Biopsychology Flashcards
Nervous system
Consists of the central nervous system and the peripheral nervous system . Communicates using electrical signals ,
Central nervous system
Consists of Rhett brain and the spinal cord and is the origin of all complex commands and deliciousness ,
Peripheral nervous system
Sends information to the CNS , from the outside world and transmits messages from the CNS to the muscles and glands in the body ,
Somatic nervous system
Trabsmits information from receptor cells in the sense organs to the CNS , it also receives information from the CNS drugs directs muscles to act ,
Autonomic nervous system
Transmits information to and from internal bodily organs . It is autonomic as the system operates involuntarily (automatic) it has two main divisions , sympathetic and parasympathetic nervous system l
First function of the nervous system
To collect and prices and respond to information in the environment ,
Second function of the nervous system
To coordinate the working of different organs in the cells in the body .
The nervous system is divided into two subsystems
Central nervous system
Peripheral nervous system
The CNS is made of the brain (1)
The brain is the centre of all conscious awareness , the brains outer layer , the cerebral corext is only k and if covers the brain like an organ be peel covers orange only found in mammas
CNS is made up of the brain (2)
The brain is highly developed in humans and is what distinguishes our higher mental functions from those other animals .
Squid for no brain
CNS also has spinal cord
The spinal cord is an extension of the brain . It passes messages or and from the Brian and connects nerves to the PNS . It is also responsible for reflex actions such as pulling your hands aaay dorm hour plate
What is the pns divided into
Autonomic nervous system
Somatic nervous systems
What is the endocrine system and five some examples of the glands
The endocrine system works alongside the nervous system to control vital functions in the body
IT ACTS more SLOWLY than the nervous stream but has very widespread and powerful effects . Various glans in the vidt such as the thyroid gland m produce hormones , Hormones are secreted Umbro the blood distress abd affect any cell in the body that has a receptor for that particular homeone ,
Most hormones affect cells in more than one body organ
This leads to many diverse and powerful responses l for example k the thyroid gland produces , the hormones leading to thyroxine m this gienibw affects cells in the heart . It also affects cells thought out the body increasing metabolic rates . This in turn affects growth rates ,
What is the main glands in the endocrine gland
Is the pituitary gland located in rain often called master gland , but it controls release hormones from all endocrine glands in the body ,
Endocrine and ANS working together fight or flight
Often the endocrine system and autonomic nervous system work in parallel with one another . For example during a stressful event m stressor is perceived , first thing that happens is a part of brain called hypothalamus activates pituitaeybfland and triggers activity in the sympathetic branch of the autonomic nervous stream l
ANS changes from its normal resting state to the physiologically aroused sympathetic state l scary movie sympathetic kick in
What is adrenaline
It is the stress hormone m which is released from the adrenal medulla . Of the adrenal gland lying near your kidneys , into the blood stream . Adrenaline triggers physiological changes in the body which creates the physiological arousal necessary for the fight or flight response
Immediate and automation
All of this happens in an instant , as soon as the threat is detected . This is an acute response ans an automatic reaction , in the body , the physiological changes associated with this sympathetic responses are listed in the table below right .
These changes explain why stress panic or even excitement are Doreen experiences as a sick feeling ,
Parasympathetic action
Finally once the regards has passed the parasympathetic nervous system , returns the body to its resting rate , the parasympathetic branch of rhe ANS works in opposition to rhe symrpshdif nervous system l
IT ACTS we w antagonistic to the sympathetic system . The parasympathetic system , acts as a brake and reduces activities sof the body that ere increased by actions of rhe sympathetic branch . This sis sometimes referred do as rets snd digest response
Neurone
The basic building blocks of the nervous system neurone are nerve cells that process and transmit fight electrical and chemical signals l
Neurone
The basic building blocks of the nervous system neurone are nerve cells that process and transmit fight electrical and chemical signals l
Sensory neurons
These carry messages from the PNS to the CNS . They have long dendrites and short axons l
Relay neurons
These connect the sensory neurons to the motor or other relay neurons , they have short dendrites and short axons ,
Motor neurons
These connect to the CNS to effector such as muscles and glands . They have short dendrites and long axons ,
Structure of neuron (1)
Neurons can vary in size from less than a m to up to a metre long , but all share the same basic structure . The cell body includes a nucleus which contains the genetic material of the cell Branchlike structures called dendrites , protrude , from the cell body . These carry nerve impulses from neighbouring from neighbouring , neurons toward the cell body ,
Structure of a neuron -axon
Axon carriers the impulse away from the cell body , down the length of the neuron . The axon is covered in a fatty layers of myelin sheath that protects the axon and appends up electrical transmission of the impulse .
The structure of a neuron (3)
If the myelin sheath was continuous , this would have the reverse effect and slow down electrical impulse . Thus , the myelin sheath is segmented by gaps called the nodes of ranvier . This speeds up the transmission of the impulse , by forcing it to jump across the gaps axon l
Finally at the end of rhe axon are terminal buttons , that communicate with the best neuron in the chain across a gap known as the synapse ,
Location of neurons
The cell bodies of motor neurons may be in the CNS. , but they have long axons which form part the PNS , sensory neurons are located outside the CNS , in the PNS is cluster known as ganglia . Relay neurons make up 97% of all neurons and most are found within the brain and rhe visual system ,
Electrical transmission - the firing of a neuron
When a neuron is in a resting state , the inside of the cell , is negatively charged compared to the outside , when a neuron is activated by a stimulus , the inside of, the cell becomes positively charged for a split Sidon causing an action potential to occur . This creates an electrical impulse that travels down the axon towards rhe end of the neuron ,
Chemical transmission
Neurons communicate with each other within groups known as neural network . Each neuron is separated from the next by ab extremely thin gal called the synapse ,
Signals within neurons are transmitted chemically , across rhe synapse ,
What happens when the electrical impulse reaches the end of the neuron
When the electrical impulse reaches the end of the neuron (presynaptic terminal ) it triggers the release of neurotransmitter from tiny sacs called synaptic vesicles.
Neurotransmitters
Neurotransmitters are chemicals , thst diffuse across the synapse to the next neuron in the chain . Once a neurotransmitter crosses the gap it is taken up by a postsynaptic receptor site . Once the dendrites of the next neuron in the chain . Once a neurotransmitter crosses the gap , it is taken up by a post synaptic receptor sites on the dendrites on the next neuron . Here the chemical message is converted back to an electrical impulse , and the process of transmission begins again in this other neuron ,
Neurotransmitter (2)
It is worth noting that the direction of travel can only be one way . This is because neurotransmitters are released from the presynapfic neuron tenal and received by rhe postsynaptic neurone
Neurotransmitter (3)
Several dozen types of neurotransmitter have been identified in the brain . Each neurotransmitter has its own specific molecular structure that fits perfectly into a postsynaptic receptor site , similar to lock and key . Neurotransmitters, also have specialises functions for instance acetylcholine , is found at each point where a motor neuron meets a muscle and upon irs release will cause muscles to contract l
Excitation and inhibition
Neurotransmitter have either an excitatory or inhibitory effect on the neighbouring neuron . For instance the neurotransmitter serotonin causes inhibition in the receiving resulting in the neuron becoming more negatively charged and less like,y ro fire ,
Summation
Whether a postsynaptic neuron fires is decided is decided by the process of summation . The excitatory and inhibitory influences are summed . If the net effect on the post synaptic neuron is inhibitory then thr, then the post synaptic neuron is less likely to fire l if the net effect is excitatory , it is more likely to fire , i.e the inside of the post synaptic neuron , m momentarily becomes positively charged . Once rhe electrical impulse is created if passes down the neuron . Therefore , thr action potential of the post synaptic neuron is only triggered if the sum of the excitatory and inhibitory signals at one time reaches the threshold .
What is the localisation function
The theory that different areas of the brain are responsible for specific behaviours processes or activities ,
What is the motor area
A region of the frontal love involved in regulating movement ,
Somatosensory area
An area of the parietal love that processes sensory information such as touch
What is the visual area
A part of the occipital lobe that receives and process sensory information such as touch
Auditory area
Located in the temporal lobe concerned with the analysis of speech base information
Broca’s area
An area in rhe frontal lobe in rhe left hemisphere , responsible for speech production
Wednickes area
An area of the temporal lobe in the left hemisphere responsible for language comprehension
Localisation vs holistic theory
Certain areas of the Brian associated with psychological and physical
Before scientists had holistic fire of brain l all parts of brain were associated with processing thought snd action
How bro a and wernicke argued for localisation of function
Different parts of the brain perform different tasks , and are involved with different powers of brain m so if a certain sort of rhe brain becomes damaged thr function associated with that area will also be affected
Hemispheres of the brain (1)
Main part of rhe brain , cerebrum is divided into two halves , the left and right hemisphere . Some of our physical and psychological functions are controlled or dominated by a particular hemisphere this is called lateralisation l
GENERAL RULE - activity on rhe LHS brain controlled by right hemisphere
ACTIVITY on RHS brain controlled by rhe left hemisphere
How is the hemisphere subdivide.
Subdivided. Into four. Centres lobes kf rhe Braun
Frontal
Parietal
Occipital
Temporal
Back of frontal lobe in both hemispheres
Motor area
At the front of both parietal lobes
Somatosensory area
Occipital lobe at the back of the brain
Visual area
Temporal lobes house
Aydifory Asda
Language centres of the brain (1)
Language is restricted to thr left side of brain in most Opelousas .
Damage to Broca’s area causes aspahasia slow speech , lacking fluency .
Damages to wernicje area causes what
Severe difficulties understanding lanagauge ,speech produced was meaningless , lanagueg undedtabdinf damages .
Evaluation of localisation of the brain evendience from neurosurgery
One strength of rhe localisation theory is the damage areas has been linked ro mental disorders ,
Neurosurgery is a last resort method for treating some mental disorders , targeting specific aesas of rhe brain which may be involved , cingulofomy involves isolation a defiant callss gurus which has been implicated with aOCD.
Evaluation of localisation of the brain evendience from neurosurgery (2)
Darin Dougherty reported 44 people with OCF who had undergone cinguloftomy , a post surgical follow up after 32 weeks about 30 perfect had met the criteria for successful response ro rhe surgery and 14 per cent for partial response l the success of these process dues suggest that behaviours associated with serious mental disorders may be localised
Localisation of the brain evidence for brain scans
Another strength is evidence from brain scans that supports rhe idea that many everyday brain functions are localised
Steven Peterson used brains scans ro demonstrate how wendickes area was active during a listening task and Broca’s area was active during a reading tasks .
Localisation evidence from brain scans (2)
Also a review of long term memory studies by Buckner ans Peterson revealed that semantic and episodic memories reside in different oarr of rhe prefrontal cortex .
These studies confirm localised areas for everyday behaviours . Therefore objective methods for measuring brain activity have provided sound scientific evidence that many brain functions are localised ,
Brain scans - counterpoint
A challenge to localisation rheory comes from rhe work of Karl Lashley . Lashley removed areas of the cortex between 10 and 50 percent in rats that were learning thr route through a mass ,no area was proven to be more improtwnt than any other area in terms of the rats ability to learn rhe route . The process of learning seemed to require every part id rhe cortex darter than being confined ro w prriculwe area
This suggests that higher cognitive processes such as learning are not localised but distributed in a more hoslifc way in rhe Brian
Language localisation questioned a limitation
One linriaifion is that langauge may not be localised just to Broca’s and wernickes area . A recent review by Anthony Dick and Pascale Tremblay found that only 2 per cent of modern researchers m thinks that langauge in the brain is completely controlled by Broca’s and wernickes areas . Advances in brain imagining techniques such as Camarillo , mean that neural processes in the brain can be studied with more clarity than ever before
Language localisation questioned (2)
It seems that language function is distributed far more holistically in the brain than was first thought . So called langauge streams , have been identified across the cortex including brain regions in rhe right hepisphere as well as subcritical regions such as the thalamus ,
This suggests that rather than being confined to a couple of key areas , langauge may be organised more holistically in the brain which contradicts localisation rheory ,
What is hemispheric lateralisation
Idea that two halves of the brain are functionally different and that certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other as in the example of langauge .
Split brain research
A series of studies which began in the 1960s (and are still ongoing ) involving people with epilepsy who had experiences surgical separation of the hemispheres , of their brain to reduce severity of their epilepsy . This enables researchers to types t lateral functions of the Brian in isolation ,
Left and right hemispheres (1) language
The two main centres are only in the LH x Broca’s area is in the left frontal lobe and wernickes area in thr left temporal lobe . So we say that langauge is lateralised x that is performed by one hemisphere rather than re rather than the other . RH only produce rudimentary words and phrases but contributes to emotional context ro what has being said .
LH is the analyser
RH is the synthesiser
Many functions of the brain are not lateralised
Vision , motor and somatosensory areas appear in both hemispheres . But there is a further twist , in the case of the motor area the brain cross wired - thr RH controls movement on the left side of the body , whilst the LH controls movement on the right .
In the case of vision , the situation is even more complex , it is both contalateral and ipsilateral , . Each eye receives light from the left visual field and the right visual field .
LVF both eyes is connected to the RH and RVF of both eyes is connected fo rhe LH .
THIS enables , the visual areas , to compare the slightly different perspective from each eye and aids , depth perception . There is a similar arrangement for auditory input ro the auditory area and rhe disparity from two inputs ro help us locate the source of sound s
What does a split brain research
A split brain operation involves severing the connections between RH and LH mainly the corpus callous . This is a surgical procedure to reduce epilepsy . During an epiletic seizure the brain experiences excessive electrical activity which travels from one hemisphere to rhe other . To reduce fits the connections are cut l splitting the brain in bald
Split brain studies how the hemispheres ducnrions when they can’t commucniwye with each other
Sperrys research
Roger skerry devised a system to study how two separated hemispheres deal with speech and vision
Roger Sperry PROCEDUREN
eleven people who has split brain operation were studies using a special set up in which an image could be projected to participants RVF and the same or different image could be projected ro rhe LVF . in thr normal brain , the corpus callosum would immediately , share the information between both hemispheres giving a complete picture of the visual world . However , presenting the images to one hemisphere of a split brain participant means that rhe information cannot be conveyed from that hemisphere to rhe Ron.er ,
Sperrys research
When a picture of an object was shown to a partricipants RVF linked ro in kf
Findings sperrys research - findings
When a picture of an object was shown to a participant RVF , linked to LH participnt could describe what was seen . But they could not do this , if the object was shown to the LVF.
-They sid there was ‘nothign here’
-This is because , in the connected brain , messages from thr RH are delayed , to the language centres in the LH , but this is not possible in the split rin ,
finidngs - sperrys research (2)
although participants could not give vebral labels to obects porjected to the LVF , tgey could select amtching object out of sight (see picture ) using thier left hand (linked to RH) . The left hand ws also able to select an object thwat e as most closelya ssoicted with an object presented to the LVG (for insace) an ashtray was selected in resposne to a picture of a cigareete . IF A PINUP picture ,w as shown to the LVF , there ws an emotional reaction but hte participants usually reported seein nothing orj ust a flash of litj .
CONCLUSIONS =- these observations show certain fucnitons are lteralised in the brain and suport the view that LH is verbal and RH is silent but emoiton .
evaluation - laterilisation in the connected brin
one strength is reserch showing that even in connected brains the wo hemispheres process informtion differentl .
-GEREON FINK used PET scans to identify which brain areas were active during a visual processing task / When prticipans with connected brains were asked to attend to GLOBAL ELEMENTS of n iamge , rgions of the RH were much MORE ACTIVE .
-when reuired to focus in on the finer detil ( such as individual teees ) the speicifc ares of the LH tended to dominte . This suggetss that at lest as far as visual processing is concerned , hemispheric lteralisaiton is a feature of the CONNECTED BRIAN as well as split brian .
evaluation - one brain
one limitaiton is he idea that the LH as analyser and Rh as a synthesiser may be wrong . There may be different funcitons in the RH and LH , but research suggetss poeple do not have dominnt side of their brain which reates different personality .
-Jared Nielsen , analysed brain scans over 1000 people aged around 7-29 yeard and did find ht ppl used certain hemispheres for certain tasks . BUT THERE WAS NO EVIDENCE o a dominant sid enot aritistsbrain or mathematicians brain , This suggest tha the notion of right / or left brained people is qwrong .
Evaluation - research support
one strength is support from more recent split-brain research .
-Michael Gazzaniga showed tha split-brain prticipans ususeally perform better thn connected controsl onc ertain tasks . FOR EXAMPLE , theyw ere faster t idenityign the odd one out in an array of similr obekcts thn normal controls in the normal brain . THE LH better cogntivie strategeis are watered don byt he inferior RH . This uspports sperrys earlier findings that left brain and right brain are disticnt .
generalisation issues
one limitiation of sperrys resaerch is that casual relationships are hrd to estblish . The behaviou of sperrys split brain paticipants was compred to a neutotypical contorlg roup .
-An issue though is that none of the paticipans in the conrol group had epilepsy .THIS IS A MAJOR confounding variable anyd ifferenes that brains were obsevred between two grous may be the resul of epilepsy rather than the spli brain . THIS MEANS soem of the unique features of split brain paritipans cogniiv ebailties might have been due to their epilepsey .
plasticity
describes the brains tendencey to change and adapt as a result of experience nd new learnign . This geenrally invovles the growth of new connections
what is funcitonal recovery
a form of plsticity folllowing damage throguh trauma , the brain’s ability to redistribute or transfer funcitons usually performed b a damaged area to other undamaged areas .
brain plasticity
during infancy , the brain experiences a rapid growth in the number of synaptic connection it hs speakign around 1k per neuron at 2-3 years of age rarely used connections are deleted nd frequently used connections are strengthened - a proces sknwona s synaptic pruning .
brai has lfielong plasticity whee neural connections are formed in response to new demands on the brain .
research into plasticity - elanor maguire
studied the brains of london taci drivers and found a significan tmore volume of gre matter int he posterior hippocmpus than in a amtched controlg roup . This prt of the brain is associatrd with the developemnt of spatial and navigational skills in humans nd other animals .
research into plasticity (2)
as part of their training - london cabbies must takr a complex test called ‘the knowledge’ which assesses thier recall of the city streets and possible routes . maguire found thsat this larning experience alters thre strcture of the taxi drivers brains ., they also found that th longeer the taaxi drivers had bee in the job , the more pronouncd was the structurual difference 9 a positive correlaiton )
research into plasticity (3)
a similar finding was observed by BOGDAN draganski , WHO IMAGED THE BRAINS OF MDICAL students three months before and after their finl exams - learning induced changes were seen to have occured in the poserior hippocampus and prietl cortex 0 presuambly from learning ..
functional recovery - after brain trauma (1)
following physical injury , or other forms of trauma such as the expereince of a stroke , unaffected areas of brain are often able to adapt and compensate for those ares that are damaged .
When may unctional recovery occur
The functional recovery that may occur in the brain after trauma is an example of neural plasticity . Healthy brain areas , may take over the functions of those areas , thst are damaged destroed or even missin .
-Neurosicenists sugegsts that this process can occur , wuickl after truama , And then slow down , after several weeks r motnhs . At this poitn the indivindual may require rehabiliative therapy to further their recoveyr .
What happens in the brain during recovery
the brain is able to reqire and reorganise , itself , by forming new synapic connecitons , close to the area ofdamage . (a bit avoiding roadworks on the way o school by idfferent route).
-Secondary neural apthways that would not typically beused to carry out certain functions are activaed or unmasked , o enable functioning to continue often in the same way as before . This process , is suppored by a number of strcutrual changes in te brain .
axonal sprouting
the growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways .
denervation supersensitivity
this occurs , when axons that do a simialr job become aroused to a higher , level to compensate for the ones tha are lost . HOweger , it can hae the negative consequence of oversensitivity to messages such as pain .
recruitment of homologous (simialr _ areas on the opposite sirs of the brain
This means , tht specific tasks cana sitll be perfomed , an example owu ldbe if the brocas area was damaged on the left sid eof the brain ,t he right sidr eqiuvalne twould carry out its functions after a period of time , funcitonality my then shift back to the left side .
evaluation - negative plasticity
one limitation of plasticity , is that it may have negative behvioural consequences . Evidence , has shown that the brain’s adaptation to prolonged drug use leads to poorer , cognitive functioning in later lfie , s wel as an increased risk of dementi .
-Also 60-80 percent of amputees , have been known to develop phantom limb syndorme - the conitnued experience of sensations , in the missing lim as if it were sitll there . THESE sensations are usually unpleant painful , and are thought due to cortical reorganisatio in somatosenosry cortex that occurs as a result of limb loss . This usggets that the brains abillity to adapt to dmage is not laeays beenficial .
evaluation age and plasticity -
one strength , is that brain plasticit may be a life-long ability . In general plasticity , reduces with age . However Ladina Bezzola et al demonstrated how 40 hrs of golf training , produced changes in the nural representations of movement in aprticipants aged 40-60 /
-Using fMRI , the researchers observed increased motor cortex , activity , in the novice golers compared to a control group , usggesting more efficent neural represenations after traingn ,t his hsowns th neural plasticity can continue throguhout the lfiespans .
evaluation - real world applications(1)
one strength of functional recovery , research is its real world appliciation , . Undwerstanifng , the processes ivnvoeld in plastciity , has contriubted to the field of neurorehabilitation . SSimply udnerstadning , the axonal growth is possible enocurages new therapies o eb tried .
plasticit - real world application (2)
- For example , constraint-induced movement therpay is sued with stroke patients wherby they repeedly practicse using the affected par of their body (such as an arm ( while tthe unaffected arm is resrained .
-This shows , that research , into funcitonal recovery is susefula s it helps medical professional h know when interentions ot be amde .
evaluation - cognitive reserve
one limitiation , of functional recovery , is that level of education may infleucne recoery rates . Eric Schneider , revealed ha the more time people with a brain injury , had spent in education - taken as an indiciaiton of the cogntiive reserve the greater their chances of a disabiity - free recovery (DFR) .
-40 percent of those who achieved DFR had more than 16 years m education compred to about 10 percent of those who has elss than 1 years educiton / This would imply that people with the brain damage who have insufficen DFRR are less liekly to achive full recovery .
funcctional magenetic resoancne imagingn
a method used to measure , brain acctivity , while a person is performing a tasks . FMri dwerect radiowaves , from chanigng magentic ifeld . This enables resarchers to detect whichr egion of the brian are rich in oxygen and this are active .
electrocenephalogam ECG
a record of the tiny electrical impulses produced by the brain activity , . By measuring , characteristic wave patterns the CG , can help diagnose certain coduction of the brain
event related potentials (ERPs)
electrophysiologcial response of the brain , to a specific sensory cgntiive , or mtor event can be isolated through sttisitical analssi of ECG dat .
post mortem examinations
the brain analysed after death to deermine whether certain observations behaviours during , the persons lifetimes , can be linked to stuctura abnormalities in the brain ,
how does fmri work
works b detecting the changes in both blood oxyegnation and flow that occcur as a resut of neural brain activity , in specific parts of th ebrain area .
-When a brain are ais more active it consumer moe oxygen and to meet this deamdn , blood flow i directed to the active sarea , to undersand loclisation of funcitons .
electrocenophalogram
measures electrical activity within the brain via eectrode that are fixed within the brain via electrodes that are fixed to an individuals scalp using a skull cap . The scan recordin represents , the brainwve pattenrs that are generated from the action of tohusand neurons proviin n overall acount , of brain activity .
-ECG is often used by clinicals as a diagnostic tool as unusual arrhytmic pattenrs of activity (no particular rhythm) may indiciate neurological abonrmalities such as epilepsy tumour , or some sleep disorders .
event related potentials
although EEG has many scientific and clinical applications in its raw form , it is a crude and overly general measure of braina ctivity . However , within EEg data are contained all the neural responses associated , with specific sensory , cogntiive and motor events that my be of interest to cogntivie neuroscientsts . As such research have developed a way of reasing out and isolaing these responses .
event related potentials (2)
using a stasticial averaging techniqus all extraneous brain actiity fromt he original EEG recording is filtered out leaving only those resposnes that relate , to say the presentation of a specific stimulus or performance , of a specific task .
-What remains are event relaed potentials , types of brainave that are triggered , by particual events . Research has revealed manyd ifferent form of ERP an dhow the example these re linked to cogntiive processes sucha s attention and percpetion .
post mortem examainations
this is a technique involign the anaylsis of a person;s brain following their death . In psychological research individuals , whose brain , are subjected , ot apost mortem examinations , are likely , to be those who have a rare diosrder , and have experiences unusual deficicts in cogntiive processes or behaviour durin their lifeitime .
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post mortem examinations (2)
AREA OF DAMAGE within , the brain are examined after death was as a eman of establishing the likely cuase of the affiliction , to the person experienced . This may also nvovle , comparison with a neutotypicl brian in order to ascertain the exrent of the difference .
evaluation - funcitonal magentic resonance imaginign - STRENGTHS
One key strength of fMRI is unlike other scanning techniques such as PET it doe snto rely on the use of radiation .
-If administered correctly it i vietually risk fre , non invasive and also straigtfroward to use .
-Produces images that have a very high spatial resolutiion , depicign , detial by m provigin clr pic of how brain activity is localised , mening fmri safely provided clear pic of brain activit /
evaluation - limitation
fMRI , is expensive compared to other neuroimagiing technique , has poor temporal reslotuion as there is a fie second time lag behind , the image on screen and the intial firing of neuronal activity . This means fMRI may not truly represne tmoment to meoent brain acitivyt .
electrocephlogram - strength
ECG has been useful in studing the stages of sleep and in the diagnosisi of conditions , such as epilepsy a disorder characterised by random bursts of activity such as epilepsy a disorder chatactaerses b random bursts of condition such as epilepsy a disorder chracterised byr andom bursts of activity int he brian that can easily be detected ons cnren .
electropehlogram strengths (2)
unlike fMRI EEG , technology , has extremely high temporal resolution . Today;s EEG technology , can accurately detect brain activity at a resoloutio of a single millisecond , this hsows real world usefulness of the technique .
electrocephalogram 0 limitiaations
the main drawback fo EEG lies in the generalised nautre of the inofrmation received (that of many thousands of neurons ) / The EEG , signal is also not useful for pinpoing , the exact source of neural;s activity . Therefore it does not llow researchers o ditinguish beteen activiries orgingiating in different but adjacent locations
event related potentials - strengths
the limitiations of EEG , are partly adressed through the use of ERPs . These bring much more specificity to the measurement , of enurl processes than could ever be achieved , usign raw ECG , data .. as ERs are derived from ECG measurement that ha excellent temproal resoltuion especiallyw hen compred to neuroimahign echniques such as FMRI .
event related potentials streengths 92)
This means that ERPS , are frequently used to measure cogntive funciton nd deficits such as he allocation of attentional resources and the maintenance of WORKING MEMMORY .
event related potentials - limitiation
crticis , have pointed to a lack of standaraisaition in ERP methodology between different research studies which make it difficult to confirm findins . A furhter issue is that in ordee to establish pure data in ERP sudies backgrounds , noise and exranoeus amterials must be completely eliamted this is a porboem because it may not be able to achieve .
postmortem examination - strengths
post mortem evidence is vital in providing a foundation for ealr understanidng of key porcesses in th ebrian . Pul Broca and Karl Wernicke , btoh relied on post morte , studies to establish links betwen lnagauge behaviour and decades before neuroimaging even became a possibility .
-post mortem studies were used to study HM brain to identify areas of damage which ocud then be assoicated with his memory deficits . This emans post mortems contineu to provid euseful informairon .
limitiation of post mortem examinations
causaiton is an issue wihtin these studies . Obserbed damage to the brian may not be linked to the deficits under review but to some other unrelated trauma or decay . A futher problem is that post mortem studies , raise ethical issues , of consent from the idnividual before death .
-Participants may not be able to provide informed consent , for example in the case of Hm , who lost his ability to form emmories and was not able to provide such consent - noentheless , post mortem research has been conducted on his brain . THIS CHALLENGES USEFULLNESS , OF post mortem studies in psychological research .
biological rhythms
distinct patterns of changes in body actbity that conform to cyclilcal time periods . Biological rhythms are influenced by intenrl body clocks (endogenous pacemakers) as well as eternal changes to the enviornemnt (exogenous zeitgebers) .
circadian rhythms
biological rhythms subject to a 24 hours , cycle , which regulate a number of body processes such as he sleep/wake cycle and changes in core body temp .
circadian rhythms - biological rhythms
all living orgniama ,plants animals and people are subject to biolofical rhythms , an these exert an important infleunce on the way in which body systens begave . All biological rhythms are govened by two things , bodies intenral body clocks endogenous pacemakers . 4changes in the envionmnt exogenous zeitgebers
circadian rh ythms - biological rhythm (2)
some of these rhythms occu many times during the day ultradian rhythms .
-oothers take longer tha a day to compelte infradian and in some case mcuh onger (circannual rhythms )
CIRCADIAN RHYTHMS - are those rhythms that lat around 24 grs m .
the sleep wake cycle
the fact we feel drowsy when its night time and alert during the day demonstates the effect of daylight an important exogenous zeigeber on our sleep wak e/cycle .
-HOWVEER , the sleep.wake ccle is also governed by an inernal endogenous pacemaker , a biological clock called SCN
What is SCN
THE SCN , lies jus above the optic chaisms , which provide difnormaitons from the ey about light .
-exogenous , zeitgebers cant rese the SCN .
wHAT IF THE BIOLOGICL CLOCK WAS LEFT TO ITS OWN DEVICES . WITHOUT THE IFLUENCES OF EXTENRLA STIMULI SUCH AS LIGHT IF WE HAD NO IDEA WHETHER IT WA SNGHT OR DAY WOULD WE ALL ASLEEP AND WAKE UP AT REGUALR ITEMS RESEARCHRS HAE TRIED TO ANSER THI QUESION .
Sifferes cave study
caveman who spent several extended periods undergound to study the effects of it own biological rhythms . Deprived of exposure to ntural ligh and sound , but with acess to adquare food and drink .
siffre cave sutdy (2)
suffre resurfaced in m id septemeber 1962 after tw motnsh int he caves of the southern alps beleiving it to be mid august . A decade alte rhe did it again for six motnhs in a texan cave .
-In each case , his fre running biological rhythms ettle down to one that was25 hrs , though he did continue to fall asleep and ekeup on a regualr scheudle .
similar researh was done like cave study
by aschoff et all eight paritpcants were spending four weeks ina world war 2 bunker which was deprived of natural light . All but one of the pariticans whose sleep wake cycle extended to 29 hrs dispaked a circadian rhythm betwene 4-25 ,
siffre expweirne an dbuker study SUGGET NATURLA SLEEP WAKE CYCLE MAY BE SLIT LONGER THAN 2 HRS BUT IT IS ENTRIANED BY EXOGENOUS ZEITGEBERS ASSOCIATED WITH 24 JR DYA /
similar researh was done like cave study (2)
despite this , we shoudl onot overstimate the infleucne of exgoenous zeitgeers on our itnenrla ioglcial cloc . simon foakrd sudie group of 12 people whoa greed to live ind akr ave thre eweeks .
1145 sleep 745 wke , over tes tudy , clock speeded up so 24 hr day lasted oly 2 hrs .
PARITICPANTS COMFROTABLY ADJUSTED TO THE NEW REGIEM . this woudl sugets the exisence o a strong feee runinig circadian rhythm canno tbe easily overidden bye xogenous zeigebers .
evaluation of shift work strength
one strength of research into circadian rhythms is that it provides an udnerstadning of adverse , consequences that occur when they are disrpted . DESYCNHRONISAITON .
NIGHTWORKERS ENAGEGD IN SHIFT WORK EXPERIENCE A PERIOD OF REDUCED COCN AROUND 6 IN THE RMONIG MEANIN MSITAKES AND ACCIDENT ARE MORE LIEKLY . RESERCH HAS ALSO POTINED T A RELITONSHIP BETWEEN
-DSHIFT WORK AND POOR HEALHT
THREE TIMES LIKELY TO DEVELOP HEART DISEASE
-THIS HSOWS that reserch into the sleep wake cycle may have real world economic impliciitons , in temrs of how ot best manage worker produciti v .
evaluation - shift work counterpoint
however , studies investigating the effects of shift work tend to use correlaitonal emthods . this means ts difficult ot esrablish whether desycnhronisation of the sleep wak ecycle is actually a cause o negative effects . There may beother facros . charlene solomon concldued that hgih divorce rates in shift workers might be due to the strain of depirved sleep and other infleunces such as missing out on important family events ..
-THIS SUGGESTS THAT IT MAY NOT BE BIOLOGICAL FACTORS THAT CREATE ADVERSE CONSEQUENCES ASSOCIATED WITH SHIFT WORK.
evaluation - medical treatment - strength
another strength of research into ciricadian rhythms is that it has been used to improve medical treatments .
-Circadian rhythms coordiante a n umber of the bodys basic processes such as heart rate digestion and hormone levels . These rise and fall during the course of day which has led o the field of chonotherapeutics - how medical treatment can be adminsited in a ay that correspns to a persons biological rhytjs/
evaluiton medical treatment - weakenesses
for example , aspririn as treatment , for hert attach is mot effective is taken last thing a tngih . Spririn , reduces blood plaelt activty and this can reduce the risk of heart atttacks / Heart attacks re most liekly to occur erly in the morning , so the itming of aking aspirirn matters . Research suported this .
-THIS SHOWS circdian rhythm reserch can help icnreae the effecrivnees of drug treatments /
evluation - individual differences
one limiitation of research into circadian rhythms is that generlaisaiton are difficult to mke .
-THe studies , descirbed on the facing page , are based on very sample , ocf paticpants , is seems tht sleep. wake cycle may eb vay didely from perosn to person . research by charles , found idnivudal differences in sleep wak ecycle varying , from 13-65 in adiditon o sjanne duffy , reela have antrual prefenrce sof going bed ealrya nd rising early .
siffre obseved his sleep wake cycle had sloed down sinc ehe as a yougn man . THIS MEAN THAT IT IS FIFFICULT TO USE HE RESEARCH DAYA to discuss anthigm more than aberages which may be meaningless .
meaning of infradian rhythm
a type of bioogical rhytghm with a frequency of less than one cycle in 24 hrs , such as menustration and seasonal disordee .
ultradian rhythm
a type of biological rhythm , with a frequency of more than one cycle n 24 grs sycg as sthe stages of sleep (sleep cycle _
menustral ccle - infradian rhythms
28 days , firs tday eriod . 2to compelte 28 .
each cycle eoestorgen cause obary to devleo egg whcih is relased , and progestoe heps womb to thicker ,r eadign wombf or peganncy , if egg not absored , womb lining comes aey and leaves body mensutal flow .
synchronising the menstrual cycle (1)
although the menustral cycle is an endogenous system , evdience sugges that it may be infleunced by exogeenous factors , such as the cycles of other women . A study by kathleen and mcclintcok demosntrated how ensutral cycles may synchronise as a result of the influence of the phermones .
stern and mcclintcok (2)
29 eomrn , history of irregual rperiods , sampel phermoens , gathe from nine of woemn differne t stages of their menustral cyles .
-cototn pad place din armipt , pad word for 8 hrs , then to enusre pehrmoens picked up
-treated with alcohol and roxne rubbed on upper lip of apriticpant , on dy one pd sta added to 20 women , were ll iven a pad for second day of cycle and so on
stern mccmlintcok found 68 percent wie xeoerubced chsngr o thie rvyvle whic brought them clsoer to odour donor .
wht is seasonal affective disorde
is a depressive disorder which ha a seasonal pattern of onsent and is described and diagnosed as a mental disorder in DSM-5 . As with other forms of depressiion , the main symptoms of SAD are PERSISTNE LOW MOOS , alongside a egenreal lack of interst and acvitiy in lfie , soemitems called winterblues , due to dalysighc hrs beign horer in winter .
sad part two
sad is a particular type of infrdian rhythm called circannual rhythm as it is subject to a yelryc yle . hwoever , it cn also be claeed as ircadian rhtym as the expeirence of SD may be due to rhe disurption in sleep wake cycle , and this can be attribute dto proonged peirods of dily darkenss udirng the winer .
sad part three
psychologists have h ypothesises that hte hormone melatonin is implicaed in the cause of SAD , during the night , the pineal gland , secretes melaatonin unutl dawn when there is an incease in lgith . during winter , the lack of light in the mornign means this secretion process contineus fo rloner . this is thought to have a knock on efect ont he porduction of serotnon in th ebrin , chemical linked oto the onset of deprressive symtpoms .
ultradian rhythms - satges sleep
psychologiss have identified five disitnct stages of sleep that span approx 90 minutes cycel thatc ontinues htoruhgot the ocurce of the night . Each of these stages is characterised b a differen level of rainwave activity which can be montitored using an EEEG .
stages 1 and 2 sleep
light sleep where a person may be woken easil . brin wave highr equency hsor ampltiue dlpha waves
stage 2 alpha wase continue btuu occional random changes in patterns called sleep spidnles .
stages 3 and 4
this is known as deep sleep /. the brainw avs are dekta waves with lwoer freuenc higher amplitude difficult to wak esomeone at his point .
stages 5 (REM)
the body paralysed yet braina ctivity closely resembles that of the brain . Duirng this time , the brain produces theta waves and eyes occasionl mvoe around thus rapid eye moemnt REM dreams re experienced here but also in deep sleep .
evaluatio - evolutinoary basis
one strength of menstrual synchrony research is tht it my be explained by natural selection . Synchronisation of the menstrual cycle of the kind observed in the stern and mcclintcok study is thought some to have evolutionary value .
-For our distance ancestors it may be advanategous for woman to mensutrate otgether and become pregannt at the same time . In social groups this owuld allow babies who had lsot thier mothers during or ater childhood to access brestmilk imporing strtageiss o surival synchornisaion adaptve .
evaluatio - methodological limitiations
one limitation of synchronistion studies is their methodologicl shortcoomings . There are manyf cors that may effect change to the menstrual cycle , inclduing stress , changes in diet , excersie . THIS MAY ACT AS confoudnign variables which means that any suppose pattern of synchronisiton is no more than would have expected to occur byc hange . THIS MAYE XPLAIN why other studies have failed to replicate the findnigs . MENSTRUAL synchorny tudies flaeed .
evaluation - improved understanding
one strength of research into ultradian rhythm is that it has improved understanding age related changes in sleep . Sleep scientits have observed , that SWS , reduce with age growth hrmone is mostl produced SWS , therefore this is reduced in odler poeple .
-According , to Eve can culture et al the resulting sleep deficit , may explainv arious issues in old age such as reduced alternes .. In order to increase SWS , relaxaction and medicaion may be used , this usggets that kwnoeldges of ultradin ehyrrhms have praxtcal value .
evaluation - idnvidual difference s
one limtiiaiton of ultradian rhythms reserch is there is significant variarion betwen people . Adrienen tucker found large differneces betwene paripcants in terms of the duration of each sleep stage paricualrly stages 3 nd 4 . Tucker suggetss that these differenves are likley to be biologicallyd eermined . This makes it difficult to describe , nromal sleep in an menaignful way .
edongenous pacemakers
internal body clocks that regulate many of our biological rhythms such as the influence of the scn in the sleep or wake cycl .
Exogenous zeitgeibers
External factors that affect or entrain our biological rhythms, such as the influence of light on the sleep wake cycle
the scn
it is a tiny bundle of nerve cells located in the hympothalamus in each hemipshere of the brain . It is one fo the primayr endogenous pacemakers , in mammals , species and is influentila in maintaining the circadian rhythms such as the sleep/wake cycle , Nwerve fibres conencting the optic chiasms on their ways to the left and rigght area of the cerebal cortex .
scn (2)
SCN lies above the optic chiams it recieves informationa bout light direclty from this strucute hsi contieus even when our eyes are closed enabling biologicl adjusts chaning pattenrs of dalishg where we re asleep
