Brain Flashcards
State the 4 lobes of the brain and where they are?
Flower pot
Frontal lobe- at the front
Parietal lobe just behind frontal
Occipital- just at back
Temporal is at side / bottom
What’s localisation of function? How’s it differ from holistic
Supported by phineas gage
Theory that different parts of the brain are responsible for different functions/ roles psychological or physical. States that if a certain area of brain is damaged by illness or injury the function associated with this part of brain will be affected.
Before this theory and Phineas gage scientists believed all parts of the brain were involved in the the processing of thought and action.
Where do the left and right hemispheres control activity?
What is the outer layer of each hemisphere called and why does this differ is from animals?
Each hemisphere controls activity on opposite side of body to itself
Cerebral cortex covers inner oats of brain and is about 3mm thick.
- ) Where is the motor area and what’s it’s function?
2. )What would damage to this area cause?
- ) It’s at the back of the frontal lobe controlling voluntary movement on the opposite side of the body.
- ) Loss of control of fine movements
- ) Where’s the somatosensory area?
- ) What type of info does it process?
- ) What separates it from the motor area?
- ) It’s at the front of both of the parietal lobes.
- ) sensory info like touch
- ) central sulcus
Where’s the visual area and what does it do?
Where’s the auditory area and what does it do?
Part of occipital lobe and receives and processes visual info.
Found in the temporal lobe the auditory area is involved with analysis of speech based info.
What’s the broca’s area and where’s it found?
What does damage to this area cause?
Found in frontal lobe in left hemisphere of the brain in most people. It’s involved in speech production.
Broca’s aphasia causing influential speech production eg. Tan.
What and where’s the wernicke’s area?
What could damage to this area cause?
Wernicke’s area- Area of the temporal lobe in left hemisphere responsible for language comprehension.
Damage to wernicke’s area can cause wernicke’s aphasia where nonsense words ( neologisms ) etc may be produced.
Phineas gage what happened to him?
What effect did it have on him?
What did it suggest?
positive evaluation points + negative
Tamping iron dropped on explosives on railways sending it through his head taking large chunk of brain with it- most of frontal lobe.
He survived but personality changed now he’s quick tempered and rude.
Change in temperament suggests frontal lobe is involved in mood regulation.
Useful as case study provides lots of data, only 1 person so hard to generalise and lacks pop val. Our views of social behaviour may have changed since 1848 and also not as scientific as brain scans.
What is plasticity?
When does functional recovery generally occur ?
When do we have most synaptic connections
Plasticity is the brains ability to change and adapt.
After damage or trauma.
Ages 2-3 we have the most around 15,000 which is twice as many as the adult brain
What’s cognitive pruning?
Why may plasticity be a negative thing?
Cognitive pruning is where rarely used connections are deleted and frequently used connections are strengthened. This can happen through out life.
Plasticity can be a bad thing eg. Prolonged drug use leads to poorer cognitive functioning and old age associated with dementia. Both are caused by changes in the brain.
Plasticity research eg . Maguire et al
- ) who were his sample group and how’d he test them?
- ) What were the findings
- ) what’s grey matter associated with
- ) what’s the knowledge test?
- ) what’s the effect of the length of time people had been doing the job ?
- ) London taxi drivers tested with MRI scans.
- ) found more grey matter in posterior hippocampus than in the control group.
- ) Spatial and navigational skills.
4) They have to be able to recall city streets and possible routes in London - ) The longer people had been doing the job a greater structural difference eg. They have more grey matter.
Evaluation of Maguire et al
Why does it matter that people weren’t tested before the study ?
Give a limitation of the study
Give a strength
1.) you don’t know if they had a high amount of grey matter before the study which made them a suitable candidate for taxi driving.
The study is limited as only 1 part of the brain was tested ( the posterior hippocampus) so its a narrow approach/ study that doesn’t test the whole brain.
Applicable to real live due to it being a real life situation. Also objective scientific measures used eg . MRI
When does functional recovery occur?
How does the brain adapt after trauma?
How quickly does functional recovery occur?
After physical injury or other forms of trauma such as infection or brain damage.
Unaffected areas of the brain adapt to help compensate for areas of the brain that are damaged. This functional recovery is an example of neural plasticity.
Functional recovery occurs quickly after trauma then slows down after several weeks or months. Eg. Phineas gage who had a tamping iron go through his head damaging his frontal lobe.
What happens during functional recovery?
Brain rewires and reorganises itself to form new synaptic connections to areas of damage. Secondary neural pathways are activated to help functioning continue.
This is helped by blood vessels reforming,
Recruitment of homologous areas of the brain eg opposite hemisphere to the specific task and axonal sprouting (new nerve endings grow and connect with undamaged areas nerves to form new pathways.)
Humble and Wiesel study
Who did they study?
What did they find?
2 limitations
They studied kittens who they sewed one eye shut on.
The visual cortex related to the damaged eye continued to process info from the other eye showing the brain adapts and functional recovery occurs.
Carried out on animals who are less developed eg . Less developed cerebral cortex so can’t generalise.
Also the study is unethical causing physiological harm.
Factors affecting functional recovery?
Age- as you get older speed and extent of functional recovery is lessened.
Gender- women supposedly have better functional recovery then males as brain functioning isn’t as lateralised.
Education - better educated = more likely to recover.
Exhaustion- alcohol consumption, stress etc can effect the effort put into functional recovery.
What application does functional recovery have?
Limitation
Has application in neurorehabilitation where recovery slows after a few weeks so therapy is needed to keep improvements.
Often little record of functioning before trauma so hard to measure recovery.
Which hemisphere controls language?
Which sides of body do left and right hemispheres control.
What’s hemispheric lateralisation?
Left hemisphere
Opposite sides eg. Left controls right and right controls left
Hemispheric lateralisation is when one hemisphere controls specific activities.
Sperry study
What kind of p’s did sperry study?
What experimental method?
Sample size
What type of tasks asked to do
People who had commissurotomy. Their corpus Callosum had been cut so they had two separate hemispheres. This helps prevent epileptic seizures. This means they would have no communication between hemispheres
Quasi experiment
11 people who had commissurotomy to treat epilepsy
Studied performance in visual / tactile tasks
Method of sperry study
Results
You project an image or word to one visual field then
an image or word to other visual field. The image is only shown for 1/10 th of a second so person can’t
move their eye across. A normal brain would share info between both hemispheres to get a complete image.
Shown to right visual field (left hemisphere) easily could describe but shown to left visual field (right hemisphere) or said nothing was there showing language centres are in left hemisphere .
Recognising by touch
Method describe
Shown an object then have to select a matching object from behind a screen. Shown to left visual field ( right hemisphere) then could select the object or select object associated eg . Ashtray related to cigarette butt. But if shown to right visual field could not verbally identify but could recognise.
Composite words task
Method
Presented two words one either side of visual field and asked to write with left hand what is seen in left visual field ( right hemisphere). They had to say what they saw in right visual field (left hemisphere)
Matching faces
Method
Function of left + right hemispheres ?
Shown a face and asked to match it to series of other faces. If shown to left vf (rh) then correctly matched but if shown to right visual field (lh) then it would be ignored.
Left hemisphere dominates verbal description
Rh dominated selecting matching pictures.
Left hemisphere contains language centres enabling it to describe what it sees
Rh recognises What it sees and dominates drawing ability
Evaluation of sperry
Negatives
Small sample size with 11 people treated for epilepsy having corpus callosum cut
Lacks ext validity as in real life things aren’t shown to 1 visual field.
Differences might be overstated and not as clear cut as sperrys research suggests
What are the ways of studying brain functioning?
Post mortems
Functional magnetic resonance imaging
Electroencephalogram
Event related potentials
When do you carry out a post mortem?
Why would you carry one out?
Who do you compare their brain too?
Famous patient carried out post mortem on?
Why did it used to be so useful?
Why does cause and effect limit it?
Why does it suffer with ethics?
After someone has died and usually somebody with a certain disorder.
To see which areas of the brain are damaged to establish a cause for their disorder.
Neurotypical brain (normal brain)
Post mortem on Tan by Broca
Before technology it was one of the only methods of looking at the brain
Observed area of damage may not necessarily be reason for a behaviour.
Hard to get informed consent as patient is dead.
FMRI ( functional magnetic resonance imaging )
What does it measure?
Why do some areas of the brain sometimes have more oxygenated blood?
How does it work?
Positives
Limitations
Measures brain activity while completing a task and the change in oxygenated blood flow.
If a part of the brain is more active during a certain activity then more oxygenated blood is sent there.
Uses radio waves and magnetic fields
Virtually risk free method that’s not invasive, very detailed and provides better understanding of localisation. High spatial resolution.
Expensive so not always possible, patient needs to be still so not always possible with some conditions eg .Turrets. Lacks temporal resolution due to delay in Neuton firing and activity detection.
Electroencephalogram
What does it measure?
How does it measure?
What’s its purpose?
Positives
Negatives
Electrical activity in the brain
Electrodes are placed on the patients scalp detecting electrical charges from brain cell activity of patients. The scan shows brain activity.
Can help diagnose disorders with unusual patterns of electrical activity sometimes indicating abnormalities eg. Epilepsy shows spikes of electrical activity.
Useful for diagnosing abnormalities, high temporal resolution as we see things at normal time and don’t have to stay still eg. Can be done on treadmill etc
Low spatial resolution as doesn’t pin point source of neural activity.
Event- related potentials
How does it work
How does it remove any extraneous brain activity from original EEG?
Why are brain waves triggered?
Positives
Negatives
Uses data from EEG but isolates responses to specific stimulus.
Uses statistical averaging techniques to remove any extraneous brain activity from original EEG
Brain waves are triggered by something specific eg. When presented with a certain stimulus.
More specific than an EEG, good temporal resolution as happens in real time
Hard to remove all extraneous activity and lack of standardisation making it hard to compare findings between studies.
Definition of autonomic ns
CNS
- ) carries info too and from bodily organs and the system is in involuntary (automatic). Can be split into 2 main divisions (sympathetic and parasympathetic ns). It controls subconscious activity. An example would be fight or flight responses.
- ) Made of the brain and spinal chord and controls all complex commands and decisions in the body. Controls conscious activities in the body like muscle contraction and an example would be a reflex.
Somatic NS:
Excitation:
- )Sends info from receptor cells in sense organs to CNS. Then may receive info from CNS and direct info to muscle so they can act.
- ) when a neurotransmitter like adrenaline increase charge of pre synaptic neuron therefore increasing the likely the neuron will fire and pass on an electrical impulse.
Inhibition:
Sensory neuron
- ) Neurotransmitter decreases the charge at the pre synaptic neuron so the charge is now more negative therefore increasing the chance the neuron will fire and will pass on an electrical impulse.
- ) carries info from peripheral ns to CNS in the brain and spinal chord. They detect info at sensory organs and carry info to the brain and spinal chord. Sensory neurones have long dendrites and short axons.
Motor neurones dendrite size and axon size
Endocrine system:
Short dendrites long axons
System in the body that tells glands to release hormones into the bloodstream. These hormones are carried to target organs in the body. Am example would be the adrenal gland secreting adrenaline which would increase the charge of the postsynaptic neuron in excitation.
Vesicle
Neurotransmitter:
A fluid filled sac containing neurotransmitters.
They are brain chemicals release from synaptic vesicles that help relay info from one neuron to another across a synapse. Can be split into those doing excitatory functions and those doing inhibitory functions.
Lashley for holistic theory
Method / what was done?
Why does it support the holistic theory?
Evaluation
Rats were put in a maze and learnt how to run around a maze. Then scientists removed around 10-50% of their brains. Then rats could still remember route of the maze.
We use all parts of our bran to do different tasks and the brain can work together in a holistic way.
Limited as rats are less developed then humans eg. Less developed cerebral cortex so hard to compare.
Task involves many different things eg. Spatial awareness, vision etc so may not be the best choice of task
Biological rhythms what are they?
What type of factors are they influenced by?
What are the 3 types of rhythm?
Changes in bodies activity depending on cycles.
external( exogenous zeitgeist ) and internal (endogenous pacemakers)
Circadian, ultradian and infradian
Circadian rhythm how long are the cycles?
Why are they needed?
Example of circadian?
What type of factor would daylight be in sleep/wake cycle
Do some illnesses symptoms fluctuate at different times of day?
Based around 24 hours eg. Daily 24hr cycle
Circadian rhythms are needed to balance behaviour and are bodily states. 24 hours
Sleep/wake cycle eg.siffre study
Exogenous zeitberger
Yes for example heart attack’s are most likely to occur in the morning when blood is prone to clotting.
Siffre study
Where did the expert stay and how long for?
Could natural sound or light reach him?
How long was his sleep wake cycle?
What does this prove?
Limitations and strengths
6 months in a cave to see the effects on biological rhythms (eg 24hr cycle)
No
Erratic at first but adapted to 25 hr cycle
Proves that we have innate system for circadian rhythms even when exogenous zeitberger factors aren’t there.
Lacks eco val and pop val + carried out by cave specialist so not representative of real life
Aschoff and Wever study - this is just additional
How long? What setting ?
Results?
4 weeks in ww2 bunker deprived of natural light
Almost all displayed 24-25 hr circadian rhythm
This shows our normal sleep/ wake cycle may be longer than 24 hours however external factors (exogenous zeitgebers) Alter this slightly.
Folkard et al
How many participants and duration?
What happened
Researchers did what to the clock
Results
12 p’s, 3 weeks in a cave
P’s got up and went to bed according to time on the clock
Gradually sped up clock so what seemed like 24 was 22
No p’s adjusted easily so circadian rhythms aren’t easily influenced by external factors
Application of circadian rhythms studies
Why does it have real life application?
What type of studies?
What does it show about artificial light?
Limitations?
Workers switching between day and night shifts are given time to adapt so they have good productivity.
Case studies and small samples
Can influence (exogenous zeitgeber)
Individual differences between p’s eg morning people vs evening or age
Infradian rhythms how long does each cycle last?
Example?
How longs menstrual cycle and why?
What happens to oestrogen levels and what does progesterone do?
Each cycle is over 24hours
Menstruation cycle and seasonal affective disorder
28 days and occurs due to monthly changes in hormone levels
Oestrogen levels rise and progesterone cause womb lining to thicken
Stern and McClintock
Who’d they study?
How many of them did they collected pheromones from? How’d they collect this?
What did they do with the pads? What did this cause?
What does this show?
29 women with irregular periods
9 at regular intervals.
Put a pad under armpit for 8 hours.
Rubbed them on lip of participant on day 1 then different pad day 2. They then copied donor menstrual cycle. 68% of p’s experiences change.
Menstrual cycle can be affected by exogenous factors (external) eg. Other women
Seasonal affective disorder what is it?
How does it follow a circadian rhythm?
How symptoms triggers?
Depressive disorder with a seasonal pattern
Circannual rhythm as happens yearly
Winter there is fewer daylight hours. Melatonin a hormone which tells you too sleep is secreted for a longer period of time. Can also serotonin production levels eg. Lower.
Evaluation infradian
Adv
Limitations
Real life application with treatment for sad using light boxes.
Can act as an evolutionary explanation for synchronisation with mothers having period at same time so can care for offspring together
Lots of things may effect menstrual cycle such as diet.
Ultradian rhythms what are they
How many stages in sleep cycle and how longs a sleep cycle?
Stage of sleep how easily woken?
Biological rhythms where cycle takes less than 24 hrs eg. Sleep cycles studied through EEG’s
5 stages and 90 mins. Each stage monitored by EEG has different brainwave activity.
Stage 1 has light sleep easily woken . Stage 2 is deep sleep. Stage 3 is REM
Biological rhythms what are they?
What type of factors are they influenced by?
What are the 3 types of rhythm?
Changes in bodies activity depending on cycles.
Internal ( exogenous zeitgeist ) and external (endogenous pacemakers)
Circadian, ultradian and infradian
Circadian rhythm how long are the cycles?
Why are they needed?
Example of circadian?
What type of factor would daylight be in sleep/wake cycle
Do some illnesses symptoms fluctuate at different times of day?
Based around 24 hours eg. Daily 24hr cycle
Circadian rhythms are needed to balance behaviour and are bodily states.
Sleep/wake cycle
Exogenous zeitberger
Yes for example heart attack’s are most likely to occur in the morning when blood is prone to clotting.
Siffre study
Where did the expert stay and how long for?
Could natural sound or light reach him?
How long was his sleep wake cycle?
What does this prove?
Limitations and strengths
6 months in a cave to see the effects on biological rhythms (eg 24hr cycle)
No
Erratic at first but adapted to 25 hr cycle
Proves that we have innate system for circadian rhythms even when exogenous zeitberger factors aren’t there.
Lacks eco val and pop val + carried out by cave specialist so not representative of real life
Aschoff and Wever study - this is just additional
How long? What setting ?
Results?
4 weeks in ww2 bunker deprived of natural light
Almost all displayed 24-25 hr circadian rhythm
This shows our normal sleep/ wake cycle may be longer than 24 hours however external factors (exogenous zeitgebers) Alter this slightly.
Folkard et al
How many participants and duration?
What happened
Researchers did what to the clock
Results
12 p’s, 3 weeks in a cave
P’s got up and went to bed according to time on the clock
Gradually sped up clock so what seemed like 24 was 22
No p’s adjusted easily so circadian rhythms aren’t easily influenced by external factors
Application of circadian rhythms studies
Why does it have real life application?
What type of studies?
What does it show about artificial light?
Limitations?
Workers switching between day and night shifts are given time to adapt so they have good productivity.
Case studies and small samples
Can influence (exogenous zeitgeber)
Individual differences between p’s eg morning people vs evening or age
Infradian rhythms how long does each cycle last?
Example?
How longs menstrual cycle and why?
What happens to oestrogen levels and what does progesterone do?
Each cycle is over 24hours
Menstruation cycle and seasonal affective disorder
28 days and occurs due to monthly changes in hormone levels
Oestrogen levels rise and progesterone cause womb lining to thicken
Stern and McClintock
Who’d they study?
How many of them did they collected pheromones from? How’d they collect this?
What did they do with the pads? What did this cause?
What does this show?
29 women with irregular periods
9 at regular intervals.
Put a pad under armpit for 8 hours.
Rubbed them on lip of participant on day 1 then different pad day 2. They then copied donor menstrual cycle. 68% of p’s experiences change.
Menstrual cycle can be affected by exogenous factors (external) eg. Other women
Seasonal affective disorder what is it?
How does it follow a circadian rhythm?
How symptoms triggers?
Depressive disorder with a seasonal pattern
Circadian rhythm as happens yearly
Winter there is fewer daylight hours. Melatonin a hormone which tells you too sleep is secreted for a longer period of time. Can also serotonin production levels eg. Lower.
Evaluation for circadian
Adv
Limitations
Real life application with treatment for sad using light boxes.
Can act as an evolutionary explanation for synchronisation with mothers having period at same time so can care for offspring together
Lots of things may effect menstrual cycle such as diet.
Ultradian rhythms what are they
How many stages in sleep cycle and how longs a sleep cycle?
Stage of sleep how easily woken?
Biological rhythms where cycle takes less than 24 hrs eg. Sleep cycles studied through EEG’s
5 stages and 90 mins. Each stage monitored by EEG has different brainwave activity.
Stage 1 has light sleep easily woken . Stage 2 is deep sleep. Stage 3 is REM
What are the waves produced in stages 1,2 and then 3+4 in sleep?
Evaluation points for this ?
Stage 1 of sleep is light sleep and produces alpha waves. Stage 2 is also a form of light sleep and produces theta waves. Deep sleep occurs in stages 3+4 and produces delta waves
Lab studies support different stages
EEG’s are a scientific, objective measure.
Endogenous pacemakers What are they and what do they do?
Exogenous zeitgebers what are they and what do they do?
What’s entrainment?
They’re an internal body clock regulating our biological rhythms (the suprachiasmatic nucleus influences our sleep /wake cycle)
External cues affecting our biological rhythms eg. Light influences our sleep/ wake cycle
It’s the resetting of biological clocks caused by exogenous zeitgebers
What’s the suprachiasmatic nucleus ? And what does it do?
How does this work?
Where’s this info about light and day length passed onto?
What does the pineal gland do ?
It’s a bundle of nerve cells in the hypothalamus of each brain hemisphere. Helps maintain the sleep / wake cycle.
Received info about light even when eyes are shut and allows our biological clock to adjust to changing patterns of daylight even when we’re asleep
The suprachiasmatic nucleus passes on info about light and day length to the pineal gland.
Pineal gland increases production of melatonin (induces sleep) during night. This relates to seasonal affective disorder where there are less daylight hours.
Outline Decoursey et al study :
How does light affect the sleep / wake cycle?
Campbell and Murphy study outline
They cut the suprachiasmatic nucleus connections in 30 chipmunks and observed them for 80 days. The chipmunks sleep/wake cycle was altered and many were killed by predators . Shows importance of suprachiasmatic nucleus in the sleep/ wake cycle.
Light influences the suprachiasmatic nucleus and affects hormone secretion.
15 p’s they shone light on the back of their knees and it affected the p’s sleep wake cycles. Shows that light can be detected by skin receptor sites and doesn’t need to be reviewed by the eyes.
How do social cues affect biological rhythms?
What happens to sleep wake cycle at 6 weeks and 16 weeks old?
Evaluation of Decoursey et al and (Campbell and Murphy)
Mealtimes and bedtimes may affect our biological rhythms
6 weeks old develop a sleep/ wake cycle and 16 weeks old we are entrained to a circadian rhythm. This is influenced by our schedule parents give us.
Animal studies have problems with generalisability due to less developed eg.cerebral cortex and also their ethical issues.
Also in real life pacemakers and zeitgebers may interact so it may not be valid to study individually
