biopsych

post mortem ao1

• Establish the underlying neurobiology of particular behaviour 

• The person dies and they examine the brain to look for abnormalities which could explain their behaviour

post mortem ao3

/ research support (Broca), Vital

X male to female study, cause and effect, informed consent

fMRI ao1

• Functional magnetic resonance imaging

• Measures brain activity while a person performs a task, blood flow

• Indicated neural activity as more blood flow goes to the active area 

• As results on changes of blood flow researcher are able to produce maps

fMRI ao3

/ non invasive, high spatial resolution

X cost, poor temporal validity, stay still

EEG ao1

• Measures electrical activity in brain

• Electrodes are placed on scalp detect small chargers resulting in activity of millions of neurons 

• When electrical signals from different electrodes are graphed over period of time

EEG ao3

/ various brain disorders, high temporalvalidty

X poor spatial resolution, general measure

ERPS ao1

• Although EEG has clinical and scientific applications, raw form is too general

• However EEG data are all contained all the neural responses associated with specific sensory, cognitive and motor events 

• Researchers have devised a way of teasing out and isolating these responses using statistical averaging technique 

• All extraneous brain activity from the original EEG is filtered out leaving only the reposes that relate to the presentation of a specific stimulus it performance of a specific task

• What remains are event related potentials, triggered by particular  events

ERPS ao3

/ clinical research, more specific, temporal reolution

X procedures change so not standardises, variables hard to control

localisation

the theory that specific areas of the brain are associated with particular physical and psychological function

lateralisation

the dominance of one hemisphere of the brain for particular physical and psychological functions- speech is lateralized in the left hemisphere

somatosensory

• parietal lobe

• sensory information is located

motor area

• frontal lobe

• controls voluntary movement in the opposite Side of the body

visual area

• occipital lobe

• visual information

auditory area

• temporal lobes

• analyses speech information

• wernickes area

localisation of function- strengths

• MRI scan, fantastic spatial resolution and direct evidence, tilting from memory showed different LTM are stored in different places

• destructive, remove and cut the brain can help severe mental health decisions, the success of procedures suggest behaviours are associated with localisation

• Phineas gage

localisation of function- weakness

• Lashley, suggested basic motor and sensory functions were localised but higher functions weren't. experimented on rats and found learning was a holistic thing

• lahsley implication, effects of damage to the brain is determined by the extent rather then location, over last 70 years humans are able to regain cognitive ability, this plasticity shows localisation can be overcome

Phineas gage case study

large iron pole through his head at his railway job, he stayed conscious but as the pole went through the brain his personality was altered

plasticity ao1

• describes the brain ability to change and adapt as we gain new experience, grow and learn new things

• Infants experience a lot more then adults but we are always capable of plasticity

• as we age, rarely used connections are deleted and regularly used connections are strengthened

plasticity ao3

• Maguire et al, found London taxi divers, against a control group, had larger amounts of grey matter in their posterior hippocampus and the longer the job the more grey

• Medical students, there was more grey matter before the exam then after, suggesting the connections delete after not used

• bilingual, bilingual people compared to monolingual had larger parietal Cortex

functional recovery ao1

• the brains ability to remap itself following trauma or stroke, if one area is damaged another area can compensate for it

• The brain is able to rewire itself by forming new synaptic connections

functional recovery ao3

• practical application

• maladaptive plastiicty, phantom limb pain

• educational attainment, schneider et al found the longer time spent in education the more likely to recover

3 things of functional recovery

1. axonal sprouting- the growth of new nerve endings which connect with other undamaged nerve cells to form new neural pathways.
   
   2. Reformation of blood vessels
   
   3. Recruitment of homologous (similar) areas on the opposite side of the brain to perform specific tasks. For example if Broca's area was damaged (left side) the same area on the right could take over its function.

split brain research

• 11 ppts that had there corpus callosum split to help their epilepsy

• this allowed speedy to investigate what actions are controlled by what hemisphere

• they would show a picture on L or R of the dot for 1/10th of a second

• language is lateralised left so when picture was right they could draw it not say it

• when presented right they could say it

sperry AO3

• Highly controlled lab setting with controlled and standardised equipment

• contribution to science, won a Nobel prize and was a seminal study that has paved the way for future research to happen

• generalisability- only had 11 patients that had a special surgery so can be argued we can’t generalise. The ppts also had epilepsy so brains could of been damaged due to that

• sparked pop psychology- he had no control over this but it has created left or right brained with no credibility

• positives of it- rogers found chickens had undergone same surgery would multi task better then before the surgery

circadian rhythm

is a specific type of biological rhythm occurring across a 24 hour period

• core body temp and hormone production are extra circadian rhythms

a biological rhythm

cyclical patterns within biological systems that have evolved in response to environmental influences

the suprachiasmatic

• every cell had a body clock and all synchronised by master circadian pacemaker

• this pacemaker must be constantly re sets so our bodies stay in synch with the outside world

• In mammals, light sensitive cells in the eye act as a brightness detector and send messages to the SCN to elp regulate circadian rhythms 

the sleep wake cycle

• daylight we feel awake and darkness we get sleepy

• therefore the absence of daylight has impact on bio rhythms

• The circadian rhythm also dips and rises at different points of the day, so our strongest desire to sleep occurs between 2-4am and 1-3pm this is heightened if bas sleep night before

• it is free running and will maintain a 24 hour cycle even with absence of external cues

circadian rhythm AO3

• siffres cave study

• wever

• folkard

• shift work- warns managers about the rhythm being out of sync and that more accidents happen at 6am

• drug application- taking medications at a certain time for them to be more effective, so they sync up with circadian rhythms

Siffres cave study

• Siffre several extended periods underground to study the effects of lack of external cues on his own biological rhythms.

• Siffre went underground in July 1962 and when he surfaced 8 weeks later in mid September he believed it was mid-August. 

• His body clock always settled into a rhythm just over 24 hours (around 25) and he always fell asleep and woke up regularly.

wever

• Ppts to spend 4 weeks in WW2 bunker deprived of natural light 

• All but one had a circadian rhythm, of 24-25 hours 

• Both these studies show that our natural circadian rhythm, may be slightly over 24 hours

folkard

• Ppts lived in cave for 3 weeks, rising at 7.45am and bed at 11.45pm 

• They gradually speed up the clock so that a 24 hour day was redacted to 22 hours 

• Results were the ppts found it difficult to adjust when they started messing with the cycle so this is further support rhythms are hard fired and free running in us

Infradian rhythms

• longer then 24 hours

• menstruation and seasonal affective disorder

Ultradian Rhythms

• less then 24 hours

• stages of sleep

infradian menstrual cycle

• average cycle is 28 days and runs from period day 1 to day before next period

• oestrogen causes ego release, progesterone thickens the lining

• if egg isn’t fertilised

infradian ao3

• Reinberg, women in a cave for 3 months with a lamp and cycle shortened from 28-25.7 days. Suggest the lack of light effected her cycle and to some extent governed exogenous zeitgebers

• changing rhythms- stern and mcclintock demonstrated women can syncronise. 9 women collected pheromones from armpit, they were treated and frozen. It got rubbed on lip of other 20. 68% synced up with their odour donor

• mate choice- when females are ovulating they prefer male features and other points more feminine. Evolutionary explanation as gives them an adaptive advantage

SAD

• 
  Seasonal affective disorder affects people during the winter when more darkness 

• As dark for longer more melatonin is released therefore less serotonin is secreted 

• More likely to have heart attack and deaths in january

Ultradian Rhythms

• stages 1-4 are non rem, 5 is Rem

• cycles last 90-100 minutes and can be shown in EEG

Ultradian Rhythms ao3

• evedicne- dement and kleitman 9 ppts in a sleep lab under controlled lab and found ppt only remembered dreams when they woke up

Basic Rest Activity cycle

• kleitman believed cycle was every 90 minutes of phases of alertness to fatigue. Human mind looses focus after 90 minutes

Basic Rest Activity cycle- AO3

• ericsson studied elite violinist, sessions were limited to 80 minutes with frequent naps to recover, same pattern was discovered with other musicians and athletes

endogenous pacemakers a01

• internal body clocks that regulate our biological rhythms

• suprachiasmatic nucleus

• pacemaker must be constantly reset

• light provided the primary input into this system

exogenous Zeitgebers a01

exogenous Zeitgebers ao3

• external factors in the environment that reset our biological clocks

• absence of cues the body attempts to keep the free running rhythms

endogenous pacemakers ao3

• mutant chipmunks had SCN connections destroyed in 30 brains, they got put in the wild and majority died as they were vulnerable to attack when they should be asleep as their sleep wake cycle disappeared

• mutant hamsters, bred hamsters with 20 hour sleep/weake cycle and transplanted scn into normal and they defaltbdto the same 20 hour cycle. These studies shoe how crucial the SCN is as an endogenous

• alt pacemakers- they exist in other cells and run independently from the SCN