Biological approach 2

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Biological approach 2

• The structure and function of the brain

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The central nervous system

• The spinal cord connects to the brain through the
  brain stem.
• Neurological functions located in the brainstem
  include those necessary for
• survival - breathing, digestion, heart rate,
  blood pressure
• arousal - being awake and alert

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Cerebral hemispheres

• Left brain

• Right brain

• Sequential Analysis
• Interpretation and production of symbolic
  information language, mathematics, abstraction
  and reasoning.
• Memory stored in a language format.
• L for logic
• L for language

• Holistic Functioning
• Visual spatial skills.
• Holistic functions such as dancing and gymnastics
  are coordinated by the right hemisphere.
• Memory is stored in auditory, visual and spatial
  modalities.

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lobes
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lobes
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Biological approach 3

• The endocrine system

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The endocrine system

• The endocrine system is composed of many glands
  which secrete hormones into the blood stream
• A hormone is a chemical that travels around the
  body and affects the action of the target organs
• Hormones influence our thinking, behaviour and
  emotions, and influence our response to stress.

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Major endocrine glands
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Pituitary gland

• Growth hormone
• Thyroid stimulating hormone
• Gonadotropic hormones
• Regulates the growth of genitals
• Prolactin
• Stimulates milk production
• Antidiuretic hormones
• Regulates absorption/loss of water
• Oxytocin
• Regulates labour

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Pineal gland

• Melatonin
• Influence on sleep and mood
• Link to cancer

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Adrenal glands

• Steroids
• Gonacorticoids
• Epinephrine and norepinephrine response to
  danger

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Gonads

• Testes androgens (testosterone)
• Ovaries oestrogen and progesterone

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Biological approach 4

• Selyes General Adaptation Syndrome

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What is stress?

• Our bodies experience stress when we perceive a
  situation to be threatening and we do not have
  the resources to cope with the threat.
• These threats are called stressors

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Adaptive function

• When we are in a threatening environment, we have
  ways of coping
• These coping methods have evolved to help us to
  survive
• This is called adaptive

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Selyes research

• How rats respond to unpleasant behaviour heat,
  fatigue
• They reacted the same regardless of the stressor
  the response reflected the bodys attempt to
  cope with the stressor
• Physiological responses increase pulse, blood
  pressure, breathing, dilated pupils and
  convergence of blood around vital organs ready
  for flight or fight

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General Adaptation Syndrome

• When faced with stressors, we follow a sequence
• Alarm reaction
• Immediate reaction to deal with the threat 
• Resistance stage
• The attempt to return to a steady physiological
  state despite the constant threat
• Exhaustion
• The failure of the body to return to a steady
  state causes depletion of bodys resources and
  eventual collapse / death

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The alarm reaction

• The immediate changes that occur in the alarm
  reaction are caused by the nervous system.
• The sympathetic system tends to stimulate a
  particular function while the parasympathetic
  tends to calm.
• The sympathetic system is responsible for
  activating the body when arousal is high
• The parasympathetic system is active during
  relaxation e.g. when we have eaten a big
  meal or when we are asleep.

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The autonomic nervous system

• If the body is stressed, the sympathetic nervous
  system dominates.
• This causes
• increase in
• heart rate,
• breathing,
• blood pressure
• blood sugar levels.

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Why?

• This prepares the body for quick and strenuous
  action.
• When the emergency situation has passed,the
  parasympathetic system takes over
• decreases the heart and breathing rates
• diverts blood supply back to activities such as
  digestion and food absorption.
• Activation of the parasympathetic system tends to
  occur independently.

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The endocrine system

• The sympathetic nervous system (SNS) stimulates
  the adrenal gland to release adrenalin.
•  
• This produces similar effects to the SNS
  accelerated breathing, heartbeat, etc.
•  
• Effects of this hormone are longer lasting, the
  defence mechanisms can be maintained for longer.

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Acute stress - SAM

• The link between the SNS and the adrenal glands
  is referred to as the sympathetic adrenal
  medullary system (SAM) it is this system that
  is responsible for the bodys reaction to short
  term (acute) stressors

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The resistance stage

• If the danger persists, the bodily state of alert
  cannot be maintained by adrenaline.
• Other hormones are released to sustain the bodys
  defence mechanism levels of these hormones can
  remain high for months or even years.

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Resistance stage - hormones

• Cortisol
• From the adrenal gland makes energy available
  by breaking down fats and releasing glucose from
  the liver
• Aldosterone
• From the adrenal gland maintains raised blood
  pressure
• Thyroxine
• From the thyroid gland increases metabolic rate
  to maintain high heart rate and breathing rate
  and allows energy to be released from food
  quickly and efficiently

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Process of hormone release

• The release of the glucocorticoids, such as
  cortisol, from the adrenal gland is in response
  to the presence of adrenocorticotropic hormone
  (ACTH) in the blood.
• The ACTH is released from the pituitary gland
  because the hypothalamus has released a small
  protein called a corticotrophin releasing factor
  (CRF).
• This link between the hypothalamus, the pituitary
  gland and the adrenal cortex is called the
  hypothalamic pituitary-adrenocortical axis (HPA).
  

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Chronic stress - HPA

• The HPA is responsible for the bodys response to
  long term (chronic) stress
• the effects of this persistently elevated hormone
  levels are themselves damaging and ultimately
  lead to illness and the exhaustion stage.

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Exhaustion stage

• Selye observed that if the threat persisted, the
  animals became sick and died.
• This exhaustion stage reflects the bodys
  inability to cope with chronic stress.

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Effects on immune system

• The immune system becomes less effective
• High levels of cortisol impairs our immunity
• Effects can be seen in an increase in allergic
  reactions such as eczema and asthma, changes in
  our lymphocytes and an increased risk of heart
  disease and cancer.

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Biological approach 6

• Psychosurgery

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psychosurgery

• The use of surgery on the brain to treat
  psychological disorders
• It relies on the identification of the areas of
  the brain and their functions
• The objective of the surgery is to relieve
  distress and anxiety, particularly to patients
  who do not respond to other treatments.

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History of psychosurgery

• Egas Moniz had learned that John Fulton had
  experimented on chimpanzees and damaged their
  prefrontal cortex
• This had remarkable impact on their distress
  levels they were calmer

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History of psychosurgery

• Moniz went on to treat humans in the same way
  with some success
• Walter Freeman developed the technique in 1936
  and it was used to treat patients

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leucotomy

• A narrow device called a leucotome is inserted
  through holes in the skull into the frontal lobe
• The blade (a wire loop) is then extended and
  rotated to lesion the tissue
• The procedure is repeated several times to
  destroy an area of the prefrontal cortex

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Transorbital lobotomy

• A special knife called an ice pick is inserted
  under the eye lid and into the back of the eye
  socket
• This breaks through the skull and enters the
  brain
• It is then moved around to destroy connections
  between the prefrontal area and the rest of the
  brain
• This is repeated on both hemispheres

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Who receives this treatment?

• Patients who are violent, emotional and unstable
• Patients who do not respond to other treatment

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How effective was it?

• It did relieve distress and anxiety calmed the
  patient down
• The treatment became common 10,000 performed in
  UK by 1961

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What about now?

• This treatment is rare because of side effects
• changes in personality,
• lethargy,
• apathy,
• irresponsible,
• socially withdrawn
• Intellectual ability may not have been affected
  but emotionally the patients were flat and
  could not make plans or judgements about their
  behaviour

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Evaluation of this therapy

• Very limited evidence of success on which to
  develop this treatment
• The growth in the therapy as a treatment has many
  factors to consider
• It can be performed outside hospital
• Quick and effective
• Made difficult patients manageable for the staff
  to deal with
• Unethical

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Pippard (1955)

• Success for 62 of leucotomised patients treated
  for depression
• Success for 50 of patients with mood disorders
• In 95 of these successes Pippard reported no
  personality side effects

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Bilateral Cingulotomy

• The cingulated gyri which connects the limbic
  system to the frontal lobe are destroyed
• There is one cingulated gyrus on each side of the
  brain
• This operation uses very accurate MRI techniques
  to identify the exact area to be lesioned
• It is destroyed with a fine electrode
• Alternatively a gamma knife can be used, whereby
  small amounts of radiation are focused on the
  area to be destroyed
• This means that the skull does not have to be
  breached

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Evaluation - Cohen et al (1999)

• Compared 12 patients before and after treatment
  treated for chronic pain
• Compared pain in these patients and 20 control
  patients
• Over 60 of cingulotomy patients reported less
  pain after the treatment and needed less pain
  relief medication
• Some side effects were found lacked ability to
  respond spontaneously (such as speech) showed
  deficits in attention

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Evaluation - Baer et al (1995)

• Studied 144 patients treated for OCD with
  psychosurgery
• Treatment was effective in 32 of cases
• Some patients reported side effects including
  seizures

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Evaluation - Mashour et al (2005)

• Psychosurgery has been useful in the development
  of brain stimulation techniques
• This is being developed as treatment in
  combination with other methods

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Application of the assumptions to the therapy

• Assumption we have four lobes that have
  separate functions and control certain types of
  behaviour
• The frontal lobe is responsible for planning,
  organizing, problem solving, selective attention,
  personality and a variety of "higher cognitive
  functions" including behaviour and emotions.
• If we cut the frontal lobe, this behaviour should
  be affected
• Mental ill-health is shown in mood disorders that
  involve the behaviour of the frontal lobe
  (emotion, planning, organisation, personality)
• Psychosurgery treats these behaviour disorders by
  surgically damaging the frontal lobe
• Therefore, this treatment supports the assumption
  that the frontal lobe controls these behaviours

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Evaluation of the biological approach

• Remember to explain WHY each point is a strength
  or weakness

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Evaluation of the biological approach

• STRENGTHS
• It is very scientific and reliable
• Practical applications have been extremely
  effective
•  
• Structure of the brain, behaviour of neurones and
  hormones can be measured objectively
•  
• It means we can treat mental disorders using
  surgery and/or drugs
•  
• Helps us to understand the functions of the brain
  helps brain damaged patients

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Evaluation of the biological approach

• WEAKNESSES
• Reductionist
• Does not explain how mind and body interact -
  consciousness and emotion are difficult to study
  objectively.
•   
• Deterministic does not take free will into
  account
•  
• Does not consider emotion and consciousness
•  
• Does not consider interaction with and influences
  of the environment
•