BASICS OF BIOLOGICAL PSYCHOLOGY Flashcards
Name 3 key assumptions of biological psychology
All that is psychological is first biological
All thoughts feelings and behaviours have a biological base
Genes have evolved over millions of years
Much of human behaviour has a genetic base
Bodily levels of chemical agents influence behaviour
Behaviour is influenced when biological bodily structures are damaged
What types of study are typically used in biological psychology?
Laboratory experiments
Case studies
Twin and Adoption studies
Define Central nervous system (CNS)
The brain and spinal cord
Define synapse
the junction between neurons
Define receptor
A site of a dendrite that is designed to bond to a specific type of neurotransmitter molecule
Define neurotransmitter
a chemical which allows neurons to communicate with one another
Define action potential
the electric triggers that pass along the axon and stimulate the neuron to release neurotransmitters
What 3 biological processes influence and cause behaviours and characteristics in biological psychology
Hormones
Genetic inheritance
Brain structure
Define neuron
A nerve cell that are specialised to transmit information throughout the body
Outline the structure of a neuron
Dendrite (tips at head) Nucleus (located in head) Myelin sheath (covering on the axon) Node of Ranvier (gap between myeline sheaths) Axon (tail of the neuron) Axon terminal (end of the nerve cell)
Outline the steps in which neurons transmit messages
- Receptors in the dendrites absorb neurotransmitters
- Electrochemical impulses (action potentials) travel along the axon in one direction only
- This triggers a release of a neaurotransmitter at the axon terminal into the synaptic gap
Define action potential
An electrical impulse triggered by a change in the elctrical potential of the neuron and stimulates the realease of neurotransmitters
Outline how an action potential works
- Neurons have a resting potential that is slightly negatively charged
- A neuron is received and one of two things happens;
a) Excitatory postsynaptic potential
b) Inhibitory postsynaptic potential - Enough excitatory signals trigger an action potential
What is an Excitatory postsynaptic potential
The neuron is depolarised and the negative charge decreases
They come quickly causing a fight response
What is an Inhibitory postsynaptic potential
The neuron is hyperpolerised and the negative charge increases
They come more slowly and cause a flight response
What is the All or None Principle?
If the depolarisation is not great enough to reach threshold
Then action potential and hence an impulse are not produced
Outline synaptic transmission
- Action potential travels along presynaptic neuron
- Presynaptic neuron releases neurotransmitters into the synaptic gap
- Neurotransmitters fit into receptors on the postsynaptic neuron
- Only if the receptor fits
- Repeating the cycle
- Neurotransmitters are reabsorbed
Outline how we catch a ball (CNS)
- Nerves in our body send information via the spinal cord to the brain
- The brain processes this information and sends a message to the body via the spinal cord
- eg. our eyes send a message about the oncoming ball to the brain
- The brain processes how far the ball is and sends a message to the body telling us to catch the ball
Define dendrite
A short branched extension of a nerve cell which absorbs neurotransmitters
Define myelin sheath
Insulates the cell in order to contain the electrical impulses (action potential)
Outline the reuptake process
The axon terminal reabsorbs (via transport proteins) some of the neurotransmitters it has released once the message has been received at the postsynaptic neuron
This regulates the information we recieve
Outline GABA
Relieves anxiety depression and fear, giving a calming effect
By inhibiting messages
Outline Norepinephrine
Stress hormone that triggers flight or fight response
Treats ADHD and is also involved in dreaming
Outline Acetylcholine
Memory and learning neurotransmitter
Important for motor control and emotions such as anger and sexuality
Low levels may link to Alzheimers
Outline Dopamine
Pleasure neurotransmitter linking to addiction
Links to schizophrenia
Outline Glutamate
Responsible for cognitive functioning
High levels can link to seizures
Outline Serotonin
Happiness hormone that regulates mood, sexual and food appetite, sleep, pain and temperature
Low levels link to depression and anxiety
Define a drug
Hijacks the natural neurotransmitter pathways and has effects on the central nervous system
Outline the effects of alcohol on the brain
interferes with communication pathways changing mood, behaviour, and co-ordination
Increases GABA reaction inhibiting glutamate
Outline the effects of heroin on the brain
Binds to receptors stimulating dopamine release giving a “rush” feeling of pleasure followed by drowsiness as the drug leaves the system
Outline the effects of amphetamines on the brain
Increases dopamine noradrenaline and serotonin levels giving an alert and energised feeling often leading to more sociable behaviour
Define mode of action
The way a drug works at the synapse and in the brain
What is the dopamine pathway?
The reqard pathway (pleasure centre) such as the lymbic system
Senstive to dopamine GABA and glutamate
How do recreational drugs have a genetic link?
It is adaptive for us to feel good after eating high calorie food as it ensures we store enough fat on our bodies in preparation for famine
It stimulates the release of dopamine GABA and glutamate to our dopamine pathways
How do most recreational drugs effect the brain
They work on the dopamine system
Producing a strong pleasurable effect ‘high’
With no evolutionary advantage
And causing a ‘low’ when dopamine levels drop again
Define tolerance
The need to take more of a drug to gain pleasure due to repeated use
Define euphoria
The ‘high’ strong pleasurable feeling felt when taking a recreational drug
Define dysphoria
The ‘come down’ feeling of the brain regulating dopamine levels again after drug use
Define addiction
The compulsive uncontrolled habit of taking drugs
Define withdrawl
The symptoms of no longer having a drug active in the nervous system after addiction
Outline 3 symptoms of drug withdrawl
Anxiety or jumpiness Shaking or trembling Sweating Nausea and vomiting Insomnia and fatigue Depression or irritability Loss of appetite Headaches
Outline Olds and Milner’s research into drugs (1954)
Identified there were probably pleasure centres in the brain that are part of our motivation system
Rats pressed a lever to receive a reward of electric to this part of the brain
The rats would cross a painful grid to reach the lever
The rats preferred the lever to food, drink and sex
Outline the effects of cocaine on the brain
Blocks the reuptake of dopamine which over stimulates post-synaptic receptors
This causes excessive movement and fidgeting but also creates enjoyment
Outline the effects of nicotine on the brain
Binds to an acetylcholine receptor triggering excessive dopamine release
Excessive use of nicotine particularly leads to desensitisation due to the change in shape of cells
Outline Gorka et al. (2013) research into alcohol
`MRI scans to study activity in the prefrontal cortex and amygdala
Alcohol interferes with the ability to pass information between the amygdala and the prefrontal cortex.
Alcohol activates the dopamine system
Outline 3 strengths of the effects of drugs on transmission
Lots of supporting evidence:
eg Olds & Milner (1954) Straiker et al (2012) Gorka et al (2013)
Straiker et al is reliable research with careful controls
Credible as dopamine does link to pleasure and recreational drugs invoke pleasure
Reliable as observations of addicts back up the desensitisation and tolerance theory
Observing addicts give mundane realism to the research making the results more valid
Outline 3 weaknesses of the effects of drugs on transmission
Supporting evidence was performed on rats and mice which doesn’t generalise to humans
Current tools cannot measure transmission
Scanning receptor activity on humans isn’t straight forward and potentially unethical
Reductionist as it does not discus how there is more than one reward pathway and generalises to all drugs
Define the peripheral nervous system
The nerve cells outside of the brain and spinal cord linking the CNS to the limbs and organs of the body
What are the 4 lobes of the brain
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Define hippocampus
Located in temporal lobe
Responsible for memory and connects emotions senses to memories (limbic system)
Define cerebellum
Controls muscle movement balance and co-ordination
Define Striatum
Receives input from the cerebral cortex
Controls movement, fine motor functions
Inhibits behaviour depending on social situations
Define hemispheres
Two halves of the brain
Right controls the left side of the body
Left controls the right side of the body
Define amygdala
Located in temporal lobe
Responsible for memory, decision making, and emotional reactions
Define parietal lobe
Responsible for perception, spatial awareness, manipulating objects and spelling
Define frontal lobe
Responsible for planning and organising
Personality and control of emotions and behaviour
Define occipital lobe
Responsible for sight
Define temporal lobe
Holds the bulk of our memories
Controls our ability to understand things and speak
Define cerebral cortex
Outer layer of neural tissue covering brain
Responsible in memory attention perception awareness thought language and consciousness
Define corpus callosum
Bundle of neural fibres between left and right hemispheres
Connects and passes information between the hemispheres
Define ventricles
Contain cerebrospinal fluid
Define thalamus
Passes sensory information to the cerebral cortex
Define hympothalamus
Controls pituitary gland
To regulate temperature, blood pressure, appetite, wakefulness and sexual arousal
Involved in some aspects of memory
Define pituitary gland
Responsible for producing hormones
eg puberty hormones, thyroid stimulating hormone and stress hormones (eg cortisol)
Define brain stem
Controls breathing heart rate consciousness blood circulation basic motor responses
Relays sensory information and regulates the sleep wake cycle
