6 - biopsychology Flashcards
what are the divisions of the nervous system?
Central nervous system split into brain and spinal cord
peripheral nervous system split up into somatic nervous system and autonomic nervous system
autonomic NS divided into parasympathetic division and sympathetic division
what is the function of the brain?
receives and processes sensory information, and initiates a response
what is the function of the spinal cord?
conducts signals to and from the brain, controls reflex activities
what does the peripheral nervous system do?
relays messages from the CNS to the rest of the body
consists of the somatic nervous system and the autonomic nervous system
what is the function of the somatic nervous system?
controls voluntary movements, we are aware and can consciously influence
- made of sensory and motor neurons
- reflex arc
what is the function of the autonomic nervous system?
controls involuntary responses and plays an important part in homeostasis
as 2 components
1. sympathetic nervous system
2. parasympathetic nervous system
what does the sympathetic nervous system do?
‘fight or flight’
- controls and prepares body for stress, danger, and physical activity
what is the function of the parasympathetic nervous system?
‘rest and digest’
- relaxes body after emergency has passed
what things in the body increase when the sympathetic nervous system is activated?
- heart rate
- blood pressure
- breathing rate
- pupil size
what happens to digestion when in fight or flight mode?
slows down
what is the role of of the cerebellum?
controls motor skills and balance
what is the role of the thallamus
relay station for incoming pulses and directs them to the brain
what is the role of the hypothallamus
regulates homeostatic functions
what is the function of the sensory neuron?
carry nerve impulses from sensory receptors to the spinal cord and brain
converts info into neural impulses
what is the location of sensory neurons
many places e.g. eyes, ears, tongue, skin
- PNS
- some go to the brain and others go to the spinal chord to speed up reflex arc
what is the function of the relay neuron?
allows sensory and motor neurons to communicate with eachother
location of relay neurons
brain and spinal chord
what is the function of motor neurons
- conducts signal from CNS to effector organs
- form synapses with muscles
- release neurotransmitters that bind receptors on the muscles
- when axon fires, muscle contracts
where are motor neurons found?
cell body in CNS
cell bodies
project from CNS
describe synaptic transmission part 1
- action potential is in presynaptic neuron
- calcium ion channels open
- calcium ions diffuse in presynaptic neuron
- synaptic vesicles move and bind with neuron membrane
- neurotransmitter is released into synaptic cleft
- neurotransmitter diffuses into the synaptic cleft
describe synaptic transmission part 2
- neurotransmitter binds to the receptor site on the sodium ion channels
- sodium ion channels open
- sodium ions diffuse in
- new action potential (nerve impulse) is sent along axon of post synaptic neuron
describe synaptic transmission part 3
- an enzyme breaks down neurotransmitter
- sodium ion channels close
- 2 bits of neurotransmitter diffuse back across cleft to presynaptic neuron
- allows NT to be recycled
- some NT are reup taken into pre synaptic neuron
what is the function if the hypothalamus?
stimulates and controls the release of hormones from pituitary gland
what hormones does the anterior pituitary gland release?
adrenocortical trophic factor
LH
FSH
what is the function of the anterior pituitary gland
stimulates adrenal cortex to release cortisol during a stress response
regulates hormones released from the ovaries
what hormones does the posterior pituitary gland release?
oxytocin
what is the function of the posterior pituitary gland?
stimulates uterine contractions in childbirth
release of milk in breasts
thought to help bonding
what hormone does the pineal gland release?
melatonin
what is the function of melatonin released from the pineal gland
helps maintain the sleep wake cycle
important rhythm
what hormone does the thyroid release
thyroxine
what is the function of thyroxine released from the thyroid
responsible for regulating metabolism
what hormones does the adrenal gland release?
medulla-adrenaline and noradrenaline
what is the function of medulla-adrenaline and noradrenaline
key hormones in the fight of flight response
what hormone does the adrenal gland release?
cortex-cortisol
what is the function of cortex-cortisol released by the adrenal gland
suppresses the immune system
what hormones are released by the ovaries?
oestrogen and progesterone
what is the function of oestrogen and progesterone released by the ovaries?
regulates control of reproductive system, including menstruation and pregnancy
what hormone is released by the testes
testosterone
what is the function of testosterone released by the testes
responsible for the development of male sex characteristics
what are the 3 stages of the adaptive response of the fight of flight mode?
- sounding the alarm - when someone is faced with danger, eyes/ears send info to the amygdala in the brain
- hypothalamus activates sympathetic nervous system by sending signals through the automatic nerves to adrenal glands
- adrenal medulla releases adrenaline into blood stream
then parasympathetic NS is activated to return body to its normal resting state
Limitation of using the fight or flight response when applying it to modern society
E - although the physiological changes associated with the f/f response could help with life threatening situations, the stressors of modern day rarely require intense levels of physical activity
E - e.g. frequent high blood pressure and heart rate can damage blood vessels and lead to heart disease
L - therefore it is hard to assume the f/f response is always adaptive
Limitation of using the fight or flight response
not comprehensive explanation
E - gray claimed that the initial reaction to threat is to freeze and assess the situation before responding. An individual will stop, gain information, and respond to a particular threat
E - this is important as it improves chances of survival when faced with a threat
L - lack of inclusion of the freeze response demonstrates a limitation of the explanation
Limitation of using the fight or flight response
male response to danger
P - research suggests that females adapt a ‘tend and befriend’ response rather than a fight or flight
E - Taylor et al claimed women are more likely to protect their offspring (tend) and form alliances with other women (befriend) rather than fight or flee
E - fleeing may also be seen as a weakness and put offspring at risk of danger.
Furthermore, this is an example of beta bias where real differences between men and women are overlooked
L - these are important considerations when assessing the usefulness of the response
what is the primary function of the auditory cortex
analyses and processes acoustic information
describe the location of the auditory cortex
temporal lobe
what is the primary function of the Broca’s area
speech production
describe the location of the Broca’s area
left frontal lobe
what is the primary function of the Wernicke’s area
understanding language and comprehending
describe the location of the Wernicke’s area
left temporal lobe
what is the primary function of the motor cortex
responsible for voluntary movements
describe the location of the motor cortex
frontal lobe
describe the location of the somatosensory cortex
parietal lobe
what is the primary function of the somatosensory cortex
receives incoming sensory info from the skin to produce sensations related to pressure, pain, temp
supporting evidence of localisation of function
P - evidence for different functions of Broca’s and Wernicke’s areas in language production and understanding comes from the discovery that damage to these areas results in different types of aphasia
E - expressive aphasia is an impaired ability to produce language, mostly caused by brain damage in Broca’s area.
Receptive aphasia is an impaired ability to understand language and extract meaning. This is usually the result of damage in Wernicke’s area
L - This demonstrates the important role played by different brain regions in different aspects of language
describe the location of the visual cortex
back of the brain
what is the primary function of the visual cortex
receives and processes visual information
different parts process different info e.g. colour and shape
criticism of localisation of function
equipotentiality
E - Lashley proposed equipotentiality theory which suggests that basic motor and sensory functions are localised but higher cognitive functions aren’t. He claimed that intact areas of the cerebral cortex have the potential to take over functions from damaged areas of the brain
E - according to this explanation, effects of brain damage would be determined by the extent, rather than the localisation of the damage
this has some support from patients who have regained functions after damage to specific brain areas
L - therefore, this casts doubt on theories about localisation of function, as other brain regions can take over specific functions
limitation of localisation of function
individual differences
E - research shows various regions are active for some visual tasks and there are different language areas for males and females. Studies have shown significant differences in sizes of brain areas associated with language
E. Herasty et al found females have a proportionally larger Broca’s and Wernicke’s area than men, which could explain greater ease of language in females
L - therefore, can’t apply findings of localisation to males and females equally
what is hemispheric lateralisation?
idea that the two hemispheres of the brain are functionally different and each half has functional specialisations
e.g. left is language dominant and the right is visual motor tasks dominant
what are the nerve fibers called that connect the two hemispheres?
corpus callosum nerve fibers
who did the split brain research key study?
Sperry and Gazzangia 1968
what was the aim of Sperry and Gazzangia’s split brain research
the examine the extent to which the two hemispheres are specialised for certain functions
what were the experiments in the split brain research?
- describe what you see
- describe what you see
- picture presented to the right visual field and processed by the left hemisphere - patients could describe what they saw - left in language superiority
- picture presented to left visual field and processed by the right hemisphere could not describe what was shown
what were the experiments in the split brain research?
- tactile test
objects placed in right hand (processed by left)
- could verbally describe wat they felt
objects placed in left hand (processed by the right)
could not describe what they felt
what were the experiments in the split brain research?
- drawing task
picture presented in to the right visual field (processed by left h)
- would attempt to draw a picture but was never clear
picture presented to left visual field and processed by the right
- consistently would draw clearer pictures
- demonstrates superiority on right hemisphere when it comes to visual motor tasks
what was the conclusion of the split brain research carried out by Sperry and Gazzangia in 1968?
- findings highlight a number of key differences between the two hemispheres
- firstly, left is dominant in speech and language
- secondly, the right hemisphere is dominant in visual motor tasks
AO3 of hemispheric lateralisation and split brain research
supporting evidence
E - Sperry and Gazzangia carried out research on split brain patients. They found when patients were presented with an image to their right visual field, they could say what they saw but when presented with an image to their left field, they couldn’t
E - it was concluded that language functions are only located in the left hemisphere
AO3 of hemispheric lateralisation and split brain research
limitation - generalisation
P - limited scope for generalisation
E - split brain procedure is rarely carried out in modern healthcare which means pp’s are difficult to recruit. This leads to studies with very limited samples.
Andrews claims most cases had either a confounding physical disorder, or had a less complete sectioning of the 2 hemispheres
L - therefore, valid cases are very rare and it is harder to apply to a wider population
AO3 of hemispheric lateralisation and split brain research
contradictory findings
P - contradictory findings cast doubt over previous conclusions
E - claims of the left hemisphere only being capable of language related processes have been challenged
E - e.g. patient JW demonstrated contradictory results. They suffered left hemisphere brain damage but developed the ability to speak
L - this suggests lateralisation isn’t fixed and the brain can adapt following damage to certain areas
AO3 of hemispheric lateralisation and split brain research
limitation - age
P - further research has suggested that lateralisation changes with age
E - Szaflarki et al found language became more lateralised to the left hemisphere with an increasing age. But after the age of 25, lateralisation decreased with each age of life
E - this could be due to the greater capacity forms both hemispheres to compensate for age related decreases in functioning
L - questions whether everyone has one hemisphere that is dominant for particular functions over the other
strength of brain plasticity
supporting evidence
P - Maguire et al discovered that changes in the brain could be detected as a result of their extensive experience of spatial navigation
E - using MRI scanners, the amount of grey matter in taxi drivers brains was significantly larger compared to the control pp’s. It was also positively correlated with the amount of time they had spent as a taxi driver
E - this suggests highest levels of plasticity were evident in those with more extensive experience
counterargument of Maguire’s supporting evidence of brain plasticity
However, Maguire didn’t test the brains of the participants before they became taxi drivers, so the differences may not be due to the experience
With the results being correlational, it can’t be concluded the experiment resulted in different brain structure
Support of grey matter increase
Kuhn
P - Kuhn et al found significant increase in grey matter in various areas of the brain after participants played video games for30 minutes a day for 2 months, compared to control group
E - this provides clear evidence for brain plasticity
AO3 of functional recovery after trauma
supporting evidence
P - Tajiri et al provided evidence for the role of stem cells in recovery from brain injury
E - Randomly assigned rats into two groups. One group received transplants of stem cells into affected brain areas. The other was a control group and received a solution with no stem cells.
3 months later, brains of stem cell rats showed clear development of neuron-like cells in the injured area
E - this development was not shown in the control group, supporting the important role played by stem cells in the recovery from brain injury
strength of research into functional recovery
RWA
P - it as contributed neurorehabilitation which helps with the recovery of patients after brain damage
E - Electrical simulation and motor therapy have been developed for example CIMT (constraint induced movement therapy) that includes the forced use and practice of the affected site/area. This helps strengthen neural pathways.
E - this demonstrated the importance of researching and improving our understanding of how the brain recovers after injury. Providing better outcomes and quality of life for patients
What is spatial resolution?
the smallest feature or measurement that a scanner can clearly detect
what is temporal resolution?
accuracy of the scanner in relation to time or how quickly the canner can detect and feed back changes in brain activity
what is invasive/non invasive?
invasive procedures usually involve needles/ injection/ surgery, therefore can cause greater anxiety and have higher risk of complications and infection
what is a direct measurement?
questions whether the scanning method shows that the brain structure/ activity directly causes the effect or not
what does fMRI stand for?
functional magnetic resonance imaging
outline fMRIs - how it works and what they are used for
oxygenated blood and deoxygenated blood have different magnetic qualities
the scanner detects changes and active areas will be deoxygenated and show on the screen
fMRI creates a moving 3D map on the screen
used to identify specific regions related to the type of task being performed e.g. visual
what is the spatial resolution of fMRI scans? is this a strength?
1-2 mm - strength
what is the temporal resolution of fMRI scans? is this a strength?
1-4 seconds - limitation
are fMRI scans invasive? compare to another brain study technique
they are non invasive, unlike PET scans which involve injecting radioactive substances
are fMRI scans a direct measure of brain activity?
no, they can only measure blood flow then infer which is a limitation
what are other practical limitations of fMRI scans?
some people may get claustrophobic or struggle to sit still which can impact the results
what does EEG stand for?
electroencepalogram
outline EEG’s - how it works and what they are used for
- they detect electrical activity in the brain using small metal disks attached to the scalp
- neurons produce electrical activity in the form of action potential
- this AP is detected by electrodes and shows up as wave patterns
what is the spatial resolution of EEG’s? p/n?
poor - can only detect activity in superficial areas (limitation)
what is the temporal resolution of EEGs?
good - 1-10ms which is a strength
are EEGs invasive ornon-invasive?
non-invasive
do EEGs directly measure brain activity?
electrical activity is often detected in several regions so it can be difficult to identify the exact region of activity (limitation)
other strengths of EEGs
less expensive than fMRI and may be uncomfortable but likely less stressful
what does ERP stand for?
event-related potentials
outline ERP’s - how it works and what they are used for
uses the same equipment as EEG
- a stimulus is presented to the participant and the researcher observes electrical activity related to the stimulus
- stimulus is presented hundreds of times and an average graph is plotted
- identifies perceptual operations
what is the spatial resolution of ERPs?
poor - can only detect activity in superficial areas (limitation)
what is the temporal resolution of ERPs?
good - 1-10ms which is a strength
do ERPs directly measure or show a correlation of brain activity?
they enable identification of how processing is affected by experimental manipulation (strength)
outline post mortems - how it works and what they are used for
when a researcher studies the physical brain of a person who displayed a particular behaviour when alive that suggested possible brain damage
are post mortems a direct measure of brain activity?
the deficit the patient displays in life may not be linked to / caused by the damage found in the brain
there may be confounding variables such as drug treatment, time since death
limitation of post mortems
dead patient
no follow ups for potential issues since it is retrospective and uses the brain of a dead person
what is a biological rhythm?
distinct patterns of chane in bodily activity influenced by internal body clockes and/or environmental canes
what are the 3 types of biological rhythms?
infradian - more than 24 hours
circadian - 24 hours
ultradian - less than 24 hours
what was the aim of Michel Siffres research?
identify is own circadian rhythms when not exposed to any external environmental cues
what was the procedure of Michel Siffres research?
he stayed in a cave for 6 months 3 times throughout his life
he woke up, ate, and slept when he felt it was right to do so
he phoned up to people above round when he did each thin
had no tv or watches or phone
what were the findings of Michel Siffres research?
when surfacing, he got the date wrong by a month
- his natural circadian rhythm settled to just over 24 hours with some dramatic variations
- found is body clock slowed down when 60 sometimes stretching to 28 hours
what was the conclusion of Michel Siffres research?
the 24 hour sleep wake cycle was increased by the lack of external cues
- humans naturally have a sleep wake cycle of 25 hours that is internally controlled but external factors such as light re-sets it to 24
supporting evidence of circadian rhythms
P - Siffres research provides support for an internal biological body clock for the sleep-wake cycle
E - he found there were no time cues given such as clocks or natural light, his internal body clock was around 25 hours each day
counterargument for Siffres work
however, there are some important limitations. Studies where individuals isolated themselves in caves are case studies so findings only apply to that person
Furthermore, although Siffre was isolated from external cues, he wasn’t isolated from dim artificial lit. it was believed that dim light would not affect is circadian rhythm
what was research about dim artificial lit?
Furter research by Czeizler et al contradicted these findings. participants circadian rhythms were altered down to 22 hours or up to 38 hours using dim artificial lighting
therefore, results from research such as Siffres may have confounding variables which decrease the validity of the results
limitation of explanation of circadian rhythms - individual differences
P - findings from case studies cant be generalised and used to produce laws about human sleep-wake cycles as there are some individual differences that should be considered
E - Duffy et al found morning people prefer to wake e.g. at 6 am and go to bed early e.g. 10pm, whereas evening people prefer to wake up later e.g. 10am and o to bed at 1am
Another difference is cycle lent Czeisler et al found that circadian rhythms can vary from 13 hours to 65 hours. these could be explained by biological functions
strength of learning about circadian rhythms - RWA
P - one RWA of CRs is chronotherapeutic - the study of how timing affects drug treatment
E - the specific time that patients take their medication is very important as it can have a significant impact on treatment success. it is essential that the right concentration of a drug is released in the target area of the body in the time the drug is most needed. For example, the risk of a heart attack is greatest during early morning hours after awakening
E - as a result, chronotherapeutic drugs have been developed with a novel drug delivery system. These meds can be administered before going to sleep at 10pm but the drug is not released until the vulnerable period of 6am to noon.
What is an example of an ultradian rhythm?
Human sleep patterns
What is an example of an ultradian rhythm?
Human sleep patterns
What is an example of an ultradian rhythm?
Human sleep patterns
How many stages are there in human sleep patterns
4-5 cycles per night
How many stages are there in human sleep patterns
4-5 cycles per night
How long do sleep stages last for
Around 90 minutes
How long do sleep stages last for
Around 90 minutes
How are sleep patterns measured
EEG scans
Describe stage 1 of sleep patterns
4-5%
Light sleep
Muscle activity slows down
Occasional muscle twitching
Describe stage 2 of sleep patterns
44-55%
Breathing pattern and heart rate slows
Slight decrease in body temperature
Describe stage 3 of sleep patterns
4-6%
Deep sleep begins
Brain begins to generate slow delta waves
Describe stage 4 of sleep patterns
12-15%
Very deep sleep
Rhythmic breathing
Limited muscle activity
Brain produces delta waves
Describe stage 5 of sleep patterns
20-25%
REM rapid eye movement
Brainwaves speed up and dreaming occurs
Muscles relax
Heart rate increase
Breathing is rapid and shallow
Give one limitation of assuming ultradian rhythms are the same
P - one issue is that sleep cycles are not all the same
E - Randy Gardner remained awake for 264 hours (11 days) and afterwards slept for just 15 hours and after several nights, recovered only 25% of his lost sleep. He recovered 70% of stage 4 sleep, 50% of REM and very little of the other stages
E - these results highlight the large degree of flexibility within sleep patterns and the variability of this ultradian rhythm
Give one limitation of assuming ultradian rhythms are the same
P - one issue is that sleep cycles are not all the same
E - Randy Gardner remained awake for 264 hours (11 days) and afterwards slept for just 15 hours and after several nights, recovered only 25% of his lost sleep. He recovered 70% of stage 4 sleep, 50% of REM and very little of the other stages
E - these results highlight the large degree of flexibility within sleep patterns and the variability of this ultradian rhythm
Limitation of ultradian rhythms (individual differences) including a counterargument
P - one limitation is that biological and situational differences influence sleep
E - Tucker et al (2007) suggested these are largely biological. Participants were studies over 11 days and nights in highly controlled labs. Researchers assessed sleep duration, time to fall asleep and amount of time in each stage.
They found large individual differences particularly in stages 3 and 4 which showed up consistently
E - this means differences were at least partially biologically determined since situational variable were the same
C - however, the monitoring devices may be invasive to some op’s and influence their normal sleep patterns
L - therefore, it is difficult to draw firm conclusions and make general laws on sleep beyond the controlled environment
briefly describe the stages of the menstrual cycle
1-5 days uterine lining breaks down and menstruation occurs
6-10 days uterus ling thickens again
11-18 days ovulation occurs usually on day 14
19-28 uterine lining continues to thicken
when are oestrogen levels generally highest?
14 days through the cycle
how long does ovulation generally last?
16-23 hours
when do progesterone levels increase?
after ovulation, ready for possible embryo implantation
support for exogenous zeitberg influence on menstrual cycles
femerones
Russel et al found that female menstrual cycles became synchronised with other females through odour exposure. In one study, sweat samples from one group of women were rubbed onto the upper lip of another group. Despite the fact the 2 groups were separate, the menstrual cycles synchronised.
what is an endogenous pacemaker?
body’s internal mechanisms that govern biological rhythms
what is an exogenous zeitberg?
external cues which help to regulate the internal bodily mechanisms
explain the steps of endogenous pacemakers to do with sleep
- low levels of light detected by the retina
- melanopsin carries signal to the supraciasmatic nucleus
- SCN sends signal to the pineal gland
- secretion of melatonin
- induced sleep
supporting evidence for SCN influence in sleep cycles
Morgan (1995) bread hamsters with a genetic variant/mutation that had a circadian rhythm of 20 hours rather than 24 hours.
Furthermore, SCN neurons from these abnormal hamsters were then transplanted into the brain of normal hamsters. these normal hamsters then displayed the same abnormal circadian rhythm of 20 hours. Then he did the same the other way around.
E - this suggests the transplanted SCN cells had imposed its pattern onto the hamsters and demonstrated the importance of the SCN role and endogenous pacemakers as biological clocks in maintaining the biological rhythms of the circadian rhythm
counter argument for hamster study
However, research with non-human animals, such as hamsters, is difficult to generalise and apply to humans.
Humans would respond very differently to manipulations of their biological rhythms, not only are we different biologically, but environmental contexts are also different.
Animals such as hamsters wouldn’t have social cues such as meal times.
Therefore, research carried out on non-humans may be unable to explain normal and disrupted biological rhythms in humans.
Support for the role of melanin
P - there is research support for the role of light and melanopsin production in setting the circadian rhythm
E - some blind people are still able to reliably entrain their circadian rhythms in response to light, despite a total lack of image forming visual perception
Skene and Arendt estimate that the vast majority of blind people still have in tact light-perceiving neurons and SCN pathway and are therefore, able to entrain their CR using light as an exogenous zeitbergs
support for RWA - light exposure to avoid jetlag
P - a useful real world application from research into EP and EZ is in reducing the effects of jet lag
E - burgess et al found that exposure to bright light prior to an east-west flight decreased the time needed to adjust to local time on arrival
one group of pp’s were exposed to continuous bright light and their cr shifted by 2.1 hours, the group exposed to intermittent bright light changed by 2.5 hours, and the group exposed to dim light only 0.6 hours
E - this suggests the exposure to light as an Exogenous zeitburg, enabled their circadian rhythms to be closer to that of their new time zone, thus reducing the negative effects of jet lag
