biopsychology Flashcards
(87 cards)
1
Q
what does the CNS consist of and its functions
A
brain- perception, motor control, homeostasis etc
spinal cord- connects the brain to PNS and is responsible for unconscious movements like reflexes
2
Q
function of peripheral nervous system
A
transmitting messages to and from the CNS
3
Q
how is PNS split and its functions
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somatic nervous system- voluntary movement and transmit information between CNS and other senses
autonomic nervous system - involuntary bodily functions like breathing and digestion
4
Q
how can autonomic nervous system be split
A
sympathetic nervous system- arouses body to expend energy
parasympathetic nervous system- calms body to conserve energy
5
Q
define neurone and what is its function
A
specialised nerve cells that receive, process and transmit information to other cells in the body
6
Q
define endocrine system
A
network of glands that release hormones into the bloodstream
7
Q
4 lobes of the brain and its functions
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frontal lobe- thinking, memory, behaviour
temporal lobe- hearing, learning, feelings
parietal lobe- language, touch
occipital lobe- sight
8
Q
different structure of neurons
A
- dendrites receive information from other neurons
- information passes along the axon in form of electrical impulse
- myelin sheath insulates axon to speed up transmission
9
Q
function of sensory neuron
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transmit information from the senses to the CNS
10
Q
function of relay neuron
A
transmit information between sensory neuron and motor neuron
11
Q
function of motor neuron
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transmit information form CNS to effectors (muscles and glands)
12
Q
define synapse
A
gap between two neurons, where information is sent through
13
Q
process of synaptic transmission
A
- nerve impulse arrives at the pre synaptic neuron and triggers the vesicle to release neurotransmitters into synaptic gap through exocytosis
- neurotransmitters diffuse across the synaptic cleft
- specialised receptions on the other neuron bind to the neurotransmitter with the same specific shape
- action potential continues through the postsynaptic neuron and response depends on type of neurotransmitter
- neurotransmitter can be taken up the reuptake channel and used again
14
Q
define excitatory neurotransmitter and how it works
A
increase the activity and likelihood of a neuron firing (dopamine, noradrenaline)
cause sodium ions to flow in and cell becomes less magnetic which leads to local depolarisation (EPSP)
15
Q
define inhibitory neurotransmitter and how does it work
A
decrease the activity and likelihood of a neuron firing (serotonin, GABA)
causes potassium ions to flow in and leads to an IPSP
16
Q
define summation
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adding up excitatory and inhibitory messages to determine the response
17
Q
features of the endocrine system
A
- works with the nervous system via the hypothalamus to signal glands to secrete hormones
- transmits information chemically and operates music slower but is longer lasting
18
Q
define hormones
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chemicals that are produced by endocrine glands in the body and released into the bloodstream. they travel to their target cells and stimulate receptors in the surface or inside cells
19
Q
examples of glands in the endocrine system
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adrenal gland
thyroid gland
tests
ovaries
pituitary gland
pancreas
pineal gland
20
Q
what does the pituitary gland do and how does it work
A
- regulates many bodily functions by releasing hormone that influence release of other hormones
- anterior pituitary- release ACTH which stimulates adrenal glands to produce cortisol and LH+FSH to produce reproductive hormones
- posterior pituitary- releases oxytocin which stimulates chloride ions and play a role in mother infant bonding
21
Q
what is the adrenal gland and how does it work
A
- adrenal cortex produces cortisol which supports bodily functions such as cardiovascular and anti inflammatory functions
- adrenal medulla releases adrenaline and noradrenaline by increasing heart rate and blood flow, or constricting blood vessels to increase blood pressure
22
Q
what is adrenaline
A
responsible for fight or flight response by activating the sympathetic side or the autonomic nervous system
23
Q
what does amygdala do
A
mobilises in the face of a threat and is associated with fear by sending distress signals to the hypothalamus
24
Q
fight or flight response for acute stress
A
- amygdala mobilises and sends signals to ANS
- signals send to adrenal medulla to release adrenaline
25
fight or flight response for chronic stress
- amygdala mobilises and sense signals to hypothalamus
- sends signal to pituitary gland to release ACTH which stimulated adrenal cortex to release cortisol
26
what is cortisol
gives quick boosts of energy and lowers our sensitivity to pain but over time it can impair cognitive performance and lower our immune system as energy is being used elsewhere
27
effects of adrenaline
- heart beats faster to push blood to muscles and organs
- rapid breathing
- glucose and fats are released for energy
- digestion decreases to allow energy to be used elsewhere
28
what happens to the body after fight or flight response
parasympathetic branch reduces these activities and returns the body back to its original state
29
evaluation of adrenaline
- women tend to have tend and befriend response where taylor et al suggests that women focus on protecting themselves and their offspring so they form alliances
=> however, von dawans et al argued that acute stress can lead to greater cooperative and friendly behaviour in male and females
- SRY gene found in men promotes aggression and results in fight or flight response
- negative consequences as responses may be adaptive to energetic behavioural responses, but repeated responses like high blood pressure can lead to damage to blood vessels
- doesn’t tell the whole story as it is argued most animals will freeze first and become hyper vigilant
30
define localisation of function in the brain
identifying specific areas that correspond to specific functions
31
features of motor cortex
- control voluntary motor movements
- found in frontal lobe along the precentral gyrus
- on both hemispheres, controlling the opposite side
- regions exert control over different areas of the body
32
features of somatosensory cortex
- detects sensory events on the skin
- found in the parietal lobe along the post central gyrus
- use information from skin to produce sensations of touch, pressure, pain and temperature which is localised to different areas
- both hemispheres controlling the opposite side
33
features of visual centres
- located in visual cortex in occipital lobe
- processing begins in retina, where nerve impulses are transmitted to the optic nerve
- some nerve impulses involved in coordination of circadian rhythms but majority terminate in the thalamus which acts as a relay station, passing information to visual cortex
- both hemispheres and act on different sides
- different areas process different types of information like colour, shape and movement
34
features of Broca’s area
- treated patient “Tan” who was able to understand spoken language but was unable to speak or express his thought in writing
- studied similar patients with lesions in their left frontal hemisphere
- language centre in the posterior portion of the frontal lobe of the left hemisphere- critical for speech production
- Fedorenho et al discovered 2 regions in the area, one for language and one for responding to many demanding cognitive tasks
35
what does damage to Broca’s area causes (broca aphasia)
slow speech, lack of fluency, inability to find the right words
36
features of Wernicke’s area
- understanding language
- posterior portion of left temporal lobe
- his patients could speak but not understand language
- motor region is close to area that controls the mouth, tongue and vocal cords
- sensory region is close the regions responsible for auditory and visual input and is transferred to Wernicke’s area where it is recognised and associated with meaning
37
what is the neural loop called linking Broca and Wernicke’s area
accurate fasciculus
38
what does damage to wernicke’s area do (wernicke’s aphasia)
speech lacks meaning despite it being fluent
39
evaluation of localisation of brain functions strengths
- support as shown through aphasia deploying through damage to broca and wernicke’s area
=> phineas gage suffered an accident where a metal pole removed most of his left frontal lobe, but his personality changed which suggests mood regulation was localised to frontal lobe
40
evaluation of localisation of brain function weaknesses
- individual differences in language centres as pattern of activation undertaking tasks varies from person to person which shows it is more complex
=> bavelier et al found different patterns of activation when reading
=> havasty found women have larger broca and wernicke’s area
- language production not confined to broca’s area- dronhers et al reexamined brains of brocas patients using MRI and found damage to other areas too
- equipotentiality theory- lashley believed basic functions are localised but not higher mental functions as other areas can take over if damaged, which focuses on extent of damage rather than location
- communication between areas may be more important- Dejerine found loss of ability to read was due to da age connecting visual cortex and Wernicke’s area
- neuroplasticty shows how brain can recover functions after damage associated with that function, as seen in Danelli et al where a boy had his entire left hemisphere removed yet still learnt how to talk
- methodological concerns- case studies
41
define hemispheric lateralisation and features of it
theory that left and right hemispheres are specialised to do different things
- contralateral- opposite side of brain control opposite side of body
- left hemisphere= language processing, logic, problem solving
- rich hemisphere= processing spatial relationships, emotion, face recognition
- two hemispheres connected via corpus callosum
42
evidence for hemispheric lateralisation
- Fink (1996) asked patients to look at a picture and identify small details
=> he found that left hemisphere was more active, when looking at picture holistically R was more active, concluded L focused on details
- Heller and Levy asked participants to look at split faces
=> emotion of left side is the one recognised by the participants, right hemisphere is processing the left visual field
43
evaluation of hemispheric lateralisation strengths
+ supported through empirical evidence like Fink which validates the claim and supports psychology as a science
+ increase neural processing capacity as only one hemisphere is engaged so the other half is free
=> rogers et al found in domestic chickens the enhanced ability to perform two tasks simultaneously
44
evaluation of hemispheric lateralisation weaknesses
- tonnessen et al found disadvantage where there was a small but significant relationship between handedness and immune system disorders, which suggests same genetic processes in lateralisation affects development of immune system
=> Morfit + Weckes found that left handlers had higher incidence of immune system disorders in their immediate families
- changed with age where Szaflarski et al found language became more lateralised to the left he,sphere with increasing age, but decreases after 25
45
Sperry and Gazzaniga split brain research
- in rare cases of epilepsy, surgeons cut the corpus callosum to contain the epilepsy in one hemisphere and investigate each side in isolation
- the experiment got patients to focus on a dot in the centre and information was shown in either the left or right visual field
- they were asked to say or signal with their hands what they saw- relied on brain being contralateral
- information in left visual field led to patients not saying correctly what they saw as language centre is in left hemisphere
- matching words and faces only worked with right hemisphere (left visual visual field) as this is associated with visuo-spatial awareness
46
conclusions of Sperry’s split brain research
- differences between hemispheres
- connectivity between different regions is as important as localisation of function
47
further split brain research
- while recovering from surgery, the hemispheres act separately (diamond)
- eventually LS takes control and suppresses RS interference by using smaller pathways that connect the hemispheres- adaptive
- patients compensate for lack of connectivity by using strategies like turning their heads so information is taken in by other hemisphere
48
evaluation of split brain research strengths
+ useful in understanding the role of each hemisphere and localisation
49
evaluation of split brain research weaknesses
- andrewes found many confounding variables like some had less lesioning of hemispheres or differing amounts of time in drug therapy
- produced is rarely carried out nowadays so lacks temporal and population validity
- early findings have disproved Sperry’s research- case of JW found that he developed capacity for speech in his right hemisphere after damage to his left
- small sample size- only 11
50
define plasticity
brains ability to change and adapt as a a result of experience by creating new neural pathways as a result of learning
51
features of plasticity
- frequently used pathways develop stronger connections whereas rarely or never used neurons eventually die
- natural decline in cognitive functioning with age
- video games has complex motor and cognitive demands in the brain
- meditation helps to change the inner workings of the brain
52
research support for brain plasticity
- boyke et al taught juggling to 60 year olds which increased their grey matter in the visual cortex
- davidson et al compared the brains of monks who meditate and students who don’t- monks show a greater increase in gamma wave activity
- maguire et al used MRI scans to show london taxi drivers had larger posterior hippocampus- linked to time as taxi driver
53
evaluation of neuroplasticity weaknesses
- differs with factors, where the brain loses neuroplasticity with age or women are better at recovering function from brain damage
54
define functional recovery
brains ability to transfer functions from damaged to undamaged areas following trauma
55
different methods of functional recovery
- neurons next to damaged areas form new circuits which aid recovery of some of the lost function
- axon spreading- other axons already connected to that neuron will sprout extra connections, only if damaged axon does a similar job to the compensatory axon
- denervation supersensitivity- axons that do a similar job become aroused to a higher level to compensate for the loss
- neuronal unmasking- dormant synapses that are blocked due to neural input being too low can be activated through increasing input to open the synapse
-stem cells- replace damaged cells, secrete growth factors or create neural network to link damaged areas to undamaged areas
56
evaluation of functional recovery strengths
+ supporting research- taijiri et al had 2 groups of rats with brain damage, where one group received stem cells and the other group had solution infused- group with stem cells developed neuron like cells
+ supporting research- danelli et al found EB had lost his left hemisphere at 2.5 years and undertook intensive rehabilitation, and by 17 his language abilities are the same as controls and RH compensated for loss
57
evaluation of functional recovery weaknesses
- mediating factors
=> perseverance
=> stress and fatigue hinders recovery
=> plasticity reduced with age
=> women recover better from brain injury as function is less lateralised
=> those with college education were more likely to be disability free
- limit to spontaneous recovery and can only repair itself to a specific point
58
features of fMRI
- measures change in blood flow when a person performs a task
- if an area is more active, there is more of a demand for oxygen and oxygenated blood responses differently to a magnetic field to a deoxygenated one
- can be used to diagnose medical problems by showing damaged areas
59
evaluation of fMRI
+ non invasive and no harmful radiation
+ objective and reliable
+ records as it happens
- overlooks the networked nature of the brain
- low temporal resolution- time between taking image and neurons firing
- expensive machines
60
features of EEG
- measures electrical activity in the brain
- electrodes places in the scalp detect small electrical changes
- pattern of waves can represent different levels of arousal or consciousness
- used in sleep studies
- data can detect brain disorders
61
evaluation of EEG
+ recording in real time
+ used in clinical diagnosis like epileptic seizures
+ non invasive and cheaper
- can only detect activity in superficial regions of the brain
- electrical activity can be picked up by neighbouring electrodes so cannot pinpoint (low spatial resolution)
62
features of ERP
- small voltage changes in the brain that are triggered by a specific event
- averaged EEG response to a stimuli
63
evaluation of EEG
+ continuous measure of processing in response to a stimulus
+ can measure processing of stimuli even in absence of behaviour response
- difficult to pick out from other electrical activity
- requires large number of trials
- only records barring voltage changes
64
features of post mortem examinations
- establish underlying neurobiology of a particular behaviour
- dissecting and looking at internal structures of a person who has died
- can examine brain for abnormalities like with broca
65
evaluation of post mortem examinations
+ allow for more detailed examination
- length of time between death and post mortem may influence
- retrospective so cannot follow up
- cannot show cause and effect
- ethical issues
66
define biological rhythms
a cyclical variation over some period of time in physical or psychological processes
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define circadian rhythms
cycles of behaviours occurring every 24 hours approximately - sleep wake cycle
- synchronised by suprachiasmatic nuclei (SCN)
68
define infradian rhythms
behaviours occurring over a period of time greater than 24 hours- menstrual cycle
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define ultradian rhythms
behaviours occurring more than once in a 24 hour cycle- heart rate, breathing
70
define internal pacemakers
mechanisms within the body that govern biological rhythms
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define external zeitgebers
environmental cues that influence biological rhythms like light
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michel siffre research on circadian rhythms
- lived underground with no external cues present
- found natural rhythm just over 24 hours
- body clock also ticked slower compared to when he was younger
- after two months. he emerged believing it was a month earlier that it actually was
73
features of sleep wake cycle
- dictates when we sleep and be awake
- light is an external zeitgebers
- dips and rises at different times of the day- strongest sleep drive during two dips (2-4am and 1-3pm)
- sleepiness in these dips are less intense with sufficient sleep
- also under homeostasis control- energy us being used up therefore body tells us we need to sleep
- internal circadian clock is a free running- around 24-25 hours
- intolerant to major alternations like jet travel
74
features of core body temperature as a circadian rhythm
- temperature drops during sleep
- rises in the last hours of sleep for alertness in the morning
75
features of hormone production as a circadian rhythm
melatonin is at peak levels during hours of darkness, which encourages feelings of sleep
76
evaluation of circadian rhythms strengths
+ chronotherapeutics help to understand how timing affects drug treatments and research has helped develop novel drug delivery system where drug is released at the right time
+ real life application as it has helped improve quality of lives for shift workers, where employees whose shift was stable over 21 days had greater employee satisfaction
77
evaluation of circadian rhythms weaknesses
- individual differences where cycles can vary from 13-65 hours and when rhythms reach their peak
- flawed methodology due to case study being used, and a participants were not isolated from dim artificial light which may be a confounding variable
- temperature may be more important than light as SCN transforms information about light levels to set body temperature, which may have a bigger impact on body clock
78
features of sleep cycle
- 90 min cycle of sleep broken into stages
- can see activity through EEG pattern
- stage 1 and 2 are light sleep- beta and alpha waves
- stage 3 and 4 are deep sleep- slower delta waves, psychological repair work and growth hormone released, hard to wake
- stage 5- rapid eye movement (REM)- brain wave speed up, dreaming occurs, complete relaxation, heightened brain activity
79
types of infradian rhythms
- menstrual cycle- governed by endogenous system by release of oestrogen and progesterone
- seasonal affective disorder- people become depressed in the winter, suggested by increased melatonin when it is dark
80
evaluation of infradian rhythms strengths
+ effective treatment for SAD, where partial to were given a light box to mimic sunlight which led to a relief in symptoms
81
evaluation of infradian rhythms weaknesses
- menstrual cycle can be influenced by exogenous factors- merging menstrual cycles, evidence of PMS, link of pheromones
=> however, not all women link their cycles so may be more external factors
- SAD can be consequences of disrupted circadian rhythms as when seasons change people go to sleep earlier
82
evaluation of ultradian rhythms
+ also seem with basic rest activity cycle, which is 90 mins clock running throughout the day where we progressively move from alertness to fatigue
- individual differences due to non-biological factors- room temperature, Tucker (2001) claims these differences are biologically determined
83
features of SCN
- cluster of nerve cells in hypothalamus
- contains info about light form optic nerve
- one in each hemisphere
- ventral SCN is quickly reset by external cues
84
features of hypothalamus and pineal gland as endogenous pacemaker
- controls ANS and endocrine system
- pineal gland controlled by SCN and releases melatonin at night
85
evaluation of endogenous pacemakers
+ research evidence like siffre
+ animal studies- bred mutant hamsters so they had 20hr circadian rhythms and then transplanted their SCNs into normal hamster and found they also displayed mutant rhythms
86
features of exogenous zeitgebers
- light is the dominant zeitgebers (photo entrainment) and can reset SCn
- protein melanopsin is sensitive to light, and can carry signals to SCN
- social cues include meal times
87
evaluation of exogenous zeitgebers
+ support for melanopsin as studies have been done on blind people with non-functional receptors to set circadian rhythms
+ artificial not enough however evidenced found that shining light on the back of someone’s knees can shift circadian rhythms
+ individuals can compensate for absence of natural light by responding to social cues as seen with people in the arctic who maintain constant sleep pattern despite months of darkness
