full transcript

From the Ted Talk by Sam Kean: What happens when you remove the hippocampus?

Unscramble the Blue Letters

On September 1st, 1953, William Scoville used a hand crank and a cheap drill saw to bore into a young man's skull, cutting away vital pieces of his brain and sucking them out through a metal tube. But this wasn't a scene from a horror film or a gruesome police report. Dr. svioclle was one of the most renowned neurosurgeons of his time, and the young man was Henry Molaison, the famous patient known as "H.M.", whose case provided amazing insights into how our brains work. As a boy, Henry had cerkcad his skull in an acdinect and soon began having seizures, blcinkag out and losing control of bodily fncoutnis. After enduring years of frequent episodes, and even dropping out of high school, the desperate young man had turned to Dr. Scoville, a dravedeil known for risky srugeeris. Partial lobotomies had been used for decades to treat mental patients based on the noiton that menatl functions were strictly localized to corresponding brain areas. Having successfully used them to reduce seizures in psychotics, Scoville decided to romeve H.M.'s hippocampus, a part of the limbic system that was associated with emotion but whose function was unknown. At first glance, the operation had scueedecd. H.M.'s seizures virtually disappeared, with no change in pitselnaory, and his IQ even iompevrd. But there was one problem: His memory was shot. Besides losing most of his memories from the previous decdae, H.M. was unable to form new ones, forgetting what day it was, reeaiptng comments, and even eating multiple meals in a row. When Scoville informed another eprext, Wilder Penfield, of the results, he sent a Ph.D student nmaed Brenda minler to study H.M. at his parents' home, where he now spent his days doing odd chores, and watching classic movies for the first time, over and over. What she discovered through a series of tests and iwvtinrees didn't just contribute greatly to the study of memory. It redefined what memory even meant. One of Milner's findings shed light on the obvious fact that although H.M. couldn't form new memories, he still retained information long enough from moment to monemt to finish a sentence or find the bathroom. When Milner gave him a random number, he managed to remember it for fifteen minutes by repeating it to himself constantly. But only five minutes later, he forgot the test had even taken place. Neuroscientists had though of memory as mnoithiolc, all of it essentially the same and stored throughout the brain. Milner's rsulets were not only the first clue for the now familiar distinction between short-term and long-term memory, but show that each uses different brain rngoies. We now know that memory fraoitmon involves several steps. After immediate sensory data is temporarily transcribed by neurons in the cortex, it tealrvs to the hpppcaomius, where spiecal proteins work to strengthen the cortical synaptic cnontoicnes. If the experience was strong enough, or we recall it pleiloiradcy in the first few days, the hippocampus then transfers the memory back to the cortex for permanent storage. H.M.'s mind could form the initial impressions, but without a hippocampus to prrefom this memory consolidation, they eerdod, like msesgeas scrawled in sand. But this was not the only memory dnciiottsin Milner found. In a now famous experiment, she asked H.M. to trace a third star in the narrow space between the outlines of two concentric ones while he could only see his paper and pencil through a mirror. Like anyone else performing such an akwward task for the first time, he did hborirly. But surprisingly, he improved over repeated trials, even though he had no memory of previous attempts. His unconscious mootr cetnres rebemremed what the conscious mind had forgotten. What Milner had discovered was that the declarative memory of names, dates and facts is different from the procedural memory of riding a bicycle or signing your name. And we now know that padocrerul memory relies more on the basal gnlagia and cerebellum, structures that were intact in H.M.'s biarn. This distinction between "knowing that" and "knowing how" has underpinned all meormy research since. H.M. died at the age of 82 after a mostly peaceful life in a nursing home. Over the years, he had been examined by more than 100 neuroscientists, making his the most studied mind in history. Upon his death, his brain was preserved and scanned before being cut into over 2000 individual slecis and ptgrohahpeod to form a digital map down to the level of individual neurons, all in a live bscaraodt watched by 400,000 people. Though H.M. spent most of his life forgetting things, he and his contributions to our uddtrasnening of memory will be remembered for generations to come.

Open Cloze

On September 1st, 1953, William Scoville used a hand crank and a cheap drill saw to bore into a young man's skull, cutting away vital pieces of his brain and sucking them out through a metal tube. But this wasn't a scene from a horror film or a gruesome police report. Dr. ________ was one of the most renowned neurosurgeons of his time, and the young man was Henry Molaison, the famous patient known as "H.M.", whose case provided amazing insights into how our brains work. As a boy, Henry had _______ his skull in an ________ and soon began having seizures, ________ out and losing control of bodily _________. After enduring years of frequent episodes, and even dropping out of high school, the desperate young man had turned to Dr. Scoville, a _________ known for risky _________. Partial lobotomies had been used for decades to treat mental patients based on the ______ that ______ functions were strictly localized to corresponding brain areas. Having successfully used them to reduce seizures in psychotics, Scoville decided to ______ H.M.'s hippocampus, a part of the limbic system that was associated with emotion but whose function was unknown. At first glance, the operation had _________. H.M.'s seizures virtually disappeared, with no change in ___________, and his IQ even ________. But there was one problem: His memory was shot. Besides losing most of his memories from the previous ______, H.M. was unable to form new ones, forgetting what day it was, _________ comments, and even eating multiple meals in a row. When Scoville informed another ______, Wilder Penfield, of the results, he sent a Ph.D student _____ Brenda ______ to study H.M. at his parents' home, where he now spent his days doing odd chores, and watching classic movies for the first time, over and over. What she discovered through a series of tests and __________ didn't just contribute greatly to the study of memory. It redefined what memory even meant. One of Milner's findings shed light on the obvious fact that although H.M. couldn't form new memories, he still retained information long enough from moment to ______ to finish a sentence or find the bathroom. When Milner gave him a random number, he managed to remember it for fifteen minutes by repeating it to himself constantly. But only five minutes later, he forgot the test had even taken place. Neuroscientists had though of memory as __________, all of it essentially the same and stored throughout the brain. Milner's _______ were not only the first clue for the now familiar distinction between short-term and long-term memory, but show that each uses different brain _______. We now know that memory _________ involves several steps. After immediate sensory data is temporarily transcribed by neurons in the cortex, it _______ to the ___________, where _______ proteins work to strengthen the cortical synaptic ___________. If the experience was strong enough, or we recall it ____________ in the first few days, the hippocampus then transfers the memory back to the cortex for permanent storage. H.M.'s mind could form the initial impressions, but without a hippocampus to _______ this memory consolidation, they ______, like ________ scrawled in sand. But this was not the only memory ___________ Milner found. In a now famous experiment, she asked H.M. to trace a third star in the narrow space between the outlines of two concentric ones while he could only see his paper and pencil through a mirror. Like anyone else performing such an _______ task for the first time, he did ________. But surprisingly, he improved over repeated trials, even though he had no memory of previous attempts. His unconscious _____ _______ __________ what the conscious mind had forgotten. What Milner had discovered was that the declarative memory of names, dates and facts is different from the procedural memory of riding a bicycle or signing your name. And we now know that __________ memory relies more on the basal _______ and cerebellum, structures that were intact in H.M.'s _____. This distinction between "knowing that" and "knowing how" has underpinned all ______ research since. H.M. died at the age of 82 after a mostly peaceful life in a nursing home. Over the years, he had been examined by more than 100 neuroscientists, making his the most studied mind in history. Upon his death, his brain was preserved and scanned before being cut into over 2000 individual ______ and ____________ to form a digital map down to the level of individual neurons, all in a live _________ watched by 400,000 people. Though H.M. spent most of his life forgetting things, he and his contributions to our _____________ of memory will be remembered for generations to come.

Solution

  1. motor
  2. personality
  3. procedural
  4. eroded
  5. photographed
  6. results
  7. special
  8. blacking
  9. centers
  10. scoville
  11. succeeded
  12. memory
  13. repeating
  14. formation
  15. improved
  16. decade
  17. hippocampus
  18. remembered
  19. regions
  20. surgeries
  21. messages
  22. interviews
  23. notion
  24. distinction
  25. cracked
  26. mental
  27. ganglia
  28. accident
  29. monolithic
  30. horribly
  31. named
  32. connections
  33. travels
  34. periodically
  35. understanding
  36. daredevil
  37. milner
  38. remove
  39. moment
  40. brain
  41. awkward
  42. expert
  43. perform
  44. broadcast
  45. slices
  46. functions

Original Text

On September 1st, 1953, William Scoville used a hand crank and a cheap drill saw to bore into a young man's skull, cutting away vital pieces of his brain and sucking them out through a metal tube. But this wasn't a scene from a horror film or a gruesome police report. Dr. Scoville was one of the most renowned neurosurgeons of his time, and the young man was Henry Molaison, the famous patient known as "H.M.", whose case provided amazing insights into how our brains work. As a boy, Henry had cracked his skull in an accident and soon began having seizures, blacking out and losing control of bodily functions. After enduring years of frequent episodes, and even dropping out of high school, the desperate young man had turned to Dr. Scoville, a daredevil known for risky surgeries. Partial lobotomies had been used for decades to treat mental patients based on the notion that mental functions were strictly localized to corresponding brain areas. Having successfully used them to reduce seizures in psychotics, Scoville decided to remove H.M.'s hippocampus, a part of the limbic system that was associated with emotion but whose function was unknown. At first glance, the operation had succeeded. H.M.'s seizures virtually disappeared, with no change in personality, and his IQ even improved. But there was one problem: His memory was shot. Besides losing most of his memories from the previous decade, H.M. was unable to form new ones, forgetting what day it was, repeating comments, and even eating multiple meals in a row. When Scoville informed another expert, Wilder Penfield, of the results, he sent a Ph.D student named Brenda Milner to study H.M. at his parents' home, where he now spent his days doing odd chores, and watching classic movies for the first time, over and over. What she discovered through a series of tests and interviews didn't just contribute greatly to the study of memory. It redefined what memory even meant. One of Milner's findings shed light on the obvious fact that although H.M. couldn't form new memories, he still retained information long enough from moment to moment to finish a sentence or find the bathroom. When Milner gave him a random number, he managed to remember it for fifteen minutes by repeating it to himself constantly. But only five minutes later, he forgot the test had even taken place. Neuroscientists had though of memory as monolithic, all of it essentially the same and stored throughout the brain. Milner's results were not only the first clue for the now familiar distinction between short-term and long-term memory, but show that each uses different brain regions. We now know that memory formation involves several steps. After immediate sensory data is temporarily transcribed by neurons in the cortex, it travels to the hippocampus, where special proteins work to strengthen the cortical synaptic connections. If the experience was strong enough, or we recall it periodically in the first few days, the hippocampus then transfers the memory back to the cortex for permanent storage. H.M.'s mind could form the initial impressions, but without a hippocampus to perform this memory consolidation, they eroded, like messages scrawled in sand. But this was not the only memory distinction Milner found. In a now famous experiment, she asked H.M. to trace a third star in the narrow space between the outlines of two concentric ones while he could only see his paper and pencil through a mirror. Like anyone else performing such an awkward task for the first time, he did horribly. But surprisingly, he improved over repeated trials, even though he had no memory of previous attempts. His unconscious motor centers remembered what the conscious mind had forgotten. What Milner had discovered was that the declarative memory of names, dates and facts is different from the procedural memory of riding a bicycle or signing your name. And we now know that procedural memory relies more on the basal ganglia and cerebellum, structures that were intact in H.M.'s brain. This distinction between "knowing that" and "knowing how" has underpinned all memory research since. H.M. died at the age of 82 after a mostly peaceful life in a nursing home. Over the years, he had been examined by more than 100 neuroscientists, making his the most studied mind in history. Upon his death, his brain was preserved and scanned before being cut into over 2000 individual slices and photographed to form a digital map down to the level of individual neurons, all in a live broadcast watched by 400,000 people. Though H.M. spent most of his life forgetting things, he and his contributions to our understanding of memory will be remembered for generations to come.

Frequently Occurring Word Combinations

ngrams of length 2

collocation frequency
young man 2
procedural memory 2

Important Words

  1. accident
  2. age
  3. amazing
  4. areas
  5. asked
  6. attempts
  7. awkward
  8. basal
  9. based
  10. bathroom
  11. began
  12. bicycle
  13. blacking
  14. bodily
  15. bore
  16. boy
  17. brain
  18. brains
  19. brenda
  20. broadcast
  21. case
  22. centers
  23. cerebellum
  24. change
  25. cheap
  26. chores
  27. classic
  28. clue
  29. comments
  30. concentric
  31. connections
  32. conscious
  33. consolidation
  34. constantly
  35. contribute
  36. contributions
  37. control
  38. cortex
  39. cortical
  40. cracked
  41. crank
  42. cut
  43. cutting
  44. daredevil
  45. data
  46. dates
  47. day
  48. days
  49. death
  50. decade
  51. decades
  52. decided
  53. declarative
  54. desperate
  55. died
  56. digital
  57. disappeared
  58. discovered
  59. distinction
  60. dr
  61. drill
  62. dropping
  63. eating
  64. emotion
  65. enduring
  66. episodes
  67. eroded
  68. essentially
  69. examined
  70. experience
  71. experiment
  72. expert
  73. fact
  74. facts
  75. familiar
  76. famous
  77. fifteen
  78. film
  79. find
  80. findings
  81. finish
  82. forgetting
  83. forgot
  84. forgotten
  85. form
  86. formation
  87. frequent
  88. function
  89. functions
  90. ganglia
  91. gave
  92. generations
  93. glance
  94. greatly
  95. gruesome
  96. hand
  97. henry
  98. high
  99. hippocampus
  100. history
  101. home
  102. horribly
  103. horror
  104. impressions
  105. improved
  106. individual
  107. information
  108. informed
  109. initial
  110. insights
  111. intact
  112. interviews
  113. involves
  114. iq
  115. level
  116. life
  117. light
  118. limbic
  119. live
  120. lobotomies
  121. localized
  122. long
  123. losing
  124. making
  125. man
  126. managed
  127. map
  128. meals
  129. meant
  130. memories
  131. memory
  132. mental
  133. messages
  134. metal
  135. milner
  136. mind
  137. minutes
  138. mirror
  139. molaison
  140. moment
  141. monolithic
  142. motor
  143. movies
  144. multiple
  145. named
  146. names
  147. narrow
  148. neurons
  149. neuroscientists
  150. neurosurgeons
  151. notion
  152. number
  153. nursing
  154. obvious
  155. odd
  156. operation
  157. outlines
  158. paper
  159. part
  160. partial
  161. patient
  162. patients
  163. peaceful
  164. pencil
  165. penfield
  166. people
  167. perform
  168. performing
  169. periodically
  170. permanent
  171. personality
  172. ph
  173. photographed
  174. pieces
  175. place
  176. police
  177. preserved
  178. previous
  179. procedural
  180. proteins
  181. psychotics
  182. random
  183. recall
  184. redefined
  185. reduce
  186. regions
  187. relies
  188. remember
  189. remembered
  190. remove
  191. renowned
  192. repeated
  193. repeating
  194. report
  195. research
  196. results
  197. retained
  198. riding
  199. risky
  200. row
  201. sand
  202. scanned
  203. scene
  204. school
  205. scoville
  206. scrawled
  207. seizures
  208. sensory
  209. sentence
  210. september
  211. series
  212. shed
  213. shot
  214. show
  215. signing
  216. skull
  217. slices
  218. space
  219. special
  220. spent
  221. star
  222. steps
  223. storage
  224. stored
  225. strengthen
  226. strictly
  227. strong
  228. structures
  229. student
  230. studied
  231. study
  232. succeeded
  233. successfully
  234. sucking
  235. surgeries
  236. surprisingly
  237. synaptic
  238. system
  239. task
  240. temporarily
  241. test
  242. tests
  243. time
  244. trace
  245. transcribed
  246. transfers
  247. travels
  248. treat
  249. trials
  250. tube
  251. turned
  252. unable
  253. unconscious
  254. underpinned
  255. understanding
  256. unknown
  257. virtually
  258. vital
  259. watched
  260. watching
  261. wilder
  262. william
  263. work
  264. years
  265. young