biological Flashcards
what are the six key assumptions of biological psychology?
- All behaviour is determined by biological factors
- the central nervous system is a major influence on behaviour
- behavioural and psychological development is assumed to be based on changes in the brain and general biology
- process of evolutions can explain the existence of much human behaviour
- genes influence behaviour
- there is behavioural continuity between species so it makes sense to study animals and make generalisation to humans
What makes up the central nervous system and what is its role in human behaviour
- the brain
- the spinal chord
The CNS acts as an information processing and control centre for info we receive and response we make
The body receives information from our senses, the peripheral nervous systems send it to the CNS. The brain processes and integrates all the information and generates a response
What are the four lobes of the brain and the PFC and what are they responsible for?
FRONTAL LOBE:
- decision making
- planning and organising
- memory and attention
PARIETAL LOBE:
- sensory info
OCCIPITAL LOBE:
- visual information
TEMPORAL LOBE:
- memory and attention
PRE-FRONTAL CORTEX:
- part of frontal lobe
- executive functions such as inhibiting inappropriate responses, design making and motivational behaviour
What makes up the limbic system and what are their roles?
THALAMUS:
- relays info from senses
AMYGDALA:
- fear and anger
- fight or flight
HIPPOCAMPUS:
- memory formation
HYPOTHALAMUS:
- regulated bodily functions
- hormones such as adrenaline
What is a neutron and what is the structure (label)?
- a specialised cell within the nervous system
- axon
- dendrites
- cell body
- nucleus
- axon hillock
- myelin sheath
- sides of ranvier
- synapse
What is the synapse and what is its structure (label)
- where the communication between one neutron and the next takes place
- presynaptic neuron
- synaptic vesicles
- action potential
- synaptic cleft
- postsynaptic neuron
- protein receptor
- neurotransmitters
How do neurons influence human behaviour?
Neurons make a chain with each other forming a passage way that allows messages to be sent from one part of the brain to another keeping the brain and body working correctly.
They form new connections and change existing connections every time we learn something new
What is the function of neurotransmitters and give three examples of them?
- chemical messengers that take info around the brain
- released from post synaptic neuron after and action potential
- stimulate post synaptic neuron to make its own action potential
- they allow neurons to communicate with one another
SERETONIN:
- mood control
- pain, sleep, body temp and hunger
DOPAMINE:
- pleasure
- dependency (addiction)
NORADRENALINE:
- fight to flight
What are the four steps to synaptic transmission?
- An action potential moves down the pre-synaptic neurone and causes the vesicles filled with neurotransmitters to move closer to terminal membrane
- the vesicles fuse with terminal membrane in a process called exocytosis. This causes neurotransmitters to be released into synaptic cleft
- Neurontramitters bind with protein receptors in the post and pre synaptic neuron. Activation on the post synaptic neuron causes an increase of liklehoof for action potential. Activation in pre synaptic neuron causes the stop of releasing neurotransmitter
- Once neurotransmitter is released into synaptic cleft, it is removed by either, reuptake, broken down by exams or diffusion
Evaluate synaptic transmission as an explanation of how messages move around the brain
- evidence from brain scans which are objective and reliable (increase scientific credibility)
- much evidence has come from animals. To generalise from rat and cat brains may not be valid
- individual differences are not always taken into account. Some people have different levels of certain neurotransmitters.
What are recreational drugs and what ate reward pathways?
- recreational drugs are used in the absence of medical grounds for personal enjoyment.
- reward pathways are circuits of structures and nerves that are linked to the activities of specific neurotransmitters
- Dopamine pathway are activated by natural rewarding behaviours such us ex or eating. Make us more likely to repeat behaviours
What are three ways in which drugs may affect synaptic transmission?
- Increasing the amount of dopamine that is released
- Blocking pre synaptic transpoters so that reuptake is stopped
- stopping the actions of enzymes that would normally break down the neurotransmitter
How does cocaine effect synaptic transmission?
- cocaine is a highly addictive stimulant
- it blocks the transporter receptors on the pre synaptic dopamine neurons in the ventral tegemntal area
- therefore pre gnostic neuron do not reuptake dopamine so it stays in the synaptic cleft longer
- this prolongs and intensifies the stimulation of post synaptic neuron
- user experiences euphoria
How does drug addiction occur?
- brain is a self regulating system so reacts to the over production of dopamine
- reduced how much dopamine it naturally produces
- brain will no longer operate properly without the drug
- without drugs, people experience dysphoria
- motivation to self administer is high to re-experince eurphoria
- this leads to repeated use snd therefore further down regulate the production of dopamine
- tolerance for the drug is built up, must take a higher dose to get high
- causes person to be physically dependent in order to avoid experience of withdrawl
Evaluation of how drugs effect brain functioning and synaptic transmission
- well controlled scientific evidence using animals (van den over)
- brain scanning techniques (Li et al used fMRI scans to show heroine had changed functioning and connections in the brain)
- applications such as enabling scientists to develop medications to help addicts
- brain scans are not sophisticated enough to show everything
- evidence comes from animals which may not straightforwardly generalise to humans
What is the aim of Van Den Oever’s study?
to investigate acute changes in the molecular composition and function of synapses in the medial prefrontal cortex upon re-exposure to heroin cues
What was the procedure of Van Den oevers study?
Stage one:
- experimental group trained to self administer heroin. When presented with an audiovisual cue, if they poked their nose in a hole, they received a dose of heorin
- control group, same but received sucrose solution
Stage two:
- experimental group split in two
- some rats kept in operate cage fro 21 days (abstinence)
- other rates kept in self administration cage but did not receive heroin (extinction)
Stage three:
- both groups split in two
- hald absietnce and extincction rats were exposed to drug associated cues for 60 min but did not receive heroin
- other hand we’re places in self adminstarion boxes but were not exposed to drug associates cues
Stage 4:
- all rats were decapitated
- brains were analysed using mass spectrometry technique which allowed detection of subtle changes
What were the results and conclusions from van den oever study?
Results:
- behavioural evidence of relapse (rates re-exposed to drug cues demonstrated greater amount of frug seeking behaviour compared to those not re-exposed)
- composition of synapses in the medial prefrontal cortex (rates re-exposed to drug cues had lower than normal levels of AMPA receptors in the medial prefrontal cortex)
- endocytosis preventive drugs reduced the amount of drug seeking behaviour
Conclusions:
- after a period of abstinence, exposure to drug associates cues can trigger a relapse back to drug seeking behaviour. Therefore, recovering addicts need to be removed from sung associated cues
- Rates re-exposed to drug associated cues related to heroin, is linked to lower number of AMPA receptors. Therefore, the molecular composition and function of the synapses had changed
- the reductions of AMPA rectors in prefrontal cortex is causing a relapse in drug seeking behaviour.
Evaluate Van Den Oevers study?
Generalisability:
- male white wistar rats used
- areas in the brain for drug addiction are similar in rats and humans (medial prefrontal context and reward pathways)
Reliability:
- used standardise procedures (all had same amount of assistance/extinction)
Applicability:
- preventing drug addicts from relapse such as a drugs preventing endocytosis
Validity:
- control over extraneous variables such as a control group
- reductionist as it only focuses on medial prefrontal cortex and ignores social factors
Ethics:
- sample was rats as it would be unethical on humans
- rats were harmed (catheters and killed)
What are hormones and what are their role in human behaviour
chemical substances produced in a specialised gland and transported in blood to stimulate specific cells or organs into action (endocrine system)
Hormones influence:
- sensory input
- intergration by CNS
- Motor output by muscles
- hormones change the probability that a particular behaviour will happen in certain situations and can also change the intensity of a behaviour
How do hormones affect development in stages of life?
In the womb:
- development of brain influenced by reproductive hormones
- impact on sex differences causing male and female brains to develop slightly differently
Early Childhood:
- stressful environments cause the release of cortisol
- if children experience high cortisol levels, this can impact development of the brain
- children experiencing abuse may overproduce neural connections in fear and anxiety and may under produce neural connections for reasoning and planning
Puberty and adulthood:
- hormonal imbalances in adulthood can result in brain changes
- these make a person more susceptible to depression, anxiety, alcoholism and drug abuse
- e.g puberty and menopause