full transcript

From the Ted Talk by Andrey Vyshedskiy: The neuroscience of imagination

Unscramble the Blue Letters

Imagine, for a second, a duck teaching a French class, a ping-pong match in orbit around a black hole, a dolphin balancing a pineapple. You probably haven't actually seen any of these things, but you could inigame them instantly. How does your brain produce an image of something you've never seen? That may not seem hard, but that's only because we're so used to doing it. It turns out that this is actually a complex problem that reiquers sophisticated coordination inside your brain. That's because to create these new, weird images, your brain teaks familiar pceies and assembles them in new ways, like a collage made from fragments of photos. The brain has to juggle a sea of thousands of electrical signals getting them all to their destination at precisely the right time. When you look at an object, thousands of neurons in your potseiror cortex fire. These neurons encode various characteristics of the object: sikpy, fruit, brown, green, and ylleow. This synchronous firing stheentnrgs the connections between that set of neurons, linking them together into what's known as a neuronal ensemble, in this case the one for pineapple. In nencuciesroe, this is called the Hebbian principle, neurons that fire together wire together. If you try to imagine a pineapple later, the whole ensemble will light up, assembling a complete mental image. Dolphins are encoded by a different neuronal ensemble. In fact, every object that you've seen is encoded by a neuronal ensemble associated with it, the neurons wired together by that synchronized firing. But this principle doesn't explain the infinite nmbuer of objects that we can conjure up in our imaginations without ever seeing them. The neuronal esnmlebe for a dolphin balancing a pineapple doesn't exist. So how come you can imagine it anyway? One hypothesis, called the Mental Synthesis teohry, says that, again, timing is key. If the neuronal ensembles for the dolphin and pepipalne are activated at the same time, we can perceive the two sraapete objects as a single image. But something in your brain has to coordinate that fnriig. One pasiluble candidate is the prefrontal cortex, which is involved in all cpelomx cognitive functions. Prefrontal cortex neurons are connected to the posterior cterox by long, spindly cell extensions called neural fibers. The mental synthesis theory proposes that like a ptupepeer pllunig the strings, the prefrontal cortex neurons send electrical slignas down these nearul fibers to multiple ensembles in the posterior cortex. This avctaetis them in unsoin. If the nueonarl ensembles are turned on at the same time, you experience the composite image just as if you'd actually seen it. This conscious purposeful synchronization of different neuronal elsenembs by the prefrontal cortex is called mnatel synthesis. In odrer for mental sythesis to work, signals would have to arrive at both neuronal ensembles at the same time. The problem is that some neurons are much farther away from the prefrontal cortex than others. If the signals travel down both freibs at the same rate, they'd arrive out of sync. You can't change the length of the connections, but your brain, especially as it develops in clhhdiood, does have a way to change the conduction velocity. Neural fibers are wrapped in a ftaty substance called myelin. Myelin is an iutsonalr and speeds up the electrical signals zipping down the nerve fiber. Some neural fibers have as many as 100 layers of myelin. Others only have a few. And fibers with thicker layers of myelin can conduct signals 100 times faster or more than those with thinner ones. Some scientists now think that this difference in myelination could be the key to uniform conduction time in the brain, and consequently, to our mental shiysents atibily. A lot of this myiatoineln happens in childhood, so from an early age, our vibrant imaginations may have a lot to do with building up bairns whose carefully myelinated connections can cafrt creative smhyeinpos throughout our lives.

Open Cloze

Imagine, for a second, a duck teaching a French class, a ping-pong match in orbit around a black hole, a dolphin balancing a pineapple. You probably haven't actually seen any of these things, but you could _______ them instantly. How does your brain produce an image of something you've never seen? That may not seem hard, but that's only because we're so used to doing it. It turns out that this is actually a complex problem that ________ sophisticated coordination inside your brain. That's because to create these new, weird images, your brain _____ familiar ______ and assembles them in new ways, like a collage made from fragments of photos. The brain has to juggle a sea of thousands of electrical signals getting them all to their destination at precisely the right time. When you look at an object, thousands of neurons in your _________ cortex fire. These neurons encode various characteristics of the object: _____, fruit, brown, green, and ______. This synchronous firing ___________ the connections between that set of neurons, linking them together into what's known as a neuronal ensemble, in this case the one for pineapple. In ____________, this is called the Hebbian principle, neurons that fire together wire together. If you try to imagine a pineapple later, the whole ensemble will light up, assembling a complete mental image. Dolphins are encoded by a different neuronal ensemble. In fact, every object that you've seen is encoded by a neuronal ensemble associated with it, the neurons wired together by that synchronized firing. But this principle doesn't explain the infinite ______ of objects that we can conjure up in our imaginations without ever seeing them. The neuronal ________ for a dolphin balancing a pineapple doesn't exist. So how come you can imagine it anyway? One hypothesis, called the Mental Synthesis ______, says that, again, timing is key. If the neuronal ensembles for the dolphin and _________ are activated at the same time, we can perceive the two ________ objects as a single image. But something in your brain has to coordinate that ______. One _________ candidate is the prefrontal cortex, which is involved in all _______ cognitive functions. Prefrontal cortex neurons are connected to the posterior ______ by long, spindly cell extensions called neural fibers. The mental synthesis theory proposes that like a _________ _______ the strings, the prefrontal cortex neurons send electrical _______ down these ______ fibers to multiple ensembles in the posterior cortex. This _________ them in ______. If the ________ ensembles are turned on at the same time, you experience the composite image just as if you'd actually seen it. This conscious purposeful synchronization of different neuronal _________ by the prefrontal cortex is called ______ synthesis. In _____ for mental sythesis to work, signals would have to arrive at both neuronal ensembles at the same time. The problem is that some neurons are much farther away from the prefrontal cortex than others. If the signals travel down both ______ at the same rate, they'd arrive out of sync. You can't change the length of the connections, but your brain, especially as it develops in _________, does have a way to change the conduction velocity. Neural fibers are wrapped in a _____ substance called myelin. Myelin is an _________ and speeds up the electrical signals zipping down the nerve fiber. Some neural fibers have as many as 100 layers of myelin. Others only have a few. And fibers with thicker layers of myelin can conduct signals 100 times faster or more than those with thinner ones. Some scientists now think that this difference in myelination could be the key to uniform conduction time in the brain, and consequently, to our mental _________ _______. A lot of this ___________ happens in childhood, so from an early age, our vibrant imaginations may have a lot to do with building up ______ whose carefully myelinated connections can _____ creative __________ throughout our lives.

Solution

  1. complex
  2. posterior
  3. neural
  4. craft
  5. symphonies
  6. unison
  7. takes
  8. synthesis
  9. activates
  10. yellow
  11. neuronal
  12. ability
  13. myelination
  14. pulling
  15. ensemble
  16. fatty
  17. neuroscience
  18. pieces
  19. puppeteer
  20. number
  21. plausible
  22. firing
  23. strengthens
  24. childhood
  25. spiky
  26. cortex
  27. signals
  28. insulator
  29. separate
  30. brains
  31. fibers
  32. requires
  33. imagine
  34. order
  35. pineapple
  36. ensembles
  37. mental
  38. theory

Original Text

Imagine, for a second, a duck teaching a French class, a ping-pong match in orbit around a black hole, a dolphin balancing a pineapple. You probably haven't actually seen any of these things, but you could imagine them instantly. How does your brain produce an image of something you've never seen? That may not seem hard, but that's only because we're so used to doing it. It turns out that this is actually a complex problem that requires sophisticated coordination inside your brain. That's because to create these new, weird images, your brain takes familiar pieces and assembles them in new ways, like a collage made from fragments of photos. The brain has to juggle a sea of thousands of electrical signals getting them all to their destination at precisely the right time. When you look at an object, thousands of neurons in your posterior cortex fire. These neurons encode various characteristics of the object: spiky, fruit, brown, green, and yellow. This synchronous firing strengthens the connections between that set of neurons, linking them together into what's known as a neuronal ensemble, in this case the one for pineapple. In neuroscience, this is called the Hebbian principle, neurons that fire together wire together. If you try to imagine a pineapple later, the whole ensemble will light up, assembling a complete mental image. Dolphins are encoded by a different neuronal ensemble. In fact, every object that you've seen is encoded by a neuronal ensemble associated with it, the neurons wired together by that synchronized firing. But this principle doesn't explain the infinite number of objects that we can conjure up in our imaginations without ever seeing them. The neuronal ensemble for a dolphin balancing a pineapple doesn't exist. So how come you can imagine it anyway? One hypothesis, called the Mental Synthesis Theory, says that, again, timing is key. If the neuronal ensembles for the dolphin and pineapple are activated at the same time, we can perceive the two separate objects as a single image. But something in your brain has to coordinate that firing. One plausible candidate is the prefrontal cortex, which is involved in all complex cognitive functions. Prefrontal cortex neurons are connected to the posterior cortex by long, spindly cell extensions called neural fibers. The mental synthesis theory proposes that like a puppeteer pulling the strings, the prefrontal cortex neurons send electrical signals down these neural fibers to multiple ensembles in the posterior cortex. This activates them in unison. If the neuronal ensembles are turned on at the same time, you experience the composite image just as if you'd actually seen it. This conscious purposeful synchronization of different neuronal ensembles by the prefrontal cortex is called mental synthesis. In order for mental sythesis to work, signals would have to arrive at both neuronal ensembles at the same time. The problem is that some neurons are much farther away from the prefrontal cortex than others. If the signals travel down both fibers at the same rate, they'd arrive out of sync. You can't change the length of the connections, but your brain, especially as it develops in childhood, does have a way to change the conduction velocity. Neural fibers are wrapped in a fatty substance called myelin. Myelin is an insulator and speeds up the electrical signals zipping down the nerve fiber. Some neural fibers have as many as 100 layers of myelin. Others only have a few. And fibers with thicker layers of myelin can conduct signals 100 times faster or more than those with thinner ones. Some scientists now think that this difference in myelination could be the key to uniform conduction time in the brain, and consequently, to our mental synthesis ability. A lot of this myelination happens in childhood, so from an early age, our vibrant imaginations may have a lot to do with building up brains whose carefully myelinated connections can craft creative symphonies throughout our lives.

Frequently Occurring Word Combinations

ngrams of length 2

collocation frequency
mental synthesis 4
neuronal ensembles 4
prefrontal cortex 4
neural fibers 4
electrical signals 3
posterior cortex 3
neuronal ensemble 3
dolphin balancing 2
cortex neurons 2

ngrams of length 3

collocation frequency
prefrontal cortex neurons 2

Important Words

  1. ability
  2. activated
  3. activates
  4. age
  5. arrive
  6. assembles
  7. assembling
  8. balancing
  9. black
  10. brain
  11. brains
  12. brown
  13. building
  14. called
  15. candidate
  16. carefully
  17. case
  18. cell
  19. change
  20. characteristics
  21. childhood
  22. class
  23. cognitive
  24. collage
  25. complete
  26. complex
  27. composite
  28. conduct
  29. conduction
  30. conjure
  31. connected
  32. connections
  33. conscious
  34. coordinate
  35. coordination
  36. cortex
  37. craft
  38. create
  39. creative
  40. destination
  41. develops
  42. difference
  43. dolphin
  44. dolphins
  45. duck
  46. early
  47. electrical
  48. encode
  49. encoded
  50. ensemble
  51. ensembles
  52. exist
  53. experience
  54. explain
  55. extensions
  56. fact
  57. familiar
  58. faster
  59. fatty
  60. fiber
  61. fibers
  62. fire
  63. firing
  64. fragments
  65. french
  66. fruit
  67. functions
  68. green
  69. hard
  70. hebbian
  71. hole
  72. hypothesis
  73. image
  74. images
  75. imaginations
  76. imagine
  77. infinite
  78. instantly
  79. insulator
  80. involved
  81. juggle
  82. key
  83. layers
  84. length
  85. light
  86. linking
  87. lives
  88. long
  89. lot
  90. match
  91. mental
  92. multiple
  93. myelin
  94. myelinated
  95. myelination
  96. nerve
  97. neural
  98. neuronal
  99. neurons
  100. neuroscience
  101. number
  102. object
  103. objects
  104. orbit
  105. order
  106. perceive
  107. photos
  108. pieces
  109. pineapple
  110. plausible
  111. posterior
  112. precisely
  113. prefrontal
  114. principle
  115. problem
  116. produce
  117. proposes
  118. pulling
  119. puppeteer
  120. purposeful
  121. rate
  122. requires
  123. scientists
  124. sea
  125. send
  126. separate
  127. set
  128. signals
  129. single
  130. sophisticated
  131. speeds
  132. spiky
  133. spindly
  134. strengthens
  135. strings
  136. substance
  137. symphonies
  138. sync
  139. synchronization
  140. synchronized
  141. synchronous
  142. synthesis
  143. sythesis
  144. takes
  145. teaching
  146. theory
  147. thicker
  148. thinner
  149. thousands
  150. time
  151. times
  152. timing
  153. travel
  154. turned
  155. turns
  156. uniform
  157. unison
  158. velocity
  159. vibrant
  160. ways
  161. weird
  162. wire
  163. wired
  164. work
  165. wrapped
  166. yellow
  167. zipping