Adventures in Memory. Hilde østby
experiences they’ve had in the water even when they are safely on shore.
Our memory networks—our fishnets of memories—benefit from context beyond just our physical surroundings. We create the strongest memory networks on our own, when we learn something truly meaningful and make an effort to understand it. Someone who is passionate about a particular subject, such as diving, will more easily learn new things about diving than about something she’s never been interested in before. This is because she already has a large memory network devoted to diving where she can store her new knowledge, and because she is motivated. It’s as if we can add another layer of netting just because the self is involved; memory is self-serving. Memories are linked to what concerns you, what you feel, what you want. Too bad, then, that so much of what we actually need to remember is so darned uninteresting!
Lately, others have tried to test context-dependent memory in other ways. Do we remember things we learn while skydiving? The researchers concluded that the stress level of skydivers was so high that it erased all effects of context. This may not be so strange—if we are so high on adrenaline that we barely notice where we are, there are no surroundings to support those memories. More practical were the researchers who wanted to examine if medical students remembered more when they were in the classroom where they had first been taught. The classroom, in this case, was either an ordinary classroom or an operating theater, where the students were dressed for surgery. Fortunately for the future patients of those medical students, it turned out in the experiment that the differences were so minimal that doctors can safely continue practicing medicine far from the context of learning.
In our experiment at Gylte, we split the divers into two groups. The divers in the first group would be tested on what they remembered on land after trying to memorize twenty-five words underwater. The others had to both learn and recall the words underwater.
The five divers in the first group come ashore, splashing as they go. They wriggle out of their masks and flippers, unhook leaden oxygen tanks and sit, legs spread apart, on the bench along the wall of the Diving Center.
Their results are miserable.
One of them remembered only words from the first test—the one for comparison—and got a zero on the underwater words. The best one remembered thirteen words from the list he saw underwater, but this too was worse than he’d done during the first test on land. The average result of the comparison test, inside the Diving Center, was 8.6 correct words. The divers remembered an average of 4.4 words when they emerged from the water.
“I sort of thought I had the words there while I was underwater, but then we got up on land, and it was as if my mind changed completely, and I lost it,” one of the divers says.
The removing of flippers, tottering up from the edge of the pier along the walk to the Diving Center, lifting the tanks from their backs, and grabbing a piece of paper may of course have disturbed their trains of thought and pushed the words out of the way. Duncan Godden and Alan Baddeley had pondered this possibility and tested whether all the trouble of getting back onto dry land could have thrown off the result. They let one group of divers learn the words on land, then dive and come up again, and compared them with a group who’d learned the words on land and waited the same amount of time, but without moving. The group that dived in the middle remembered just as much as those who had remained still in the same place. So all the hassle of changing location could not have explained why the divers who learned in the water remembered less on land.
Deep beneath the surface, the divers in the second group have taken out their flashlights and waterproof notepads that make it possible for them to write underwater. Bubbles from their breathing pop on the water’s surface; they are fifty or fifty-five feet down, and it’s hard to handle the plastic-covered sheet to write the twenty-five new words. They’ve gathered in a circle in the dark, and short flashes from the flashlights tied to their arms shine through the water every time they move their hands and write. Like the words they learned on land, these are mainly one-syllable words: short and concrete and easy to write with gloves on.
This group had remembered an average of 9.2 words when they were tested in the Diving Center. But what happened when they tried to learn twenty-five words underwater and were supposed to remember them underwater? As the bubbles grow bigger and the divers slowly rise to the surface, those of us on the pier are long since soaked through and clinging to empty and wet paper coffee cups. Even the seagulls have stayed at home today.
The divers, on the other hand, are not in a hurry. They rest for a while a few feet under the surface before they get out of the water. Around us, clumps of old snow lie between tufts of rotten grass. Our excitement has been building this whole ice-cold morning, as has our longing for hot chocolate and dry socks; the divers, however, are satisfied with their dive. They proudly hand us their notes.
When we examine the results, it occurs to us that we have managed to re-create the experiment from the 1970s almost down to the smallest detail. The divers who were supposed to learn and remember underwater have remembered on average 8.4 words in the deep, almost matching their achievement on land earlier that day. They pulled this off despite factors like increased pressure underwater, gas mixtures and masks and wet suits and the sound of breathing, clouds of bubbles swirling toward the surface, flashes from flashlights sweeping the bottom of the sea, blurry vision, uncomfortable wet gloves, and difficulties holding pens and waterproof notepads. In the famous experiment from the 1970s, it was clear that the context had an obvious effect—the divers had remembered the list of words much better in the water when they had also memorized it in the water. Actually, they remembered it equally as well as the list they memorized and recalled on land.
When the divers were in the water, they recognized where they had been before, and this memory triggered the memories of what they had learned, so that the words popped up almost by themselves, like images on a screen.
Caterina Cattaneo led the divers in our experiment. She has almost thirty years of underwater experience and has dived at a depth of two hundred feet. This was a simple dive for her. The water temperature was comfortable, she claims, as she swings herself up on the pier and wrestles herself out of her diving mask. The February rain sprinkles the fjord behind her.
“I’ve never seen seahorses here,” she tells us. “I’ve seen two on Madeira. They were tiny and very cute. They bobbed up and down, their tails wound around a sea plant. But the current was strong, and suddenly I was far away from them. I only caught a glimpse of them.”
— 3 —
THE SKYDIVER’S FINAL THOUGHTS
Or: What are personal memories?
All the flowers in our garden and in M. Swann’s park, and the water-lilies on the Vivonne and the good folk of the village and their little dwellings and the parish church and the whole of Combray and of its surroundings, taking their proper shapes and growing solid, sprang into being, town and gardens alike, from my cup of tea.
MARCEL PROUST, In Search of Lost Time
FOR MANY YEARS, our sister was an active skydiver. Every weekend she would set out for the skydiving field at Jarlsberg or travel to the United States or Poland to jump in large formations with hundreds of other skydivers.
Watching Tonje skydive was often a terrible experience for us. During the minutes we observed her falling from the sky we imagined her funeral, complete with flowers and the music we’d choose to play as the coffin was carried out. Even though there are few accidents in skydiving, the few that happen are gruesome. You don’t plummet toward the ground from fifteen thousand feet without it being dangerous. Every time she was about to land, we drew the deep sigh of relief that comes after holding your breath for too long. The cheeriness of the large, brightly colored parachute belies the grim reality of the accident it can cause if it doesn’t unfold or if a sudden gust of wind grabs hold of the lightweight material. Tonje’s parachute was reddish orange, like a sunset.
The plane drones so loudly on its way to jumping height that you have to shout to be heard. This Saturday, a day in July