biological approach

What is the biological approach?

The approach investigates how biological structures and processes within the body impacts on behaviour

What are the basic assumptions in the biological approach?

• Everything psychological is at first biological

• Genes affect behaviour and influence individual psychological differences between people

• Evolutionary psychology considers genetic influences in common behaviours

• Psychologist should study the anatomy of the brain, nervous system and other biological system (e.g. hormones - endocrine system, chemicals acting on the brain - neutransmitter)

GANE

Genetics

Anatomy

Neurotransmitter

Evolution / Endocrine

What is evolution and the 2 main concepts within it?

Evolution is the changes in inherited characteristics in a biological population over successive generations

• Natural selection: animals with particular traits that provide them with an advantages are more likely to survive and reproduce thereby passing on their ‘adaptive traits’ to their offspring

• Sexual selection: choosing a mate with genetic ‘fitness’ ensures that your genes will be passed onto future generations

How is the human nervous system organised?

What is the excitation and inhibition effect?

Neurotransmitters have wither an excitatory or inhibitory effect on the neighbouring neurone

• An excitatory effect increases the likelihood of a new action potential - e.g. adrenaline causes excitation of the post-synaptic neurone by increasing its positive charge and making it more likely to fire

• An inhibitory effect decrease the likelihood of a new action potential - e.g. serotonin causes inhibition in the receiving neurone, resulting in the neurone becoming more negatively charged and less likely to fire

(Mention summation)

What is summation?

Summation decides whether a post-synaptic neurone fires - the excitatory and inhibitory influences are summed

• If the net effect on the post-synaptic neurone is inhibitory then the post-synaptic neurone is less likely to fire

• If postsynaptic neurone is excitatory, then the postsynaptic neurone is less likely to fire + momentarily, the inside of the postsynaptic neurone becomes positively charged

The action potential of the postsynaptic neurone is only triggered if the sum of the excitatory and inhibitory signals are at any one time reaches the threshold