The Biological Approach (Week 17) Flashcards
What is the Biological Approach?
- Focuses on the relationship between our biological makeup and our behaviour.
- It looks to explain behaviour by reference to genetics, brain function, hormones and neurotransmitters.
- This approach is also known as biopsychology or psychobiology
Areas of interest are:
1. Mental disorders
2. Health
3. Treatments of mental disorders
4. Sleep
5. Circadian rhythms
6. Localisation of brain function
Assumptions of the Biological Approach
- Emotions, behaviour and cognition are controlled by biological systems and processes such as, evolution, genes, nervous system and hormones.
- Similarities and differences between people can be understood in terms of biological factors and their interaction with other factors.
Genes
- A gene is a herediary unit; an instruction that is passed from parent to child.
- Everyone’s genes are individual - except identical twins.
- Our genes determine our biological structure and function, including the brain and nervous system.
- Biological psychologists study how genes and the environment interact to produce our behaviour, cognitions and emotions.
Evolution
- Mutations can occur in our genes and they produce variations between individuals which can be advantageous.
- Any mutation which aids survival would be more likely to be transferred to future generations because those individuals were more likely to reproduce.
- This process of ‘natural selection’ drives evolution.
Brain and Nervous system
- Cells in the brain are called neurons.
- Brain and nervous system are specialised for communication.
- Neurons send electrical signals along their length and interact using neurotransmitters at synapses.
- Neurotransmitters like dopamine & seratonin serve specific functions such as regulating mood, appetite and sleep.
- Fight or Flight response is an automatic physiological reaction in which the sympathetic nervous system triggers an acute stress response that prepares the body to fight or run away.
- The fight of flight response can be a response of anxiety.
Hormones
- Used to communicate within the body.
- These chemicals are released into the bloodstream via glands. eg. adrenal glands produce adrenalin, Ovaries release oestrogen.
- The NS sends rapid, short-lived messages whereas the messages sent to target organs using hormones are slower and longer lasting.
Brain Structure
Lateralisation of function
- The two halves of the brain are functionally different.
- Each hemisphere has functional specialisations
eg. the left is dominant for language and the right excels at visual motor tasks.
Brain Structure
Localisation of function
Certain functions (eg. language, memory) have certain locations and areas within the brain.
Brain Structure
Brain Plasticity
Is the ability of the brain to change in response to intrinsic or extrinsic stimuli by increasing or decreasing the volume of areas of the brain.
Methods of research
- Biological approach tends to use more scientific methods.
- This approach is seen a more scientific.
- Methods like; lab experiments, medical case studies.
- Methods of data collection are more objective;
- Brain scans
- Blood, saliva and urine tests
- Family & twin studies
Neuroimaging
- We can study the brains of living people and draw conclusions between behaviour and brain activity.
- Neuroimaging/brain scanning is a process producing images of the brain or other parts of the nervous system.
- They can show the structure and functions of the brain.
- Important in psych because; study what areas are responsible for and identify brain differences in those with brain disorders or mental health conditions.
Electroencephalogram (EEG)
- EEG was invented by Berger in 1924
- Used to detect electrical activity in the brain
- Is made up of small metal discs (electrodes) which attach to the scalp.
- It measures the brain’s electrical activity, to provide accurate insight into mental proccess.
Computerised Tomography (CT/CAT)
- Can produce detailed images of many structures insides the body. eg. internal organs, blood vessels, bones.
- They use radiation
They can be used to:
**Diagnose conditions **> damage to bones, injuries to internal organs, stroke and cancer.
Be a guide for further tests/treatments > can determine the location, size and shape of a tumour.
Monitor conditions > checking size of tumours during and after cancer treatment.
Positron Emission Tomography (PET) scans
- The images clearly show the part of the body being investigated, including abnormal areas.
- Can highlight how well certain functions of the body are working.
- Can help diagnose some conditions that affect the normal functioning of the brain. eg. dementia
- PET scanners work by detecting the radiation given off by a radiotracer as it collects in different parts of your body.
fMRI scans
- Used for measuring brain activity.
- It detects the changes in blood oxygenation and flow that occur in response to neural activity (When an area of the brain is more active it consumes more oxygen).
- fMRI can be used to produce activation maps showing which parts of the brain are involved in a particular mental process.
Blood, Saliva and Urine tests
Used to provide objective measures of:
* Levels of hormones in the body (testosterone or cortisol)
* Substances that might have been consumed which have an effect on the brain (alcohol or cannabis)
* Some blood tests measure the levels of neurotransmitters (dopamine). These don’t represent the levels of neurotransmitters in the nervous system itself and so have limited use.
Family Studies
- Investigate the heritability of certain psychological traits/disorders.
- Compares the prevalence of a trait/disorder amoung family members
- Researchers can estimate the genetic and environmental contributions to a particular condition.
Twin Studies
- Focus on genetic and environmental influences on behaviour and psychological traits.
- These studies help in unravelling the contributions of nature and nurture to various psychological characteristics.
evaluation
Strengths of the biological approach
Very Scientific: uses methods like lab experiments, blood tests, brain scans. They are highly controlled + can be tested for reliability easily + can draw cause-effect relationships easily.
**Obejective: **Uses sophisticated equipment (PET & MRI scans) provide objective measurements.
Useful: Reveals areas of the brain that have specific functions. Useful for diagnosing/treating those after brain damage.
Nature-nurture: good way to access which of our behaviours are due to nature or nurture.
Evaluation
Weaknesses of the biological approach
Reductionist: it ignores roles of social & emotional factions in our development.
Low ecological validity: most studies are conducted in lab conditions and tasks lack mundane realism. Some biological reactions may be triggered by the controlled environment and not be the same in the real world.
Correlations: it’s often impossible to directly observe psychological processes. eg. instead of measuring thoughts, we measure blood flow but a change in blood flow doesn’t directly mean the same change in the train of thoughts.
