biological approach + biopsychology?

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?

Describe the functions of the peripheral NS

The peripheral NS transmits messages to and from the CNS

1. The autonomic NS transmits information to and from internal bodily organs

   • The sympathetic NS works with the endocrine system to bring about physiological arousal in the flight to fight response

   • The parasympathetic NS works with the endocrine system to return the body back to its resting state in the rest and digest response

2. The somatic NS transmits information from sense organs to the CNS, then to effectors

What is the excitation and inhibition effect?

Neurotransmitters have either 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

• The excitatory and inhibitory signals are summed across all the dendrites of the postsynaptic neuron

• If the postsynaptic neuron receives more excitatory signals than inhibitory signals, it will be more likely to create an action potential

• If more inhibitory signals are received than excitatory signals, it will be less likely to create an action potential

What are genes?

They are the basic units of heredity

• function in pairs and recombination of genes from parents offsprings provide the basis for genetic variability

What are genotype and phenotype?

Genotype: genes - only determine the potential for characteristics

Phenotype: the observable characteristics of an individual - depends on the interaction between genetic and environmental factors

What is the structure of a neurone and its function?

When an electrical signal called an action potential reaches the axon terminal (terminal buttons),it triggers the release of neurotransmitters into the synaptic cleft

• these neurotransmitters then bind to receptors on the postsynaptic neuron

1. The cell body includes a nucleus

2. Dendrites protrude from the cell body - carry nerve impulses from neighbouring neurons towar the cell body

3. Axon carries the impulses away from the cell body, down the length of the neuron

• Axon covered in a layer of myelin sheath - protects the axon and speeds up electrical transmission of impulse

• Axon has gaps called Node of Ranvier - speeds up transmission by forcing impulse to ‘jump’ across the gap

4. Axon terminal communicate with the next neuron (dendrite of the posts synaptic neuron) across the synapse

What is the synaptic connection? What is its structure?

Neurons don’t physically touch each other - there is a gap between them known as the synaptic cleft

At this location, known as the synapse, the electrical signal must be converted into a chemical signal to continue its journey to the next neurone

Explain the process of synaptic transmission

1. Electrical impulses (action potentials) reach the presynaptic terminal

2. Electrical impulses (active potentials) trigger release of neurotransmitters from synaptic vesicles

3. Neurotransmitters diffuse across the synaptic cleft

4. Neurotransmitters bind to receptors on the postsynaptic membrane

What are the 3 types of neurones?

Sensory neurons: carry signals from receptors to the spinal cord and brain

Relay neurons: carry messages from one part of the CNS to another

Motor neurons: carry signals from the CNS to effectors

What is the reflex arc?

Stimulus > receptor > sensory neuron > relay neuron > motor neuron > effector > response

In a reflex arc, like the knee-jerk reflex, a stimulus, suck as a hammer hitting the knee, is detected by sense organs in the peripheral nervous system, which conveys a message along a sensory neuron.

This message reaches the central nervous system where it connects with a relay neuron.

This then transfers the message to a motor neuron.

This then carries the message to an effector such as a muscle, which causes the muscle to contract and hence the knee to move

What is the difference between parasympathetic and sympathetic nervous system?

Parasympathetic: rest and digest - normal

Sympathetic: flight or fight

(No need to know kidney in sympathetic, but add adrenal glands- releases adrenaline)

What is the endocrine system?

The endocrine system consists of glands - produce hormones which are released in the blood stream to the target organs which contain receptors for specific hormones

• The pituitary gland consists the release of hormones from all the other endocrine glands

• Hormones work more slowly than nerve impulses but often together with the nervous system

How do the endocrine system and the nervous system work together?

They work together to produce the acute stress response

Hypothalamus > sends a signal to the Adrenal Medulla > which produces Adrenaline > causing a flight or fight response > then the parasympathetic nervous system brings the body back to an optimum state by slowing down the heart rate and bringing blood pressure back to an optimum level

What are the different glands and hormones? What are their functions?

Pituitary gland (master gland)

• Gonadotropin: development of ovaries and testes

• Growth hormone: growth of bones and muscles

• Anti-diuretic hormone: increase re absorption of water in kidneys

Pineal gland

• Melatonin: involved in sleep

Thyroid gland

• Thyroxine: rate of metabolism

Thymus

• Thymosin: promotes production and maturation of white blood cells

Adrenal gland

• Adrenaline: flight or fight

Pancreas

• Insulin: converts glucose to glycogen

• Glucagon: converts glycogen to glucose

Ovary

• Oestrogen: controls ovulation and sexual characteristics

• Progesterone: prepares the uterus lining for embryo

Testis

• Testosterone: controls sperm production and sexual characteristics

What are twin studies?

Determines the likelihood that certain traits have a genetic basis by comparing the concordance rate between pairs of twins

• Concordance rate: the extent to which a pair of twins share similar traits or characteristics

Comparisons can be made between twins raised together and twins raised apart

What are the 2 different types of twins?

• Monozygotic twins are identical - share 100% of each others’ genes = should have a 100% concordance rate

• Dizygotic twins are not identical - share about 50% of each others’ genes = should have a lower concordance rate

What is cognitive neuroscience?

• Scientific study of neurological structures, mechanisms, processes and chemistry that are responsible for cognitive processes

• Use of scanning methods

• The study of neurotypical individuals to locate the physical basis of cognitive processes in the brain

• E.g. Lisofsky et al. (2014) - identified areas of the brain that are active when we tell lies