paper 2-biopschology Flashcards
flight or fight response
when person experiences stressful situation, heart beats faster, breathing increases
recations are collectively known as flight or fight repsonse
body changes are either to fight off threat or flee to safety
flight or fight repsonse to stress
amygdala and hypothalamus
someone is faced with threat
amygdala is mobiled in brain
asssoicates sensory signals with emtoions assositefd with fight or flight, e.g fear or anger
sends distress singal to hypothalmus
bodys repsonse to stressos, involves two main systems
acute stressors and chronic stressors
response to acute(sudden) stressors
SAM
sympathetic nervous system
adrenaline
parasympathetic nervous system
sympathetic nervous system
when SNS triggered
begins process of preparing body for action necessary to flight or fight
sends signal to adrenalla medula
reponds by releasing hormone, adrenline into blood stream
adrenline stage of SAM
adrenaline circulates through body
causes number of psychological changes e.g heart beats faster
tiggers release of glucose and fats, supplying energy to parts of body associated with fight or flight
parasympathetic nervous system
branch dampens down the stress response
slows heart rate down and blood pressure
digestion begins again after SNS has inhibited
response to chronic stressors (ongoing)
HPA
hypothalamus
pituitary gland
adrenal gland
if brain perceives something as threating the second system kicks in
hypothalumus activates stress response system called the HPA axis
hypothalamus
response to continued threat, releases a chemical messenger releasing hormone CRH
released in bloodstream in repsonse to stressor
pituitary gland
CRH causes pituaotry to release ACTH
ACTH transported in blodstream to target site in adrenal gland
adrenal gland
stimulates adrenal cortex
to release hormone cortisol
repsonsible for several a=effects in body that are importanet in flight or fight response
some postive (quick burst of energy)
some negative (lowered immune system)
feedback
efficient in regulating itself
A03 points for flight or fight response
does not tell the whole story
tend or befreind reponse
DT
weakness-does not tell the whole story
gray argues first response to a threat, is not by either flight or flee
the first stage is to avoid confrontation
most animals display the freeze response
essentially stop look and listen
animal alert to slightest danger
focuses attention and makes them look for new info for better response to a threat
weakness-tend or befreind response
fight or flight has been critisized because females disply different patterns to males
involves protecting themselvea and their young through nurturing behaviours(tending)
forming postive alliances with women(befriending)
fleeing too readily would put their offspring at risk
localistion
our physcial and psychological abilities all come from specific brain areas
before discivery holistic approach belives which assumes whole brain is involved in all the brain processes
hemispheres of the brain
brain split into two halves (hemispheres)
each hemisphere is dominat for diffreent abilities =lateralisation
left is dominant for language processing
right is dominant for spatial processing
also contralacterial-rigth hemisphere controls left side of body
left hemisphere contols rigth side of body
outerlayers of hemispheres=cerebrullum cortex
consists of grey matternthat seperates us intellectually with other animals
lobes of the brain
Frontal-brain processes body movement
pareitnal-brain pocesses touch
occupital-brain porcesses sight
temporal-brain processes what you hear
what is plasticity
how flexible something is
brain plasticity
brain constantly changes throughout life
due to experiences
very adaptable to new situations
pruning-connections lost due to lack of use
bridging-new connections made due to use
limit to plasticity
while, thought that changes were restricted to childhood (critical period)
adult brain was fixed in terms of structure and function
new, research shows neural connections change at any time in life
continue to gain new neural connectiosn due to experinece
this is plasticity
research into plasticity
maguire
studied brains of london cab drivers
all passed knowlegded test of recalling city streets and city routes
brain were alterned
had more grey matter in the posterior hippocampus then a control gorup
part of the brain associated with navigational skills
hemispheric lateralisation and split brain research
corpus callosum-bundle of nerve fibres which joins two halves of the brains
commissurotomy-division of two hemsipheres by surgery
left hemisphere
language centre of brain
controls right hand
receives info from right visual field
right hemisphere
visual spatial task
controls the left hand
receives info from the left-visual field
hempersheric lacterilistion
assumtpion that both hemisheres or halves are functionally different
sperrys split brain research
quasi experiment
11 participants
participants were epileptics who could not be treated by drugs
already had their corpus collosum split
split brain procedure
participant focuses on a fixed ppint on an upright translucent screen
slides projected either side of fixtation point
rate of one picture per 1/10 second
if it was tactile task (using objects) participants had hands undernearth s could not see what they were doing, just had to feel
ways of investigating the brain
spatial resolution-level of accuracy in identifying the exact location of the brain structure in space (where the activity happened)
temporal resolution-level of accuracy in identifying the exact location of the brain structure in time (when the activity happened)
FMRI scans
works by detecting changes in blood oxygenation and flow
brain is more active, requires more oxygen
due to this demand more oxygenated blood directed to area which is most active
HAEMODYNAMIC RESPONSE
produces 3D activity maps shows where oxygenated blood is flowing and how concentrated
STRENGTHS OF FMRI SCANS
non invasive
risk free
have good spatial resolution
provides clear pictures of how function is localised
WEAKNESSES OF FMRI SCANS
expensive
can only get good picture if person standing completely still
EEG
measure electrical activity within brain
electrodes attached to individuals scalp by a skull cap
scan recordings represent brain wave patterns
strengths of EEG
have been useful in diagnonsis of psychological coonditions e.g epilepsy
very high temporal resolution
weaknesses of EEG
poor spatial resoultion as we can not pinpot exact location of neuron activity
ERP
data which involves all neural responses that are sensory, cognitive and motor events, may be of interest to cognitive neuroscientists
made an EEG recording more specific by eliminating all extraneous neural activity and taking a statistical average
brainwaves which are triggered by particular events
strengths of ERP
make EEGs more specific
good temproal resoultion-have good undertanding of time activity happened
weaknesses of ERP
lack of standardisation between differnt studies making it difficult to confirm findings
backgroup noise and exrtanous variabkes must be elimianted which can sometimes be hard to achieve
post morterms
technique where they look at brain after a persons death
indivudals who are subject to post moretns are those that have had rare disorder or unusl deficits in lifetime
areas of damage examined after death for researchers to find a cause to orginal deficit
may also comapre with a control brain
person who experineced no deficits in lifetime
strengths of Post mortems
provided foundation of undertanding processes in the brain
e.g paul broca and karl wernicke used this
weaknesses of post mortems
ethical issues
person may not consent for their brain to be looked at before their death
biological rythm
distinct patterns of changes in body activity that conform to cyclical time periods
can be influenced by internal body clocks (endogenous pacemakers)
can be influenced by external changes in environment
(exogenous pacemakers)
circadian rythmn
type of biological rhythm that operates on a 24 hour schedule
regulates a number of bodily processes e.g sleep/wake cycle
sleep wake cycle
most improant hormones affected by circadian rythms are melotonin
producede in the pineal gland
chemicaly causes drowsiness and klower body temp
cortisol produced in adrenal gland used o form glucose and blodo sugar
