biopsych new Flashcards
(85 cards)
1
Q
draganski et al
A
- imaged brains of medical students 3 months before and after their final exams
- learning-induced changes occured in posterior hippocampus and parietal cortex
2
Q
rohan et al
A
- using light therapy, relapse of SAD was 46%
- using CBT it was 27%
3
Q
summation definition
A
- likelihood that a neuron will fire is based upon sum of inhibitory and excitatory influences
- if net effect is excitatory, then post synaptic neuron is likely to fire
4
Q
tucker et al
A
- found large differences between participants’ duration of sleep stages
5
Q
circadian rhythms
A
- rhythms that last around 24 hours
- e.g. sleep wake cycle and core body temperature
6
Q
endogenous pacemaker
A
- internal body clocks
7
Q
lashley et al
A
- removed areas of rats brains (between 10% and 50%) who were learning routes through a maze
- no area was proven to be more important
- learning seemed to require every part of the cortex
8
Q
folkard et al
A
- 12 ppts in a dark cave for 3 weeks
- told to go to bed at 11:45 and wake at 7:45
- clock was changed to a 22 hour day
- only one person could adjust
9
Q
occipital lobe
A
- contains visual area
- each eye sends information from the left visual field to the right visual cortex
10
Q
hormone
A
a biochemical substance that circulates in the blood but only afects target organs
11
Q
functional recovery
A
- a form of plasticity which may come after psychical injuries, strokes or other brain trauma
- healthy areas of the brain may take over functions of those which are damaged
- this initially occurs quickly (spontaneous recovery) then slows down after several weeks, then may require rehabilitative therapy
12
Q
SAD
A
seasonal affective disorder
- depressive disorder with seasonal pattern of onset
- characterised by persistent low moods and lack of activity and interest in life
- example of a circannual rhythm
13
Q
relay neuron
A
- connect the sensory neurons to motor or other relay neurons
- they have short axons and short dendrites
- make up 97% of all neurons
14
Q
bezzola et al
A
- demonstrated how 40 hours of golf training produced changes in neural representations of movement in participants ages 40-60
- using fMRI, the researchers observed reduced motor cortex activity suggesting more efficient pathways
15
Q
left hemisphere
A
- controls right side of the body, contains language centres (Broca / Wernicke’s area)
16
Q
FMRI
A
functional magnetic resonance imaging
- detects changes in blood oxygenation and flow which occur as a result of neural activity
- when a brain area is more active, it consumes more oxygen, so blood flow is directed there to keep up with demand (known as haemodynamic response)
- it produces 3d images showing which parts of the brain are active
17
Q
temporal lobe
A
- auditory area (speech-based and hearing information)
- wernicke’s area (involved in language comprehension)
18
Q
hirstein et al
A
60-80% of amputees develop phantom limb syndrome due to reoganisation of the somatosensory area
- unpleasant and painful sensations
- shows that brain plasticity may not always be helpful
19
Q
main functions of the nervous system
A
- to collect, process and respond to information in the environment
- to co-ordinate the working of different organs and cells in the body
20
Q
weakness of ERPs
A
- lack of standardisation in methodology
- may not always be easy to isolate brain wave
21
Q
EEG
A
electroencephalogram
- measures electrical activity within the brain via electrodes which are fixed to your scalp
- the recording represents the brainwave patterns that are generated from the action of thousands of neurons
- arrhythmic patterns indicate epilepsy or tumors.
22
Q
limitation of fMRIs
A
- expensive
- poor temporal resolution (5 second lag)
23
Q
czeisler et al
A
found individual differences varying from 13 to 65 hours in sleep wake cycle
24
Q
whats the main part of the brain called
A
cerebrum
25
excitatory neurotransmitter
- increases the positive charge of the post synaptic neuron
- this increases the likelihood that the post synaptic neuron will fire
26
strength of EEG
- helps to diagnose epilepsy
- high temporal resolution (up to a milisecond)
27
Siffre
- spent 2 months in a cave deprived of natural light and sound
- resurfaced in mid-september and thought it was mid-august
- biological rhythm extended to 25 hours long
28
how does the endocrine system operate
- secretes hormones into the blood stream
- these hormones affect any cell in the body which has a receptor for the particular receptor
29
strength of post mortems
- provided an early understanding of key processes in the brain
- used in Wernicke and Broca's research, as well as HM memory study
30
how does a neuron fire
- when resting, the inside of the neuron is negatively charged compared to the outside.
- when activated by a stimulus, the inside of the cell becomes positively charged for a split second
- this causes an action potential to occur, which creates an electrical impulse
31
components of the central nervous system
- spinal cord
- brain
32
synaptic pruning
- at 2-3 years old, we have around 15,000 synaptic connections per neuron
- as we age, less used connections are deleted, and commonly used connections are strengthened.
- this enables lifelong plasticity, where new connections can be formed in response to demand
33
kim peek
- born with a natural split brain
- could read both pages of a book simultaneously
- drawback of sperry's research, as it shows language can be bilateral
34
infradian rhythms
- a biological rhythm which occurs less than once every 24 hours
- e.g. menstrual cycle
35
schneider et al
- the greater someone's cognitive reserve (time spent in education), the greater their chances of disability free recovery (DFR)
- 40% of DFR has over 16y of education, vs 10% who has less than 12y education
36
lateralisation definition
- some physical or psychological functions are controlled by a certain hemisphere
- generally, the right hand side of the body is controlled by the left hand side of the brain and vice versa
37
Decoursey et al
- destroyed SCN connections of 30 chipmunks + returned to natural habitat
- sleep wake cycle disappeared + number had been killed by predators
38
sleep wake cycle
- governed by an endogenous pacemaker
- suprachiasmatic nucleus (SCN)
- this lies just above the optic chiasm which provides information about light
39
forms of functional recovery
- axon sprouting - the growth of new nerve endings in order to form new pathways
- denervation supersensitivity - when axons which do a similar job become aroused to a higher level to compensate for the ones which are lost
- recruitment of homologous areas - areas on the opposite side of the brain are used
40
localisation of function
- the idea that different parts of the brain perform different tasks and are involved with different parts of the body
41
ralph et al
- bred mutant hamsters with 20 hour sleep wake cycle
- transplanted SCN to normal hamsters + their sleep wake cycle defaulted to 20 hours
42
types of neurotransmitters
- excitatory
- inhibitory
43
event related potentials
- a type of EEG which uses a statistical averaging technique, extraneous brain activity is filtered out
- this leaves only the brainwaves triggered by particular events
44
knutsson
shift workers are 3x more likely to develop heart disease
45
sensory neuron
- carries messages from PNS to CNS
- has long dendrites and short axons
46
post mortem exams
- analysis of a person's brain following their death
- may include comparison with neurotypical brain
47
murphy et al
- 15 participants woken at various times and had light shone on the back of their knees
- deviation in sleep wake cycle of up to 3 hours
48
SCN
suprachiasmatic nucleus
- small bundle of nerve cells found in the hypothalamus
- one of primary endogenous pacemakers in mammals
- lies above optic chiasm and can receive direct information about light, even when eyes closed
49
parietal lobe
- contains somatosensory area
- this is where sensory information from the skin (e.g. heat, touch, pressure) is represented
- the amount of the somatosensory area which a body part takes up represents its sensitivity
50
limitations of post mortems
- causation cannot be determined
- ethical issues, may not have provided consent
51
response time in endocrine system
- slower than nervous system
- around 2-3 seconds
- but effects are more long-lasting and widespread
52
sanassi
- light therapy helped to reduce effects of SAD in 80% of people
53
types of neurons
- sensory
- motor
- relay
54
components of the peripheral nervous system
- autonomic nervous system
- somatic nervous system
55
number of neurons in the human nervous system
100 billion (80% are in the brain)
56
role of somatic nervous system
- deliberate movements
- muscle movement and receives info from sensory receptors
57
role of autonomic nervous system
- automatic functions
- breathing, heart rate, digestion, stress
58
limitations of EEG
- data is generalised
- cannot pinpoint exact source of activity
59
dougherty et al
- investigated 44 OCD patients who has undergone cingulotomy (isolating a region called cingulate gyrus)
- after 32 weeks, 30% met criteria for successful response, 14% partial response
- supports localisation of function
60
miles et al
- studied a blind man with circadian rhythm of 24.9 hours
- despite regular meal times, still had abnormal rhythm length
61
stages of sleep
5 stages which cycle through every 90 minutes
1 - light sleep. brain waves are at high frequency (alpha waves)
2 - alpha waves continue but there are occasional changes in pattern (sleep spindles)
3/4 - deep sleep. waves are lower frequency (delta waves)
5 - REM sleep, body is paralysed but brain activity is same as if awake (theta waves)
62
sperry
- 11 people with split brains (severed corpus-callosum)
- when an image was shown to the participants' RVF (linked to LH) they could describe what was shown
- when shown to LVF (linked to RH), they said there was 'nothing there'
- they couldn't send the messages from the RH to the language centres in the LH
- if a funny image was shown to LVF, there was an emotional reaction, but reported seeing nothing / flash of light
63
response time of nervous system
- faster than endocrine
- average is 0.25 seconds
64
exogenous zeitgebers
- external factors in environment that reset our body clocks in a process called entrainment
- e.g. light or social cues
65
role of the brain
- centre of all conscious awareness
- contains a cerebral cortex (outer layer, about 3mm thick, only found in mammals)
66
structural features of a neuron
- cell body (soma) contains nucleus, which holds the genetic material of the cell
- dendrites protrude from cell body and carry nerve impulses towards the cell body from neighbouring neurons
- axon carries signals away from cell body
- myelin sheath - a fatty layer which covers the axon
- nodes of ranvier - gaps in the myelin sheath which the signal has to jump across (helps to speed up transmission)
- terminal buttons - at the end of the axon that communicate with next neuron
67
strengths of ERPs
- more specificitity to measurement of neural processes
- high temporal resolution
68
gland
an organ in the body which synthesises substances like hormones
69
frontal lobe
- front of the head
- contains motor area (controls voluntary muscle movement in opposite side of the body
- left frontal lobe contains broca's area (responsible for speech production)
70
motor neuron
- connects CNS to effectors (like muscles or glands)
- short dendrites and long axons
71
damiola et al
- changing feeding patterns in mice altered the circadian rhythms in liver by up to 12 hours
72
chemical transmission of a neuron
- neurons are separated by synapses, which are tiny gaps
- when the electrical impulse reaches the presynaptic terminal, it triggers the release of a neurotransmitter from tiny sacs called synaptic vesicles.
73
buckner et al
- review of long-term memory studies
- revealed that semantic and episodic memories reside in different parts of the prefrontal cortex
74
stern et al
- 29 women with irregular periods
- samples of pheromones gathered from armpits of 9 of the women at different menstrual cycle phases
- pads were frozen and treated with alcohol and rubbed on upper lip of other participants
- 68% of women experienced changes to cycle which bought them closer to cycle of odour donor
75
maguire
- found significantly more volume of grey matter in posterior hippocampus than matched control group
- this part of the brain is associated with the development of spatial and navigational skills
- the longer they had been a taxi driver, the more pronounced the structural difference
76
Phineas Gage
- work accident
- metre long pole shot through his left cheek, passed behind his left eye + exited from the top of his head
- removed a huge portion of his left frontal lobe
- went from being calm and reserved to rude and quick-tempered
77
inhibitory neurotransmitter
- increases the negative charge of the post synaptic neuron
- this decreases the likelihood that it will fire
78
fink et al
used PET scans
- the RH was more active when participants were asked to look at a whole image, LH was more active when asked to focus on specific details
79
role of spinal cord
- passes messages to and from the brain
- connects nerves to the PNS
- responsible for reflex actions
80
ultradian rhythms
- occur more than once in 24 hours
- e.g. stages of sleep
81
define neurotransmitter
- chemicals released from synaptic vesicles that relay signals across the synapse from one neuron to the other
82
strength of fMRIs
- doesn't use radiation
- risk free
- non invasive
- high spatial resolution
83
hemispheric lateralisation
the idea that the two hemispheres of the brain are functionally different and certain processes and behaviour are controlled by a certain hemisphere
84
petersen et al
- used brain scans to show that Broca's area was active during a reading task, and Wernicke's area was active during a listening task
85
