Brain & Behaviour 1/2 Flashcards
What is materialism in relation to psychology?
the mind results from activities of the brain
What is dualism? and what is the supposed role of the pineal gland?
The mind and body are believed to be wholly separate
believe the pineal gland connects with the soul
What is phrenology?
bulges on the skull equate to swollen brain parts of specific function
What is equipotentiality?
there is no functional localisation in the brain, it works as a whole
What is Broca’s area?
language part of the brain that if damaged causes aphasia
What is the neurone doctrine?
individual neurone cells make up the brain
What do single neurone recordings show us?
when specific cells respond to particular stimulus
What is an EEG?
A measure of electrical impulses of a group of neurones
What is MEG?
A measure of the magnetic field created by neurones
What do fMRI and PET scans look for in the brain?
Change in magnetic signal that occurs when blood flows to a brain region that has become active
What is TMS?
Transcranial magnetic stimulation :
magnetic field created through the skull causing a disruption in electrical activity in the brain - can interfere with brain functions e.g. speaking
Which of the imaging techniques used in cognitive neuro has the best temporal resolution?
EEG (and MEG)
Which of the imaging techniques used in cognitive neuro has the best spatial resolution?
fMRI (actually single neurone recordings but not so widely used)
Describe the steps leading to an action potential crossing a synapse?
- action potential reaches synaptic knob and causes voltage gated Ca2+ ion channels to open
- vesicles containing neurotransmitter move towards the presynaptic membrane and diffuse into the synaptic cleft
- neurotransmitter binds to receptors on the post synaptic membrane allowing Na+ to enter, depolarising the membrane
What are antagonists?
chemicals that can bind to neurotransmitters and prevent ions entering the postsynapse
What are agonists?
chemicals that allow ions to enter the postsynapse such as neurotransmitters
Name 3 agonists and what they do
Alcohol: allows GABA uptake
Nicotine: allows acetylcholine uptake
Cocaine: allows dopamine, norepinephrine and serotonin uptake
Name 3 antagonists and what they do
Alcohol: prevents uptake of glutamate
Prozac: prevents re-uptake of serotonin
Chloropromazine: prevents uptake of dopamine
What is an EPSP?
excitatory post-synaptic potential
What is an IPSP?
inhibitory post-synaptic potential
When will an axon depolarise to threshold?
When the sum of EPSPs and IPSPs is sufficient to depolarise to that level despite cancelling each other out
What is temporal summation?
When multiple EPSPs come together at one time to create a large action potential
What is spatial summation?
the summation of potentials from different physical locations across the cell body
What is happening at resting potential?
Diffusion pulls K+ out of the cell and electrical force moves it back into the cell
How many Na+ for K+ exchanages are there per cell?
3 Na+ out = 2 K+ in (creating a net charge loss inside the cell)
What is the first step in an action potential?
Voltage gated Na+ and K+ ions channels open when the membrane depolarises
What is threshold potential?
+40mV
How many neurones are there in the brain?
100 billion
What are glial cells?
The glue that sticks the brain together
What are the 3 types of glial cell?
Astrocytes, oligodendrocytes, microglial cells
Are there more glial cells that neurones in the cerebellum or cerebral cortex?
cerebral cortex
Why is grey matter grey?
Contains neurones, cell bodies, dendrites
Why is white matter white?
contains lots of axons with myelin (which is white)
What is a gyrus?
A ‘hill’ on the brain’s surface
What is a sulcus?
A ‘valley’ on the brain’s surface
What are the 4 main lobes of the cerebral cortex and what do they do?
Frontal lobe - motor control, planning, thinking
Parietal lobe - sensory-motor information
Temporal lobe - higher level visual information
Occipital lobe - visual information
What does the Sylvian fissure do?
Divides the temporal lobe from the frontal and parietal lobes
What coordinates does the anterior commissure have?
000
What does the basal ganglia consist of?
Caudate, putamen, globus pallidus
What does the amygdala do?
memory and emotional responses
What does the Thalamus do?
directs sensory information en route to the cerebral cortex
What does the Hypothalamus do?
homeostasis
What does the pineal gland do?
control sleep/wake patterns
What does the brainstem consist of? What does each part do?
Midbrain: sensory motor integration
Pons: connection with the cerebellum
Medulla: controls vital organs
What are meninges?
membranes that keep the fluid in the brain
What is the circle or Willis and what does it do?
The brain’s main blood supply - pools blood from internal carotid and basilar artery and distributes it to the brain
What are the 6 layers of the cortex?
Molecular, external granular, pyramidal, inner granular, ganglionic and multiform
What is Savant syndrome?
When an individual is generally cognitively impaired but excel in one aspect
What is neuroethology?
The study of animal behaviour and its underlying control by the nervous system
What is allometry?
The importance of brain size relative to body mass
What is residual brain?
Extra brain weight than expected for given body weight (deviation from allometric prediction)
Which gene is important in controlling brain size?
Microcephalin gene
What is ‘proper mass’
The correct mass of brain areas needed for specific functions
What does the superior colliculus control?
vision
What does the inferior colliculus control?
hearing
What does a larger than average hippocampus suggest?
More of the brain is needed for memory which may be linked to behaviour such as long term food storage
What does a larger than average neocortex suggest?
increase in social intelligence as neurones in the NC are very receptive to faces helping to identify others easily
What is Dunbar’s number?
more residual cortex = larger social group size
What part of the brain do songbirds have a residual amount of?
the HVC (does not stand for anything) - allows large song repertoire
Can the size of brain regions change even after growing has stopped?
Yes.
Taxi drivers have larger hippocampuses than the average person
Strong players have more neurones representing thir left hand in the somatosensory cortex
What has IQ shown to be roughly correlated to in terms of the brain?
increased cortical thickness
What is the mosaic brain evolution model?
the idea that different modular regions elaborated each individually over time (evolution)
How many people are predicted to have dementia by 2050?
2 million
What percentage of dementia cases are Alzheimer’s?
60%
How many people in the UK have some sort of dementia?
820000
On average how much does a patient with dementia cost the NHS per year?
£25,000
What are the symptoms of mild dementia?
memory loss (episodic and semantic), problems thinking + making decisions
What are symptoms of moderate dementia?
confusion, disturbed sleep, disorientation, poor judgement, apathy, personality changes, hallucinations
What are the symptoms of severe dementia?
forgetting own identity, not recognising others, loss of mobility/control, inability to communicate
What forms inside the brain causing dementia?
Plaques and tangles
What is a ‘plaque’?
A beta amyloid plaque forms from small fragments of beta amyloid protein released from membranes of the neurones
What is a ‘tangle’?
A neurofibrillary tangle forms from Tau proteins that have separated from microtubules. Tangles disable cell transport, causing cell death
What do plaques and tangles cause in the brain?
neurones die, brain shrinks (atrophy)
sulci and ventricles expand
Who discovered Alzheimers? When was this?
Alois Alzheimer in 1906
What network do patients with AD often show abnormalities in even early on?
Default mode network - associated with memory retrieval
What is dementia?
Any neurodegenerative disease
How heritable is AD?
It is autosomally dominant - only one copy of the gene needed in order for the disease to develop
What chance do children have of inheriting AD if one parent has it?
50% chance
What 3 genes are associated with AD?
Presenilin 1 (chromosome 14) Presenilin 2 (chromosome 1) Amyloid beta (A4) precursor protein (chromosome 21)
What gene implicates late onset AD?
APOE4 (chromosome 19), presence of this gene increases likelihood of onset 4x
What environmental factors can increase the likelihood of developing AD?
Diet - reduced risk of AD with mediterranean diet
- moderate alcohol intake decreases risk
- smoking may increase risk of AD in APOE 4 carriers
Education - higher level = lower risk of AD
What are some symptoms of Mild Cognitive Impairment (MCI)?
misplacing everyday items, losing train of thought, failing to recognise familiar faces/places, problems ‘word finding’
Why is the MCI test important?
It can help determine whether there is degeneration in any brain regions such as the hippocampus which can start degeneration up to 3 years before AD diagnosed
This means treatment may be more effective if given earlier
What type of memory is well preserved even in patients with AD? How come?
Habit memory
It does not use the hippocampus or complex semantic processing
What did Kemper’s (2001) ‘Nun study’ show?
Nuns that developed dementia in later life had lower scores for grammatical complexity and density of ideas in their writing at a young age
What did the EClipSE study show?
More educated participants are less likely to be diagnosed with AD HOWEVER level of education does not matter
What treatment is currently available for Alzheimers?
slowing of progression and amelioration of some symptoms
What is Cognitive stimulation?
Exercise and improved nutrition to boost performance and improve mood
What is reminiscence theory?
Helping patients make use of early memories and knowledge to promote social interaction and wellbeing
What is the purpose of giving AD patients Vitamin B?
Smith (2010) found that Vit B can reduce brain atrophy by 30% in patients who might have the very earliest stages of dementia but no diagnosis
What can long term alcoholism cause?
damage to the brain causing Wernicke-Korsakoff syndrome which is amnesia
What is the best known AD medication and what does it do?
Aricept
It is a cholinesterase inhibitor so prevents the breakdown of acetylcholine so more neurones fire
What other medication can be given to patients with AD?
NMDA inhibitors
block glutamate from binding as it is released in large quantities from damaged cells and is toxic to surrounding cells
Which areas of the brain are worst affected by AD?
inferior, medial and anterior
Which two lobes, affected by AD, are important for semantic memory and language?
anterior temporal lobe, inferior frontal lobe
Which lobe, affected by AD, is especially important for controlling thought and behaviour?
frontal lobe
What symptoms can degeneration of the frontal lobe cause?
problems coordinating multiple activities
personality changes
Which parts of the brain degenerate to cause apathy?
orbitofrontal cortex, frontal pole
What was interesting about the last book Murdoch wrote?
There was a higher frequency of ‘normal’ words than in her other books
What are the 3 types of dementia?
Vascular
Focal
Subcortical
What is vascular dementia?
loss of cognitive functioning due to loss of blood supply to the brain
Where in the world is vascular dementia most common?
Asia
What are people with vascular dementia prone to?
Strokes - blood supply disruption to the brain caused by a blocked artery (thrombosis) or bleed (haemorrhage)
What part of the brain is particularly prone to strokes?Why?
frontal lobes
receive blood form a single artery
What do many patients with vascular dementia have a history of?
Hypertension (over 80% of people diagnosed with VD have this)
What is frontotemporal dementia (FTD)?
damage focussed on one area of one lobe
What is frontal-variant FTD? Symptoms?
atrophy of the frontal lobes (70% of FTD cases)
- personality changes, lack of inhibition, loss of empathy, compulsive ritualised behaviours
What is semantic FTD? Symptoms?
atrophy of anterior temporal lobes bilaterally
- loss of grey matter (knife edge atrophy)
What is posterior cortical FTD? Symptoms?
atrophy of posterior parietal cortex
- blurred vision, light sensitivity, progressive inability to recognise faces, impaired reading + writing
What is ‘knife edge’ atrophy?
where the lower side of the brain loses grey matter causing sharp looking gyri
What are the two subcortical dementias and what causes them?
Huntington’s disease
Parkinson’s disease
caused by basal ganglia degeneration
What parts of the brain are affected in Huntington’s disease?
Putamen and caudate
What parts of the brain are affected in Parkinson’s disease?
Substantia nigra
How heritable is HD?
It is dominant to chromosome 4
50% chance of inheritance if one parent has it, 100% will develop if possess gene
What does HD cause?
Breakdown of Basal Ganglia’s inhibitory pathway to thalamus and cortex, affecting motor, cognitive and emotional control
What are some of the first symptoms of HD? Around what age do they start appearing?
30-45
restlessness, clumsiness, involuntary movements, cognitive/emotional changes
What does degeneration of the substantia nigra in PD cause?
deficit in dopamine making it hard to initiate movement
What medication can be given to patients with PD?
Levodopa - aimed at boosting dopamine levels
What are some of the symptoms of PD?
loss of spontaneous movement, slowness in movement, disturbed speech (bradykinesia), tremor when resting (hyperkinesia), muscular rigidity, involuntary movements (akinesia)
Can boxing cause brain damage?
Professional boxers can damage their brains long term by boxing - especially if they carry the APOE4 gene they are more vulnerable
What do some professional boxers do before a fight that can mean they damage their brain even more?
Dehydrate themselves in order to fit into a weight category meaning there is less fluid protecting their brain from hitting their skull = more brain damage
What are Pick bodies?
Clumps of Tau proteins inside cells (not outside as in AD)
What is Rivastigmine?
A drug used to treat AD and Parkinson’s that is a cholinesterase inhibitor
