Biological Flashcards
1
Q
what does the cns include?
A
- brain
- spinal cord
2
Q
what is the cns responsible for?
A
- receiving and processing information
- evaluating stimuli and formulating appropriate responses
- spinal cord consists of a large network of neurons, which connects the barin to the body
3
Q
what are neurotransmitters?
A
- chemical messengers that transmit nerve impulses across the synaptic gap during the process of synaptic transmission
- inhibitory neurotransmitters like serotonin make neurons less likely to fire, promoting calmess and sleep
- excitory neurotransmitters like adrenaline increase the likelihood of a neuron firing, promoting alertness and arousal
4
Q
what is synaptic transmission?
A
- the process by which 1 neuron communicates with another
- information is passed down the axon of the neuron as an electrical impulse known as AP
- once the AP reaches the end of the axon, it needs to be transferred to another neuron or tissue
- it must cross over the synaptic gap between the presynaptic neuron and the post synaptic neuron
- at the end of the neuron (in the axon terminal) are the synaptic vesicles which contain neurotransmitters
- neurotransmitters then carry the signal across the synaptic gap
- they bind to receptor sites on the post-synaptic cell, or are reabsorbed through reuptake back into the vesicles of the presynaptic neuron to be reused
5
Q
what is serotonin?
A
- a neurotransmitter that exerts a calming effect on the brain, inhibiting neurons from firing
- lower levels of serotonin are associated with less control in relation to aggressive responses
6
Q
what is dopamine?
A
- a neurotransmitter which produces pleasure when the reward pathway of the brain is activated
- responsible for movement coordination and is implicated in parkinsons disease
7
Q
explain how recreational drugs affect the CNS
A
- recreational drugs alter brain function and change how neurotransmitters operate
- the brain contains the reward pathway
- when this is activated by drugs, there is a feeling of euphoria caused by a flooding of dopamine-addictive
- when the brain downregulated the natural protection of dopamine, there is a feeling of dysphoria
- repeated use of recreational drugs causes further reduction in natural dopamine production, which causes the CNS to crave drugs
- drugs can also increase or decrease the speed of electrical impulses which can increase awareness or decrease it
8
Q
how do amphetamines affect neurotransmission?
A
- amphetamines block the reuptake of dopamine
- this means that dopamine isnt reabsorbed into the vesicles, but remains in the synapse
- a high dosage of amphetamines blocks enzymes from degrading the extra dopamine, so they are transmitted to the post-synaptic neuron
- the increase in dopamine levels leads to feelings of euphoria, so the consumer will become addicted
- amphetamines also cause sickness when the drug isnt taken, leading to addiction
9
Q
what is the role of sensory neurons?
A
- found in receptors such as the eyes, ears, tongue and skin
- they carry nerve impulses to the spinal cord and brain
10
Q
what is the role of motor neurons?
A
- found in the cns and control muscle movements
- when theyre stimulated, they release neurotransmitters that bind to the receptors on muscles to trigger a response, which lead to movement
11
Q
what is the role of the frontal lobe? (COLT)
A
- concious planning
- thinking
- language
- organisation
12
Q
what is the role of the pre-frontal cortex?
A
- self control
- decision making
13
Q
what is the role of the temporal lobe?
A
- memory
- understanding
- facial and object recognition
14
Q
what is the role of the parietal lobe?
A
- abstract thinking
- spatial awareness
15
Q
who is phineas gage?
A
- american railway worker
- an unexpected explosion blasted a tamping iron through his skull
- the iron entered through his cheek, passed through his brain and shot out the top of his head
- caused damage to the frontal lobe (decision making)
16
Q
define aggression
A
- an act carried out with the intention to harm another person
- hostile: driven by anger or hurt
- instrumental: to solve a problem
17
Q
what is the role of the amygdala in aggression?
A
- integrates internal and external stimuli and assess whether x is a threat
- fight or flight
- can produce aggression in harmless situations
18
Q
what is the role of the hippocampus in aggression?
A
- key role in memory formation
- hard to learn from past consequences
19
Q
what is the role of the pre-frontal cortex in aggression?
A
- delayed gratification
- act on immediate impulse
20
Q
what are hormones?
A
- chemical messengers that transmit information around the body
- they are produced and secreted by the endocrine system
21
Q
explain the role of testosterone in aggression
A
- males have higher levels than females
- its an androgen responsible for the development of masculine features
- role in regulating social behaviour via its influence on certain areas on the brain related to aggression
22
Q
explain the role of cortisol in aggression
A
- an antagonist to testosterone
- cortisol increases anxiety and the likelihood of social withdrawal
- low levels cause reduced stress when committing acts of aggression against others
23
Q
why are people with lower levels of cortisol more aggressive? - link to the ANS
A
- their ans is understimulated
- aggressive behaviour is an attempt to create stressful situations to provoke cortisol release
- this stimulates the ans
24
Q
+ evaluation: explain the credibility/supporting research for the biological explanation of aggression
A
- raine et al
- suggests the amygdala and pfc are linked to aggression
- ngri murderers had less activity in the pfc which is associated with rational thinking and self control
- less activity in the left of the amygdala which is involved in emotional regulation
25
- evaluation: explain an issue with the supporting evidence for the biological explanation of aggression
- raine et al reliability
- some of the pet scan results were unclear and had to be interpreted
- subjectivity
26
+ evaluation: explain opposing research for the biological explanation of aggression
- freuds psychodynamic theory
- unconcious mind contains instincts and desires that are repressed
- id, ego, superego
- erosis the urge to enjoy
- thatanos is the urge to destroy
27
+ evaluation: explain an application of the biological explanation for aggression
- identify people with extreme aggression at a young age by genetic screening
- monitor these individuals
- restrain them from certain jobs like being a teacher
28
what is natural selection?
- traits that enhance survival and reproduction are more likely to be passed on
- leads to changes in characteristics of a population over time
29
what is evolution?
- the gradual development of organisms from earlier forms
- successive mutations that convey adaptive advantage dominate gene pools
- driven by natural selection
30
- evaluation: explain how evolutionary theory is reductionist
- reduces behaviour to evolutionary pressures that happened millions of years ago
31
+ evaluation: explain the credibility of evolutionary theory
- darwins theory is a well established scientific theory
- the theory that the brain structures or processes that enhance fitness will be passed on as survival traits is logical and matches with whats observed in animal and human studies
32
- evaluation: explain an objection of evolutionary theory
- religious reaons
- contradicts the account for creation in the bible and suggests we are here by chance
33
- evaluation: explain an opposing theory to evolutionary theory
- freuds psychodynamic theory
- unconcious mind contains instincts and desires that are repressed
- id, ego, superego
- erosis the urge to enjoy
- thatanos is the urge to destroy
34
what is catharisis?
- the expression of formerly repressed feelings in order to overcome problems associated with them
35
what is the biological classic study?
- raine et al
36
what do pet scans measure?
- brain activity
- areas of the brain involved in functions
37
what is the process of pet scans?
- injected with a radioactive tracer
- scanned whilst inactive, then whilst doing a task
38
explain how pet scans actually work in the body
- once the radioactive tracer is in the bloodstream, it flows through the brain
- oxygen and glucose accumulate in brain areas that are metobolically active
- by measuring radiation levels in the brain, it determines areas in the brain where blood is flowing
- hence which areas of the brain are most active
39
how do areas of low versus high activity appear on pet scans?
- high: red and yellow
low: blue and darker colours
40
what are 2 strengths of pet scans?
- non invasive
- shows localisation
41
what are 2 weaknesses of pet scans?
- injections are invasive
- hard to isolate different brain functions precisely because behaviours can use more than 1 area of the brain, no cause and effect
42
what do cat scans measure?
- brain structure NOT function/activity
43
what do cat scans highlight?
- brain damage
- potential tumours in the brain
44
what are patients injected with before cat scans?
- iodine
- flows around the bloodstream to highlight blood vessels in the brain
45
how do cat scans work?
- a series of x-ray beams are passed through the head, creating cross sectional slice images of the brain
- patient lays on a moving platform and they are passed through the scanner
- they have to lie very still
46
what are 2 pros of cat scans?
- shows a range of different tissue types
- 3d images generated
47
what are 2 cons of cat scans?
- use ionising radiation
- injection is invasive
48
what does fMRI measure?
- blood flow in the brain
49
what do fMRIs detect?
- changes in blood oxygenation and flow that occur due to neural activity in specific parts of the brain
- more active=more blood flow and oxygen consumption
50
what are 2 pros of fMRI scans?
- non invasive, no injection
- good spatial resolution
51
what are 2 cons of fMRI scans?
- dont provide a direct measure of neural activity, cant establish cause and effect
- poor temporal resolution
52
what was the aim of raine et al?
- see if there is a difference in the structure of brain activity between people who are ngri murderes and non-murderer controls
53
AO1 of raine et al
- 41 ngri, 39m, 2f
- some ngris had a history of brain damage, drug abuse, schizophrenia and 2 had epilepsy
- 41 control
- tested at uni of california
- injected with glucose tracer and then performed the CPT fpr 32 mins
- after, the pet scan was carried out
- ngris showed less activity in the pfc and left side of amygdala
54
+ evaluation: explain the reliability of raine
- pet scans are objective and replicable
- cpt ensured all ppts were concentrating on the same thing, standardised
55
- evaluation: explain the validity of raine
- cpt was artificial
- lacks ecological validity
- cpt is unconnected to violence or provocation
56
+ evaluation: explain the ethics of raine
- informed consent or presumptive consent from a carer or lawyer
- ngris agreed as it would help their court cases
- served as evidence that they werent in control of themselves when they committed the crime
57
- evaluation: explain the generalisability of raine
- unusual murderers
- they either dont remember the killing or are too confused to stand trial
- unrepresentative of typical murderers
- not all of the ngris killed their victims violently
58
what is the biological contemporary study?
- brendgen et al
59
what are MZ twins?
- monozygotic twins
- genetically identical
- they split from the same egg shortly after conception
- share 100% of genes
60
what are DZ twins?
- dizygotic twins
- non identical
- share up to 50% of genes
- may be mixed sex
61
what do twin studies look at?
- they look for a concordance between sets of MZ vs DZ twins in a certain behaviour
- if MZ twins share the behaviour more than DZ twins, then the behaviour likely has a genetic basis
- we can be sure about this because both sets of twins share the same home life and upbringing
- only their genetics set each other apart
62
what were the 3 aims of brendgen?
- find out if theres a difference between physical and social aggression in 6yr old school children by surveying their teachers and classmates
- see if physically aggressive children are also socially aggressive
- investigate whether the link between social and physical aggression is down to genetics or by social situation by comparing MZ and DZ twins
63
AO1 of brendgen
- 234 pairs of twins
- 6yr olds
- they were taken from the quebec newborn twin study
- assigned to MZ or DZ based on physical resemblance
- teachers questionnares asked them to rate each child on a 3 point scale on questions such as 'hits bites or kicks others'
- teachers rated boys are more physically aggressive and girls as more socially aggressive
- MZ correlations for physical aggression were twice as high as same sex DZ correlations
64
+ evaluation: explain the generalisability of brendgen
- large sample of 234 twin pairs, anomalies with very high or low aggression will be averaged out
- high generalisability
65
+ evaluation: explain the reliability of brendgen
- standardised questionnares
- 2 researchers visited each classroom, high IRR
66
- evaluation: explain the validity of brendgen
- correlations dont prove causation
- teacher and peer ratings might have been influenced by sterotypes, with both children being given the same rating regardless of their behaviour
67
- evaluation: explain the ethics of brendgen
- protection from harm
- getting children to look at pictures of their classmates and judge them which may impact friendships
- could lead to hurt feelings or revenge
68
why are adoption studies used in the nature-nurture debate?
- theres no biological connection between the parent and child
- if the child grows up to share the parents traits, then these are likely produced by nurture
69
what was the aim of heston?
- see how many adopted children of biological mothers with schizophrenia would go on to develop it themselves
70
AO1 of heston
- 41 ppts, 30m, 17f (experimental)
- 50 ppts, 33m, 17f (control)
- the rate of schizophrenia to those with schizophrenic mothers was 10% to 0%
- some of the experimental groups were successful adults
71
AO3 of heston
G - small sample from oregon
R + interviews followed standardised procedures, used school records
V + ecological, conducted in ppts homes
E + informed consent,. ppts contacted by letter asking if theyd like to take part
72
whats the biological kq?
- what are the implications for society is aggression is found to be caused by nature and not nurture?
73
AO1 of bio kq
- aggression is carrying out an act with intent to harm others
- over 1 million deaths occur a year due to violence
- the existence of violent behaviour in chimps and humans suggests evolutionary reasoning
- youre 25 times more likely to be murdered in brazil than the UK
- MAO-A gene is found in a 3rd of men
74
AO2 of bio kq
- difference between murder rates in countries suggests aggression is caused by nurture
- screen young boys for the MAO-A gene
- sherif's idea of superordinate goals
- cog psych and psychodynamic theories suggest concepts of schemas and defence mechanisms
