Hormones

1. Hormones Sample question: Explain the function of two hormones in human behaviour.

2. Adrenaline • Behaviour – “Fight or flight” responses – preparing body to deal with threats. • May be responsible for the creation of emotion

4. Examples • Associated with fear but also excitement and positive feeling. • Increased alertness • Increased the flow of oxygen and blood to the brain • Increased heart activity- heart rate, blood pressure • Dilates blood vessels, eye pupils • Moves glucose and oxygen away from internal organs to the extremities • Released from the adrenal medulla of the adrenal glands

5. Melatonin • Behaviour – regulates the sleep cycle and related behaviours • Secreted from the pineal gland – has the ability to sense light • secreted during darkness but not light

7. Example • Melatonin also affects activity of the pituitary gland and wakefulness – “turns off the body” • SAD – Seasonal Affective Disorder – depression linked to the beginning and the end of winter. • Avery et al. 2005 – rated the depression in 95 subjects grouped by various degrees of light exposure. Found that symptoms were related to shifts in subjects sleep patterns resulting from dawn simulation, bright light therapy, or dim red light exposure. • Lewy et al 2006 – found that the duration of melatonin exposure triggered activities in the brain. SAD may result from biological instincts becoming incompatible with lifestyle demands. • Jet-lag is a result of changes in melatonin cycles – dose of melatonin can alleviate jet lag

8. Oxytocin • Behaviour - The “love hormone” or “trust hormone”

9. Example • Released during birth and physical stimulation during breast feeding. • Involved in formation of social bonds – rats injected with oxytocin would switch from grooming themselves to grooming their pups. • Also involved in stress reduction – positive physical contact between husband and wife resulted in lower blood pressure

10. Example contd. • Morhenn et al. 2008 – grouped 96 volunteers into three groups by massage, rest, and trust exercises. They found that people who received massages showed no rise in oxytocin levels but would be more generous and trustworthy with money sacrifices. Donations were more likely to be reciprocated after a massage and when a donation was returned in the experiment, a rise in oxytocin was detected. Therefore oxytocin is related to increased generosity and co-operation

11. Schachter and Singer, 1962Adrenaline and emotion • Aims– to test the effect of context on the cognitive evaluation of emotion during the release of adrenaline in subjects • Method – 184 male participant volunteers, three experimental groups and one control group. All informed they were getting vitamin injections while three groups got adrenaline injections and one final group received a saline placebo. Three experimental groups were informed of three different anticipated side effects. Two emotional contexts were added by confederates, one of euphoria (playing office games) and the other of anger (personal questions in a questionnaire) • Structured observations followed along with self-reports of emotional mood for each subject when their context exposure was complete.

12. Schachter and Singer 1962 contd. • Findings - Subjects who received incorrect side effect information in the euphoric context showed corresponding euphoric behaviours and reported more happiness • Subjects who received incorrect side effect information in the angry context did not report corresponding angry feelings but subjects in this context who received correct side effect information performed less angry behaviours than those who received incorrect side effect information. • Therefore, emotion occurs as a result of cognitive labelling in which the physiological cues are combined with contextual cues to create the subjective experience of emotion.

13. Variables and validity • Independent variable – the contextual cues of anger and euphoria, the anticipated side effects of each group, the differences between subjects in the experimental group and the control group. • Dependant variable - behaviour displayed during the context experiences as well as the self-reports of emotional states of the participants. • Validity – Some unanticipated data – shouldn’t anger groups have shown angry behaviours? Shouldn’t anger groups have reported angry emotions? • Possible susceptibility to demand characteristics – was the experiment double blind or single blind? • Others??????