Our Ancient Laughing Brain

1. Our Ancient Laughing Brain 1

2. Why do we laugh?

3. What makes us laugh? Is humor the main ingredient of laughter?

4. Scientific investigation of laughter • Public places - only 10 to 20% has to do with humour (1200 conversations) Dr.Robert Provine Neurobiologist

5. Laboratory: brought people • in his lab to observe • laughter Scientific investigation of laughter Dr.Robert Provine Neurobiologist What were the results??? 5

6. “Laughter disappears just when we are ready to observe it -- especially in the laboratory” 6 Robert Provine

7. Laughter: A Social Behaviour Laughter disarms people, creates a bridge between them, and facilitates amicable behavior 7

8. Why do we laugh? The function of laughter is .....

9. Why do we laugh? ...Communication! It seems to be a message that we send to other people communicating joyful disposition, bonding, happiness, willining to play.

10. Why do we laugh? We need to build social structures in order to live well in our society and laughter signalize this disposition. We rarely laugh alone

11. ??? “If we see someone laughing alone he or she would seem to be crazy”

12. What makes us laugh Organism Facial, body, physiological and behavioral changes Stimuli Responses • Expression of • laughter • Situations in social • environment • Humor Processing “Black Box” approachfor studying laughter

13. Expression of laughter “Laughter has powerful influences on the body” Dr. J. Mercola, MD 9

14. During vigorous laughter You must get unobstructed upper airways in order to laugh Therefore a spasm occurs, so that neck and head are thrown back to provide a free respiratory intake.

15. Compare the contrast between waves of sound during O2 Normal Respiration CO2 Laughter Laughter is accompanied by a strong increase of amplitude and frequency of respiratory movement with a consequent increase in the intake of oxigen and output of carbon dioxide “Laughter is a good aerobic exercice that ventilates the lungs” Dr. William Fry Jr.

16. Blushing The venous return from the face by the jugular veins is partially blocked due to a strong contraction of neck muscles Arterioles in the face dilate provoking an increase in the blood flow Jugular vein

17. Lacrimal glands Shedding of tears The repeated contraction of the muscles around the eyes compressess the lacrimal glands provoking the outflow of tears.

18. Pressure in the abdomen Repeated short, strong contractions of the muscles of thoracic wall, abdomen, and diafragm increase blood flow into our internal organs

19. Muscle weakness Muscle tension decreases, and we may temporarily lose control of our limbs. “Being weak with laughter”

20. Laughter activates the cardiovascular system, so heart rate and blood pressure increase The arteries then dilate, causing blood pressure to fall

21. Wetting oneself Loss of control of urinary sphincter

22. Laughter promotes social bonding “Shared laughter creates a bond of friendship. When people laugh together, they cease to be young and old, master and pupils. They have become a single group of human beings, enjoying their existence." W. Grant Lee

23. Laughter is contagious “Laughter is a powerful sound” Dr. Joseph M. Mercola

24. Contrivances for contagious laughter • Laugh tracks of television • Laugh records in toys • Laughing boxes

25. Coupling the Black Boxes:Laughter as Communication Person A Person B A Sociobiological Perspective

26. Laugh generation Auditory feature detector Contagious laughter:Roots in the neurological mechanism of laugh detection and replication Wave of Sound Laugh generation

27. Laughter: “The Best Medicine” "The old saying that 'laughter is the best medicine,' definitely appears to be true” Michael Miller, M.D. University of Maryland Medical Center

28. Does laughter have the same meaning in all human cultures? Scientists wondered if there was any cross- cultural differences in social context of laughter.

29. Eibl-Eibesfeldt documented laughter’s universality recording unstaged and undisturbed social interactions in a number of traditional societies Irenäus Eibl-Eibesfeldt Ethologist 1928-present

30. Laughing is a universal phenomenon Native Brazilians, African tribesmen, Greek fishermen, etc.

31. Where does laughter come from? Do we learn to laugh? Or is laughter innate in human beings?

32. Evidences point to an innate, preprogrammed basis for laughter Congenitally blind, deaf, and dumb child Premature baby

33. Video Analysis of Laughter Sequence + + + ++ +++ Voice

34. Do animals also laugh?

35. Laughter is not unique to humans Apes open their mouths wide, expose their teeth, retract the corners of their lips, and emit loud and repetitive vocalizations

36. Apes Human being Ah Ah Ah Hah Hah Hah Produce a pant “ah” for every expiration and inspiration Produced by interrupting a single expiration Contrast of chimpanzee and human laugh production.

37. What are the origins of laughter?

38. Playful BehaviourLaugh and fun "The true origins of laughter lie in the rough-and-tumble play of our primate ancestors”

39. AMAZON Playing in the rain forest with monkeys Monkeys also laugh when they are playing with humans

40. Playful Behaviour Fighting in make-believe aggression is not for real. Laughter indicates that aggressive play is just fun

41. Breath exalation Playing Standarts pants Playful Behaviour Dogs make a specific noise during play that is distinctive from other sounds made during passive or aggressive confrontation.

42. Laughter even evolved long before higher mammals appeared on the scene. Rats emit short, high-frequency, ultrasonic vocalizations during rough-and-tumble play.

43. Laughter’s dark side “Laughter also can serve as a weapon to humiliate and ostracize its victims” Is there a common evolutionary origin of laughter and aggression?

44. Laughter in primates may have originated as a group threatening behaviour against strangers They mean to keep the stranger: • Away and feel undesired, without actually resorting to direct aggression; • It reinforces the group social cohesion; • It may explains why “being laughed at” by a group is so stressful. Outside the group Inside the group

45. Animals are able to modify the sound of their vocalization. “I am no threat to you” It is trying to sound bigger than it actually is. They mean that they can bite Contrast between laughter and aggression Both involve showing the teeth

46. Laughter x Aggression Definite function: communicative signal

47. What are the brain mechanisms of laughter? Laughter involves the whole brain

48. Basic structures of the brain • Neocortex • Visual, auditory,etc. - PERCEPTION • Memory, thinking, understanding • HUMOR Limbic system Pleasure, happiness, joy Brainstem, hypothalamus, basal ganglia Vocalization, respiration, gland excretion 47

49. Motor cortex Prefrontalcortex Visual cortex Cerebellum Basal ganglia Hypothalamus Limbicsystem Pyramidal system Brainstem A Brain Alight with Laughter…

50. When something goes wrong with this complex system Areas involved with laughter expression mechanism Damage provoked in the neural circuit responsible for the motor expression of laughter, may cause a "desinhibition" of the laughter mechanism