Biological Flashcards
Name 4 main lobes of the brain
Parietal
frontal
occipital
temporal
What is the outer layer of the brain
Cerebral cortex
Function of parietal lobe
process sensory information
Function of frontal lobe
Motor function, problem solving
Function of occipital lobe
Processing visual stimuli
Function of temporal lobe
Information retrieval
What connects the left and right cerebral hemispheres
Corpus callosum
What is a dendrite
receive messages from other neurons
What is an axon
passes electrical impulses down the end of the neuron to allow it to communicate with others
Axon terminal
The end of the axon that leads to the terminal buttons
Neurotransmitters
Chemicals that pass messages between neurons
axon hillcock
connects cell body to axon
Neuron
Cell within the nervous system
Cell body
main part of the cell where the nucleus sits (also contains mitochondria)
Nucleus
Houses genetic material
Mitochondria
site of aerobic respiration, where energy is released from glucose
Myelin sheath
Fatty deposit that provides electrical insulation for an axon and allows electrical nerve impulse to be passed along
Node of ranvier
gaps between adjacent myelin sheaths
Terminal buttons
nerve impulse becomes a chemical message that can be passed to the dendrite of another neuron
Vesicles
tiny sacs that contain molecules of neurotransmitter chemicals
explain action potential
Electrical impulse that passes along the axon and stimulates the neuron and releases neutrons.
When neurone receives a message it either stimulates excitatory or inhibitory post synaptic potential.
When neuron has received enough messages it reaches threshhold and AP is triggered
explain synaptic transmission
- cells impulse generated at axon and once messages reaches axon terminal it changes to chemical impulse to cross synaptic gap
- when action potential reaches axon terminal calcium channels is open flooding terminal buttons with calcium ions. vessicles containing neurotransmitters will be released into synaptic gap
- receptors on post synaptic neuron bind to specific neurotransmitters and absorbed into post synaptic neurone. Molecules are destroyed or absorbed into pre synaptic n in reuptake process.
Heroine increases the amount of D____________ in R___________ P_________ by boosting ________ __________
Dopamine
reward pathways
Dopaminergic
synapses
Explain the effects of heroine
increases dopamine in reward pathways by boosting dopaminergic synapses = euphoria Brain naturally adjusts and reduces natural production of dopamine = dysphoria
How does person become dependant on heroine
Repeated use in order to avoid negative experience of withdrawal
tolerance to drugs
Tolerance is when a person has to take a greater dose to get the same effect as previously. Brain reacts and down regulates its own natural production so in order to get the same high more dopamine is needed.
explain how alcohol effects the brain
Acts to inhibit neural transmission by increasing the action of GABA (inhibitory neurotransmitter)
How cocaine effects brain
Increases activity in the dopamine pathways by blocking reuptake of dopamine
The midbrain
- coordinates behavioural responses to perceived internal and external stressors e.g. pain
- contains PAG which links to amygdala and prefrontal cortex
The hypothalamus
regulate hormones by maintaining homeostasis and sexual function
- linked to aggressive behaviour in males via testosterone
The amygdala
Centre for emotions and motivation
How does evolution explain aggression?
M- bigger and stronger to provide food and protect mates and offspring
F- breastfeed and look after offspring so less physically aggressive and more verbal
define 4 aggression types
Person-oriented = goal is to cause harm Instrumental = goal is to obtain a reward Reactive = response to aggressive situation Sanctioned = aggression which is legal
Pre-frontal cortex (emotions) is involved with
decision making and social behaviour
- lower activity more likely for depression
- aggression comes from lack of regulation of behaviour
Limbic system (response to emotions) and it..
responds automatically to danger
and contains amygdala(recognise facial expressions and avoid upsetting situations)
Hormones
- messengers transmit information
- carried in blood
- Produced by glands
Glands
Organs that produce hormones
Endocrine system
Glands that secrete hormone messages around body
Pituitary gland
small organ in the brain that produces hormones
Psychodynamic - Freud
Unconscious drive that causes aggressive behaviour
Catharsis
Emotional release
Displacement
Take anger out on something
Sublimation
Channelling aggression into other behaviour
2 parts of ID
eros - focused on enjoyment of life
thanatos - drive towards death and destruction
ID
- urges and desires made up of feelings
- not rational or reflective
- exists entirely in unconscious mind
- pleasure principle so doesn’t understand logic
- if the ID is denied of its pleasure = frustration which can lead to aggressive urges
> resembles function of the limbic system (brains emotion centre) and sources for our appetites, fear and aggression
Ego
Developed in toddlers
- conscious mind
reality principle because it understands the outside world
- no desires but finds a way to grant desires that comes from ID
> resembles function of pre frontal cortex (brains decision making centre) which handles messages from limbic system and decides how to act on them
- no conscious, no sense of right or wrong
- understands punishment and will try to avoid it but feels no guilt and has no problem using aggression to get what the ID wants
Superego
- straddles unconscious and conscious mind
morality principle and acts as a voice of conscious mind - tells ego whether its thoughts are morally accepted or not
- when super-ego objects to egos thoughts it generates guilt and shame
- may restrict ego from using aggression
- young children use physical aggression bu as they get older switch to social aggression as social is less likely to oftend the super ego
- Super ego makes us feel guilty about being aggressive
Raine et al year?
1997
Raine et al ASPRC
A- brain abnormalities in murderers
S- 41ppts 39M 2F NGRI
P - matched pairs, medication free 2 weeks prior to PET scan
- PET SCAN to trace brain functioning
- tracer injected to trace brain metabolism
- continuous performance task (blurred numbers) to make frontal lobe work
Pilot study - 22ppts 22 control
Raine et al evaluation points
- > good validity
- > Not representative explanation of violence
- > Reliable comparisons
- > Extraneous variables
issue and debate: socially sensitive research
Contemporary study
Brendgen 2005
A: examine genetic and environmental effects on social and physical aggression using 6 year old twins
S: 234 twins, longitudinal, Canada, opportunity sample
84% european decent 16 ethnic minoriteis
P: 25.2% twins attended same classroom
Teacher = 2 questionnaire; social and physical
Social: ‘tries to make other child dislike child’
Physical: 3 point scale questionnaire ‘hit’ ‘bites’
Peer review= children given pics of classmates checked if students could identify pics and asked if which child fit description
R: 82% twins 1 nom for social
62% twins 1 nom for physical
- teacher more likely to find boys more physically aggressive girls more socially
- peers more likely to find boys more physically and social
3 brain scans
CAT scan
PET scan
FMRI scan
CAT scan
Structure
- Xrays beams creat cross sectional images of the brain
- 20-30 mins on scanner table
- Injection, black dye to highlight blood vessels
PET scan
Function
- Scanner detects radioactive material
- Oxygen and glucose accumulate in metabolically active parts
- Radioactive material breaks down and gives off positron and neutron
- When positron hits electron gamma rays released and detected by gamma ray detectors as it moves to the part fo the brain that are working at that moment
FMRI scan
function
- Detects change in blood oxygenation
- Increased activity = increased o2 levels
- Shows which part of the brain is involved in particular process’
- head may be placed in brace to steady
Biological key question?
What are the implications for society is aggression is found to be caused by nature and not nurture?
- Hormones
- Evolutionary
- Brain structure (raine et al)
Biological practical aim
- Investigate the correlation between hormones and aggression
Practical hypothesis
- positive correlation between 2D;4D finger ratio and aggression scores on buss perry questionnaire in YR12 males in psychology
- negative correlation between 2D;4D finger ratio and aggression scores on buss perry questionnaire in YR12 females in psychology
- No correlation
Practical procedure and results
Sample: 8 males 16-17 10 females yr 12 psychology opportunity sample
Procedure: measured index and ring finger on right hand then answered Buss Perry questionnaire on aggression. Divided index digit by ring digit to find average. Then misused ranked scores from finger ratio
Results: Spearman
M: = 0.65 > critical value when N=8 and P<0.05 so accept hypothesis
F= 0.51 < critical value when N=10 and P<0.05 so reject
twin studies
Brendgen 2005
Adoption studies
leve et al 2010
A: see interaction between adopted childs genes and adoptive environment whilst seeing what interventions might be put to help child and families
S: 360 sets of triads
- children began school
- child adopted before 3 months
- no medical conditions
- families given chance to opt out
M: longitudinal study \9infancy/toddler
- face-face interviews, questionnaires, observations
- saliva samples 3-6months - 7yrs
R: children kept attention when adoptive mother had anxiety/depression
C: genetic issues in an adoptive child interacted with environmental issues. Used to inform interventions to help children and adoptive families
Advantages of adoption studies
- Removes extraneous variable; environment
- Useful in showing twin studies overestimate genetic factor
Disadvantage of adoption studies
- Children adopted in to families similar to biological ones
- Adopted parents ‘unusual’ so not representative
Advantage of twin studies
- Look at influence of genes of MZ compared ti DZ
- Twin registries so large amounts of data
Disadvantages of twin studies
- Twins share same environment so nature VS. nurture
- Cannot tell which specific gene
strength of freud
- can be applied to treat those with aggressive behaviours through psychoanalysis where the client explores unconscious causes of aggression in a safe context with support from a therapist
weakness of freud
- viewed as scientific as concepts of ID, ego and superego cannot be accurately measured
cons to cat scans
- high radiation
- no info on activity
cons to PET scans
- interpretation difficulties
- can’t pinpoint locations
- may damage tissues
cons to FMRI scans
- expensive
- person has to stay very still
- time lag may cause interpretation difficulties
strength of Freud
can be applied to treat those with aggressive behaviour through psychoanalysis where client explores unconscious causes of aggression in a safe context with support from a therapist
weakness of Freud
viewed as unscientific as concepts of ID, ego and superego cannot be accurately measured
how recreational drugs change the way neurotransmitters operate within the brain
- Recreational drugs work by increasing or decreasing neurotransmitters at the synaptic gap.
- If a drug increases the level of dopamine, the user experiences an intense feeling of pleasure or euphoria
unconditioned response
A response that is naturally occuring without any prior
learning
