Biological Flashcards
Outline the use of experiments in the biological approach
Psychologists often use experiments to establish cause-and-effect relationships.
Researcher manipulates IV and records effect on DV, whilst ensuring all other potentially confounding variables are kept constant.
Participants are randomly allocated to conditions.
Draganski et al, 2004 (Brain and Behaviour: Neuroplasticity)
Aim?
Aim: Investigate whether structural changes would occur in the brain in response to practising a simple juggling routine.
Draganski et al, 2004 (Brain and Behaviour: Neuroplasticity)
Hypothesis?
Hypothesis: People who practised juggling for an extended period of time would develop structural changes in the brain.
Draganski et al, 2004 (Brain and Behaviour: Neuroplasticity)
Procedure?
Participants randomly allocated to one of two groups : Jugglers or non - jugglers (control).
Jugglers spent 3 months practising, followed by 3 months of no practise.
Participants had MRI scans recording brain structure on 3 occasions :
-Before experiment
- After 3 months
-After 6 months
The experiment used a mixed design, meaning research group compared to control group and also itself under different conditions.
Draganski et al, 2004 (Brain and Behaviour: Neuroplasticity)
Results ?
Before experiment: No difference in brain structure
3 months: jugglers had significantly more grey matter in the mid-temporal area of the cortex in both hemispheres - areas responsible for co-ordination of movement.
6 months: Differences decreased, but still more grey matter than before experiment.
Newcomer et al, 1999 (Hormones on human behaviour)
Aim?
Aim: Investigate whether stress can impair verbal declarative memory
Newcomer et al, 1999 (Hormones on human behaviour)
Hypothesis?
Higher Levels of Cortisol (IV) - the hormone secreted when we are stressed- would impair memory formation (DV).
Newcomer et al, 1999 (Hormones on human behaviour)
Procedure?
Participants randomly allocated to one of 3 conditions:
- High Dose (160 mg, major stress event)
-Low Dose ( minor surgical procedure)
-Placebo (thought was cortisol but wasn’t)
4 measures over 10 days of ptps. ability to recall prose passage.
Double Blind Trial; neither researcher nor ppts. aware of what dose had been ingested.
Newcomer et al, 1999 (Hormones on human behaviour)
Results?
- High dose group lowest recall ability
- Thus from manipulation of IV, can conclude that cortisol levels affected ppts. ability to form verbal declarative memories.
- Cortisol receptor sites on hippocampus.
Wedekind, 1995 (Genetics and behaviour)
Aim?
Investigate the effects MHC gene compatibility (IV) between individuals had on how attractive their scent (DV) was found to be.
Wedekind, 1995 (Genetics and behaviour)
Hypothesis?
MHC genes are responsible for our immune systems.
Inherited from both parents, and co-dominant, thus offspring acquires both immune systems.
- Wedekind hypothesised that “smell” is based on MHC profile and women should choose a partner who’s smell is distinct from their own to maximise their offspring’s immune efficacy.
Wedekind, 1995 (Genetics and behaviour)
Procedure?
Ppts. tested to establish MHC types.
Men asked to wear a cotton t-shirt for 2 nights and keep it in a plastic bag when not in use, asked to avoid smell changing activities and foods.
Starting from next day, Women first asked whether taking oral contraceptive as this affects smell preference.
Asked to rate 7 shirts for smell preference:
3 x similar MHC
3x distinct MHC
1x unworn, control t-shirt
Blind participant to prevent DC
2nd week menstrual cycle; smell more sensitive
Wedekind, 1995 (Genetics and behaviour)
Results?
Females preferred smell of distinct MHC types ( provided wasn’t taking oral contraceptive); would provide offspring with best immune system to increase chance of survival.
Outline ‘Informed Consent’ in the Biological Approach
Before experiment, researcher explains to participant: -Purpose and procedure of study -person's rights - right to withdraw and anonymity - Potential Effects of Participation In Bio Approach: -Animals can't consent -Mental Illness -Layman
Outline fMRI
- Allows researchers to see brain in real time
- magnetic field responds to change in levels of blood and flow of blood in response to neural activity.
- When neurons more active, use more O2, thus blood flow increases to active area.
Sharot et al, 2007
Use of fMRI
Used fMRI to study emotional memories
24 people in NY on 9/11
lay in MRI whilst words flashed on screen, accompanied by another word, either “Summer” or “September”.
Those not near attack, equal activation of amygdala for both words.
For those near attack, activation of amygdala far higher when recalling september event.
Amygdala plays a role in emotional memories, potentially even more significant in flashbulb; fight x flight activated.
Although fMRI able to show brain activity, doesn’t explain events.
fMRI allowed Sharot to localise activity in the amygdala for further hypothesis on formation of Flashbulb Memories.
Outline Localisation
Specific parts of the brain have specific functions related to specific behaviours.
However, behaviours quite complex thus can involve several different parts of the brain.
Although may have specialised functions, parts work together to create behaviours.
Example = role of hippocampus in memory formation.
Why was HM amnesia boi
When young had accident -> epilepsy
Lobotomy of temporal lobe resulted in severe memory loss Retrograde + Anterograde
Couldn’t form episodic nor semantic memories.
HM Milner (1966)
IQ tests, direct obs, interview, cog testing ( inc memory tasks and learning tasks.
One such task = drawing an image whilst looking in a mirror -> HM learned how to do the task, showing he could create procedural memories but didn’t remember doing task; no episodic memory.
HM Corkin (1997)
Corkin (1997) - MRI on HM’s brain
Severely damaged hippocamus from lobotomy.
Explains problem of transferring STM -> LTM as area where acetylcholine plays a role in memory formation.
Demonstrates that hippocampus is responsible for episodic and semantic memory formation.
Outline Neuroplasticity
Ability of brain to chane itself in response to environmental demands.
Made by making/breaking of synaptic connections between neurons.
When neurons fire continuously, as a result of stimulation in the environment, sprout new dendrites - dendritic branching.
Maguire (2k) Aim x Hypothesis
Aim: Can neuroplasticity be seen in brain of London taxi drivers.
Hypothesis: “The knowledge” requires repeated use of the brain for spatial memory would result in neuroplasticity; hippocampus would be come more dense.
Maguire Procedure
16 male taxi drivers
compared to 50 non taxi drivers
MRI used to detect changes in brain structure
Maguire Results
Taxi drivers had more grey matter (more dense) posterior hippocampi and less dense anterior hippocampi compared to normal males.
+ve correlation between no years taxing and density of posterior, -ve for anterior.
Shows plasticity of hippocampus
posterior responsible for use of previously learned spatial info thus increased in taxi drivers due to their reliance on it.
Antonova et al 2011 (Neurotransmission in behaviour)
Acetylcholine, Scopolamine, VR “pole”
Aim:
effect of Acetylcholine on memory
Seems to play a role on the encoding of spatial memories.
Procedure
Double blind study, either injected with scopolamine (antagonist of acetylcholine) or placebo.
VR game where specific locations had to be remembered (the pole)
Then returned to new location and asked to find pole again.
in fMRI whilst activity carried out.
Results:
took longer to find pole when injected with scopolamine.
more activity in hippocampus (site of acetylcholine receptors STM -> LTM) of placebo group.
Therefore, Acetylcholine plays a key role in the formation of spatial memories.
Outline Pheromone
Chemical substance that is released into the environment and affects animals own species.
Sexual x Mating behaviours
Zhou et al (2014)
Androstadienone - semen and sweat
sample of heterosexuals, gay men and lesbian women.
Procedure
stick people walking on screen, ppts asked to identify gender.
2 conditions
Androstadienone x Cloves
Cloves
heterosexual females and gay men had higher rate of identifying stick man as masculine when exposed to androstadienone.
Thus, could influence mating behaviour in humans.
