topic 6: biopsychology Flashcards
what are the 4 brain lobes found in each hemisphere
frontal lobe - front top
parietal lobe - middle top
occipital lobe - back (but not as clear as others)
temporal lobe - middle bottom
label this
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what is the role of the frontal lobe
planning, organisation
the back of the frontal lobe contains the motor cortex
speech production (broca’s area)
outline the temporal lobe
Auditory processing and contains the auditory cortex
Language comprehension (Wernicke’s area)
Memory/information retrieval
outline the parietal lobe
Body orientation
Sensory input
contains the somatosensory cortex at the front of the parietal lobe - touch perception
define nervous system
network of nerve cells and fibres, helps all parts of the body communicate with each oher
define peripheral nervous system
the part of the nervous system found outside the brain and spinal cord
The PNS transmits messages throughout the whole body from the brain and also relays messages back to the brain
define somatic nervous system
transmits and receives sensory and motor info to and from the CNS
consist of sensory and motor neurons
enables reflex actions
define autonomic nervous system
transmits and receives info from the organs
governs the brains involuntary activities and is self regulating
define sympathetic nervous system
involved in responses that help in dealing with emergencies eg. fight or flight
define parasympathetic nervous system
calms the body after an emergency state
involved in increased digestion and energy conservation
‘rest and digest’
define central nervous system
made up of the brain and spinal cord, receives info from the senses and sends the body a response
define spinal cord
a bundle of enclosed fibres which connects nearly all parts of the body with the brain
what is the brain
the part of the CNS responsible for coordinating any sensational, intellectual and nervous activity
break down the structure of the nervous system
one letter instead
what is the difference between axons and dendrites
axon - carries nerve impulses away from the cell body
dendrite - transport nerve impulses from synapse to cell body
there’s usually just 1 axon, but multiple dendrites
what are the 3 types of neuron and outline general neuron structure
sensory neuron
motor neuron
relay neuron
dendrite –> cell body
axon away from cell body
axon can be myelinated to increase nerve transmission speed
cell body aka soma, contains genetic material
outline sensory neurons
they send info regarding sense to the brain
aka afferent neurons, they carry from PNS –> CNS
have long dendrites and relatively short axons with the cell body usually found at the centre to the side
SENSory has CELL body to the side
outline motor neurons
aka efferent neurons, carry info from CNS –> PNS
have short dendrites nd relatively long axons
outline relay neurons
connect sensory neurons to motor neurons
based in CNS and carry info across the CNS
short axons and short dendrites
describe synaptic transmission
- the action potential (an electrical impulse) arrives at the end of the pre-synaptic neuron (axon)
- vesicles (found only on pre-synaptic) release inhibitory and excitatory neurotransmitters (chemicals) into the synaptic cleft
- the neurotransmitters diffuse (high conc to low conc) across the synaptic cleft
- they attack to their specific, receptor (found only) on the post-synaptic neuron (dendrite)
- if more excitatory neurotransmitters are received, AP continues but if more inhibitory neurotransmitters are received, AP will slow
- the neurotransmitters are then taken back by the reuptake cell or they are destroyed
what is the endocrine system
a network of glands across the body that secrete chemical messengers called hormones via blood vessels, around the body to a specific target organ depending on the hormone
outline the pituitary gland
aka the master gland
controlled by the hypothalamus, releases hormones that control and stimulate the release of hormones from other glands in the endocrine system
outline the gland and purpose of melatonin
the Pineal gland
its involved in the sleep-wake cycle
outline the gland and purpose of thyroxine
the thyroid gland
regulates metabolism
outline the gland and purpose of adrenaline
adrenal gland - produces noradrenaline and adrenaline
involved in the fight or flight response
outline the gland and purpose of insulin
pancreas gland
regulates blood glucose
outline the gland and purpose of testosterone
testes
development of male sex characteristics eg. muscle growth
outline the gland and purpose of oestrogen
ovaries
regulation of the female reproductive cycle eg. menstrual cycle and pregnancy
outline the fight or flight response
the endocrine and autonomic system work together to bring it about
situations that create fear or stress stimulate neurones in the sympathetic nervous system to stimulate the adrenal gland to release adrenaline
adrenaline is transported to target organs (eg. SAN) via the blood stream
this causes:
- increased heart rate to get more blood to muscles -> more aerobic respiration –> release more energy to respond to the situation
- blood vessels to less important organs contract so more blood flows to the necessary organs at that point
what is the localisation of function
where specific functions have specific locations in the brains
outline Broca’s area and supporting evidence
only in left hemisphere
found in the frontal lobe, just in front of the motor cortex
required for language production
damage = Broca’s aphasia, it involves slow speech lacking in fluency but language comprehension is generally preserved
case study: a man called tan
Tan had a stroke that led to him only being able to say Tan
Broca examined his brain after he died and as Tan couldn’t speak, he concluded that the damaged area of his brain was responsible for language (broca’s area)
the brain was rediscovered and analysed using a CAT scan; it was found that broca was mostly right and damage to broca’s area does cause speech issues
outline Wernicke’s area
only in left hemisphere
found in the temporal lobe, just behind the auditory cortex
required for the understanding of language
damage = Wernicke’s aphasia, severe damage in understanding of language, speech may be fluent but meaningless (neologisms; nonsensical words)
what is the Wernicke-Geschwind model
proposes that, Wernicke’s area chooses the words needed for speech and Broca’s area takes these words and generates the words needed to vocalise them
- this model is now thought to be too simplistic as studies suggest that language involves widespread networks
evaluate localisation of brain function
+ wernicke’s area was found to be activated during a listening task using fMRI and broca’s was activated during a read aloud task
these match up with what they were expected to be responsible for
— functions like language are too complex to just be one area, they probs use large brain regions; Wernicke-Geschwind is over simplistic
– every function might not be localised
learning processes and cognitive functions may be distributed across the brain
Lashley removed different areas of cortices from a rat’s brain to investigate the resultant effect on their ability to learn how to traverse through a maze
he found no areas to have a specific influence
+ Broca has evidence from a case study; Tan had a stroke that led to him only being able to say Tan
Broca examined his brain after he died and as Tan couldn’t speak, he concluded that the damaged area of his brain was responsible for language (broca’s area)
the brain was rediscovered and analysed using a CAT scan; it was found that broca was mostly right and damage to broca’s area does cause speech issues
what is the role of the left hemisphere
it is where most people process language, it contains Broca and Wernicke’s areas
having a stroke in left hemisphere will most likely affect speech
it controls the right hand side of the body and receives information from the right visual field
what is the role of the right hemisphere
It is dominant in recognising emotions in others
dominant in spatial information
controls the left side of the body and receives info from the left visual field
what are right and left visual fields
the right visual field = right side of both eyes, info goes to left hemisphere
the left visual field = left side of both eyes, info goes to right hemisphere
outline split brain research
conducted by Sperry
as a treatment for extreme epilepsy, some people have their corpus callosum cut to stop electric seizures bouncing between the 2 hemispheres and reduce the number of fits
he studied
sample: 11 patients that had a corpus callosotomy
procedure: asked p’s to focus on a centre point and projected info into each visual field and controlled which info each field accessed
findings: info in the right visual field could be identified via speech bc it was sent to the left hemisphere
info in the left visual field could be drawn or picked out with the left hand bc it went to the right hemisphere
this supports lateralisation of function and shows the hemispheres independently functioning
how are the two hemispheres connected
by the corpus callosum
evaluate Sperry’s split brain research
– the sample was just 11 people and the all had epilepsy, this could mean that their brains were differently structured… results may not be generalisable
+ sperry’s work is what stimulated later research, it was after found that some brains are more lateralised than others
eg. RH: 95% lang in left
LH: 75% left ,and, 25% bilateral lang
+ he used a highly controlled procedure
eg. used flashing images to prevent eyes moving and both visual fields being used
this increases validity by making sure only one hemisphere is being tested at a time
+ the improved knowledge can be applied; Tony Buzan: students are encouraged to be multi sensory in their revision techniques to utilise both sides of their brains
what is brain plasticity
the brains ability to change based on experience
every experience excites certain neural circuits and leaves others inactive, those used over time, consistently will be strengthened and those that are rarely excited may be dropped away
after neural loss, regeneration can occur
outline the study by Maguire
brain plasticity
hypothesis: would human beings that navigate a lot show comparatively more hippocampus, like has been found in animals
sample: licensed London taxi drivers; they have The Knowledge (takes 3-4 years to learn)
volunteer sample, all male, 16 participants, all right handed
matched with control group
method:
- experts carried out manual calculations on volume of grey matter in the hippocampus’ anterior, body and posterior
- used voxel based morphometry; computer based version of the above
-> triangulation of data
it was researcher blind, they didn’t know if they were calculating control or taxi drivers
results:
taxi drivers had more grey matter volume on the posterior hippocampus and less in the anterior than the control
SO, the grey matter was redistributed, posterior grey matter was found to increase with years driving
what is functional recovery
the brains ability to redistribute or transfer functions usually performed by a damaged area to other, undamaged areas
evaluate Maguire’s study on brain plasticity
– small sample: 16 participants
+ used an all male sample, all right handed
accounts for participant variables and individual differences
– would be better as a longitudinal study to see how the brain matter changed because they could have just always had more posterior hippocampus grey matter
– only looks at one skill, navigation
outline some key studies on brain plasticity
- Maguire
found taxi drivers to have greater grey matter volume in their posterior hippocampus than non taxi drivers and found that the volume increased with no. of years as a taxi driver - Lazar
used MRI scans to show that experienced meditators had a thicker cortex than non-meditators. individuals that took an 8-week mindfulness-based stress reduction course showed an increase in grey matter in the left hippocampus - Gabby Giffords
she was shot In the head and had to placed into a waking coma, within months she made progress with the aid of physical rehabilitation and was able to walk under supervision with perfect left arm and leg control and could speak in short phrases; places her in top 5% of people recovering from serious brain injury
outline the circadian rhythm
a pattern of behaviour over 24 hours
regulates a series of bodily processes
eg. sleepwake cycle/ core body temperature
light provides the primary input into the sleep-wake cycle and it’s used by the SCN to coordinate the activity of the whole circadian system
without light the system is said to be free-running
sleep and wake are also homeostatically controlled because when awake for too long, homeostasis tells the body that u need to sleep because of energy consumption and this drive increases through the day with max in evening at bedtime
body temp is another circadian rhythm that is lowest at 36deg at 4:30am and 38deg at 6pm
outline infradian rhythm
one cycle lasts for over 24 hours
eg. menstruation (monthly)/ SAD (seasonal affective disorder)
outline ultradian rhythm
multiple cycles occur in 24 hours
eg. sleep stages; each one is around 1.5 hoursw
what are the 3 biological rhythms
circadian
infradian
ultradian
what can influence biological rhythms
endogenous pacemakers and exogenous zeitgebers
outline endogenous pacemakers and the surrounding research
endogenous pacemakers are internal mechanisms that govern biological rhythms
information from the optic nerve passes over the optic chiasma on the way to the visual cortex. the SCN is just above and so can receive info on light levels even when eyes are closed
SCN is a bundle of nerve cells in the hypothalamus and stimulates the pineal gland to produce/inhibit melatonin production after light level info from optic nerve
more melatonin at night vs less in day
animal research was carried out on hamsters to see how they effect the sleep wake cycle
when SCN present - circadian rhythm
no SCN - disrupted rhythm
SCN transplanted back - circadian rhythm
SO, SCN is involved in circadian rhythm
outline exogenous Zeitgebers and surrounding research
things like light/time on clock/peers
light suppresses melatonin production from pineal glad and influence sleep-wake cycle
light is the key zeitgeber for human as it resets the SCN and so, plays a crucial role in sleep-wake cycle maintenance as well as indirectly influencing melatonin production
social cues like mealtimes can help conpensate for a lack of natural light/disruption eg. follow social meal times to get over jet lag vs the body’s natural drive
Siffre - stayed in a cave for 6 months, had a sleep-wake cycle of approximately 24 hours
but when he came out, he thought it was mid September but it was actually mid august
– there was still artificial light and human interaction to report to team above ground
outline the occipital lobe
processes visual info
outline and evaluate the use of fMRI scans
- Uses magnetic field and radio waves to monitor blood flow; it measures the change in the energy released by haemoglobin, reflecting activity of the brain (oxygen consumption) to give a moving picture of the brain showing which parts of the brain are involved in a particular mental process
+ non-invasive
+ straightforward to use
+ high spatial resolution which provides a clear picture of how brain activity is localised
- expensive so smaller sample
- patient has to remain incredibly still for a clear picture
- only measure blood flow so can not focus in on individual neurons
outline and evaluate the use of EEG’s
electrodes are put on the scalp and detect neuronal activity directly below where they are placed
records brainwave patterns an overall account of brain activity is provided
+ contributed to understanding stages of sleep (ultradian rhythms)
+ high temporal resolution-resolution is around a millisecond
+ cheaper than fMRI so larger sample
– generalised nature of information received makes it hard to pinpoint the exact source of neural activity
outline and evaluate the use of ERP’s
lectrodes are put on the scalp and detect neuronal activity (directly below where they are placed) in response to a stimulus introduced by the researcher and a wave graph is produced
+ more specific measurements of neural processes
+ high temporal resolution
+ cheaper than fMRI so larger sample
- lack of standardisation of methodology between studies makes it hard to confirm findings
- to establish pure data, extraneous material (noise) must be completely eliminated which is hard
outline and evaluate the use of post-mortems
brain is analysed after death and may be compared to a neurotypical brain
+ improve medical knowledge and help generate hypotheses .
+ Broca and Wernicke used this to make links with the brain and language
- causation, may be other factors such as trauma or decay
- ethical issues; informed consent e.g the case study of HM, could he actually give it with his impairements?
evaluate the fight or flight response
– evidence/explanation to show that FFR is thought to apply mainly to males, researchers found that the SRY gene on the male Y chromosome is responsible for FFR, this gene is absent in females
— beta bias: women don’t experience fight or flight
taylor found that in stressful times women will protect by caring and hurting their young or forming alliances, tend and befriend
– we no longer need this response, modern day stressors like exam stress do not require increased heart rate etc. it can actually increase risk of heart disease from high blood pressure
– it has been criticised for being incomplete, animals freeze before responding by FF to gather info on the best response, whilst staying hyper vigilant.
how does light influence sleep-wake
it suppresses melatonin production from the pineal gland
evaluate endogenous pacemakers and exogenous zeitgebers
+ SCN hamster evidence
— hamsters aren’t humans, so differences aren’t only bc of differences biologically but differences in environmental contexts
– SCN research might obscure other body clocks
they are found in many organs and cells like the liver lungs skin etc. theyre highly influenced by SCN but can also act independently
damiola showed how changing mice feeding patterns altered circadian rhythm’s of liver cells for up to 12 hours, leaving SCN rhythm unaffected
so, there could be other complex influence other than SCN on sleep-wake etc.
+ Siffre evidence
— limitation of studies looking into light as an exogenous zeitgeber is that artificial light is still present which lowers validity
– influence of exogenous zeitgebers may be overstated
miles saw a blind man from birth have a 24.9 hour circadian rhythm, he couldn’t adjust via social cues and took sedatives and stimulants to align instead
sim. Atic with long nights and short days still show. normal sleep patterns
– exogenous and endogenous interact all the time and also do it in real life so no need to separate to explain or to study.
evaluate circadian rhythms
+ practical applications to shift work
shows that desynchronisation can have serious consequences like obesity and low HDL conc, these studies can help look into the best policies for companies with shift workers to improve health and days off sick
— BUT these studies often use correlational methods; so it’s hard to establish causation between desynchronisation of sleep-wake and adverse effects. eg. high divorce rates could be because of missing out on family events due to sleep deprivation
doesn’t disregard past research but we do need more causal researcg
— artificial light as a confounding variable
— individual differences; found GCSE scores to increase by 20% in Monkseaton high school when school started at 10am vs 8am
teenagers and adults don’t have the same circadian rhythms, so we cant make and generalise conclusions
outline infradian rhythms
biological rhythms that take over 24 hours to complete
eg menstrual cycle which takes around 28 days and is regulated but the hormone oestrogen
this causes ovaries to develop and release an egg as well as progesterone which is used by the womb in preparation for pregnancy
SAD or seasonal affective disorder is a depressive disorder triggered in the winter months
it’s thought that increased melatonin production from less daylight hours may have a knock on effect on serotonin production in the brain —> depression symptoms
outline ultradian rhythms
rhythms that take less than 24 hours to complete
eg stages of sleep
psychologists found 5 distinct sleep stages that span around 90mins overall
each stage has a different level of brainwave activity
eg. 1+2 have alpha waves and sleep spindles vs REM has theta waves
evaluate infradian rhythms
— evidence suggests that exogenous zeitgebers can also influence the menstrual cycle even though it’s an endogenous process
stern ans mcClintock found menstrual cycles synced via odour exposure
one study rubbed sweat from one group into the upper lip of a separate group and found they became closer
so, pheromones can influence and they have and effect on people nearby vs the person producing
so consider external factors and be more holistic
+ evidence support for impact of melatonin on SAD from Terman; found SAD rate to be more common in northern countries with longer winter nights
eg. 10% of new hampshire vs 2% of southern florida had SAD
results suggest that SAD is partly affected by light (exogenous zeitgeber) that results in increase melatonin levels
+ evolutionary basis to the menstrual cycle
it may have been advantageous for females to menstruate and fall pregnant together so that newborns could be collectively cared for by the group
+ real world application of SAD research
understanding the role of darkness led to revoking phototherapy where strong lights equivalent to daylight are used in the evening +/ morning
SAD habers say that using daily is enough to relieve them of lethargy, depression and other symptoms
evaluate ultradian rhythms
+ useful insight into age related sleep changes
eg. scientists found reduction is slow wave sleep with age; linked to many deficits with old age like reduced alertness, as growth hormones are produced during SWS. such findings could lead to development of treatments for age related issues and so has sig. practical value in health sector
— individual differences, hard to investigate patterns
Tucker found sig. diff in stage duration between p’s, especially Slow wave sleep. said these may by biologically determined, making it hard to describe ‘normal’ sleep in any way
— lab controlled setting which stops attribution of sleep pattern differences to situation factors and just bio, gives convincing bio evidence but we should also consider situational
— low ecological validity bc p’s are in highly controlled environments and attached to monitors so this can make them sleep differently
false conclusions may be drawn
is the menstrual cycle exogenous our endogenous
thought to be endogenous!
outline the somatic vs autonomic nervous systems
