Biopscyhology Flashcards
Define plasticity
The brain adapts to both its function and structure as a result of change in the environment.
What are the reasons for plasticity?
-learning new skills
-result of developmental changes
-response to direct trauma to an area of the brain
-response to indirect effects of damage such as brain swelling or bleeding from stroke
Define functional recovery
The functions that were preformed by areas of the brain that are lost (neuronal cell death) or damaged are preformed by undamaged areas of the brain :functional reorganisation
Define synaptic pruning
Synapses that are used frequently become stronger overtime however unused synaptic connections are lost this makes the brain a more efficient communication system overtime.
Define axonal sprouting
Existing neurons growing new axons to connect to adjacent neurons neural regeneration is the growth of new neuronal cells
Define Denervation supersensitivity
To compensate for the loss of axons in a pathway the remaining axons become more sensitive this can result in side effects such as pain.
Factors affecting functional recovery
-age, children have a better ability to recover
-gender, woman are more able to recover from brain damage
-rehabilitative access
What’s constraint induced therapy?
Stopping patients from using coping strategies like body and language for communication or using undamaged limbs for tasks which makes them improve via functional reorganisation.
What study did Maguire et al 2000 research?
Structural MRI brain scans of 16 male taxi drivers were compared to the brain scans of 16 matched non taxi drivers as a control. The posterior hippocampi in the London taxi drivers were found to be significantly larger than the controls also the size of the posterior hippocampi was positively correlated with the amount of the time working as a taxi driver.
What do maguire et al 2000 study findings suggest?
Suggests the physical structure of the brain is plastic able to reconfigure itself to better adapt to psychological demands in taxing drivers to improve memory formation.
What did Danelli et al 2013 study discover?
Case study of a 14 year old EB at the age of two and a half eb has a hemispherectomy of the left side of his brain to remove a tumour. This removed the language centres of brocas and wernickes areas immediately after surgery be had lost all language availability its however two years after recovery be had recovered his language ability even without his left hemisphere be developed normally as he ages aside form some dyslexia like symptoms researchers noted fmri scans showed the right hemisphere followed a left like blueprint for language this research’ suggests that the brain can adapt and recover after significant damage especially early in life with the right hemisphere taking roles usually performed by the left
Practical applications of brain plasticity and functional recovery
It’s been useful in rehabilitative therapy helping people return to their lives and productive work ultimately benefiting the economy
A strength of doing research on brain
Research on the individuals recovering lost function can help psychologists understand more about the functions of regions of the brain that were initially damaged
Individual differences in recovery of brain plasiticity and functional recovery Mathias 2015 do they have a positive or negative background?
Mathias 2015 metanalysis demonstrated in iq and educational background are positively correlated with better outcomes after traumatic brain injury suggesting some individuals have a greater cognitive reserve helping in recovery
Define the human nervous system
Body wide system of nerve cells that collects info from the world processes this info and then takes action by directing body organs and muscles via the transmission of electro chemical messages
What is the central nervous system made out of and what are their functions?
The brain and it controls all conscious and most unconscious processing
The spinal cord and it receives and transmits info and some reflex processing
What is the peripheral nervous system and what does it do?
Body wide network for messenger neurones where the sensory neurons deliver info to the CNS and motor neurons deliver info away from the CNS.
What does the somatic nervous system control?
Controls skeletal muscles for movement this is a voluntary system which means its under conscious control
What does the autonomic nervous system control?
Controls actions of internal organs and glands and its an involuntary system which means its not under conscious control
What does the ANS sympathetic response do ?
Increases bodily activity and releases noradrenaline activates in stress responses flight to flight
-increases 💗 rate
-increases sweat
-breathing rate increases
-dilates pupils
-inhibits digestion
What does the ANS parasympathetic response do?
Decreases bodily activities and releases acetylcholine activates in rest
-💗 rate decreases
-sweat decreases
-breathing rate decreases
-constricts pupils
-stimulates digestion
Define homeostasis
Regulation of the internal environment in normal conditions there is a balance between sympathetic and parasympathetic systems this is called maintaining homeostasis.
What is the process of the reflex arc?
Sensations are detected and electrical impulses are sent through the cell body to the axon its then transformed into a chemical neuron the reflex response us passed onto the motor neuron the signal will reach the effector and cause the muscle to move.
What are the features of the relflex arc?
LOOK AT PIC
Define synapse
The point where one neuron can send a chemical message to an adjacent neuron
Define neruotrasmitter
Chemical messengers released by neurons stimulating the development of an action potential in other neurons
Define synaptic transmission
When the action potential arrives at axon terminal this causes the vesicles to merge the membrane of the presynaptic cell releasing neurtransmitters into the synaptic cleft these neurtransmitters diffuse over the synaptic cleft reaching the postsynaptic cell
What is the summation process?
The effects of all the excitatory and inhibitatory neurotransmitters influences on the postsynaptic cell and if the threshold is reached a new action potential is formed and travels down the next axon.
Define excitatory neurotransmitters
Neurotransmitters that increase the likelihood of a new action potential forming they make the electrical charge inside more positive and more likely to fire (depolarisation)
Define inhibitory neurotransmitters
Decrease the likelihood of a new action potential forming as they make the electrical charge inside more negative and less likely to fire (hyperpolarisation)
What is reuptake?
Neurotransmitters are reabsorbed into the presynaptic cell after transmitting a neural impulse this happens at transport proteins and prepares the cell to fire again
What is the endocrine system?
Collection of glands around the body that regulate bodily function growth and psychological factors acts by releasing chemical messengers called hormones into the bloodstream
What does the pituitary gland do and what hormone controls this?
Controls release of hormones from other glands known as the master gland
Hormone- ACTH adrenocorticotropic hormone
What does the hypothalamus do and hormone?
Links the nervous system to the endocrine system in combination with pituitary. maintains homeostasis of bodily systems
Hormone CRH corticotropin releasing hormone
What does the pineal gland do and hormone?
Modulates sleep pattern keeping the body to a day/night circadian rhythm
Hormone-melatonin
What does the thyroid gland do and hormone?
Modulates metabolism hormone thyroxine
What does the thymus gland do and hormone?
Stimulates the development of T cells that work in the immune system helping with disease resistance active until puberty hormone-thymosin
What does the pancreas gland do and hormone?
Regulates blood sugar levels problems with this system leads to diabetes hormone-insulin and glucagon
What does the adrenal glands do and hormone?
Regulates biological effects of the fight or flight response increasing 💗 rate blood supply to muscles and sweating extensively hormone-adrenaline and cortisol
What do testicles and ovaries do and hormones?
Reproductive glands develops secondary sexual characteristics appearing at puberty hormone -oestrogen and testosterone
What is the fight or flight response ?
Evolutionary survival mechanism in reponse to a threat primes the body for extreme action the body returns to homeostasis after the threat has passed
What is acute stress?
Common form of stress in response to immediate pressures can be exciting in small amounts and give you focus and energy but exhausting if maintained
What is chronic stress?
Long term form of stress in response to prolonged emotional pressure this often occurs in situations that the individual feels unable to control.
What is the process of flight or fight?
-a stressor is perceived
-the hypothalamus activates the pituitary gland triggering the systematic branch of ANS
-ANS enters systematic state
-adrenaline which is released from the adrenal medulla enters the bloodstream which triggers physiological changes in the body
-this occurs immediately and automatically
-once the threat has passed the PNS returns the body to its resting state
What are the effects of adrenaline?
-increased blood flow
-dialated pupils
-increased sweat
-increased alertness
What is a stress repeated illness?
Constant triggering of fight or flight reponse in chronic stress has long term effects on physical and mental health fight or flight response shuts down immune system
Define localisation of function?
Functions such as movement speech and memory are preformed in distinct regions of the brain the opposite view is the brain acts holistically to perform functions.
What areas of the brain are functionally specialised?
Motor,somatosensory, visual and auditory cortices are on both sides of the brain, Broca’s and wernickes areas
define hemispheric lateralisation
Each hemisphere of the brain is specialised to perform different functions
define contralateral
Each hemisphere of the brain controls the opposite side of the body
Define cortex
Surface layer of the brain referred to as grey matter as its mostly cell bodies
Look at brain pic and where each functionally specialised part of the brain is
Where are the motor and somatosensory cortex?
Motor cortex is at the back of the frontal lobe and the somatosensory cortex is at the front of the parietal they are divided by a fold called the central sulcus and are contralateral
What can damage to the visual cortex do?
Damage leads to partial or complete loss of vision called cortical blindness
What is the motor cortex responsible for and what can damage to it cause?
Responsible for voluntary motor movements damage to it can result in loss of muscle function or after severe trauma paralysis
What is the somatosensory cortex reponsible for and what can damage to it cause?
Responsible for recieveing sense impressions from around the body damage can lead to loss of sensation ignoring areas of the body loss of a ability in recognising objects by their feel
What is the auditory cortex reposible for?
Receives and processes sound info from ears
What is Broca’s area responsible for and what does damage cause?
Responsible for speech production discovered after case study and post mortem of tan whon damage can lead to brocas aphasia difficulty in producing fluent speech
What is wernickes area responsible for and what does damage causes?
Responsible for speech comprehension damage can lead to wernickes aphasia difficulty to understand language
Why are clinical case study research a strength of LOF?
Clinical case study research demonstrates loss of certain function if damage is caused to particular areas of the brain e.g. Clive wearing amnesia this suggests functions are localised in these areas
Why are modern brain scanning techniques a strength of LOF?
Support older research on language centres showing activation in the regions associated when healthy ppts perform language tasks
Why can case studies be a weakness in LOF?
The use of case studies are seen as unscientific especially in brain research with damage often covering multiple regions
Why are the funtions of the brain being connected be a weakness in LOF?
Motor and somatosensory functions are highly localised suggesting the correct approach in arguing for the localised or holistic nautrue of the brain is dependant on the function also due to high connectivity of the brain no one area is dependant
What did Lashley in 1925 research?
50 rats ran a maze before and after areas of their brain cortex were destroyed Lashley found ability to successfully re run the maze was affected by how much of the brain cortex wasn’t destroyed not which area this suggest higher cognitive processes such as learning and memory aren’t localised but distributed across the brain as the more brain is destroyed the worse functioning becomes
Define corpus callousum
Thick bundle of nerve fibers connecting the left and right hemispheres
What did Sperry research and find in his 1968 split brain study ?
Research on 11 patients who had their corpus callosum cut to treat epilepsy a quasi experiment comparing patients who had undergone corpus callosotomy using experiment that would project info to each visual field sperry controlled the info that each hemisphere had access to ina series of tests ppts would be required to either say what they had seen, draw the object or select the object that were hidden from view with their hands.
Sperry found that info presented to the left hemisphere could be spoken but not spoken if delivered to the right hemisphere however the right hemisphere could draw or select the object by using the left hand suggesting the hemispheres are both capable of acting indpendantly also supporting the theory that language centres are the the left side of the brain
What did Gazzaniga find in his 1983 facial recognition study?
Found that when each hemisphere of split brain patients were presented with faces the right hemisphere was much more able to recognise them suggesting that the right hemisphere is specialised for facial recognition.
Why is a small sample and a weakness in split brain research? And why are the results ungeneralisable
The sample of split brain patients was small ppts and were compared against non epileptics had varying amounts of connections cut and all undergone drug therapy this suggests some of the results may have been due to ppts variables making the results ungeneralisable to the wider problem
Why do research on split brain have a low external validity?
The experimental procedures used in split brain patients in unlike how these individuals would process info and act in normal day to day life
How does the research on split brain having a fundamental impact a strength?
It had a fundamental impact of the psychological understanding of the consciousness and identity suggesting that the brain is a combination of separate intelligent processes working together.
Define spatial resolution
Level of accuracy in identifying the exact location of a brain structure or brain activity in space.
Define temporal resolution
Level of accuracy in identifying the exact location of a brain activity in time
What happens in a postmortem dissection?
Brains are precisely cut after treatment to give a firmer texture unusual brains are dissected such as brains suffered trauma or from individuals with mental illness these brains are compared with neurotypical brains
How was the Broca’s area discovered and what was the name of the patients?
Broca’s area responsible for language production and was discovered using postmortem on a patient called tan who could only say the world tan damage in an area of the frontal lobe was found after.
Why is high spatial resolution a strength of postmortem?
High spatial resolution of post mortem allows the study of microscopic brain structures down to the neuronal level
How can theories be generated with post mortem technique (strength)
As postmortem isn’t conducted on a living Brian and there is damage you can’t find out everything but theories that are tested with different techniques can be found
How have post mortem techniques been significant strength ?
They’ve been significant in historical development of psychology understanding of brain functioning such as the discovery of language centres.
What does FMRI stand for ?
Functional magnetic resonance imaging
How do FMRIs work ?
Detects blood flow in the brain as more active areas of the brain need more blood these active areas can be compared to low activation areas with a lower blood supply and displayed on an fmri image
Do fmris have good spatial resolution?
Have good spatial resolution of approx 1 mm precisely identifying active regions of the brain and patterns of activation overtime while ppts complete experimental conditions.
Are fmris non invasive?
Non invasive and safe technique for experiments compared to options that use radiation like PET scans
Do fmris have good or bad temporal resolution?
Poor temporal resolution as one image is taken every few secs and delay in blood flow after activity many brain processes are too fast to study
What are other weaknesses of fmris?
Expensive machine, must be perfectly still
What does EEG stand for?
Electroencephalogram
What does an EEG do ?
The device collects between 22-34 electrodes that are attached to a cap and fitted carefully to the scalp with. Conductive gel and read out from each electrode is the sum total of activation of the brain cortex under the electrode this is displayed as a series of lines showing distinct patterns called brain waves amplitude show brain wave intensity frequency shows the speed of the activation
How is lack of spatial activity a weakness in EEG?
Lack of spatial activity as pattern is sum of large number of neurons in the cortex under the electrode also can’t detect activity deep within the brain
Why is the research found through eegs important ?
Historically important in understanding brain activity in areas such as sleep research and medical diagnosis.
Are eegs cheaper or more expensive than fmri?
Cheaper and able to be used in experiments in which the ppts moves
Do eegs have good or bad temporal resolution?
Very good temporal resolution accuracy meaning the brain activation with a resolution measured in milliseconds
What do ERP stand for?
Event related potential
How do ERPs work?
Uses the same technique and equipment as EEG but presents a stimulus many times creating a smooth curve of activation by combining the data in a process called statistical averaging this removes background electrical noise unrelated to the stimulus the waveforms peak and dips show exactly when cognitive processes in the brain happen after the stimulus is presented
Strength of ERPs finding isolated research?
Allow researchers to isolate and study how individual cognitive processes take place in the brain while EEG records general brain activity
Do ERPs have a good or bad temporal resolution?
Good temporal resolution with a millisecond sampling rate
Do ERPs have a good or bad spatial resolution?
Poor spatial resolution some processes can’t be studied with ERP as they can’t be presented a large number of times with the same response
Define endogenous pacemakers
Internal body clocks that keep biological processes to time
Define exogenous zeitgebers
External cues that entrain internal body clocks meaning alternating body clocks to match the environment
What is a circadian rhythm?
A biological rhythm that lasts around 24h
What do we have a circadian rhythm for?
We have a circadian rhythm for regulating sleep and wake the release of hormones and varying our body temp and blood pressure the sleep wake cycle is the pattern of sleep and wakefulness that repeats every 24h.
Why do we need an internal body clock?
There must be an internal body clock that keeps this pattern and we are aware of conflicts between EP and EZ like light and social cues in situations like jet lag
What does SCN stand for?
Suprachiasmatic nucleus
What is the Suprachiasmatic nucleus?
The SCN is the endogenous pacemaker for the sleep wake cycle it is also known as the master clock the SCN is part of the hypothalamus within the limbic system its located in the optic chiasm the point on the optic nerves where they cross when light is detected by the SCN it sends light to the pineal gland stopping the production of melatonin
What acts as an exogenous zeitgerber?
Light is the primary EZ, social cues like when we time our meals or exercise when others go to bed or environmental cues like clocks are thought to be EZ.
What are the procedures and findings of Siffre 1975 free running circadian rhythm?
The circadian sleep wake cycle endogenous pacemaker is thought to be free running maintains a predictable cycle without constant entertainment by ez. This was tested by spending 179 days in a cave with no natural light or other potential ez such as clocks or social cues. Siffres body clock maintained a regular cycle of around 25h without ez longer than the expected 24h cycle suggesting the ep for the sleep wake cycle is free running but need entrainment to keep to the 24h day and night cycle.
What are the criticisms of natural light isolation studies?
Psychologists have criticised the use of artifical light in isolation experiments on the sleep wake cycle suggesting the artifical lights have disrupted measurements of the free running circadian rhythm by acting as an ez in a study controlling for artifical light Czeisler 1999 found the circadian rhythm was closer to 24h with little drift
What were the procedures and findings of Vetter 2011 evidence light in EZ study?
When 27 office workers in an experimental group were exposed to strong blue light they would shift their circadian rhythm to match the office lighting a control group of 27 office workers with normal office lighting rhythms matched the shifting time of the natural light of dawn suggesting that. Both light is an ez and artifical lights can distrust the ep by over riding natural light as the primary ez
Ralph 1990 evidence Suprachiasmatic nucleus is a endogenous pacemaker study
Golden hamsters with the tau mutation have a circadian rhythm of 20 h compared with 24h for normal golden hamsters when the scn from normal hamsters was transplanted into the brain of tau mutant hamsters these hamsters gained a sleep cycle of 24h normal hamsters gained a 20h cycle when given the scn from tau mutant hamsters this suggest the scn is the main ep in the sleep wake cycle
What type of psychological understanding do the circadian rhythm lead to?
Due to sleep pattern distribution leading to anxiety and decreased alertness a psychological understanding will lead to solutions to the negative effects of jet lag and shift work resulting in psychology having a positive effect on the wider economy understanding the circadian blood pressure rhythm helps with timing drug treatments and health treatments
What implications does technology have on the psychological effects to exposure to light?
Blue light has implications as technology changes and we are exposed to more blue light late at night from personal devices and new led road lighting this provides ppl with a dive on how to maintain a healthy sleep pattern
What was found through research on a blind man miles 1977?
Even with social cues the blind man had a 24.9h circadian rhythm meaning his sleep was out of synchronisation with the rest of society
What is an infradian rhythm?
A biological process that are longer than 24h
What are examples of infradian rhythm?
Seasonal affective disorder this rhythm takes a year to complete emotional mood lowers in winter and improves in summer is it suspected this us due to lack of bright sunlight in winter
How long does a menstrual cycle last ?
28 day cycle with a 6 day period of fertility however cycles can be shorter or longer ranging between 24-35 days
What is the biological process of the menstrual cycle?
Releasing the egg, thickening of the womb lining and losing the womb lining during menstruation these are regulated by oestrogen and pre ovulation and progestogen post ovulation the levels of these hormones act as endogenous pacemakers keeping the biological processes to time acting as an internal body clock for the menstrual cycle
What did McClintock 1971 study find and research?
Studied 135 women who lived in the same dormitory at uni recording period onset and duration results showed women appeared to synchronise their cycles with their freindship groups
What did stern and McClintock investigate in 1998?
Investigated if synchronisation was due to women sharing pheromones 20 women were given pads to wipe on their top lip each day the pads had been taken from the armpits of 9 donor women at varying stages of their menstrual cycle the researchers found that the women would either shorten or extend their menstrual cycle to match the donor depending on when it the donor menstrual cycle the pad had been collected suggesting synchronisation due to the presence of pheromones acting as an ez an external cue for the timing of infradian rhythm.
Are pheromones accepted as chemical messengers?
Pheromones as chemical messengers aren’t accepted widely as a process that happens in humans
Why can Trevathen 1993 study of lesbian couples be used as evaluation?
Shows cohabiting lesbian couples didn’t synchronise the optimal conditions for possible sychronisation
Define ultradium rhythm
A biological process that repeats less frequently than once every 24h.
What are the five distinctive patterns of sleep stages?
Delta, theta,alpha,beta,gamma
What are the four sleep stages?
Stage 1-REM N1,N2,N3
How long does one sleep cycle take?
90 mins
What does N1 represent?
Light sleep
What is n2?
Deeper sleep
What is n3?
Deepest sleep
What is rem?
Rapid eye movement sleep
What did dermot and kleitman 1957 investigate? Study 1 and 2
EEG recordings made of 33 ppts over a nights sleep brain waves followed a cyclic pattern of activation with bodily relaxation occurring during slow wave sleep and rapid eye movement during periods of high activation
2- 9 ppts woken at diff stages in their sleep cycle reported dreaming more frequently when woken in the rem stage
What did Shapiro 1981 investigate?
Ultramarathon runners showed longer sleep after intense physical activity also an increased portion in slow wave sleep suggesting N3 is for physical recovery of the body
What did Haider 1970 investigate ?
EEG of 10 patients recovering from drug overdose showed increased REM sleep suggesting REM for mental recovery
Are the stages of sleep simple or complex and what evidence is there?
Newborn babies spend 80% of their time sleeping in REM compared to 20-25% in adults suggesting the stages of sleep aren’t simple process but adapt to the developmental needs of the individual
How have technology being developed based on the understanding of the sleep stage cycle a positive?
These track sleep and help individuals improve sleep avoiding waking in stage 4 stops people feeling groggy and disorientated this technology leads to happier healthier and more economically procudtve economy
Why is circadian and ultradian rhythm being connected a weakness?
If they’re connected perhaps they shouldn’t be seen ass separate processes Czeisler1980 showed the longest period of REM sleep coincides with the lowest point in the circadian body temperature cycle this could mean both processes could use the same internal body clock. EP
