Biopsychology Flashcards
(105 cards)
1
Q
what is the Nervous System?
A
a specialised network of cells in the body that has two main functions: - to collect, process and respond to information from the environment
- to coordinate the working of different organs and cells in the body.
2
Q
what are the two sub-systems of the nervous system?
A
- the central nervous system
- the peripheral nervous system
3
Q
what is the central nervous system?
A
it is made up of the brain, which is responsible for all conscious decisions and awareness. and the spinal cord, which is responsible for reflex arcs. the CNS passes messages to and from the brain and orchestrates complex demands and decisions.
4
Q
what is the peripheral nervous system?
A
sends information from the outside world to the CNS and from the CNS to the body. it is divided into the atonomic nervous system (ANS) and the somatic nervous system (SNS)
5
Q
what is the somantic nervous system?
A
transmits information from receptor cells in organs such as the eyes to the CNS it also receives information that instructs the muscles to act (from the CNS) - a conscious process
6
Q
what is the autonomic nervous system?
A
it governs vital functions in the body such as breathing and heart rate. it is automatic and operates involuntarily. it consists of the sympathetic nervous system and the parasympathetic nervous system.
7
Q
what is the endocrine system?
A
one of the bodies major information systems that instructs glands to release hormones directly into the bloodstream. these hormones are carried toward target organs in the body.
8
Q
what is a gland?
A
an organ that synthesises and releases substances such as hormones.
9
Q
what is the fight or flight response?
A
the bodies stress response - when a threatening stimulus is detected the body enters a state of physiological arousal in order to fight or flee.
10
Q
what is adrenaline?
A
a stress hormone produced in the adrenal gland that causes an increased heart rate, dilated pupils, diverted bloodflow to muscles etc.
11
Q
what happens during the fight or flight response?
A
the bodies normal state is the parasympathetic state - when triggered by a stimulus the hypothalamus triggers the sympathetic branch of the ANS. This causes the adrenal medulla to release adrenaline into the bloodstream which readies the body for action.
12
Q
what is a neuron?
A
nerve cells which transmit chemical and electrical messages. there are 100 billion in the human nervous system and 80% of these are in the brain.
13
Q
what are the three types of neuron?
A
motor neuron, sensory neuron and relay neuron.
14
Q
what is a sensory neuron?
A
carry messages from the PNS to the the CNS. they have long dendrites and short axons.
15
Q
what is a relay neuron?
A
connect sensory neurons to motor neurons - they have short axons and short dendrites.
16
Q
what is a motor neuron?
A
connect the CNS to effectors such as muscles or glands to cause a response. they have short dendrites and long axons.
17
Q
what is the structure of a neuron?
A
dendrites carry signals to the cell body or soma that contains the nucleus of the cell. the axon then carries the signal away towards other neurons. the axon is covered by an insulating myelin sheath that speeds up transmission. gaps in the myelin sheath called nodes of ranvier also speed up transmission. terminal buttons at the end of the axon connect to the dendrites of other neurons.
18
Q
what is action potential?
A
the inside of a neuron is usually negative. when a neuron fires it becomes positive for a split second - this is an action potential and is what generates the electrical impulse.
19
Q
what is synaptic transmission?
A
the process by which neurons communicate with each other by passing chemicals across a synapse. from the pre synaptic terminal to the post synaptic receptor sites.
20
Q
what is a neurotransmitter?
A
brain chemicals released from synaptic vesicles that relay signals across the synapse from one neuron to another. neurotransmitters can be broadly divided into those that perform excitatory functions and those that perform inhibitory functions.
21
Q
what is excitation?
A
when a neurotransmitter such as adrenaline, increases the positive charge of a neuron, increasing the likelihood that it will fire.
22
Q
what is inhibition?
A
when a neurotransmitter such as seratonin makes the charge of the post synaptic neuron more negative. this decreases the likelihood that the neuron will fire.
23
Q
what is holistic theory?
A
that all parts of the brain are responsible for all behaviour, thoughts and actions.
24
Q
what is localisation of function?
A
the theory that different parts of the brain are responsible for different behaviours.
25
what is the basic structure of the brain?
two hemispheres, left and right (in general the left hemisphere controls the right side of the body and vice versa) the outer layer of the brain is called the cerebral cortex, which is around 3mm thick.
26
what are the four lobes of the brain?
the frontal lobe, the parietal lobe, the occipital lobe and the temporal lobe.
27
where and what is the motor area?
an area at the back of the frontal lobe in both hemispheres that controls voluntary movement in the opposite side of the body.
28
where and what is the somatosensory area?
an area at the back of the parietal lobe that processes sensory information such as touch.
29
where and what is the auditory area?
an area in the temporal lobe that is concerned with the analysis of speech based information.
30
where and what is the visual area?
a part of the occipital lobe that processes visual information.
31
where and what is Broca's area?
an area of the frontal lobe in the left hemisphere that is responsible for the production of speech.
32
what can damage to Broca's area do?
it means that patients fully understand speech but cannot produce it - such as 'Tan' named so because he could only produce the word tan.
33
what and where is Wernicke's area?
an area of the temporal lobe (encircling the auditory cortex) in the left hemisphere responsible for language comprehension.
34
what can damage to Wernicke's area do?
it results in Wernicke's aphasia where speech is fluent but nonsensical as the patient can produce language but not comprehend the meaning of language.
35
what is the brain scanning evidence for localisation?
- Petersen et al. used brain scans to show that Broca's area was active during reading tasks and Wernicke's area was active during listening tasks.
- Tulving's study of memory found that semantic memories were stored in the left prefrontal cortex whereas episodic memories were stored in the right.
36
what is the neurosurgical evidence for localisation?
- lobotomy such as cingulotomy (severing the cingulate gyrus) is still sometimes used to treat severe OCD or depression. Dougherty studied 44 patients who had undergone the procedure and found that a third had achieved successful results.
37
how does the case of Phineas Gage support the theory of localisation?
he had an accident where a piece of metal was driven through his frontal lobe - he survived but his personality was greatly changed - therefore we can assume that the frontal lobe is responsible for regulating personality.
38
what counter argument to localisation of function does Lashley provide?
he suggested that higher cognitive processes such as learning were holistic. to test this he systematically removed parts of rats cortex as they were learning a maze - he found that no single area had a greater effect than any other.
39
what is plasticity?
this describes the brains tendency to change and adapt as a result of experience and learning.
40
what is functional recovery?
a form of plasticity, following damage through trauma, the brains ability to redistribute or transfer functions usually performed by the damaged area to other, undamaged areas.
41
what is synaptic pruning?
when we are 2-3 the amount of synaptic connections we have in our brain peaks at 15,000 - adults have around half this so as we grow the less used synaptic connections are deleted and frequently used ones are strengthened.
42
what is some research that has been done into plasticity?
- maguire et al. took images of taxi drivers brains and compared to a matched control group found that the grey matter of their hippocampus was enlarged. this is the area involved with spatial processing and navigational skills.
- Draginski et al. took images of medical students brains before and after medical exams. they found changes in the parietal cortex and posterior hippocampus - as a result of the exam.
43
what three structural changes happen in the brain during functional recovery?
- axonal sprouting: the growth of new nerve endings which connect to other undamaged nerve cells to create new neural pathways.
- reformation of blood vessels
- recruitment of homologous areas on the opposite side of the brain to perform a specific task.
44
what is the practical application for brain plasticity?
it is vital for developing new neurorehabilitation techniques such as electrically stimulating the brain to create new neural pathways or movement therapy.
45
what is negative plasticity?
phantom limb syndrome effects up to 80% of amputees who feel painful or unpleasant sensations in a limb they have lost, this is down to reorganisation in the somatosensory cortex that occurs when one area (feelings from an arm that is no longer there) is taken over by another area (feelings in the face)
also drug use has been shown to increase chances of dementia and decrease intelligence.
46
how does age affect plasticity?
the older you are the less plastic your brain is thought to be. however Bezzola et al. demonstrated that the brain is still plastic in 40-60 year olds with her golf study.
47
how does education affect functional recovery?
Schneider et al. found that the greater a persons 'cognitive reserve' or time spent in education the greater their chances of a disability free recovery.
48
what is hemispheric lateralisation?
the idea that the two hemispheres of the brain are functionally different from each other. that certain mental processes and behaviours are mainly controlled by one hemisphere over the other.
49
what is split brain research?
a series of studies which began in the 1960's involving epileptic patients who had experienced a surgical procedure to separate the hemispheres of the brain by severing the corpus collosum. this allowed the extent of lateralisation to be studied experimentally.
50
what was the basic procedure of Sperry's split brain study?
an image or word was flashed up on either side of the patients visual field - the patient stared at a fixed point in the center of a screen - if a picture was flashed up for a fraction of a second on the left visual field it would be processed by the right hemisphere.
51
briefly outline the four versions of the split brain study.
describing what you see: when an image was flashed up in the left visual field information travels to the right hemisphere where there is no language ability so ppts. would report seeing nothing there.
recognition by touch: when an image was flashed to the left visual field ppts. would not be able to verbalize what they had seen but would be able to pick the object out of a bag they could not see with their left hand (right hemisphere)
composite words: if two different words were flashed into each visual field the ppt would draw the image from the left visual field with their left hand and say the word flashed into the right visual field.
matching faces: when a face was flashed up to each visual field the image processed by the right hemisphere was consistently selected when asked to match the face to another whereas the left hemisphere was consistently ignored.
52
how has Sperry's research contributed to our knowledge of the brain?
the left side of the brain is now known to control analytic and verbal tasks whereas the right side of the brain performs spatial and musical tasks. the right hemisphere is much less capable of producing language but adds the emotional and holistic content to speech.
53
what are the strengths of Sperry's methodology?
he standardised the procedure.
| image flashed up for one tenth of a second to ensure that it only reached one hemisphere of the brain.
54
what theoretical debate has Sperry's work started?
some researchers say that the two hemispheres of the brain are so functionally different that they represent the duality of the brain that is present in everyone and only emphasised in split brain patients.
other researchers argue that the two hemispheres are only marginally different and actually work together to perform most everyday tasks.
55
what is the issue with generalising split brain research to everyone?
these are individuals who've undergone a serious surgical procedure. there are just a few of them and they also have a history of epilepsy which means that they cannot be compared to people without a history of epilepsy like those that Sperry used in his control group.
56
what does fMRI stand for?
functional magnetic resonance imaging.
57
what does EEG stand for?
electroencephalogram
58
what does ERP stand for?
event related potentials
59
what is an fMRI?
a method used to measure brain activity whilst a person is performing a task that uses MRI technology (detecting radio waves from changing magnetic fields) this enables researchers to determine which areas of the brain are oxygenated and therefor active.
60
what is an EEG?
a method of measuring brain activity by recording the tiny electrical impulses that brain activity produces. by measuring characteristic wave patterns it can help diagnose brain conditions.
61
what is an ERP?
a form of EEG where the brains response to various stimuli is isolated and analysed. this also involves pinpointing specific waves related to these events.
62
what is a post mortem?
where the brain is analysed after death to determine whether certain observed behaviours during the patients lifetime can be linked to abnormalities in the brain.
63
what are the strengths of fMRI?
does not rely on radiation, it is risk free and non invasive when performed correctly.
has very high spatial resolution that can map each millimeter of the brain.
64
what are the weaknesses of fMRI?
expensive compared to other methods.
patient has to stay completely still to produce a clear image.
low temporal resolution as there is a five second time delay in the images produced.
looks at bloodflow not the individual neurons so doesn't show the kind of brain activity.
65
what are the strengths of an EEG?
it has helped us to diagnose brain conditions like epilepsy characterised by random bursts of brain activity.
it has also helped our understanding of the sleep cycle and other circadian rhythms.
has an extremely high temporal resolution.
66
what are the weaknesses of EEG?
the EEG produces very generalised data, it cannot pinpoint specific areas of activity or eq.
67
what are the strengths of ERP's?
data is more specific than an EEG and allows scientists to pinpoint certain event related potentials to do with different cognitive functions etc.
derived from the EEG so also has very high temporal resolution.
68
what are the weaknesses of ERP's?
lack of standardisation in ERP technology and methodology makes findings hard to confirm.
in order to pinpoint specific reactions in the brain all background noise and distractions must be eliminated.
69
what are the strengths of post-mortem examinations?
improve general medical knowledge, especially historically, and help to generate hypotheses and further areas of study.
70
what are the weaknesses of post-mortem examinations?
causation is a problem obviously as the patient is dead we don't know whether damage has caused behaviour or if it's due to decay/death related things.
also an issue of informed consent as many people such as HM do not have the ability to consent yet science will advance from post-mortem examinations of their brain.
71
what is a biological rhythm?
distinct patterns of changes in body activity that conform to cyclical time periods. they are influenced by internal body clocks - endogenous pacemakers and external influences - exogenous zeitgabers.
72
what is a circadian rhythm?
a type of biological rhythm that is subject to a 24 hour cycle which regulates the number of body processes such as the sleep/wake cycle and changes in core body temperature.
73
what did Michael Siffre do and what did he find?
he lived in a cave for six months without daylight or other external factors to measure his free-running sleep wake cycle. he continued to fall asleep and wake up on a regular schedule but his sleep/wake cycle lasted for around 25 hours instead of the usual 24.
74
who, other than Siffre found a 25 hour sleep/wake cycle?
Aschoff and Rutger convinced a group of people to live in a WWII bunker for four weeks deprived of any natural light. all but one of the participants displayed a sleep wake cycle of 24-25 hours.
75
what were Folkard's findings on the sleep/wake cycle?
when 12 participants were placed into a cave on a strict sleep and wake time cycle and the clocks were sped up so that the cycle lasted for 22 hours rather than 24 only one participant was able to comfortably adjust. this shows that there is a powerful free-running internal pacemaker that cannot easily be changed.
76
how does our knowledge of circadian rhythms apply to shift work?
we know that workers who work night shifts etc have a disrupted seep/wake cycle that leads to poor concentration or accidents as well as being detrimental to the workers mental health. knowing this helps us to minimise these effects by changing shifts less often etc.
77
how does our knowledge of circadian rhythms apply to drug treatments?
circadian rhythms control a number of bodily processes such as heart rate and body temperature that effects pharmacokinetics - the timing of drug dosages in order to maximise the effect of the drugs.
78
what issues are there with research into circadian rhythms?
generalisations cannot really be made as all the studies use either very few individuals or a single person in the case of Siffre.
also there may be issues with control as whilst the studies deprived people of natural light they still had artificial light which has been shown to alter the sleep/wake cycle.
also there are individual differences in terms of sleep/wake cycles that mean generalisation is hard. for example the owl and lark categorizations.
79
what is an infradian rhythm?
a type of biological rhythm with a frequency of less than 24 hours, such as menstruation and seasonal affective disorder.
80
what is an ultradian rhythm?
a type of biological rhythm with a frequency of more than 24 hours such as the stages of sleep.
81
what is the menstrual cycle?
an example of an infradian rhythm - it refers to the time between the first day of a womans period when the uterus lining sheds and the last day, the day before her next period. it lasts anywhere from 24 to 35 days. oestrogen causes an egg to be released and progesterone maintains the uterus lining. the whole cycle is controlled by hormones.
82
What is one research study done on the menstrual cycle?
McClintock et al. wanted to study the synchronization of women's periods and the effect of pheromones. to do this they took samples of 9 womens pheromones who were on their periods and rubbed these on the top lip of 29 women with irregular periods. they found that 68% of the women showed changes in their cycle that bought them closer to the woman who's pheromones they were smelling.
83
what is seasonal affective disorder (SAD)?
SAD is a depressive disorder where symptoms arise during the winter months. it is a circannual rhythm as it happens yearly but also a circadian rhythm. scientists think that SAD occurs due to the extended periods of darkness in winter months leading to extended times of melatonin production. it can be treated with light therapy.
84
how long does one cycle through the stages of sleep last?
approximately 90 minutes.
85
describe the different stages of sleep.
stages 1 and 2: light sleep where the person is easily woken. brain wave patterns become slower and more rhythmical. alpha waves then turn to theta waves.
stages 3 and 4: delta waves begin which are lower in frequency and larger in amplitude than before. it is known as slow wave sleep and it becomes difficult to wake the person at this point.
stage 5/REM sleep: the body becomes paralysed but the brain is active, brainwaves resemble waking patterns and this stage is highly correlated with dreaming. REM stands for Rapid Eye Movement as the eyes are the only part of the body that moves during this stage of sleep.
86
what are the two main evolutionary theories on synchronised menstrual cycles?
- if women fell pregnant around the same time babies would be cared for collectively.
- if women menstruate at the same time it creates competition for the highest quality males therefore decreasing the fitness of potential offspring. so it would not be advantageous for cycles to sync.
87
what are the methodological limitations to synchronisation studies?
there are many factors that affect the menstrual cycle such as stress levels, activity levels etc. that were not controlled for in the studies.
88
what research evidence supports the idea of distinct sleep stages?
Dement and Kleitman monitored sleep patterns in a sleep lab. brainwave activity was recorded by EEG and caffeine and alcohol consumption was controlled. they found that when ppts were woken during REM sleep they would often report a dream. brainwave activity also varied according to how vivid the dreams were.
89
What is an endogenous pacemaker?
Internal body clocks that regulate many of our biological rhythms, such as the influence of light on the sleep/wake cycle
90
What is an exogenous zeitgaber?
External cues that may affect or entrain our biological rhythms, such as the influence of light on the sleep/wake cycle
91
What is the sleep/wake cycle?
A daily cycle of biological activity based on a 24 hour period that is influenced by regular variations in the environment, such as the alteration of night and day
92
What does SCN stand for?
Supra chiasmatic nucleus
93
What is the SCN?
A bundle of nerve cells located in the hypothalamus in each hemisphere of the brain. It is one of the primary endogenous pacemakers and sits just above the optic chiasm so receives information about light and dark
94
what is an endogenous pacemaker?
internal body clocks that regulate many of our biological rhythms
95
what is an exogenous zeitgaber?
external cues that may affect or entrain our biological rhythms
96
what is the sleep/wake cycle?
a daily cycle of biological activity based on a 24 hour period that is influenced by regular variations in the environment such as day and night
97
what is the SCN?
the supra chiasmatic nucleus. it is a bundle of nerve cells in the hypothalamus that is a primary endogenous pacemaker. it sits just above the optic chiasm and receives information about light from this structure.
98
what are some animal studies into the SCN?
- Patricia DeCoursey et al. did a study where they destroyed the SCN connections of 30 chipmunks and observed them in their natural habitat for 80 days - a significant proportion had been killed by predators as they were awake at unnatural times.
- Martin Ralph et al. bred 'mutant' hamsters with 20 hour sleep/wake cycles. when tissue from the hamsters was placed into the brains of other hamsters they also developed a 20 hour sleep/wake cycle.
99
what is the role of the pineal gland and melatonin?
the pineal gland sits just above the hypothalamus and during the night it secretes melatonin which is a chemical that induces sleep.
100
what does entrainment mean?
changing or resetting our biological clocks through the use of environmental factors.
101
what research has been done into light as an exogenous zeitgaber?
Campbell and Murphy did a study where fifteen ppts. were woken throughout the night and light was shone on the back of their knees - they were able to alter the sleep/wake cycles of some participants by up to three hours. showing light acts as an exogenous zeitgaber even when not detected by the eyes.
102
how can social cues act as exogenous zeitgabers?
in babies there is no obvious sleep/wake cycle but by around 16 weeks most babies are entrained - this may be due to regular adult eating and sleeping times which provide a structure to follow.
103
what are peripheral oscillators?
different organs and even cells may have different circadian rhythms. Damiola et al. were able to change the rhythm of the liver in mice while the SCN remained unaffected.
104
what are the issues with using animal studies to study sleep/wake cycles?
- issues with generalizing results
| - animals were exposed to considerable harm and often died as a result of the study
105
why might the influence of exogenous zeitgabers be overstated?
- people who live in polar regions where there are long periods of light in summer and long periods of dark in winter have a normal length circadian rhythm.
- people who are blind from birth may not have their sleep/wake cycles adjusted by social cues.
