Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

6
...

•
CNS – brain and spinal cord
...

CNS
•
Brain involved in psychological
processes – main job is to ensure life
maintained
...

•
Spinal cord helps transfer messages to
and from brain to PNS
...

PNS
•
Extends beyond CNS – transmits
messages to whole body from brain
...
g
...
Directs muscles to react and
move
...
Further
divided
...

•
Parasympathetic system –
conserves the body’s natural
activity levels by decreasing
or maintaining it
...
3 Influence of neurochemistry on behaviour: Function of the
endocrine system
•
Series of glands which release chemicals throughout
body via blood and other bodily fluids
...

•
Specialist glands in body
...

•
Testes: facilitate release of testosterone
...

•
Behaviour thought to be influenced by hormones –
each hormone is thought to affect behaviour in
different way
...
4 Fight-or-flight response, including role of adrenaline
Generated from autonomic nervous system – specifically
sympathetic
...

•
Also activated in times of stress – body perceives stress and
threat
...

•
Hypothalamus recognises threat – sends message to adrenal
gland (specifically adrenal medulla) – triggers release of
adrenaline to endocrine system and noradrenaline in brain
...

•
Faster breathing rate – increase oxygen intake
...
2 Structure and function of sensory, relay and motor neurons
•
Muscle tension – improve reaction time and
•
Neurons receive and transmit info to other cells
...

•
100 billion in brain, 1 billion in spinal cord
...

Sensory Neuron
•
Physical changes help individual to fight or run away from
•
Tell rest off brain about external and internal
potentially
threatening
situation
...

•
EVALUATION:
Relay Neuron
Assessing extent to which biological structures affect
•
Carry messages from one part of CNS to another, •
behaviour is very difficult
...

make behaviour happen rather than being cause
...

investigated
...

•
Biological structures that underpin behaviour can be seen as
•
Motor and relay send and receive messages
reductionist
...

processes down to biological processes e
...
level of
•
Dendrite/receptor cell receive the signal and it
hormones
...

travels through neuron to pre-synaptic terminal
...
Increases reliability
...
6 Ways of studying the brain
Functional magnetic resonance imaging (fMRI)
•
Operates same as MRI scan – also shows activity as it occurs
...

•
fMRI uses same principle - measure the energy released by
haemoglobin
...

•
Amount of energy released by haemoglobin is detected by scanner
and change measured
...

EVALUATION:
•
Provides moving picture of brain activity – patterns of activity can be
compared rather than just the physiology of the brain
...

•
Machines expensive to buy and maintain and require trained
operators
...

•
Sample size in studies often small due to availability and funding –
results different to generalise
...
Measure activity of cells immediately under
electrode – using more gives fuller picture
...
Greater accuracy
than self-report
...

•
Cheaper methods of scanning – widely available to researchers
...

•
Useful method to test reliability of self-report answers
...

•
Used to see where damage had occurred in brain and how that
might explain behaviour exhibited by individual
...

•
Issues with comparison of functioning prior to death
...

•
Some brains may have been effected by the reason for death
...


•

Synaptic Transmission:
•
Process of transmitting messages from neuron to
neuron
...

•
Electrical nerve impulse travels down the neuron
and prompts release of neurotransmitters at presynaptic terminal
...

•
Other neuron then must quickly take up
neurotransmitters and convert them into electrical
impulse to travel down neuron to next pre-synaptic
terminal
...

•
Only certain neurotransmitters can unlock a
message channel in certain receptors in postsynaptic neuron
...

•
Right key (neurotransmitter_ meets right lock
(receptor) – specific ion channel in membrane is
opened up
...

•
Flooding of ions can cause potential in the
dendrites
...
If synapse is more likely to
cause post-synaptic neuron to fire –
excitatory synapse
...
If
message likely to be stopped at postsynaptic neuron – inhibitory synapse
...
5 Localisation of the brain
Hemispheric Lateralisation
•
Brain is contralateral – left hemisphere deal with right
side etc
...

•
Same with auditory info, taste and smell
...

•
RIGHT – dominant for recognising emotions in others and
at spatial relationships
...

MOTOR CORTEX
•
Movement centred on primary motor cortex of brain –
sends messages to muscles via brain stem and spinal
cord
...

•
Within motor cortex there are areas which control
specific parts of body
...

•
When motor cortex instructs an outcome – spinal cord
and other areas co-ordinate areas of body into a
movement
...

•
Lies next to motor cortex in brain
...


Split-brain research
•
Corpus callosum – link between the hemisphere
...

•
Cut corpus callosum so epilepsy contained in one hemisphere – reduce number
of fits
...

•
Patients can tell us about roles of each hemisphere
...
Flashed image for 1/10 second
...

•
Image/object only recognised when presented to same eye/hand again
...

•
Objects/images presented to left eye/hand can be identified by pointing to
pictures, feeling for it in array of objects or drawing it with left hand
...

•
Only the left hemisphere able to produce language (speech and writing)
...

•
Two hemispheres have independent perception, awareness and memory
...

•
Possible that there were other effects during surgery in addition to procedure
itself – evidence may be flawed
...

•
Primary visual cortex is in occipital lobe – back of brain
...
Patients with damage to that area
report no vision of any kind, when awake or in dreams
...

PRIMARY AUDITORY CORTEX
•
Two primary auditory cortices – one in each hemisphere
...

•
Info from right eye goes primarily to left hemisphere etc
...


LANGUAGE CENTRES
•
In left hemisphere for most people
...

•
Not all words affected equality
...

Wernicke’s Area
•
Wernicke found patients with damage to area close to auditory cortex
had specific language impairment
•
Inability to comprehend language and struggle to find right word
...

EVALUATION:
•
Holistic theory argues localisation of function is incorrect – work on rats did
not show specific brain area for memory stored all over brain
...

•
Case studies of brain damage indicates localisation and lateralisation of
function
•
Fact rehabilitation works following brain injury suggests there is no
localisation
or lateralisation
...
7 Biological Rhythms
CIRCADIAN RHYTHM
•
Biological rhythm lasting a day
...
g
...

•
Body clocks regulated by internal system including factors such as release of hormones like
melatonin, metabolic rate and body temperature
...
Internal body clock
allowed to free-run, settled into a sleep/wake cycle of 25-30 hours
...
Natural light sources in the
environment are vital for keeping individuals 24 hour cycle
...

•
Can be affected by the environment
...

•
Suprachiasmatic nucleus seems to be most influential endogenous pacemaker in the body – in
centre of brain, regulated by light from the environment
...

Exogenous zeitgebers:
•
Cues from environment that play an important role in regulating time and circadian rhythm in
humans
...

•
Sunlight, noise, seasons and the moon are all zeitgebers
...

•
Happens when a traveller crosses time zones – pacemakers not synchronised with environment
anymore
...

Evaluation:
•
Most research criticised for external validity – often carried out in artificial conditions – resulting
behaviour could be argued to be false
...

•
Using animals in research raises concerns about extrapolation – physiological differences – make
generalising to humans problematic
...

INFRADIAN RHYTHMS
•
Lasts more than 24 hours
...
g
...

•
Rhythm not imposed purely by release of hormones – zeitgebers such as light and odours involved
...
9 hours, menstrual
cycle shortened to 25
...
Level of light in cave could of affect cycle
...


Evaluation:
•
Effects of pheromones can help explain menstrual synchronicity – groups of women who live
together have menstrual cycles synchronised with each other – something in shared
environment that acts as zeitgeber
...

ULTRADIAN RHYTHMS
•
Lasts less than 24 hours
...
g
...


Dement et al
...

•
Took measurements throughout time asleep
...

•
High incidents of dream recall when participants were awakened during REM – if awakened in
other stages very fewer reported dreaming
...

•
Stages of sleep follow typical pattern throughout the night, dreams mostly occur in REM sleep
...

•
Way data collected could of caused atypical reaction from participants and the frequency
of occurrence of REM sleep might be different in non-experimental setting
...

•
EEG – objective measure, scientific, increased reliability
...

•
Cell body can never be replaced but sometimes axons can
...
If undamaged hemisphere stimulated, recovery can be improved
...
Other axons
already connect with that neuron will sprout extra connections, replacing ones destroyed –
compensating for loss
...

FUNCTIONAL RECOVERY OF BRAIN AFTER TRAUMA
•
Much recover after trauma is due to anatomical compensation – intensive rehabilitation
...

•
Taught how to use working faculties and function to compensate for the ones that are lost
...
Function may appear to be lost but
may be that individual not trying and takes view that it is unrecoverable
...
Stress and alcohol
consumption can affect ability to use function that has been regained
...
Following brain trauma
40+ regained less function in treatment than younger patients
...

•
Gender – women recover better from brain injury as their function not as lateralised
...




---