Evolution of Emotion: Adaptive Responses to Threats and Opportunities

1. Chapter 11 Evolution of Emotion

2. Emotions • Evolutionarily selected adjustments to physiological, psychological, and behavioural parameters, allowing an organism to adaptively respond to threats and opportunities in the environment • Adapted from Nesse (1990)

3. Principle of Hedonism • Seek pleasure • (Appetitive events) • Avoid pain • (Aversive events) • Consider emotional states in this context

4. Evolution and Emotions • Selective forces • Emotions • Effect on inclusive fitness?

5. Three Hairy Men

6. Early Views on Emotion • Charles Darwin • The Expression of the Emotions in Man and Animals (1872) • Each emotional state will have its own expression • Emotions occur in opposing pairs • Emotional reaction independent of will • Emotional state results in external expression of emotion • William James • Internal, visceral state monitored by brain • Physiological response subsequently creates emotion • Sigmund Freud • Understanding emotion central to understanding behaviour

7. Innateness of Emotions • Cross-species comparisons • Similar expressions under similar situations • Primate facial expression as byproduct of vocalizations in particular emotional state (Andrew 1963) http://webdrive.service.emory.edu/groups/research/chimpanzee-cognition/CCL/facs.htm

8. Later Reinterpretation • Innate nature of emotion challenged • Behaviorists • Anthropologists (e.g., Bateson & Mead) • Does each culture really develop its own unique emotional states?

9. Ekman & Friesen (1971) • Emotions not culturally determined • Anger, disgust, fear, joy, sadness, surprise • Other research suggests 5-8 basic emotion types • Blending of emotion types to create full range of expressions displayed • Cross-cultural recognition of facial expression

10. Learning, Cultural Display Rules • There are cultural differences in the use of facial expression and emotional response • Issue of suppression/modification of display, rather than lack of emotion itself • Individual learning influences emotional displays (e.g., specific phobias) • Observational learning • Preparedness towards certain fears

11. ToM and Emotional Display • Adaptive value in knowing your own and others’ emotional states • Sociality • An aspect of Theory of Mind • Displaying your emotional state gives others information; similarly, can gain information from observing others’ • Concealment and deception

12. Neurology of Sociality • Frontal cortex • Weigh future consequences of actions and plan accordingly • Sociality Amount of brain taken up by frontal association cortex. From: Kandel, Schwartz, Jessell (1991), p. 827

13. orbitofrontal cortex Frontal Cortex • Two main regions: • Prefrontal association cortex • Orbitofrontal cortex (OFC) • Part of limbic association cortex • Direct connections with amygdala From: Kandel, Schwartz, Jessell (1991), p. 827, 306

14. Deficits with Medial Frontal Cortex Damage • Mental state attributions • Appropriate social behaviour • Understanding high-level language and metaphor • Positive or negative emotions • Autistics show many of the same problems

15. Amygdala • Part of limbic system • “Old” part of brain • Activated by emotional displays • Facial expressions • Fear and threat

16. Lesion OFC Normal aggressiveness and emotional response reduced Reduction of chronic pain Socially inappropriate behaviour and humour Low empathy Poor social decision-making Electrical stimulation of OFC Autonomic responses Increased blood pressure, pupil dilation, salivation, etc. Generalized arousal reaction Orbitofrontal Cortex

17. Orbitofrontal Cortex • Combine mental state and emotional information • Damage still allows cognitive understanding of social issues • But, cognitive assessment can’t be put in emotional context

18. Endocrinology • Besides neural role, endocrine glands • Secrete hormones to bloodstream • Affect target organs, including brain • Is it the initial brain action that produces the emotion, or the subsequent effect of the hormone on body and brain systems?

19. Adrenalin • Stress --> • Amygdala --> • Activates autonomic nervous system --> • Adrenal glands --> • Release of adrenalin to bloodstream --> • Into brain --> • Receptor sites in temporal lobe and amygdala --> • Enervation of higher cognitive areas

20. Function • Core emotions • Negative • Fear, anger, sadness • Positive • Love, happiness

21. Negative Core Emotions • Fear, anger, sadness • Appropriate response to aversive stimuli • Generally related to specific events • Large number of particular types of threats • Consequences of wrong response to threat worse than wrong response to opportunity • Fear has obvious survival benefit • Particular subforms, e.g., panic, agoraphobia, with specific responses

22. Specific Action Tendencies • Fear --> urge to retreat • Anger --> urge to attack/injure • Both serve to focus attention to potential threat • What about sadness, though?

23. Sadness • May result in withdrawal from activities • Could serve to conserve energy • Seek out support; kin • Pre-linguistically, emotional display of sadness may have served to elicit aid and support

24. Positive Core Emotions • Love • Different forms: parents, children, mates • Influence on inclusive fitness • Happiness • Joy --> play, develop mental & physical skills, social development • Interest --> exploration, information seeking • Contentment --> “low arousal positive state”; maintain successful situation