Biopsychology Flashcards
How is the nervous system divided
into CNS and peripheral NS
what is the CNS split up into
Brain and spinal chord
What does the brain do in the CNS
centre of conscious awareness. cerebral cortex highly developed and distinguishes our higher mental functions from those of animals.
what does the spine do in the CNS
extension of the brain. responsible for reflex actions. receives and passes messages to and from the brain and connects nerves to the peripheral NS
What is the function of the peripheral NS as a whole and what is it divided into
transmits messages via millions of neurons to and from the CNS. Further subdivided into somatic and autonomic NS.
What does the autonomic NS (ANS) do
divided into sympathetic and parasympathetic. ANS links the CNS to internal organs, controls functions including breathing, stress response and sexual arousal.
can the ANS be controlled voluntarily
no
what does the somatic NS do
transmits info received by receptors (eyes, ears nose etc.) to the CNS and transmits messages from the CNS to the muscles to instruct them to act.
What is the structure of a neuron
nucleus cell body dendrite axon myelin sheath schwanns cells nodes of ranvier axon terminals
what does the nucleus do
holds genetic material of the cell
what does the dendrites do
branch like structures that protrude from the cell body, they carry nerve impulses from neighbouring neurons to the cell body.
what does the axon do
carries the impulses away from the cell body and down the length of the neuron
what does the myelin sheath do
protects the axon and speeds up the electrical transmission of the impulse.
what do the nodes of ranvier do
if the myelin sheath was continuous it would slow down the impulse. the nodes of ranvier are gaps in the sheath that force the impulse to jump across the gaps and along the axon.
what do the axon terminals do
terminal buttons that communicate with the next neuron in the chain, they communicate across the synapse.
describe a neuron in its resting state
inside of the cell is negatively charged compared to the outside
what happens when the neuron is activated by a stimulus
activated by stimulus= inside of the cell becomes positively charged causing an action potential to occur. this creates an electrical impulse that travels down the axon to the end of the neuron.
what are the three types of neurons
sensory, relay and motor
describe sensory neurons and what they do
long dendrites short axons
tells brain about external and internal environment by processing info from the 5 senses. carry messages from PNS to CNS
describe relay neurons and what they do
short dendrites short axons
carry messages from one part of CNS to another.
connect motor and sensory neurons
describe motor neurons and what they do
short dendrites long axons
carry signals from CNS to control effector organs, including glands, muscles and their functions.
where does transmission of an impulse take place
the synapse. the transmission of an impulse between neurons is chemical.
describe synaptic transmission
the impulse reaches the pre synaptic terminal on the pre synaptic neuron, causing the synaptic vesicles to release neurotransmitters into the synapse. they diffuse across the synapse and are taken up by the post synaptic receptor site. the chemical message is then converted back into an electrical impulse and transmission begins again in the post synaptic neuron
why does the shape of the neurotransmitter (ntm) matter
each one has its own specific molecular structure that is complementary to the post synaptic receptor site. fits like a lock and key.
give an example of a neurotransmitter with a specialist function
acetylcholine is found where a motor neuron meets a muscle and upon its release causes the muscle to contract
what is excitation
when a neurotransmitter increases the positive charge of the post synaptic neuron, increasing the likelihood that the neuron will fire and pass on the impulse.
what is inhibition
when a neurotransmitter increases the negative charge of the post synaptic neuron. decreases the likelihood the neuron will fire and pass on the impulse.
what effect does serotonin have as a ntm
causes inhibition in the receiving neuron, more neg charge less likely to fire
what effect does adrenaline have as a ntm
causes excitation of post synaptic neuron more pos charge increase likelihood next neuron will fire
how does the endocrine system vary from the nervouse system
acts much slower but has a widespread effect. ns more localised. uses hormones rather than electrical impulse.
what produces hormones
glands
what do hormones effect
any cell that has the receptor for that particular hormone
what is the major endocrine gland
pituitary gland located in the brain and controls the release of hormones from all other glands in the body
what does the thyroid gland do
produces thyroxin for the regulation of growth and metabolism
what does the adrenal gland do
produces adrenaline responsible for the flight or fight response
ovaries gland function
produce oestrogen and progesterone, responsible for female sexual behaviour
testes as gland function
produce testosterone responsible for male sexual behaviour
what are the effects of sympathetic action
gets fight or flight ready heart rate increases pupils dilate intestine (gut) action slows salivation stops and mouth dries
what is the parasympathetic action
heart rate decreases
pupil constricts
intestine/ gut action restored
salivation restored
how do the parasymp and the symp NS link
symp gets you prepared for a fight or flight response
parasymp restores bodily functions to normal state of rest and digest
describe the fight or flight response
stressor perceived by hypothalamus and ANS changes from resting state to physiologically aroused sympathetic state
hypothalamus recognises threat sends message to adrenal medulla
triggers release of adrenaline into the bloodstream and noradrenaline in the brain results in sympathetic responses.
threat passed parasym ns works in opposition to symp ns - its actions are antagonistic to symp ns reduces the activities of the body increased by symp branch.
what might you feel during the fight or flight response
stress panic excitement sick feeling as blood is diverted away from the digestive system
what is localisation of function in the brain
the principle that specific functions e,g language have specific locations within the brain
also referred to as cortical specialisation
what happened to Phineas Gage
railroad worker Gage suffered an explosive accident that resulted in him having a railroad spike through his left eye and out the back of his head. accident removed most of left frontal lobe.
what was Gage like after the accident and what does it suggest for localisation of function
he survived but new personality.
calm and reserved to rude and quick tempered
provides evidence that the frontal lobe may be responsible for regulating mood
what is the cerebral cortex
outer layer of both hemispheres
3mm thick
separates us from animals because the human cortex much more developed.
appears grey due to location of cell bodies.
what are the hemispheres of the brain
two symmetrical halves - the left and right hemisphere
right hemisphere controls activity of the left side of the body
left hemisphere controls activity of the right hand side of the body
some psychological and physical functions controlled by one hemisphere alone
what are the 4 lobes
frontal
parietal
occipital
temporal
whats the function of the frontal lobe and whats in it
both hemispheres of FL is the motor cortex which controls voluntary movement in the opposite side of the body. damage to this area may lead to loss of control over fine movements. FL as a whole = problem solving and higher level thinking and personality. left frontal lobe is brocas area
function of parietal lobe and what’s in it
somatosensory cortex - where sensory info from skin represented. amount of somatosensory cortex devoted to a body part indicates how sensitive it is. PL = processing sensory information
function of the occipital lobe and whats in it
visual cortex is in occipital lobe. left eye sends visual info to right visual cortex. right eye sends visual info to left visual cortex. damage in left hemisphere can cause blindness in right visual field of both eyes and vice versa
function of temporal lobe and whats in it
houses the auditory area which analyses speech based information. damage may produce hearing loss the severity of which is proportional to the extent of the damage. left temporal lobe = wernickes area
which hemisphere is language production and comprehension located in
left
what are the two parts of the brain to do with auditory info
Broca’s area- small area in left frontal lobe responsible for speech production. Broca studied brain damaged patients, one who had damage to this area could only say “Tan”.
Wernicke’s area- in the left temporal lobe, responsible for language comprehension.
name the brain damage conditions related to brocas and wernickes area
Brocas aphasia
wernickes aphasia
describe brocas aphasia
characterised by slow speech that is laborious and lacks fluency.
describe Wernickes aphasia
no problem producing language but difficulties understanding it. speech produced fluent but meaningless. patients often produce nonsense words as part of their speech.
AO3 for localisation of function in the brain
brain scan evidence of localisation- Broca Wernicke and Phineas Gage provide proof. Tulving et al used a brain scan to prove that episodic memory and semantic memory in different parts of the brain.
There are some higher cognitive functions that cant be localised to one area of the brain. Lashley suggests learning more holistic. had rats learn maze removing certain portion of grey matter. no one area seemed related, learning too complex to be localised
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
what are split brain studies
pp who have undergone surgical operation to separate two hemisphere. done by cutting corpus callosum down the middle. done to control seizures. split brain patients cant communicate between left and right hemisphere. allow sperry to see to what extent hemispheres perform tasks independently
what was the procedure for the split brain studies
an image or word could be projected to a patients right visual field and sent to the left hemisphere and the same or a different image projected to the left visual field and sent to the right hemi. in normal brain corpus callosum shares info between two hemi. split brain means info not conveyed from one to the other
what were the key findings for describing what you see (split brain)
object right visual field= describe easily
object left visual field = couldn’t describe said nothing was there
speech production limited to left hemi as brocas area is there. cant describe when in left visual field because theres no speech production in right hemisphere
what were the key findings for sperry composite words
2 words presented simultaneously one in each visual field. key in left, ring in right. pick up/draw key as left visual field to right hemi. right hemi control movement of left side. say ring right visual field left hemi which includes speech production.
key findings sperry matching faces
two people one in each visual field. asked to match to a set of faces. face from left visual field consistently chosen therefore right hemisphere dominant in face recognition. left hemisphere dominant in terms of verbal description
AO3 for split brain research
generalisability issues- patients often had other neurological problems which may have acted as a confounding variable. patients didn’t always have complete splitting of the two hemispheres. patients had severe epilepsy before may have caused differences in the brain
case study of JW had split brain experiment. developed ability to speak out of right hemisphere meaning can say info in either left or right visual field. challenges sperry conclusion right hemi cant process even most rudimentary speech
methodological strengths- highly specialised and standardised procedures. method of isolating visual fields very advanced for the time. allowed him to vary aspects of basic procedure and ensure only one hemi got the info. useful and controlled procedure
what is plasticity
the idea that the brain has the capacity to change throughout life.
describe plasticity in children
rapid growth in number of synaptic connections, peaks at 15,000 between 2-3 years. twice as many as adults
whats synaptic pruning
when the brain deletes rarely used connections and strengthens frequently used ones.
what was the original thought on plasticity in adults
once moved past a critical period brain would remain fixed and static in terms of function.
what does recent research suggest about plasticity of adult brains
any time in life existing neural connections can change or new neural connections can be formed as a result of learning and experience.
what is the study into plasticity
Eleanor maguire et al
London taxi drivers found to have larger volume of grey matter in posterior hippocampus than control group. part of brain associated with spatial and navigational skills. have to take complex test called the knowledge assess recall of streets and routes. learning experience lead to structural difference. (which way round though) longer taxi driver more pronounced the difference.
whats a similar study for plasticity
Draganski- medical students before and after exam. larger volume of grey matter after exam due to learning induced changes in posterior hippocampus and parietal cortex
how is functional recovery an example of brain plasticity
unaffected areas are able to adapt and compensate for damaged areas. take over function of damaged areas. process can occur quickly after (spontaneous recovery) then slow down, requires rehabilitative processes to continue
what happens during brain recovery
brain rewire and reorganise itself forming new synaptic connections close to area of damage
secondary neural pathways activated to allow functioning to continue
what are the structural changes to the brain during recovery
axonal sprouting- growth of new nerve endings connect other undamaged nerve cells to form new pathways
reformation of blood cells
recruitment of homologous areas on opposite side of the brain to perform specific tasks.
AO3 for brain plasticity and functional recovery
prac app - understanding process of plasticity contributed to the field of neurorehabilitation. spontaneous recovery slows down, physical therapy needed to continue. techniques include movement therapy electrical stimulation to counter deficits of motor and or cog functioning.
brains ability to rewire can have maladaptive consequences. 60-80% of amputees develop phantom limb syndrome. unpleasant and painful sensations in the limb that is no longer there. thought to be due to cortical reorganisation in the somatosensory cortex
evidence that neural plasticity continues throughout lifespan. bezzola- 40 hours of golf training pp 40-60 years old. fMRI showed reduced motor cortex activity in novice golfers compared to control group shows more efficient neural representations after training
what are the three scanning techniques
fMRI
electroencephalogram
event related potentials
describe how fMRI works
measure brain activity while performing a task. detects changes in blood oxygenation and flow as a result of neural activity. more active area consumes more oxygen so increased blood flow to that area. produces 3D images showing which parts of the brain involved in mental processes - localisation of function
evaluate fMRI
unlike PET or CT scans doesn’t rely on use of radiation. if done correctly virtually risk free non invasive and straight forward
image has high spatial resolution, detail down to mm. clear pic of how function localised.
expensive, clearness relies on perfect stillness of person. poor temporal resolution, lag time between image on screen and firing of neuronal activity.
only blood flow, no neuron activity. can’t tell exactly what brain activity is on the screen
describe electroencephalogram
EEG- record electrical impulses produced by brain activity via electrodes placed on scalp using a skull cap. represents brainwave patterns. diagnostic tool for arrhythmic patterns of activity indicate neurological abnormalities e.g epilepsy
AO3 EEG
prac app of diagnosing epilepsy. also contributed to understanding of the stages involved in sleep
extremely high temporal validity, accurately detect brain activity to the resolution of a millisecond
generalised nature is a drawback, not useful for pinpointing exact point of neural activity and doesn’t help to distinguish between activities originating in different but adjacent locations
describe event related potentials
ERP- within EEG data there are neural responses associated with specific sensory cognitive and motor events that may be of interest to neuroscientists. isolate these responses by filtering out extraneous brain activity leaving only responses related to a specific stimulus. what remains are ERPs
AO3 ERP
bring more specificity to measurement of neural processes than EEG. derived from EEG means excellent temporal resolution. more pin pointing than fMFRI
lack of standardisation between ERP methodology means lack of reliability, makes it difficult to confirm findings
issue- in order to establish pure data in ERP studies background noise and extraneous material must be removed completely not easy to achieve
describe post mortem
studying brain after death. likely to have rare disorder/ unusual deficits in mental processes or behaviour when alive. establish likely cause of affliction. could involve comparing to neurotypical brain
AO3 post mortem
vital in early understanding of key processes in brain. Broca and Wernicke used post mortem to establish links between language and brain decades before brain imaging. improve medical knowledge + help generate hypotheses for further studies
causation, observed brain damage may not be linked to the deficits under review but to some other unrelated trauma or decay. some patients unable to give informed consent before death ethical issue. e.g HM couldn’t form memories so couldn’t provide consent but had a post mortem anyway.
what is a circadian rhythm
rhythms that last for around 24 hours.
describe the sleep wake cycle
drowsy at night time alert in the day. demonstrates importance of exogenous zeitgeber of daylight on sleep wake cycle. biological clock can be left to its own devices without influence of daylight to become free running.
describe the core body temperature circadian rhythm
lowest temp. 4:30 am 36 degrees
highest 6pm 38 degrees
sleep occurs when core temp begins to drop
core temp rises during last hours of sleep to promote alertness
small drop between 2pm and 4pm explains afternoon drowsiness
study for sleep wake cycle and time findings
siffre cave study
deprived himself of natural light and sound, access to adequate food and drink. came out in mid September 1962 after 2 month but believed still mid august.
study for sleep wake cycle biological findings
free running biological rhythm settled to beyond 24 hours at 25 hours. continued to fall asleep and wake up on a regular schedule. provides support for the rhythm being around 24 hours with or without exogenous zeitgebers
whats the other circadian rhythm study
folkard. 12 pp dark cave 3 week. bed at 11;45 awake 7;45. gradually speeded up clock so it was actually 22 hour day. no pp comfortably adjusted to new regime. provide evidence for strong free running circadian rhythm that cant easily be over ridden by changes in external environment. over estimate importance of EZ
AO3 circadian rhythms
prac app- knowledge of C.R given researchers better understanding of bad consequence of disrupted rhythm. night workers in shift work experience period of reduced concentration more likely to make mistake could be dangerous if factory/ building site setting
prac app- C.R coordinate digestion heart rate and hormone level. effect on pharmacokinetics ( action of drugs on body and how well absorbed and distributed) peak times to take medication such as anti cancer respiratory and anti epileptic drugs.
studies use small samples or case studies, may mean findings have generalisability issues.
what are infradian rhythms
take longer than 24 hours to complete. occur less than once a day.
describe the menstrual cycle as an infradian rhythm
governed by monthly changes in hormone levels to regulate ovulation. cycle between when womb lining shed to day before next period. generally 28 days. oestrogen causes ovary to develop egg and release it (ovulation). progesterone helps womb lining grow thicker readying body for pregnant. no preg = egg absorbed into body womb lining leaves body.
describe SAD as infradian rhythm
seasonal affective disorder- depressive disorder, seasonal pattern of onset. lowered mood and activity levels. symptoms triggered during winter months low no. of daylight hours. circannual rhythm
research for infradian rhythm (procedure)
McClintock- 29 women irregular periods. samples of pheromone from 9 women at different stages of cycle gathered via cotton pad under armpit. pad treated with alcohol and frozen. pad from day one of cycle rubbed on upper lips of 20 other women on day one. pad from day 2 on day 2 of cycle and so on.
research on infradian rhythm results
68% of women experienced changes to cycle bringing them closer to odour donor. menstrual cycle endogenous, study suggests influenced by exogenous factors and shows menstrual cycles can synchronize.
what are ultradian rhythms
take less than 24 hours to complete
how is the stages of sleep an ultradian rhythm
five distinct stages of sleep that altogether span approx. 90 minutes in a cycle that continues throughout the course of the night. each stage characterised by different level of brain activity monitored using EEG
describe the stages
1 and 2- the sleep escalator, light sleep person easily woken. at beginning of sleep brain waves start to become deeper
3 and 4- delta waves which are slower still have greater amplitude than earlier wave patterns. deep/low wave sleep difficult to wake someone
5- REM sleep. body paralysed brain activity speeds to resemble awake brain. REM= rapid eye movement associated with dreaming
AO3 infradian and ultradian rhythms
individual differences have biological basis as well as outside factors. Tucker et al pp studied 11 days in lab environment. assessed sleep duration time to fall asleep and amount of time in each sleep stage. large individual differences across all nights and sateg 3 and 4 (deep sleep) most variation. diff. not environmental but biologically driven.
McClintock research shows importance of external factors on menstrual cycle
methodological issues of synchronisation studies - many factors such as stress changes in diet and exercise change cycle length might act as confounding variables. patterns observed by McClintock could be due to chance
what are biological rhythms influenced by
endogenous pacemakers- internal body clocks
exogenous zeitgebers- external factors in the environment that reset biological clocks through process called entrainment. without them E.P become free running.
name the two endogenous pacemakers in the sleep wake cycle
suprachiasmatic nucleus
pineal gland and melatonin
describe the suprachiasmatic nucleus
bundle of nerve cells located in the hypothalamus of each hemi of the brain. influential in sleep wake cycle. located above optic chiasm which is where the optic nerves from both eyes cross. receives info from this. continues even when eyes are closed enabling biological clock to adjust to changing daylight levels when we are asleep.
describe the pineal gland and melatonin
SCN passes info on day length and light to the pineal gland. during night pineal gland increases production of melatonin which induces sleep and inhibits wakefulness. during periods of wakefulness less is produced.
what is the animal research for the SCN
Decoursey et al destroyed SCN connections in 30 chipmunks returned them to natural habitat for 80 days. sleep wake cycle disappeared by the end of the study. significant proportion killed by predators because they were awake when should have been in hiding and asleep.
ralph et al bred mutant hamsters with 20 hour sleep wake cycle. transplanted SCN cells from mutant to normal the cycle of the normal hamsters defaulted to 20 hours.
both emphasise role of SCN in establishing sleep wake cycle
what are the two exogenous zeitgebers in the sleep wake cycle
light and social cues
describe light as an exogenous zeitgeber
it can reset the bodies main E.P (SCN) and plays a role in the maintenance of the sleep wake cycle. also has indirect influence on key processes such as hormone secretion and blood circulation.
describe social cues as an exogenous zeitgeber
infants not on the same sleep wake cycle as adults, its pretty much random. 6 weeks circadian rhythm kicks in, 16 weeks babies are entrained. schedule imposed by parents key factor.
research for light as an exogenous zeitgeber
Campbell and Murphy. light may be detected by receptors on the skin. 15 pp woken at various times and light pad shone onto back of their knees. managed to produce a deviation of up to 3 hours in some cases. suggests that light is a powerful exogenous zeitgeber that may not rely on the eyes to be influential on the brain
AO3 for endogenous pacemakers and exogenous zeitgebers
campbell and murphy study
research to suggest other e.p can work independently of the SCN (the master clock) there are many circadian rhythms in organs and cells, these are called peripheral oscillators. research to support is damiola et al changing feeding patterns in mice could alter circadian rhythm od liver cells by up to 12 hours but kept rhythm of SCN unaffected. may be many other complex influences on the sleep wake cycle other than the SCN.
influence of exogenous zeitgebers may be overstated. studies of individuals who live in Arctic regions where the sun doesn’t set in the summer have normal sleep patterns despite the continuous presence of light. suggests E.Z have little bearing on our sleep wake cycle.
ethics of animals - considerable harm, does the information gleaned justify the harm to the animals???
