Unit 2:Biological Level of

AnalysisSession 10

‘All that is psychological is first physiological’

Today’s learning outcome

Explain, using examples, functions of two hormones in human behaviour

A Quick Recap

Explain, using examples, functions of two hormones in human behaviour

1.Oxytocin2.Melatonin3.Cortisol

Examples of hormones

Plays role in inducing labour & lactation Released with touches & hugs Associated with bonding between mother &

child and lovers Research is being carried out to see

whether people suffering from social anxiety may benefit from doses of oxytocin

Oxytocin

Oxytocin has been linked to trusting other people

According to evolutionary psychologists, trust is an important social tool in the relationship between humans

Learning who to trust and who to avoid is important for survival and well-being

Humans should be able to move on after betrayal if mental well-being are to be preserved

Oxytocin could play a role in reducing fear that may arise as a consequence of betrayal

Oxytocin & Trust

Investigated role of oxytocin after breaches of trust in a trust game

Participants played a trust game used by economists and psychologists to study social interaction

They recieved either oxytocin or placebo via a nasal spray

In 50% of games trust was broken They received feedback on this from

experimenters during the games

Oxytocin & Trust: Baumgartner et al. (2008)

Oxytocin & Trust: Baumgartner et al. (2008)

Placebo Group Oxytocin Group

Less likely to show trust after feedback on betrayal. They invested less.

Continued to invest at similar rates even after recieving feedback on a breach of trust

Oxytocin could explain why people are able to restore trust and forgive in long term relationships

Giving oxytocin like this in an experiment may not reflect natural physiological processes. Function of oxytocin very complex and it’s too simplistic to say it’s the “trust hormone”

Wednesday’s Journal Entry 1Summarise Baumgartner et al (2008)

You must include:1. Procedure2. Findings 3. Evaluation of study

Production of melatonin stimulated by darkness and inhibited by light. Correlates with circadian rhythm

Suggested that taking melatonin in the early evening may improve one’s ability to fall asleep

Through study of melatonin researchers hope to find a solution for those who suffer from insomnia and jet lag

Melatonin

Rosenthal (1987)

Evidence to suggest that higher levels of melatonin contribute to seasonal affective disorder (SAD)

Reduced levels of sunlight in autumn and winter believed to disrupt circadian rhythm is certain people leading to this depression

Perhaps why we see higher levels of SAD in Scandinavia

Melatonin & SAD

As increased sunlight improves the symptoms, phototherapy (prolonged exposure to bright light) often main treatment for people with SAD

Despite some claims success, there is lack of definitive evidence of its effectiveness One has to be careful about seeking quick solutions to complex questions

Melatonin & SAD

Wednesday’s Journal Entry 2What is melatonin?

What is its link with SAD?

How might SAD be treated?

Produced by the adrenal cortex in response to stress to restore homeostatis (the body’s normal balance)

Chronic stress may result in prolonged cortisol secretion. This can result in physiological changes such as damaged immune system and impairment of learning and memory

This is because high amounts of cortisol results in deterioration of the hippocampus (Sapolsky, 1996)

Cortisol

Used as example for principle of BLOA “there are biological correlates of behaviour

Aim: To investigare how levels of stress hormone cortisol interfere with verbal declarative memory

Design: Randomised, controlled, double blind experiment that ran for four days

Participants: self selected sample (recruited through advertisement) of 51 normal & healthy people aged 18-30

*double blind- neither participants nor experimenters knew which condition each participant assigned to

Cortisol: Newcomer et al (1999)

Participants listened to a prose paragraph and had to recall is as a test of verbal declarative memory

Group 1 showed worst performance on task Group 2 showed no memory decrease Shows that an increase in cortisol has a negative

effect on memory

Cortisol: Newcomer et al (1999)

Group 1 (high dose) Group 2 (low dose) Group 3(control)

Tablets containing 160mg of cortisol for 4 days (equivalent to cortisol levels in blood as a consequence of major stressful event)

Tablets containing 40mg of cortisol for 4 days (equivalent to cortisol levels in blood as a consequence of minor stressful event)

Placebo Tablets(tablets with no active ingredient)

Controlled randomised experiment so possible to establish cause and effect relationship between levels of cortisol and scores on verbal declaritive memory test

The negative effects of taking cortisol was reversible so no harm was done

Evaluation of Newcomer et al (1999)

Journal Entry

Summarise Newcomer et al (1999)

You must include:

1. Procedure2. Findings 3. Evaluation Points