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Unit 2: Biological Level of Analysis Session 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. Examples of hormones.
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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
Examples of hormones • Explain, using examples, functions of two hormones in human behaviour • Oxytocin • Melatonin • Cortisol
Oxytocin • 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 & Trust • 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: Baumgartner et al. (2008) • 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 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 1 • Summarise Baumgartner et al (2008) • You must include: • Procedure • Findings • Evaluation of study
Melatonin • 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 & SAD 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
Wednesday’s Journal Entry 2 What is melatonin? What is its link with SAD? How might SAD be treated?
Cortisol • 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: Newcomer et al (1999) • 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
Evaluation of Newcomer et al (1999) • 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
Journal Entry • Summarise Newcomer et al (1999) • You must include: • Procedure • Findings • Evaluation Points