Biological Psychology Flashcards
Define aggression
Behaviour intended to cause injury, both psychologically and physically
Helps maintain or establish dominance, but often a ritualised way to prevent actual physical harm
raising ur arm as a threat
What does the prefrontal cortex do
decision making and rational thinking
What does the occipital lobe do
process visual information.
What does the parietal lobe do
sensory and movement processing
temporal lobe
Auditory processing and emotions
language
what is cortex
outermost layer of brain
What does the hypothalamus do
to do with hunger, sex drive , thirst
flight or flight response
secrets hormones and manipulates pituitary gland to regulate bodily functions in endocrine
How do these things in the brain affect aggression
prefrontal cortex- damage means lack of impulse control and rational thinking
hypothalamus controls motivational behaviours and the flight or fight response, over activity can cause more aggro
amygdala plays a role in threat perception if things are deemed as threats u may be more aggressive
what is it called when one side of the brain controls the other side of the body
contralaterally
what does the cell body do
contains nucleus ( genetic material) produces energy in mito
function of dendrites
receive neurotransmitters from neighbouring cells towards cell body, receptors specific to neurotransmitters on them
axon function
tube like structure
carries electrical impulse away from cell body
myelin sheath function
insulate axon allowing impulse to travel faster
nodes of ranvier function
gaps in myelin sheath allows signal to jump along axon
Terminal buttons function
ends of axons,l
communicate with neighbouring neurons by releasing neurotransmitters through synapse
What do sensory neurons do
Carry impulse from sensory organ to CNS
what do motor neurons do
carry impulse from CNS to specific effectors
What do relay neurons do
communicate between motor and sensory neurons
How do neurons communicate
by an electrochemical process
action potential
What is a neurons resting state
-70mv
How is action potential triggered and what happens
once it reaches -55mV , reaches its threshold needed to fire electrical signal down its axon to terminal buttons
neurons own neurotransmitters are sent to the neighbouring cell
What does it mean if signals are excitatory
more positive closer to -55mV
what does it mean if impulse is inhibitory
more negative, further from -55mV
What is cancellation
excitatory and inhibitory signals from neighbouring neurons cancel eachother oht
what is spatial summation
multiple excitatory signals from multiple sources combine to reach neuron threshold
what is temporal summation
multiple signals from same source combine over time to reach neurons threshold
What does acetylcholine do
muscle contraction, motor control and movement ( excitatory)
needed for attention wakefulness and emotion
Noradrenaline
linked to emotions and mood control , sleep dreaming and learning
excitatory
serotonin
inhibitory
stabilises mood, feelings of well being and happiness
helps with sleeping eating and digestion
dopamine
involved in emotion cognition and reinforcement , released when good things happen
excitatory
what does the amygdala do
processes emotion, emotion regulation and motivation
assesses and responds to threats and challenges
more aggressive people have more active amygdalas
midbrain function
coordinates responses to pain and threats
what is localisation of function
specific areas of the brain are involved in particular tasks
for example amygdala-> threat perception
how does serotonin affect brain function
more serotonin, more self control , less impulse
vikkunen et al found serotonin is lower in the spinal fluid of violent impulsive offenders
Raine et al aims
to investigate whether brain areas of PFC, angular cyrus, amygdala, hippocampus, thalamus and corpus callosum where related to aggro behaviour
role of hippocampus
role in learning and memory
role of thalamus
relays sensory and motor signals to and from brain
Corpus callosum
large c shaped nerve fibre bundle connecting right and left hempisphere
What sample did Raine use
41 murders NGRI
41 controls
matched by age gender ethnicity and mental health (6 w schizophrenia)
these groups are the independent variables
What was raines dependent variable
thing being measured
amount of glucose metabolism in specific brain areas
Raine procedure
ppt injected w radioactive radiotracer for pet scan to measure brain metabolism
performed 32 minute continous performance task for 32 minutes
pet scan took 10 images of brain at 10 mm intervals
Raine findings
M- less activity in prefrontal cortex, medial prefrontal cortex, corpus callosum, parietal cortex
More activity in right thalamus, right amygdala, right hippocampus
Raine conclusion
Murders pleading NgRi have dif brain structure to non violent offenders, suggests no single brain area is responsible for aggression but various areas interact together
Raine strength + counter
High level of control (internal validity)
32min CPT tasks , drug tests, PET scans were consistent
High levels of internal validity and confounding variable that could’ve affected brain activations were controlled for
Counter- Other key elements were not controlled for
23 murders had suffered head injuries , which could’ve explained corpus callosum differences further situational factors could’ve affected brain
researchers cannot be certain that other factors than brain structure could’ve lead to violent behaviour
Raine Strength 2
Matched ppt
matched on 3 potential confounding variables (age,sex,mental health)
Researches could then make fair and direct comparison of brain activations of murders and controls and show differences
Recreational drugs
takes for enjoyment rather than medical reasons, affect levels of existing neurotransmitter in CNS
How does cocaine work
cocaine mimics structure of dopamine, then blocks receptors at terminal buttons leading to dopamine molecules staying in synapse leading to large buildup that binds to the postsynaptic neuron
creating a high
Why do people have cocaine tolerance
overtime , dopamine receptors become down regulated - fewer receptors are active as they are damaged by cocaine, dopamine declines ( withdrawal) and craving of the drug and tolerance
how does heroin work
uses opioid receptors in the brain to trick the body to release endorphins produced by the body to relieve stress and pain and hypothalamus is affected endorphins are natural painkillers that slow cns activity , overtime opioid receptors become t , quality of endorphins decline, and leads to pains after we body compensates for the large loads it releases during drug usage by reducing natural endorphin production
research supporting drug addiction
weinshenker and schroeder
Animal research shows that cocaine works on the dopamine reward system, researches deliberate changes the reward system of mouse brains, meaning mice were unable to create dopamine associated w rewards. these mice were using cocaine given to them in lab , once the brain, once this change was made they no longer used cocaine and this behaviour did not occur when other parts of the brain were destroyed , suggesting cocaine effects are due to the reward system
weakness of animal support for drugs
oversimplified
social aspect
more complex human brain , dopamine also affects human serotonin and noradrenaline
lack of validity and non generalisable
strength for drug addiction theory
know the effects
helps create treatment
has helped develop naloxone , opioid receptor drug in addiction treatment reduces symptoms and withdrawal
real life application.
what are the three brain scans
cat scan
fMRI
PET scan
structural imaging
static image of the brain deals with structure of nervous system example computerised axial tomography CAT
functional imaging
produces images of what brain is doing and what areas are active during tasks
example
PET and FMRI
glucose or metabolism oxygen usage
Stuctural: CAT scan Positives
shows structure - like tumours and growth and development and damage of that area
useful for cancer
CT SCAN SUMMARY
It involved using X-rays that pass through the brain in multiple angles to
get more information. As the brain is complex multiple angles are
needed.
From those multiple angles, a computer creates an image of the brain
There are potential risks due to X-ray radiation. It can damage unborn
babies for example.
It is measures what areas of the brain are damaged or the positioning of
tumours. It does not tell us about how the brain is functioning.
Structural images
-Very quick to conduct showing
accurate details of brain structure.
The quality of these images can
show tumors or structural damage
that could lead to better
understanding the the area
-It cannot tell you about how the
brain is functioning, only providing
structural information. This means
it has limited use in researcher
linking brain areas to specific
behaviours
PET SUMMARY
Patients are injected with FDG, a radioactive tracer substance that is
absorbed into the bloodstream and binds to glucose molecules in the blood
High concentrations of gamma rays can be found in areas of high activity
(which consume the glucose)and images produced by PET scans will show
these.
Low risk, but it is unclear whether there will be long term effects
Glucose usage in the brain, the more glucose is being used in one area
means that the area is more active
-PET scans indicate the specific areas
of be the brain involved in an
experience. They can provide
evidence of localisation of function in
the brain when ppts are doing tasks.
For example, it can be used to see
lower glucose activity in the frontal
lobe in self control tasks in participants
-As the FDG is radioactive, with the
potential to damage cells and tissues
in the body, this means the scans
can only be one every six months
with any individual. Limited the
usage of these scans for research
fMRI SUMMARY
A very powerful electromagnet is used, inside this magnet, hydrogen in water
molecules in your brain will align with the magnet. Blood cells with oxygen will
repel the magnetic field, whereas blood cells with no oxygen will follow the
magnetic field.
These changes to the magnetic field are measured by a computer,
There are little risks, but people who have metal surgical implants and
pacemakers cannot go through an MRI
Areas of the brain that use more oxygen are more active, by looking at the oxygen levels of the blood in the brain, you can see which areas are being
used in tasks.
-MRI scans indicate the specific areas of
be the brain involved in an experience.
They can provide evidence of localisation
of function in the brain when ppts are doing tasks. For example, it can be used to
observe increased oxygen usage in the
amygdala when the pots is being
aggressive
-The fMRI scan is only effective
when the person being
investigated stays perfectly still.
Meaning this may be
problematic for young children
or people with motor disorders,
limiting the usage of the fMRI in
investigating aggressive children
for example
Brengden aim
the extent to which social and physical aggression can be explained by genetics and environmental influences
whether the overlap between social and physical aggression is explained by the type of aggression affecting the other
brengden procedure
-Researchers used a twin study to calculate correlations of the social and
physical aggression demonstrated by MZ and DZ twins.
-234 pairs of twins were selected from the longitudinal (long lasting)
Quebec Newborn Twin Study (QNTS)
-The study collected data on the twins regularly, starting from when they
are 5 months old up until they are 6 years old.
-The sample was 44 pairs of male MZ twins, 50 pairs of female MZ twins, 41
male DZ twins, 32 pairs of DZ twins.
-Kindergarten teachers rated the social and physical aggression of the
children on a 3 point scale, ranging from (never, sometimes and often)
-Social aggression questions were
“says mean things and spread
rumours”
-Physical aggression questions were “hits, bites and kicks others”
-Levels of aggression were also recorded from the children’s peers.
-Each classmate was checked to see if they knew everyone in their class,
then they were shown 3 photos of their classmates
brengden findings
Physical aggression mainly explained by genetic factors
only 20-23% of SA explained by genetic factors
SA explained by non shared environmental factors such as upbringing
high PA leads to SA
but SA does not lead to PAIN
brengden conclusion
genetic factors can predispose children to be aggressive but environmental factors can also lead to specific forms of aggression to manifest by copying things from home
this directionality of aggression suggests children may be predisposed to be physically aggressive but learn it’s not acceptable so adopt other methods such as being socially aggressive
brengden strength 1
Ratings of aggression from multiple sources were utilised in the study
that being the teacher and the peer ratings. This was one of the earliest studies to also utilise peer ratings. If there were a large difference between the two ratings, it would highlight potential biases the teachers/peers had against the child.
As the two sets of rating were very similar, it provides reassurance to the researchers that the ratings used were a reliable method to measure the aggressive behaviour of the children being investigated.
Brengden strength 2 with counter
Real life application
show children go from PA to SA
meaning interventions and public education may help child control PA and block them from using SA instead reducing both types
However findings from this may not be able to generalise intervention for aggression as the age group is v specific ( 5m-6yr) and may not be able to applied to other age groups, researchers even state caution needs to be taken in trying to generalise results beyond assessed age, suggestion aggression of groups of older children are different and the study isn’t applicable
Why are aggressive gene mutations advantageous
hunting off animals
fighting off rivals
scare off potential competitors or right for resources for survival
guarding off spring
What is natural selection
some mutations in genes are better suited for the environment we live in, those with useful mutations survive better and pass on their genes ,
nature chooses the best fit of creature to survive and produce
what does evolution suggest
Evolution suggests change in human characteristics
over time, according to Darwin’s theory of natural
selection those with the most desirable characteristics
are more likely to survive and pass on their genes. This
is known a survival of the fittest. Aggression is a useful
trait in survival and would ensure the best resources,
status and mates to pass on these genes to offspring.
Aggression can be seen in today’s society in order to
assert social dominance and prevent infidelity in
couples.
Strength for aggression being advantageous
This explanation has evidence in terms of benefitting survival and social
standing. Hill and Hurtado (1996) found that heightened aggression was linked
to higher social status in tribal communities in South America. This is associated
with more access to food, and benefits chances of reproducing with a mate.
This supports the evolutionary theory as it shows that aggression promotes
survival and the passes on of genes. Showing that aggressiveness may be
passed on through genes
weakness for aggression being advantageous
The evolutionary argument cannot explain differences between aggression
levels between cultures. Wolfgang and Ferracuti (1967) found that the Kung
San people (From Kalahari region in Africa) have very low levels of aggression,
as that behaviour is discouraged from childhood. Whereas the Yanomami
people of Venezuela and Brazil are much more aggressive, as aggressiveness
was used to gain status in their society.
These differences between the aggression levels of different cultures
demonstrates that aggression levels are not universal and that innately
determined aggression can be outweighed by cultural norms.
What is eros and thanos
eros- life instinct - desire to preserve life and enjoy it
thanos- death instinct a driver towards death and destruction
(aggression comes from thanatos)
What is catharsis
release of internal drive of aggression in the id
preventing catharsis can lead to inward outbursts or outward outbursts
What is the superego
Super ego: based on morality principle, represents moral standards a person was raised with
punishes ego for wrongdoings
What is ego
based on reality principle , meditates the id and superego to satisfy both, reducing conflict between to
develops at age 2
What is ID
based on pleasure principle, primitive part of brain, just wants pleasurable things instantly
sexual desires, food
What is sublimation
when an individual displaces emotions in a constructive way rather than destructive
What is displacement
Redirecting anger towards an object or person ,( an available substitute)
Freud evaluations: STRENGTH with counter
Research showing processing aggro is beneficial
Graham et al found in their sample of 51, those who ranted and processed emotions had improved in control over pain and depressed mood after consistently ranting
suggests expression of anger leads to health benefits, linking to freuds concept of catharsis
Freud theory cannot be scientifically or empirically observed for example unconscious cannot be measured with brain scan and ego superego and id cannot be experimentally proven to exist, lack of scientific credibility
Weakness of freud
Bushman suggested freuds concept on catharsis heightens aggression rather than reducing it
in his study he made 600 students angry by making confederate critique an essay the student wrote
he found that students who were allowed to vent anger hit punching bag were more aggressive with confederate compared to control
suggests opposite of freuds theory of aggression being cathartic
Freud strength 2
explains hot blooded and cold blooded aggression
hot blooded aggression ( impulsive anger, no purpose than someone’s personal satisfaction- ID) where as cold blooded is when anger is deliberate and planned out serving a purpose ( ego controlling and guiding ID impulses)
freuds explanation for unconscious seems t fit reality of aggressive behaviour
What are hormones
chemicals produced by body that send signals to organs via bloodstream
Hormones link to aggression
testosterone
hint rats
Testosterone- male sex hormone, secreted by adrenal glands and testes( ovaries in females) needed to produce male features
supportive research:
Edwards and roffi
researchers had male rates castrated and found castrated rats showed little to no aggression, but when given testosterone injection they demonstrated aggressive behaviour, demonstrating simple cause
and effect
HOWEVER…age of rat matters as castrated new born rats do not demonstrate more aggression with testosterone injection. But 10 day year old castrated rats showed increased aggression
showing cause and effect can only occur at certain age, not as simple as theory suggests
Testosterone supportive research 2
people
Dabbs et al- measured testosterone in saliva of 692 male adult prisoners, found higher levels in rapists and violent offenders compared to burglars and thieves, same affect found in women
dabbs et al- testosterone in 84 female prisoners, higher cases in unprovoked violence and lower in defensive violence supporting testosterone is correlated with aggression increasing reliability and validity
counter - criminals are not applicable to everyone
cortisol link to aggression
secreted to protect body against stress and regulated aggression from stress
Cortisol inhibits aggression
Virkkunen reported low levels of cortisol in violent offenders
dual hormone hypothesis (supportive research) -popma et al found adolescent males high levels of testosterone only lead to aggressive behaviour when levels of cortisol were low, therefore combined activity of testerone and cortisol may be a better predictor of human aggression than either hormone alone
hormone link to aggression
evaluation
- If this nature viewpoint is correct and testosterone levels cause aggression than it might be possible to identify people with extreme aggression at an early age, by testing their testosterone levels. These individuals could be carefully monitored and perhaps from jobs where they present danger to public ( healthcare/schools) and put them into jobs that suit them (the Armed Forces).
- There are applications to controlling behaviour in the real world. If aggression can be chemically controlled we might be able to create a drug that controls hormonal mechanisms and reduces aggressive behaviour, making society a safer place
Negative implications of hormones linked to aggression eval AO3
• This can easily turns into eugenics, which is the belief that some people are
biologically inferior and should be prevented from having children. This is an ethical
debate that needs to be considered when using hormones to explain human
behaviour.
• Not everyone with high testosterone levels is a violent person, it is an interaction of
factors which leads to aggressive behaviours therefore this hormone explanation is
not entirely true and individuals could be treated unfairly as a result.
• Possible side effects of drugs need to be considered!
how appropriate is it to use animals to generalise to human behaviour
• In some respects humans are similar to other species.
For example we exhibit territoriality, courtship rituals, a “pecking order”. We defend our young,
are aggressive when threatened, engage in play and so on. There are many parallels which can be
drawn between ourselves and especially other mammals with complex forms of social
organisation.
• Studying other species often avoids the complex ethical problems involved in studying humans.
For example one could not look at the effects of maternal deprivation by removing infants from
their mothers or conduct isolation experiment on humans in the way that has been done on
other species.
• Although in some respects we are like other species in others we are not.
For example humans have a much more sophisticatedintelligence than other species and much
more of our behaviour is the outcome of a conscious decision rather than the product of an instinct or drive
synaptic transmission
When an action potential reaches the presynaptic
terminal, it causes the vesicles to fuse with the
presynaptic membrane and release their contents
(neurotransmitters) into the synaptic cleft.
neurotransmitter
• Neurotransmitter molecules that remain in the synaptic cleft are either reabsorbed
into the presynaptic neuron by an uptake pump, this is a process called reuptake
and means the neurotransmitters can be used again.
• Once the neurotransmitters are in the synaptic
cleft they diffuse across and bind to the receptors
on the postsynaptic neuron. The chemical signal is
converted back into an electrical signal in the
postsynaptic neuron, which may fire another AP.
