental demands
and their own capacity to cope
with them.
Therefore according to Cox,
stress is the result of the
perceived demands
outweighing the perceived
capability to cope
• This perception is influenced
by a number of factors:
• personality,
• situational demands,
• previous experiences
• any current stress state
already existing.
Critique in comparison to other
definitions