The Biological Approach Revision

Hormones (studies to use)

Hormones (studies to use)

Baumgartner (Oxytocin)

Meaney (Cortisol)

Hormone

A chemical released by a gland directly into the bloodstream which has an effect on behaviour

Cortisol

A stress hormone responsible for the fight or flight response

HPA Axis

A set of interactions between the hippocampus, the pituitary gland and the adrenal glands and is the basis of the stress response

Permissive effect

The presence of the hormone causes the behaviour rather than the amount of hormone (Saplosky)

Target Cells

Cells that have receptors for the hormone and responds to the hormone

Baumgartner et al (2008) Aim

To investogate role of oxytocin in trust and when it is breached

Baumgartner Research Methods

Lab experiment (low ecological validity)
fMRI used for brain activity to allow a correlational relationship between oxytocin and trust to be established

Single blind study - participants unaware of whether they recieved placebo or oxytocin (researchers were aware increases researcher bias)

IV operationalised - extra oxytocin into blood and DV was levels of trust, measured by how much they chose to invest

Baumgartner Sampling Methods

49 participants - large sample size

Baumgartner procedures

Participants given oxytocin or placebo via nasal spray

They played multiple rounds of an economic trust game against a computer where they played as an investor with a trustee.

During their round they were given feedback about how successful their investment decisions had been (e.g trust had been breached or gamble had not payed off)

Brain activity measured using fMRI

Baumgartner results

Participants in placebo group more likely to lower their rate of trust after it had been breached

Participants in oxytocin group continued to invest at compatible rates despite trust being breached.

Baumgartner Conclusion

Results only seen in the trust game suggesting oxytocin is exclusive to trust and doesn’t play a large role in risk taking

The researchers concluded that from the fMRI scan that different areas of the brain were active in the two groups

Oxytocin groups showed decreased responses in the caudate nucleus (linked to reward and trust) and the amygdala (fear response).

Study shows a clear correlation between the hormone oxytocin and the human behaviour of trust

Saplosky Aim

To investogate the effect that stress and a lack of control had on baboon physiology

Sapolsky Research and Sampling Methods

Event sampling - the researcher noted baboons behaviours

Naturalistic observation - baboons observes in natural enviornment (high eco vad)

Covert observation - baboons unaware that they were being observed

Qualitative data - researcher observed and documented/interpreted behaviour

Sampled a Kenya baboon troop, particularly observed those that were lower in the social hierachy

Sapolsky Procedures

Baboon behaviour documented and was catalogued to where baboons stood in the social hierachy

Used a blow dart to tranquilise that baboon so he didn’t induce any extra stress hormones to be released, affecting the results. Blood of baboons was analysed

Sapolsky Results

Baboons who were lower in the social hierachy displayed different behaviour (more differential) and were the last to have food and suffereed from more disease, living shorter lives overall.

Lower hierachy had higher cortisol in blood levels compared to the other baboons (correlation established)

Sapolsky Conclusion + Strengths and Limitations

Increased cortisol was a direct result of the baboon’s social standing in the troop.

Concluded that high levels of cortisol for a long period of time can create a detrimental effect on the immune system leading to many health problems.

Strength: Can design experiments to investigate the same relationship in humans

Limitation: A lack of control of extraneous variables that may have affected the results

Localisation of Function Studies

Maguire (2000)

Milner

Distributive Processing

The theory that behaviour is a result if interaction between several parts of the brain and not strictly localised to one part

Equipotentiality

The theory that the brain has the potential to transfer functions to other parts of the brain when a portion is injured

Localisation of Function

The theory that behaviours have their origin in specific areas of the brain. Damage to that part of the brain would result in an inability to carry out that behaviour

Relative localisation

The theory that although one part of the brain may play a key role several parts also play a lesser role

Strict localisation

Behaviours attributed to a single area of the brain

Maguire (2000) aim

To see if the hippocampus of experienced London taxi drivers have grown in comparison to beginner London Taxi drivers

Maguire Research and Sampling methods

Naturalistic study (taxi drivers were carrying out normal day to day life)

MRI scan used to measure brain activity

VBM and pixel counting used

Sampled beginner and experienced London taxi drivers (purposive sample as have a specifc characteristic). 50 right handed males used as a control

Maguire procedures

16 right handed male London Taxi drivers and given MRI scans. They had to have completed the knowledge test and had to have their licence for 1.5 years. There was a range of ages (age not confounding variable)

Compared with control group scans

MRI data was measured using VBM and pixel-counting

Maguire Results

Hippocampus larger in experienced taxi drivers compared to beginner ones

Volume of right side was increased directly proportional to amount of time driving

Pixel counting showed the back of the hippocampi larger and the front smaller and there was no change in any other parts of the brain

Maguire Conclusion

Parts of the brain able to grow and adapt

This experiment cannot be repeated due to development of GPS and other navigation techonolgy so don’t have to memorise to the same extent.

Milner (1966) aim

To understand the effects that surgery had on HM’s brain

Milner Research methods

Method triangulation - many tests were used

Data triangulation - qualitative and quantitative data collected

Milner Procedure

IQ test, direct observation, interviews with HM and family, cognitive testing and MRI was later done

Milner Results

HM could not aquire new episodic knowledge (events) and new semantic knowledge (general knowledge)

He was able to forma cognitive map demonstrated when he was able to draw a floor plan of his house

Had capacity for working memory

Memories of motor skills were maintained (procedural memories)

Milner (HM) Conclusion

Memory in the brain is a highly specialised system.

The hippocampus plays a key role in converting memorues of experiences from short term to long term memory.

Short term memory not stored in the hippocampus as HM was able to retain information for a while if he rehearsed it

Memory contains several stores - procedural memory, long term memory stored elsewhere in the brain

Milner Evaluation

Strength: High ecological validity

Strength: High ethical standards - consent, confidentiality, protection from harm

Strength: Method and data triangualtion

Limitation: Case study can’t be replicated

Limitation: Restrospective study so no evidence on HM’s cognitive abilities before accident

Neuroplasiticty Studies

Maguire (2000) and Draginski (2004)

Neural Networks (SAQ) study

Draginski (2004)

Neural Pruning Study (SAQ)

Draginski (2004)

Apoptosis

Neurnal cell death

Cortical remapping

When one area of the brain assumes the functions of another part of the brain when it is damaged

Neurogenesis

The proces by which new neurons are formed

Long Term potentiation

Repeated firing of neruons strengthens the connections

Neural Network

The human brain consists of neurons and nerve cells that transmit the information from our senses. The pass electrical cells from one neuron to the next

Neuroplasticity

The ability of neural networks to change through growth and reoganisation.S

Neual Pruning

When the brain eliminated extra synapses that are no longer needed

Draginski (2004) aim

To see whether learning a new skill would affect the brains of participants

Dragniski research method

Pre and post test design

Prospective study

Sampling methods for Dragniski

Volunteers and all between 20 and 24, 21 females and 3 males

Draginski Procedures

Participants split into a juggling and non juggling group (served as control) and the juggling group taught a juggling routine and were told to notify the researchers when they had mastered the routine.

MRI scans taken before and after they had mastered the routine (and at start of study for control)

Once mastered were told not to practice for 3 months and then had another MRI

VBM used to detect changes in grey matter in the brains of jugglers vs non-jugglers

Draginski Results (2004)

Before study, no specific differences in the grey matter between the two groups of participants.

At the end of the first oart of study when mastered skill, the jugglers showed a larger amount of grey matter in the mid temporal area on both sides (associated with visual memory)

After 3 months the participants could no longer carry out the routine and the amount of grey matter areas decreased. No change in grey matter for the non-juggling sample.

Draginski Conclusion

This study shows that when a skill is practiced and mastered, the formation of new neural pathewsays form. These weaken and disappear overtime if not used.

Juggling relies more on visual memory rather than procedural memory

Scanning Techniques studies

Maguire (2000) and Draginski (2004)

Pixel counting

Consists of counting the pixels in the images provided by the MRI scans. This allows area of brain to be calculated

VBM

Voxel-based morphometry - VBM is a technique using MRI that allows researchers to measure volume of parts of brain

Research Methods studies

Milner (1986) Draginski (2004)

Natural experiment

IV not manipulated, it is naturally occuring (case studies)

Experiment

Researcher manipulates IV and measures its effect on DV, controlled conditions

Quasi-experiment

Manipulates an IV and DV is measured but participants not put into controlled groups, are assigned to conditions based on pre-existing traits

Method Triangulation

When a researcher uses more than one research method. Increases credibility and confirms results

MHC

MHC genes make molecules that enable the immune system to recognize pathogens. Some psychologists argue that our smell is a sign if our MHC

Wedekind et al (1995) Aim

To determine whether one’s MHC would affect “mate choice”

Wedekind Sample

49 female and 44 male university students, they didn’t know each other as they were taking courses

Each participant was typed for MHC and a range of variety of MHC was included in the sample.

Wedekind Research Methods

Lab experiment (highly controlled, low ecological validity)

Wedekind Procedures

Men asked to wear a T shirt for two nights and to keep the T shirt in an open plastic bag during the day. They were given purfume-free detergent to wash clothes and asked not to smoke or drink alcohol for this time.

After this women were asked to rank the smell of 7 t-shirts, each in a cardboard box with a smelling hole. 14 days leading up to this women had to use a nasal spray to regenerate the nasal membrane and the researchers tried to carry out the test during their menstruation as this was when they were the most odour sensitive.

3 of seven boxes had similar MHC to the womans and 3 had different and one had an unworn T-shirt as a control. They had to rate the odours for intensity, pleasentness and sexiness out of 10.

Wedekind results

Woman scored male body odors as more pleas more plesant when they differed from their own MHC than when they were more similar.

Wedekind Conclusion

This may suggest that MHC may influence human mate choice

Wedekind Strengths and Limitations

Strengths:
Double blind experiment to minimise demand characteristics and researcher bias
Met ethical standards as participants were debreifed and gave consent
Replicable - replicated twice and found similar results

Limitations:
Theory may be too reductionist (oversimplified)
Sample may not be considered as representative as all the same age and culture.

Signalling Pheromones

Chemical substances that produce rapid behavioural effects such as mating

Putative Pheromone

The pheromone is potentially a human pheromone but not definitive

Androstadienone

Human steroid present in sweat and male seme. It heightens sympathetic arousal and promotes positive mood state in females. It activates the hypothalamus of heterosexual females and homosexual males

Estratetraenol (EST)

Female equivalent of AND.

Zhou (2014) aim

To invesitgate the effect of AND and EST on heterosexual and homosexual men and women.

Zhou (2014) Sample

Four groups of healthy non-smokers including 24 heterosexual males, 24 heterosexual females, 24 homosexual males and 24 bisexual or homosexual females

Zhou (2014) Procedures

Participants presented with a point light walker task, a set of dots that move in a way that represent the properties of human motion. Participants were asked to obsere the figure and identify its gender.

The same task was done for 3 consecutive days at the same time while being exposed to either AND mixed with cloves, EST and cloves, or a control solution mixed with cloves.

Zhou (2014) Results

When heterosexual females and homosexual males were exposed to AND they had a higher rate of identifying the stick figure as masculine than the control group. AND had no significant effect on straight men or lesbian women.

Similarly, the presence of EST made straoght males more likely to precieve the figure as feminine. It had no effect on bisexual or lesbian women.

Zhou (2014) Conclusion

AND and EST have some effect on human behaviour.

Zhou (2014) Strengths and Limitations

Strengths: IV manipulate (cause and effect), counter balanced to control for order effects (e.g practice effect)

Limitations: Experiment carried out with different groups and obtained different results, Hare et al failed to replicate, low eco vad as dose of AND and EST was higher than natural dose.

Antagonist

A chmical or drug that binds to receptors to stop hormone from having effect on behaviour (e.g scopolamine)

Excitatory function

Increases the likelihood that the neuron will fire an action potential

Inhibitory function

Decreases the likelihood that an action potential will fire

Neurotransmitter

Chemical messenger that carries signals between neurons. They are released at the end of axons and reach the receptor site on the next neuron

Reuptake

Reabsorbtion of a neurotransmitter in the presynaptic neuron after it has performed its funtion. This rpevents any further activity

Neurotransmitter studies

Antonova & Rogers + Kesner

Anotnova (2011) Aim

To see if scololamine (actylcholine antagonist) affected hippocampal activity in the creation of spatial memory

Antonova Sampling

20 healthy male adults with an average age of 28

Antonova research methods

double - blind research

Random allocation to their condition

Respeated measures - got to try both conditions

Antonova (2011) Procedures

The reseachers injected the participanst with either scopolamine or a placebo 70-90 minutes before taking part in the experiment.

They were then put into an fMRI where they were scanned while playing the “Arena Task.” This is a VR game were they had to navigate around the area to reach a pole. After learning where the pole was located the screen would go blank for 30 seconds and participants told to actively rehearse how to get to the pole. They had to use spatial memory to remember this.

They made sure they were comfortable with the use of the game before bginning and the researchers did six rounds. 3 - 4 weeks later they came back and did the opposite condition to what they were originally assigned (repeated measures)

Antonova (2011) Results

The researchers found that participants injected with scopolamine had a significant reduction in the activation of the hippocampus compared to when they had a placebo.

Antonova (2011) Conclusion

Acetylcholine could play a role in the encoding of spatial memories in humans as well as in rats.

Antonova strengths and limitations

Limitations
Not a significant difference between placebo and experimental group
Small sample size
Several participants expressed that they had been stressed, either due to the drug injection or the fMRI encolsure. This could affect how the hippocampus works as stress interferes with encoding

Strengths
Double blind - controls for researcher bias
Repeated measures design - eliminates participant variability
Study was counter - balanced: some started with placebo and others started with scopolamine which reduces the practice effect

Exogenous agonist

A drug (external) that excites the neuron

Endogenous agonist

A biological chemical that binds to the receptor site

Diathesis-stress model

A disorder as the result of an interaction between a predisposition and sress caused by life experiences

Gene Expression

The process by which the instructions in our DNA are converted into a functional product (when a gene is turned on or off resulting in behaviour)

Genetic vulnerability

The theory that you may have genes that may make you more likely to have certain traits if you are exposed to the right environmental stresses

Genomewide Association study

An examination of genetic variants in a large sample of individuals to see if any variant is associated with a trait

Polymorphism

A genetic mutation resulting in the occurence of several different forms or types of individuals among the members of a single species

Transgenic Mice

Mice that have a single gene changed or removed

Kendler (2006) Aim

To investigate the heritability of major depression

Kendler (2006) Sampling Methods

15,493 twin pairs (Swedesh)

Kendler (2006) Research Methods

Correlational study as no particular genes isolated and tested in the study