Unit 2: Biological Level of Analysis Session 9

1. Unit 2:Biological Level of AnalysisSession 9 ‘All that is psychological is first physiological’

2. A Quick Recap

3. What are hormones? • Hormones are chemicals that affect behaviour. • They are produced by the glands that make up the endocrine system • Hormones are a contributingfactor to behavior.

4. Hormones and Neurotransmitters Neurotransmitter: A chemical in the synapse that transmits signals between neurons Hormone: A chemical secreted by an endocrine gland. Travels through the bloodstream. Usually involved in longterm functioning of the body.

5. Similarities & Differences between neurotransmitters and hormones

6. Last session’s Journal Entry • Outline the similarities and differences between neurotransmitters and hormones

7. Today’s learning outcome • Explain, using examples, functions of two hormones in human behaviour

8. Examples of hormones • Explain, using examples, functions of two hormones in human behaviour • Oxytocin • Melatonin • Cortisol

9. Oxytocin • Produced by the hypothalamus & released into bloodstream by pituitary gland • Plays role in inducing labour & lactation • Released with touches & hugs • Associated with bonding between mother & child

10. Oxytocin • Also associated with bonding between lovers • Has been called the “love hormone” as it seems to be such an effective mediator of human social behaviour

11. Oxytocin • Watch the video on Oxytocin the “love hormone” • Take notes

12. Oxytocin & Trust • Oxytocin has been linked to trusting other people • Experimental manipulation of oxytocin levels has shown increase in trust • According to evolutionary psychologists, trust is an important social tool in the relationship between humans • Research is being carried out to see whether people suffering from social anxiety may benefit from doses of oxytocin

13. Oxytocin & Trust: an evolutionary perspective • Trust is an adaptive mechanism as is helps humans to form meaningful relationships at a personal and professional level • Betrayal disrupts bonds of trust and may result in avoidance of person who has betrayed you • 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 reactions via the amygdala that may arise as a consequence of betrayal

14. Oxytocin & Trust: Baumgartner et al. (2008) Aim • To investigate role of oxytocin after breaches of trust in a trust game Procedure: • Participants played a trust game used by economists and psychologists to study social interaction • The “investor” (player 1) receives a sum of money and must decide whether to keep it or share it with a “trustee” (player 2) • If sum is shared sum is tripled • Then player 2 (trustee) must decide if this sum should be shared (trust) or kept (violation of trust)

15. Oxytocin & Trust: Baumgartner et al. (2008) Procedure • fMRI scans were carried out of 49 participants • They recieved either oxytocin or placebo via a nasal spray • Participants played against different trustees in the trust game and against a computer in a risk game • In 50% of games trust was broken • They received feedback on this from experimenters during the games

16. Oxytocin & Trust: Baumgartner et al. (2008) Results fMRI scans showed decreases in responses in amygdala and caudate nucleus in Oxytocin group. Amygdala involved in emotional processing & has many oxytocin receptors Caudate nucleus associated with learning & memory and plays a role in learning to trust

17. Evaluation: Baumgartner et al. (2008) • Oxytocin could explain why people are able to restore trust and forgive in long term relationships • Scanner research merely maping brain activity but nothing definite can be said about what it really means with current technology • 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”

18. Journal Entry • Summarise Baumgartner et al (2008) • You must include: • Procedure • Findings • Evaluation of study

19. Melatonin • Production of melatonin by pineal gland is stimulated by darkness and inhibited by light • Melatonin levels in bloodstream peak in middle of night and gradually decrease towards morning

20. Melatonin • In temperate climates when the days get shorter and winter approaches, the earlier onset of darkness means we become tired earlier • Until recent history, humans in temperate climates had up to 18 hours of darkness in winter months • The use of artificial lighting has increased awake time dramatically

21. Melatonin • Melatonin release correlates with the circadian rhythm (the biological clock that is based on a 24 hour day/night cycle) • It is 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

22. Melatonin & Circadian Rhythm

23. Melatonin & SAD Rosenthal (1987) • Evidence to suggest that higher levels of melatonin contribute to seasonal affective disorder (SAD) • SAD= a subcategory of depression that is characterised by sleepiness, cravings for carbohyodrates & lethargy • 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

24. 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

25. Melatonin & SAD • Watch the video on SAD

26. Journal Entry What is melatonin? What is its link with SAD? How might SAD be treated?

27. Next session... • More on hormones and behaviour • Cortisol