Why do we dream? - Amy Adkins — Transcript

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1. 0:06In the third millenium BCE,
2. 0:08Mesopotamian kings recorded and interpreted their dreams on wax tablets.
3. 0:13A thousand years later,
4. 0:15Ancient Egyptians wrote a dream book
5. 0:17listing over a hundred common dreams and their meanings.
6. 0:20And in the years since,
7. 0:21we haven't paused in our quest to understand why we dream.
8. 0:25So, after a great deal of scientific research,
9. 0:28technological advancement,
10. 0:29and persistence,
11. 0:31we still don't have any definite answers, but we have some interesting theories.
12. 0:36We dream to fulfill our wishes.
13. 0:40In the early 1900s,
14. 0:42Sigmund Freud proposed that while all of our dreams, including our nightmares,
15. 0:46are a collection of images from our daily conscious lives,
16. 0:49they also have symbolic meanings,
17. 0:51which relate to the fulfillment of our subconscious wishes.
18. 0:55Freud theorized that everything we remember when we wake up from a dream
19. 0:59is a symbolic representation
20. 1:01of our unconscious primitive thoughts, urges, and desires.
21. 1:05Freud believed that by analyzing those remembered elements,
22. 1:08the unconscious content would be revealed to our conscious mind,
23. 1:12and psychological issues stemming from its repression
24. 1:14could be addressed and resolved.
25. 1:17We dream to remember.
26. 1:20To increase performance on certain mental tasks,
27. 1:23sleep is good,
28. 1:24but dreaming while sleeping is better.
29. 1:27In 2010, researchers found
30. 1:28that subjects were much better at getting through a complex 3-D maze
31. 1:32if they had napped and dreamed of the maze prior to their second attempt.
32. 1:37In fact, they were up to ten times better at it
33. 1:39than those who only thought of the maze while awake between attempts,
34. 1:44and those who napped but did not dream about the maze.
35. 1:48Researchers theorize that certain memory processes
36. 1:51can happen only when we are asleep,
37. 1:53and our dreams are a signal that these processes are taking place.
38. 1:58We dream to forget.
39. 2:02There are about 10,000 trillion neural connections
40. 2:05within the architecture of your brain.
41. 2:07They are created by everything you think and everything you do.
42. 2:11A 1983 neurobiological theory of dreaming, called reverse learning,
43. 2:15holds that while sleeping, and mainly during REM sleep cycles,
44. 2:19your neocortex reviews these neural connections
45. 2:22and dumps the unnecessary ones.
46. 2:25Without this unlearning process,
47. 2:27which results in your dreams,
48. 2:28your brain could be overrun by useless connections
49. 2:31and parasitic thoughts could disrupt the necessary thinking
50. 2:34you need to do while you're awake.
51. 2:37We dream to keep our brains working.
52. 2:42The continual activation theory proposes that your dreams result
53. 2:46from your brain's need to constantly consolidate and create long-term memories
54. 2:51in order to function properly.
55. 2:53So when external input falls below a certain level,
56. 2:55like when you're asleep,
57. 2:57your brain automatically triggers
58. 2:58the generation of data from its memory storages,
59. 3:01which appear to you in the form of the thoughts and feelings
60. 3:04you experience in your dreams.
61. 3:06In other words,
62. 3:07your dreams might be a random screen saver your brain turns on
63. 3:10so it doesn't completely shut down.
64. 3:14We dream to rehearse.
65. 3:18Dreams involving dangerous and threatening situations are very common,
66. 3:21and the primitive instinct rehearsal theory
67. 3:24holds that the content of a dream is significant to its purpose.
68. 3:27Whether it's an anxiety-filled night of being chased through the woods by a bear
69. 3:31or fighting off a ninja in a dark alley,
70. 3:34these dreams allow you to practice your fight or flight instincts
71. 3:37and keep them sharp and dependable in case you'll need them in real life.
72. 3:41But it doesn't always have to be unpleasant.
73. 3:43For instance, dreams about your attractive neighbor
74. 3:46could actually give your reproductive instinct some practice, too.
75. 3:50We dream to heal.
76. 3:54Stress neurotransmitters in the brain are much less active
77. 3:57during the REM stage of sleep,
78. 3:59even during dreams of traumatic experiences,
79. 4:02leading some researchers to theorize
80. 4:04that one purpose of dreaming is to take the edge off painful experiences
81. 4:08to allow for psychological healing.
82. 4:10Reviewing traumatic events in your dreams with less mental stress
83. 4:14may grant you a clearer perspective
84. 4:16and enhanced ability to process them in psychologically healthy ways.
85. 4:20People with certain mood disorders and PTSD often have difficulty sleeping,
86. 4:25leading some scientists to believe that lack of dreaming
87. 4:28may be a contributing factor to their illnesses.
88. 4:32We dream to solve problems.
89. 4:37Unconstrained by reality and the rules of conventional logic,
90. 4:40in your dreams, your mind can create limitless scenarios
91. 4:43to help you grasp problems
92. 4:45and formulate solutions that you may not consider while awake.
93. 4:49John Steinbeck called it the committee of sleep,
94. 4:51and research has demonstrated
95. 4:53the effectiveness of dreaming on problem solving.
96. 4:56It's also how renowned chemist August Kekule
97. 4:58discovered the structure of the benzene molecule,
98. 5:01and it's the reason that sometimes the best solution for a problem
99. 5:05is to sleep on it.
100. 5:06And those are just a few of the more prominent theories.
101. 5:10As technology increases our capability for understanding the brain,
102. 5:13it's possible that one day
103. 5:15we will discover the definitive reason for them.
104. 5:18But until that time arrives, we'll just have to keep on dreaming.