biopsych Flashcards
It was previously believed the brain worked ____________
Holistically
The main part of the brain is known as the ________
Cerebrum
The cerebrum is split into two hemispheres - this is known as __________
Lateralisation
How many lobes is the brain divided into?
4
Which lobe is the motor cortex located in?
Frontal
Which lobe is the visual cortex located in?
Occipital
What are the four lobes?
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
What is the motor cortex responsible for?
Voluntary movement
What is the somatosensory cortex responsible for?
Skin sensations
Where is the visual cortex located?
The occipital lobe
Where is the auditory cortex located?
The temporal lobe
Where is wernicke’s area located and what is it responsible for?
Left temporal lobe
Speech comprehension
Where is Broca’s area and what is it responsible for?
Left frontal lobe
Speech production
Language is concentrated (localised) to the _____ hemisphere
Left
What are two strengths of localisation?
Case study support - Phineas Gage: reinforces the idea that personality is localised to then frontal lobe as Gage experienced a post traumatic personality change after a sever head injury. It was reported Gage shifted from calm and reserved to hostile and quick tempered - adding validity to the theory of localisation and refuting the idea that the brain works holistically
Brain scans - Peterson et al: demonstrated how Broca’s area was active during a reading task and Wernicke’s area was active during a listening task (language centres responsible for speech comprehension & production) - boosts credibility/validity of localisation as it supports the idea that different areas of the brain are responsible for different functions
What are two limitations of localisation?
Counter evidence - Lashley’s rats: conducted using animals specifically rats, 10- 50% of the rats brains were removed to test how they would navigate a maze and it was found there was no one area that impacted their navigation and the rat’s ability to learn the maze was unaffected supporting the idea that the brain works holistically and diminishing the validity of localisation
Reductionist/ oversimplified - plasticity: plasticity is the concept that the brain adapts itself to recover a lost or compromised function after trauma, this is done by the surviving brain circuits adjusting to allow the same neurological action to be achieved - this implies the brain works in a holistic way as functions can be recovered in different areas of the brain - localisation is an incomplete theory diminishing the validity of it
The left hemisphere dominates the ______ side of the body
Right
The right hemisphere dominates the ____ side of the body
Left
The right hem dominates the left side of the body and the left hem dominates the right side - this is known as ___________ wiring
Contralateral
Damage to wernicke’s area leads to wernicke’s ______
Aphasia
What is experienced during wernicke’s aphasia?
Unable to understand meaning of words
Produce nonsense words in speech
Damage to Broca’s area leads to Broca’s ______
Aphasia
What is experienced during Broca’s aphasia?
Slow speech that lacks fluency
The occipital lobes are ___________
Ipsilateral
I.e. the left occipital lobe is not solely responsible for our right eye
Each eye has a right and a left _____ field
Visual
The left visual field is controlled by the _____ hemisphere
Right
The right visual field is controlled by the ____ hemisphere
Left
The idea that each hemisphere is responsible for certain functions is known as …..
Lateralisation
If the left occipital lobe is damaged the ____ visual field is impaired in both eyes
Right
Sperry’s split brain research was a _______ experiment
Quasi
What was Sperry’s sample?
11 epileptic people who had undergone a commissurotomy to treat their epilepsy compared to a control group who hadn’t had a commissurotomy
What did Sperry find?
When information was shown to their right visual field they can verbalise what they see (because it is processed in the LH where Broca’s area is)
When information is show to their left visual field they can see it but can’t verbalise it as it is processed in the RH (no Broca’s area) and the corpus colossum is severed meaning the language centres in the LH can’t be reached
What are strengths of split brain research?
Research support
It has been found that those with a split brain are better at certain cognitive tasks like spot the odd one out as they can utilise one hemisphere effectively with no interference - boosts the validity of hemispheric lateralisation
Standardised procedures - highly specialised and controlled procedures are used e.g. lab experiment with ppts shown images to both visual fields - increased validity and reliability - adds scientific credibility
What is a limitation of Sperry’s research?
Confounding variables - CG also didn’t have epilepsy - their ability to complete tasks may have been due to the lack of epilepsy instead of their intact corpus colossum - diminished validity
What is a strength of hemispheric lateralisation?
Animal studies with chickens show lateralisation is adaptive as the chickens with lateralised brains can do two things at once e.g. look for food & predators whereas unlateralised chickens can only do one - boosted validity for hemispheric lateralisation
What are two limitations of hemispheric lateralisation?
Plasticity - the brain is considered plastic because it has the ability to change & move functions after a trauma -diminishes the validity of hemispheric lateralisation - incomplete theory
Differences in functions perhaps overstated - popular psychology oversimplifies and over emphasises differences between hemispheres - each hemisphere can perform each task when and if the situation requires it - incomplete theory - lack of validity
When are post mortems conducted?
after death - first method of studying the brain
Why are post mortems conducted?
Likely conducted on those with rare circumstances/ disorders compared to a neuro typical brain e.g HM
What are two strengths of post mortems as a way of studying the brain?
first influential methods - paved the way for other methods of brain studying to be discovered
Discovery of language centres - Broca’s area (speech production) & Wernicke’s area (speech comprehension) - associated with speech and a key finding - boosted validity & effectiveness
What are two limitations of post mortems?
correlation/ not causation
Can’t say for certain any abnormalities in the brain caused certain behaviours - & theories can’t be tested as the subject is dead which means variables can’t be manipulated - lack of validity
Ethical issues i.e. obtaining consent - difficult to obtain consent from the deceased e.g HM was unable to give consent and the individual may not be in the right state of mind to be capable of giving consent
What does FMRI stand for?
Functional magnetic resonance imaging
What do FMRI’s do?
produces 3D images of active brain areas & measures haemodynamic response (blood flow & oxygenation)
What are FMRI’s used for?
used to detect where brain functions happen while carrying out a task
What are two strengths of FMRI’s as a way of studying the brain?
A safe method of studying the brain - FMRI’s are non invasive & dont involve radiation - virtually risk free
High spatial resolution - can show down to the millimetre exactly where blood flow is/ being directed - adds to the validity of FMRI’s
What are two limitations of FMRI’s as a way of studying the brain?
Expensive - using an FMRI is expensive as electromagnets require a lot of electricity - buying an FMRI is expensive too - limited applicability as it can’t be used regularly due to financial restrictions
Poor temporal resolution - works 5 seconds behind real time and so can’t tell exactly when brain functions happen
What does EEG stand for?
Electroencephalogram
What do EEG’S do?
Detects electrical activity i.e. action potentials across the cortex or specifically abnormal patterns e.g. epilepsy
What are 3 strengths of EEG’s as a way of studying the brain?
A safe & cheap method - non invasive & cheaper than FMRI’s also virtually risk free
High temporal resolution - no delay - to the millisecond of transmission - preciseness boosts validity
Practical application - EEG’s have been used to diagnose epilepsy and sleep disorders (measures brainwaves whilst people sleep) - prove effectiveness/usefulness - boosted validity/ credibility
What does ERP stand for?
event related potential
What do ERP’s do?
detect brain activity in relation to a specific stimulus
What do ERP’s measure?
ERP’s
How do ERP’s work?
start of with an EEG then unrelated items are removed to have it become an ERP
What are two limitations of EEG’s?
only measures cortex activity (the outer area of the brain) - doesn’t measure activity elsewhere in the brain - lacks validity - ineffective
Low spatial resolution - unable to locate where the activity is occurring in the cortex
What are two strengths of ERP’s as a way of studying the brain?
high temporal resolution - cant find when brain activity is occurring down to the millisecond
Practical application - used in court e.g. brain fingerprinting - useful in the real world - boosts validity
What are two limitations of ERP’s?
hard to eliminate all extraneous variables - difficult to eliminate all distractions other than the stimulus that brain activity is related to - lacks validity
Poor spatial resolution - difficulty locating where in the brain the activity is occurring
What does plasticity mean?
The brain has the ability to form and strengthen new synaptic connections from learning and experiences
________ brains have far more synaptic connections than ________ brains
infant
Adult
Connections that are rarely used are deleted through a process known as…..
synaptic pruning
(Whilst connections that are used frequently are strengthened)
Who conducted research into plasticity on London cabbies?
Maguire
What did Maguire find? (Plasticity)
He found cabbies had a large volume of grey matter (connections) in their posterior hippocampus compared to a control group (spatial/navigation skills)
He found a positive correlation between the length of time they had been a cabbie and the amount of brain matter in the posterior hippocampus
At what age does the brain have a peak number of synaptic connections?
2-3 years old
What is functional recovery?
a type of plasticity where the brain adapts and compensates after damage/ injury
What are the two types of functional recovery?
Axonal sprouting
Recruitment of homologous areas
What is axonal sprouting?
When new nerve endings grow and connect to undamaged nerve cells
What is recruitment of homologous areas?
Recruiting areas on the opposite hemisphere to perform specific tasks
When does functional recovery occur?
After damage/injury to the brain or synaptic connections
What are some strengths of plasticity?
practical application - the more research into plasticity and functional recovery the better our rehabilitative therapies are - effectiveness
Seasonal changes - research on animals has found seasonal changes in brain structure - the SCN sits just above the optic nerve - passes information to the pineal gland - for animals their SCN grows in in the autumn & shrinks in the spring/summer - shows brain has a natural plasticity
Research support - Bezzola looked into the idea that plasticity reduces with age 40-60 yr old people played 40hrs of golf and afterwards more synaptic connections were found in the motor cortex - validates plasticity as a theory showing it continues across the lifespan -
What are two limitations of plasticity?
influence of education - Schneider et al showed that the longer you spend in education the better your chances of a disability free recovery from damage - this was seen in 2/5 of people who had 16yrs of education over the 3/5 who had less than 12yrs -
Negative plasticity - the idea that the brain can adapt to things in a negative way - plasticity is not always beneficial e.g. the brain could adapt to prolonged drug use resulting in impaired cognitive functions & risk of dementia
What is a biological rhythm?
patterns of changes in body activity that conform to cyclical time periods
What is a circadian rhythm?
One that lasts roughly 24 hours e.g. the sleep wake cycle
What did Schiffre do in his cave study?
deprived himself of exposure to natural light, sound and clocks to see whether it would affect his circadian rhythm (SW cycle) - he measured his SW cycle with EEG’s
What did Schiffre find?
That his cycle expanded to 25 hours - our SW cycle is entrained by exogenous zeitgebers e.g. light
Give an example of an endogenous pacemaker
The SCN/ pineal gland
Given an example of an exogenous zeitgeber
Light
How does the SCN work as an endogenous pacemaker?
- sits above the optic nerve and receives information about light
- The SCN passes this information to the pineal gland
- the PG increases melatonin production at night & inhibits melatonin production in the day
What are three strengths of research into circadian rhythms?
Animal research - Decorsey destroyed 30 chipmunks SCN’s then released then back into the wild - he found that their SW cycles disappeared showing the SCN is vital to the SW cycle -
Medical application - the more we know about our bodies sleep cycles the more we can adjust timetables for giving medication effectively - exemplifies usefulness of research into circadian rhythms
Shift work application - researchers found shift workers specifically those working at night are at a greater risk for health consequences e.g. heart disease as it disrupts our natural sleep cycle - effectiveness of research into circadian rhythms - boosts validity
What is a limitation of research into circadian rhythms?
Individual differences - SW cycles can vary in different people e.g. some people show a natural preference for going to bed early and waking up early whereas others are the opposite
What are neurons?
electro chemical messages communicated around the body
How does the PNS do it’s job of transmitting messages to and from the CNS?
Via neurons
Which part of the neuron coordinates messages out?
axon
Which part of the neuron coordinates messages in?
dendrites
What is the CNS comprised of?
the brain & the spinal cord
What does the CNS do?
It controls activities in the body
What are the two divisions of the PNS?
Autonomic nervous system
Somatic nervous system
What is the somatic nervous system responsible for?
It is responsible for for carrying sensory & motor information to and from the CNS
It is associated with voluntary movements e.g. writing
What is the autonomic nervous system responsible for?
regulates involuntary movements e.g. breathing & digestion
What are the two parts of the autonomic nervous system?
sympathetic nervous system
Parasympathetic nervous system
What is the sympathetic nervous system responsible for?
Responsible for fight & flight response i.e. reduces digestive secretions, speeds up the heart rate & contracts blood vessels
What is the parasympathetic nervous system responsible for?
resting state - stimulate digestive secretions, slow the heart rate, dilate blood vessels etc
What are the three main types of neurons
Sensory
Relay
Motor
What is the job of the sensory neuron?
carries information from sensory receptors to the CNS - produces sensations
Where are sensory neurons located?
Near the skin
What do sensory neurons look like?
long dendrites
Short axons (1 axon split into two branches)
Myelin sheath
What is the job of the motor neuron?
carries information from the CNS to the muscles - produces movement
What do motor neurons look like?
short dendrites
Long axon
Myelin sheath
What is the job of the relay neuron?
Allows sensory & motor neurons to interact by connecting the other two neurons - located in the CNS
What do relay neurons look like?
Short dendrites
Short axon
No myelin sheath
Describe the process of synaptic transmission?
An electrical impulse in the pre synaptic axon triggers vesicles to release NT’s into the synapse
These then bind to post synaptic dendrite receptor sights
MOVEMENT IS ONLY ONE WAY (can only go from pre to post as receptor sights are only on post)
Neurotransmitters are either ____________ or _____________
excitatory
Inhibitory
What does a NT with an excitatory effect do?
increases positive charge - creates action potential - electrical impulse fired
What does a NT with an inhibitory effect do?
increases negative charge which means no firing
What is an example of an inhibitory neurotransmitter?
Serotonin
Whether the post synaptic neuron fires on is down to ___________
Summation
Which glands are a part of the endocrine system?
Testes
Pineal gland
Ovaries
Pituitary gland
Adrenal gland
Thyroid gland
Pancreas
What do the testes produce?
Testosterone
What does the pineal gland produce?
Melatonin
What do the ovaries produce?
Oestrogen
What is the pituitary gland known as?
The master gland
What does the adrenal gland produce?
Adrenaline (fight or flight)
What does the thyroid gland produce?
thyroxine (metabolic rate)
What does the pancreas produce?
insulin (regulates blood sugar levels)
What is an infradian rhythm?
Anything that takes longer than 24hrs to complete
What is an example of an infradian rhythm?
the menstrual cycle (roughly 28 days to complete)
How long does a circadian rhythm last?
24 hrs
Outline a study into an infradian rhythm
- McClintock studied a group of women who had irregular cycles
- She collected pheromones from these women via pads in their armpits
- the pads were then frozen and treated
- they were then rubbed under the noses of other women
What did McClintock find? (Infradian rhythms)
McClintock noticed that for the receiving women their cycles changed to match the women who the pheromones had come from
What is the McClintock effect?
menstrual synchronisation
What are pheromones?
external hormones that affect other people’s behaviours
Seasonal affective disorder is an ____________ and ___________ rhythm
infradian
Circannual (yearly cycle)
What is an Ultradian rhythm?
One that takes less than 24hrs to complete
What is an example of an Ultradian rhythm?
the sleep cycle
What are the 5 steps of the sleep cycle?
(1) light sleep - very easily woke - brain produces alpha waves - frequency is high
(2) light sleep
(3) deep sleep
(4) deep sleep - hard to wake - brain producing delta waves - low frequency
(5) REM sleep (rapid eye movement) - producing theta waves - likely to have dreams -
What are two strengths of research into infradian rhythms?
Adaptive: it was suggested that synchronisation in women can be adaptive as they would produce breast milk at the same time i.e. if a woman died her infant could still be cared for and carry on the gene line
Practical application: SAD - the development of light therapy to treat SAD - effective
What is a strength of research into Ultradian rhythms?
High internal validity: sleep studies have highly controlled settings - lab experiments which regulate light
What are two limitations of research into infradian rhythms?
individual differences: McClintock study could have been affected by CV’s e.g. other internal biological processes she couldn’t have controlled - diminished internal validity
Low reliability: nobody has successfully repeated McClintock’s study - the findings lack reliability and so the validity can be questioned
What is a limitation of research into Ultradian rhythms?
Low external validity: sleep studies aren’t usually set in ideal sleeping conditions - lack mundane realism and therefore findings have limited applicability
