biopsychology Flashcards
(74 cards)
1
Q
human nervous system
A
central nervous system - brain and spinal cord
peripheral - somantic and autonomic nervous system
autonomic nervous system - sympathetic and parasympathetic
2
Q
the brain
A
two hemispheres and outer layer is called cerebral cortex
3
Q
spinal cord
A
passes messages to/from the brain and the PNS
also responsible for reflexes
4
Q
somatic nervous system
A
transmits information from senses to the CNS and directs muscles to act
5
Q
autonomic nervous system
A
transmits automatic signals ie breathing
6
Q
sympathetic nervous system
A
involved in preparation for fight or flight response
7
Q
parasympathetic nervous system
A
returns body to resting state, also involved in fight or flight response
8
Q
structure of neurons
A
cell body contains nucleus
dendrites extend from the cell body and carry electrical impulses from other neurons towards the cell body
the axon carries impulses away from the cell body and is covered by a fatty layer or myelin sheath - increases speed of transmission
breaks in myelin sheath - nodes of ranvier - force impulses jump across the gaps and speed up the transmission
9
Q
motor neuron
A
carry signals from CNS to effectors
short dendrites and long axons
10
Q
relay neuron
A
connect sensory neurons to motor neurons or other relay neurons
short dendrites and short axons
11
Q
sensory neuron
A
carry signals from receptors to the central nervous system
long dendrites and short axons
12
Q
synaptic transmission
A
- electrical impulse called action potential travels down axon of the transmitting neuron to the dendrites
- triggers the nerve-ending of the pre-synaptic neuron to release neurotransmitters from synaptic vesicles
- these chemicals diffuse across synapse and bind with receptor sites on post-synaptic neuron which stimulates an action potential
- reuptake - some of the neurotransmitter is reabsorbed back into the pre-synaptic neuron or is broken down by enzymes
13
Q
summation
A
- neurotransmitters can either be excitatory or inhibitory
- excitatory potentials increases a neuron’s positive charge and make it more likely for a neuron to fire
- inhibitory potentials increases a neuron’s negative charge and make it less likely to fire
- summation of these determines whether neuron has a net effect that will trigger action potential once at threshold
14
Q
endocrine system - glands and hormones
A
consists of glands that produces hormones which are released into the blood stream to control vitual functions
pituitary gland controls release of hormones from all the other endocrine glands
15
Q
fight or flight
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- a stressor perceived
- amygdala sends a stress signal to hypothalamus
- hypothalamus activates pituitary gland - triggers SNS
- SNS activates adrenal medulla
- adrenal medulla releases adrenaline
- adrenaline prepares body for fight or flight
- after a few minutes - PNS activates bringing body back to normal
16
Q
role of adrenaline
A
increases heart rate
increases breathing rate
dilates pupils
inhibits digestion
inhibits saliva production
increased sweat
17
Q
localisation of function
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frontal lobe - motor centre and broca’s area
parietal lobe - somatosensory centre
occipital lobe - visual centre
cerebellum
temporal lobe - wernicke’s area and auditory area
18
Q
motor centre
A
controls voluntary movement in opposite side of body
19
Q
somatosensory centre
A
sensory information from skin processed
20
Q
visual centre
A
receives visual information from each eye
left in right hemisphere and vice versa
21
Q
auditory centre
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processes speech based information
22
Q
broca’s area
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speech production
23
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wernicke’s area
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processing of words
24
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evaluation of localisation of function - brain scans
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peterson et al
used brain scans to show how Wernicke’s area was active during a listening task and broca’s during a reading task
areas of brain have different functions
25
evaluation of localisation of function - broca
two of broca’s patients had their brains preserved
MRI scanning
findings revealed that other areas of the brain could have also contributed to the patients’ reduced speech abilities
26
evaluation of localisation of function - evidence against
Lashley - found that by removing different areas of the cortex in rats learning a route through a maze that there was no difference in their ability to learn after surgey
it suggests processes, such as learning, are not localised but processed more holistically
27
left and right hemispheres
language is lateralised as broca’s and wenicke’s areas there
brain is cross-wired in that the left hemisphere controls the right side of the body and vice verse
28
split brain research
sperry
11 participants who had an operation to cut corpus callosum studied
right visual field - could describe
left visual field - couldnt describe - could select matching object
due to right hemisphere not processing language or communication
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evaluation of lateralisation of function - individual differences
Some of the brains of the participants were more 'disconnected' than others and some had been on drug therapy longer than others.
30
evaluation of lateralisation of function - oversimplified
split brain research has caused oversimplification of the functional differences between hemispheres
plasticity shows us that the other hemisphere can perform the same function when required to do so - functional recovery
31
evaluation of lateralisation of function - validity
set up study - artificial and lacked ecological validity
real life - both eyes would compensate for severed corpus callosum so study not representative of how brain works in reality
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evaluation of lateralisation of function - generalisability
control groups did not have a history of epilepsy so not a valid comparison
split brain patients also have very different brains
not generalisable
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plasticity
describes the brains tendency to change and adapt as a result of experience and new learning
between 2 and 3 years old we have twice as many neural connections as we do as an adult
synaptic pruning strengthens connects we use and deletes ones we dont use
34
plasticity study
maguire et al
used london taxi drivers as participants who had taken the knowledge test
mri scans - increased grey matter in posterior hippocampus - spatial and navigation skills
longer been on job - more grey matter
35
evaluation of taxi drivers plasticity - supporting research
draganski et al examined brains of medical students three months before and after final exams
changes in the posterior hippocampus and parietal cortex
36
evaluation of taxi drivers plasticity - good design
use of a control group allows us to say there is a significant difference between taxi-drivers and non-taxi drivers
37
evaluation of taxi drivers plasticity - meditation
tang et al found that 4 weeks of meditation increases white matter in the anterior cingulate cortex - self control and regulation
38
functional recovery
after injury or trauma
unaffected areas compensate for damaged area - form of plasticity
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how does functional recovery occur
axon sprouting. new nerve endings grow and connect with undamaged areas to create new pathways
recruitment of homologous areas - the same areas on opposite side of brain take over
reformation of blood vessels
neuronal unmasking - dormant synapses open connections near damaged areas
40
evaluation of functional recovery - supporting research
taijiri et al
if rats brains injected with stem cells at sight of trauma then new neuron-like cells migrated to the injury site
41
evaluation of functional recovery - real world application
led to development of neurorehabilitation which uses movement therapy with stroke patients
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evaluation of functional recovery - age
erbert et al found that neural regeneration is less effective in order brains
individual differences need to be considered when assessing recovery
43
post mortem examinations - what
when person dies - researcher examines brain to look at structure to explain behaviour
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post mortem examinations - useful
useful before technology was developed eg brocas and wernicke
can see middle of brain
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post mortem examinations - not useful
cause and effect is a problem - observe something unrelated
informed consent
46
functional magnetic resonance imaging
measures changes in blood flow in the brain which indicates increased activity
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fmri useful
risk free and non invasive
high resolution images that are accurate to the millimetre
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fmri not useful
poor temporal resolution as 5 second time delay between neuron firing and detection
49
EEG
measures electrical activity in brain
electrodes placed on the scalp detect small electrical charges resulting from activity of brain
helps detect epilepsy
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EEG useful
high temporal resolution
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EEG not useful
cannot pinpoint exact sources of activity as it only detects many neurons firing at once
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ERP
EEG and statistical averaging technique to isolate specific neural responses
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ERP useful
high temporal resolution and more specific than EEG
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ERP not useful
lack of standardisation of procedures amongth researchers
to be successful, all extraneous variables need to be eliminated
55
circadian rhythms
24 hour cycle
sleep-wake cycle
- daylight (exogenous zeitgeber) alters the feeling of alertness during the day and drowsiness at night
- superchiasmatic nucleus also governs cycle
56
evaluation of circadian rhythms - cave study
siffre
spent time living in cave with no natural light and found his biorhythm settled around 25 hours
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evaluation of circadian rhythms - shift work
research has shown disruption to circadian rhythms due to shift work can cause poor health and implications for productivity
58
evaluation of circadian rhythms - real world application
by understanding circadian rhythms and their impact on health, can help determine the best time to administer drug treatments
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infradian rhythms
less than one cycle in 24 hours
- longer than one day
menstrual cycle - oestrogen levels rise to release an egg from the ovary and progesterone helps the womb lining to grow
60
evaluation of infradian rhythms - mate preference
research suggest women prefer feminised faces of men in their least fertile stage and more masculine faces in their most fertile
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evaluation of infradian rhythms - real world application
a lightbox can be used to reset melatonin levels and relieve symptoms of SAD
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evaluation of infradian rhythms - external factors
stern and McClintock
woman could synchronise their periods by being exposed to other womens’ pheromones
- we should take into account external factors
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ultradian rhythms
more than one cycle in 24 hours
sleep cycle
stage 1 and 2 - light sleep - alpha waves
stage 3 and 4 - deep sleep - delta waves
stage 5 - rem - theta waves
64
evaluation of ultradian rhythms - controlled measures
using EEGs to record sleep brain wave activity is very controlled
can be invasive and disturb sleep
lack ecological validity
65
evaluation of ultradian rhythms - improved understanding
researchers now understand that older people have less slow save sleep and can recommend medications and relaxation techniques
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evaluation of ultradian rhythms - individual differences
tucker et al - large differences between durations of each stage for different people
67
effects of endogenous pacemakers on sleep cycle
endogenous pacemaker - internal biological clock
suprachiasmatic nucleus - in optic chiasm - receives light information - passes information to pineal gland that controls melatonin production
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evaluation of endogenous pacemakers - reductionist
peripheral oscillators found in other organs - own circadian rhythms
- influence on the sleep-wake cycle is more complex than previously thought
69
evaluation of endogenous pacemakers - research support
morgan - bred hamsters with circadian rhythms of 20 hours rathe and then transplanted their SCN neurons into brains of normal hamsters - displayed same rhythm
70
evaluation of endogenous pacemakers - chipmunks
decoursey et al - destroyed SCN connection in 30 chipmunks and returned them to the wild - many of them were killed by predators not long after
71
effect of exogenous zeitgebers on sleep-wake cycle
two external factors - light and social cues
light can be detected by the eyes and skin - influences hormone secretion and blood circulation
social cues such as mealtimes and bedtimes train babies circadian rhythms to match 24 hours
72
evaluation of exogenous zeitgebers - real world application
knowledge of exogenous zeitgebers can help decreases the impact jetlag has on our sleep wake cycles by providing light and meals at certain times
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evaluation of exogenous zeitgebers - endogenous pacemakers
people who live in arctic circle experience around 6 months of total darkness per year
sleep patterns do not vary - endogenous pacemakers more important
74
evaluation of exogenous zeitgebers - siffre
siffre believed the date to be a month earlier than it was when he emerged
his cycle increased by lack of external cues
