Biological Psychology Flashcards
What brain functions are localised to the frontal lobe?
- problem solving (PFC)
- producing speech (Brocas area)
- muscle movement (motor strip)
What brain functions are localised to the parietal lobe?
- senses (sensory strip)
What brain functions are localised to the temporal lobe?
- memory
- language understanding it (Wernickes area)
What brain functions are localised to the occipital lobe?
- vision
- visual cortex
What is the difference between Brocas Aphasia and Wernickes aphasia?
Broca = unable to speak but can still undertsnad language Wenicke = unable to understand language but can make speech sounds
What is localisation of function?
where each part of the brain is responsible a specific different job
- If a certain area of the brain becomes damaged, the function associated with that area will also be affected.
What is cross lateralisation?
where the brain corresponds with the opposite side of the body
Name the three types of brain scan
PET
CAT/CT
fMRI
What is temporal resolution?
how well the scanner tracks changes in brain activity
What is the temporal resolution of a fMRI scan?
20 seconds, it has the highest temporal resolution
What is the temporal resolution of a PET scan?
5 - 15 minutes, it has a lower temporal resolution than an fMRI scan
What is voxel size?
smaller voxel size means there is more detail so the scan has a higher spatial resolution
What is spatial resolution?
how fine the detail on a scan is
Rank the 3 scans spatial resolution from highest to lowest
CAT/CT = highest spatial resolution fMRI = high spatial resolution but lower than a CAT scan PET = lowest spatial resolution
What is the voxel size of a CAT/CT scan?
0.5mm
What is the voxel size of a fMRI scan?
1.5mm
What is the voxel size of a PET scan?
6mm
Describe a CAT/CT scan
produces a detailed image of brain structure uses x rays quickest scan = 5 mins not too susceptible to motion artefacts cheap £100-400
Describe a PET scan
positron emission tomography mainly shows brain activity works by detecting radioactive tracers that are injected into the person very expensive low temporal resolution 5-15mins lowest spatial resolution scan is in colour
Describe a fMRI scan
scan shows detail of both brain activity and structure
good spatial resolution
high temporal resolution 20 seconds
really long 30-40 mins
not suitable for someone with a pacemaker or metal
very susceptible to motion artefacts
What is the cost of each scan?
CAT/CT cheapest = £100 - £400
fMRI= £200 - £500
PET expensive= £500 per scan, cost of the tracer
Describe the structure of a neuron
- list the parts
- dendrites
- soma
- cytoplasm
- nucleus
- myelin sheath
- nodes of ranvier
- axon
- terminal
check folder for a diagram
Explain how an action potential is transmitted
- at rest = neural membrane is positive outside and negative inside
- the dendrites are disturbed by neurotransmitters and depolarisation occurs as neural membrane opens and negative charges move in
- this prompts a chain reaction and depolarisation occurs down the axon passing the signal down the dendrites to terminals.
What is the action of an inhibitory synapse?
if the inhibitory neuron action potential frequency increases the other neurons frequency will decrease (it does the opposite).
What is the action of an excitatory synapse?
both act the same e.g. both decrease or both increase
What is a neurotransmitter?
- a chemical messenger that acts between 2 neurons,
- specific neurotransmitters have specific and different affects
What is a synapse?
- a junction between 2 neurons, dendrites to terminals
What is synaptic transmission?
- action potential prompts vesicles to release neurotransmitters at the terminal into the synapse
- neurotransmitters diffuse across the synaptic gap
- receptors at the postsynaptic neuron binds to neurotransmitter and increase the probability of an action potential
How do we regulate the amount of neurotransmitter in the synaptic gap?
- enzymes breakdown excess neurotransmitters
- reuptake proteins are used to move excess neurotransmitters from the synaptic gap to the presynaptic neuron
What are psychoactive drugs?
- drugs that change brain functioning, cognition, emotion and behaviour
What is tolerance?
- it is when the brain becomes used to the effect of the drug so more drug is needed to stimulate the same effect
What is dependence?
- dependence is when a user is unable to fully function unless they take the drug
What is the reward pathway?
- the drug leads to pleasure, the want to achieve this effect again and gain the reward leads to addiction.
How does nicotine affect synaptic transmission and the nervous system?
- it causes more neurotransmitter to be released in response to an impulse
- this affects the reward pathway
How does cocaine affect synaptic transmission and the nervous system?
it is a REUPTAKE INHIBITOR
- cocaine latches on to reuptake mechanism for dopamine
- more dopamine is released into the synapse (agonist)
- it is a stimulant and activates the reward pathway, feel more alert, better mood and confident
How does heroin (opiods) affect synaptic transmission and the nervous system?
- morphine binds to receptors for endorphine acting as endorphine (endorphine analogue)
- endorphine levels increase
- GABA levels decrease
- dopamine level increase
- this activates the reward pathway so you feel no pain, sedative, fell dreamy, euphoric and drowsy
How do cannabinoids affect synaptic transmission and the nervous system?
- anandamide acts as a GABA regulator by binding to GABA receptors
- delta A THC is the analogues of anandamide and so it acts as anandamide and binds to and stimulates the anandamide receptors
- GABA levels decrease
- dopamine levels increase
- feel sedated, deeper senses, more relaxed, hungry
In detail describe the steps of synaptic transmission
- action potentials arrive at the terminals
- vesicles release neurotransmitters
- increased concentration of neurotransmitter in ths synaptic gao
- increased probability that neurotransmitters bind to receptors
- change in probability of action potential of post synaptic neuron
- reuptake and enzymes break down neurotransmitter
What are the 4 drug mechanisms?
block enzyme activity
block reuptake
block receptor
activate receptor