Tahlequah Daily Press

Get the scoop!

April 7, 2014

A man with amnesia taught us how memories become personal

Kent Cochrane, the amnesiac known throughout the world of neuroscience and psychology as K.C., died last week at age 62 in his nursing home in Toronto, probably of a stroke or heart attack. Although not as celebrated as the late American amnesiac H.M., for my money K.C. taught us more important and poignant things about how memory works. He showed how we make memories personal and personally meaningful. He also had a heck of a life story.

During a wild and extended adolescence, K.C. jammed in rock bands, partied at Mardi Gras, played cards till all hours, and got into fights in bars; he was also knocked unconscious twice, once in a dune-buggy accident, once when a bale of hay conked him on the head. In October 1981, at age 30, he skidded off an exit ramp on his motorcycle. He spent a month in intensive care and lost, among other brain structures, both his hippocampuses.

As H.M.'s case demonstrated in the early 1950s, the hippocampus - you have one in each hemisphere of your brain - helps form and store new memories and retrieve old ones. Without a functioning hippocampus, names, dates and other information falls straight through the mind like a sieve. At least that's what supposed to happen. K.C. proved that that's not quite true - memories can sometimes bypass the hippocampus.

After the motorcycle accident, K.C. lost most of his past memories and could make almost no new memories. But a neuroscientist named Endel Tulving began studying K.C., and he determined that K.C. could remember certain things from his past life just fine. Oddly, though, everything K.C. remembered fell within one restricted category: It was all stuff you could look up in reference books, like the difference between stalactites and stalagmites or between spares and strikes in bowling. Tulving called these bare facts "semantic memories," memories devoid of all context and emotion.

At the same time K.C. had zero "episodic memory" - no memories of things he'd personally done or felt or seen. For instance, in 1979 K.C. surprised his family the night before his brother's wedding by getting a perm. For the rest of his life he knew his brother had gotten married and could recognize family members in the wedding album (the facts), but he didn't remember being at the wedding and had no idea how his family reacted to his curly hair (the personal experiences).

The little that K.C. did retain about his pre-accident life sounds like something he looked up in a particularly dry biography of himself. Even pivotal moments had been reduced to bullet points in an index. He knew his family had to abandon his childhood home because a train derailed and spilled toxic chemicals nearby; he knew a beloved brother died two years before his own accident. But these events had no emotional import anymore. They were just stuff that happened.

This work, along with studies of similar patients, provided strong evidence that our episodic and semantic memories rely on different brain circuits. The hippocampus helps record both types of memories initially, and it helps retain them for the medium term. The hippocampus also helps us access old personal memories in long-term storage in other parts of the brain. But to access old semantic memories, the brain seems to use the parahippocampus, an extension of the hippocampus on the brain's southernmost surface. K.C., whose parahippocampuses survived, could therefore remember to sink the eight ball last in pool (semantic knowledge), even though every last memory of playing pool with his buddies had disappeared (personal knowledge).

What's more, while a healthy hippocampus usually records new semantic, factual memories, the parahippocampus can - albeit excruciatingly slowly - absorb new facts if it has to. For instance, after years of shelving books as a volunteer at a local library, K.C.'s parahippocampus learned the Dewey decimal system, even though he had no idea why he knew it.

Scientists later realized that H.M., who also had a healthy parahippocampus, had similarly picked up a few choice facts after the 1953 surgery that destroyed his hippocampuses. H.M. loved doing crossword puzzles, and after seeing the clue a thousand times, he dimly recalled that "Salk vaccine target" equaled P-O-L-I-O. And through incessant references, H.M. retained a sliver of information about the 1969 moon landing and 1963 Kennedy assassination. Unlike all the people who, according to the cliché, knew exactly where they were when they learned those things, H.M. didn't - that's episodic memory. But he retained the basic fact.

In general, all memories are probably stored as personal memories initially: You might have first learned that Abraham Lincoln was the 16th president while on a field trip to Washington or more likely when you got that item wrong on a quiz and it got seared into your brain. After that, however, the memory gradually shifted to become semantic, and you retained only the more abstract knowledge that Abe = 16.

Still, there's one thing K.C. never lost - his sense of self, his sense of who he was deep down. He knew his own personality traits and knew where he came from. Knew his likes and dislikes and what he looked like in the mirror. Kent Cochrane always knew he was Kent Cochrane - not even severe trauma could take that away from him.

That's actually a common theme in the neuroscience of accidents. It's easy to see the victims of brain damage as reduced or diminished, and they are in some ways. But much of what they feel from moment to moment is exactly what you or I feel, and there's almost nothing short of death that can make you forget who you are. Amid all the fascinating injuries in neuroscience history, you'll come across a lot of tales of woe and heartbreak. But there's an amazing amount of resiliency in the brain, too.

 

1
Text Only
Get the scoop!
  • 3.2 quake shakes area near Enid

    A magnitude 3.2 earthquake shook the Enid area Thursday evening.

    August 1, 2014

  • Why a see-through mouse is a big deal for scientists

    A group of Caltech researchers announced in Cell Thursday their success in making an entire organism transparent. Unfortunately, this isn't any kind of "Invisible Man" scenario: The organism in question is a mouse, and the mouse in question is quite dead.

    July 31, 2014

  • Lindley, Tom.jpg Grandstands feel a little empty at NASCAR races

    Two decades after NASCAR started running at Indianapolis Motor Speedway, the crowds have thinned considerably. It's probably no reflection on the sport's massive following, which stretches from coast to coast, but it surely doesn't NASCAR's image help when the cameras pan across all of those empty seats.

    July 31, 2014 1 Photo

  • The virtues of lying

    Two computational scientists set out recently to simulate the effects of lying in a virtual human population. Their results, published in the Proceedings of the Royal Society B, show that lying is essential for the growth of a cohesive social network.

    July 31, 2014

  • lockport-police.jpg Police department turns to Facebook for guidance on use of 'negro'

    What seems to be a data entry mistake by a small town police department in western New York has turned into a social media firestorm centered around the word "negro" and whether it's acceptable to use in modern society.

    July 31, 2014 3 Photos

  • Sunburn isn't the only sign of summer that can leave you itchy and blistered

    You've got a rash. You quickly rule out the usual suspects: You haven't been gardening or hiking or even picnicking, so it's probably not a plant irritant such as poison ivy or wild parsnip; likewise, it's probably not chiggers or ticks carrying Lyme disease; and you haven't been swimming in a pond, which can harbor the parasite that causes swimmer's itch.

    July 30, 2014

  • Rodden, Danny.jpg Sheriff accused of lying about relationship with prostitute

    The sheriff of Clark County, Ind., faces an eight-count federal indictment that accuses him of lying about paying a prostitute for a sex act and giving her a badge so that she could claim a discount rate at a hotel.

    July 30, 2014 1 Photo

  • Sharknado.jpg Sharknado 2 set to attack viewers tonight

    In the face of another "Sharknado" TV movie (the even-more-inane "Sharknado 2: The Second One," premiering Wednesday night on Syfy), there isn't much for a critic to say except to echo what the characters themselves so frequently scream when confronted by a great white shark spinning toward them in a funnel cloud:
    "LOOK OUT!!"

    July 30, 2014 1 Photo

  • Lindley, Tom.jpg Sideshows involving Rice and Dungy stain NFL's image

    Pro football training camps should be all about, well, football. But the talk around the NFL is about Baltimore Ravens running back Ray Rice's two-game suspension, Tony Dungy's indelicate remarks about Michael Sam and Jim Irsay's largesse. What kind of league is Roger Goodell running?

    July 30, 2014 1 Photo

  • 20140729-AMX-GIVHAN292.jpg Spanx stretches into new territory with jeans, but promised magic is elusive

    The Spanx empire of stomach-flattening, thigh-slimming, jiggle-reducing foundation garments has expanded to include what the brand promises is the mother of all body-shaping miracles: Spanx jeans.

    July 30, 2014 1 Photo

  • linda-ronstadt.jpg Obama had crush on First Lady of Rock

    Linda Ronstadt remained composed as she walked up to claim her National Medal of Arts at a White House ceremony Monday afternoon.

    July 30, 2014 1 Photo

  • Medical marijuana opponents' most powerful argument is at odds with a mountain of research

    Opponents of marijuana legalization are rapidly losing the battle for hearts and minds. Simply put, the public understands that however you measure the consequences of marijuana use, the drug is significantly less harmful to users and society than tobacco or alcohol.

    July 30, 2014

  • Can black women have it all?

    In a powerful new essay for the National Journal, my friend Michel Martin makes a compelling case for why we need to continue the having-it-all conversation.

    July 30, 2014

  • 20140727-AMX-GUNS271.jpg Beretta, other gun makers heading to friendlier states

    In moving south and taking 160 jobs with it, Beretta joins several other prominent gunmakers abandoning liberal states that passed tough gun laws after the Newtown shooting.

    July 28, 2014 1 Photo

  • Fast food comes to standstill in China

    The shortage of meat is the result of China's latest food scandal, in which a Shanghai supplier allegedly tackled the problem of expired meat by putting it in new packaging and shipping it to fast-food restaurants around the country

    July 28, 2014

Poll

Do you think "blue laws" related to Sunday alcohol sales in Oklahoma should be relaxed? Choose the option that most closely reflects your opinion.

Alcoholic drinks should be sold Sundays in restaurants and bars, and liquor stores should be open.
Alcoholic drinks should be sold Sundays in restaurants and bars only; liquor stores should stay closed.
Liquor stores should be open Sundays, but drinks should not be served anywhere on Sundays.
The law should remain as it is now; liquor stores should be closed, and drinks should be served on Sundays according to county option.
No alcohol should be sold or served publicly on Sundays.
Undecided.
     View Results
Tahlequah Daily Press Twitter
Follow us on twitter
AP Video
Renewed Violence Taking Toll on Gaza Residents 2 Americans Detained in North Korea Seek Help US Employers Add 209K Jobs, Rate 6.2 Pct House GOP Optimistic About New Border Bill Gaza Truce Unravels; Israel, Hamas Trade Blame Raw: Tunisia Closes Borders With Libya Four Rescued From Crashed Plane Couple Channel Grief Into Soldiers' Retreat WWI Aviation Still Alive at Aerodrome in NY Raw: Rescuers at Taiwan Explosion Scene Raw: Woman Who Faced Death Over Faith in N.H. Clinton Before 9-11: Could Have Killed Bin Laden Netanyahu Vows to Destroy Hamas Tunnels Obama Slams Republicans Over Lawsuit House Leaders Trade Blame for Inaction
Stocks