Authors: Delia Sherman
With rest, the reflex can recover.
By adding more stimulations over days, the same withdrawal reflex can be diminished and remain diminished for several days or weeks. This is a simple form of learning. If we now look at the motor neurons involved in the reflex, we come to realize that not only are their connections diminished, but their structure is changed. For example, they now have fewer transmitting synaptic buttons than before, leading to less effectiveness in their messages. If by using another experimental protocol, such as giving a shock to the tail of the snail, the reflex is facilitated, the same motor neurons will now be more excited; and if the change is long lasting, we can observe that the synaptic buttons will be more numerous.
Thus the brain is continuously removing or adding connections according to the learning that has happened.
Dunbar's experiments using this simple reflex and other model systems led him to find some molecules that could enhance synaptic transmission and therefore improve memory.
A drug was being developed to enhance memory.
The developer, a private company called Memory, Inc., had head-hunted Dunbar after reading his recent paper, “Molecular Strategies for Diminishing Consolidation of Memory looking at CAM kinase II."
Memory, Inc., had hired Dunbar for his expertise. His research in the mechanisms of memory was something to behold. With their funding, he believed that he could finally accomplish what he had set about as his life's work.
Memory
suppression.
"You can build your own team,” they said.
He thought of Heidi.
Heidi was his most difficult student. She wanted to remember, and he had wanted to forget. They were at odds with each other, but it seemed logical that if one of them could succeed in the lab, it would benefit the other.
They became collaborators.
HEIDI: How do I make sure that I can remember everything?
DUNBAR: How can I forget one specific thing?
In front of them, they had the model systems of
Aplysia
and the hippocampal structure of the vertebrate brain. They looked at how these systems learned and forgot.
Dunbar knew if he could figure out the right chemical cocktail to prevent the neurotransmitters from consolidating, he could successfully eliminate an experience from turning into a long-term memory. He did have some success, but the trouble was this: if he successfully eliminated consolidation, how could he be sure which pathways in the brain were associated with a specific memory? He might wipe out other important aspects of a person's personality.
In theory, the chemical cocktail and the molecular strategy worked. But how could you look at a brain and say what specific structure held what specific traumatic memory?
He did not mention the flaw to his superiors. He just presented the fact that it seemed possible, in theory. They were sold on the idea that memory suppression would lead to memory enhancement. They reasoned that if you could figure out how to turn it off, you could figure out how to turn it on. They continued to fund his lab.
And while Dunbar failed, Heidi had some small success.
One type of intelligence is measured by the ability to recall details. And Heidi had found a way to make everyone remember the details.
She had three different memory enhancers in Phase IV of the trials.
But every time Heidi had a success, she reminded Dunbar of the thing he was trying to forget, and he did not like that.
He began to resent her.
Worse, he did not like that she had taken the drug she created herself.
That she'd use perfume to cover up the fact she didn't bathe when she was running an experiment.
That she looked gaunt and worn down.
That she was essential to his science and that he could not function without her.
That she deserved equal partnership in their papers.
Heidi became an emotional wreck. It was not a pretty sight.
Heidi could not forget anything, no matter how big or small.
Betrayal. Jealousy. Love. Happiness. Regret. Hope. Frustration. Euphoria. Empathy. Disappointment. Disgust. Interest. Pity. These feelings and more were her constant companions.
Heidi hadn't considered the fact that remembering everything meant that she would remember every single emotion associated with every memory, as well.
Heidi began to despair. But the pharmaceutical companies were very excited. The board members, all elderly, all facing their own degrading memories, were waiting for the drug to be approved.
But before that could happen, the bioethics community had a meeting about the goings on at Memory, Inc.
"Memory suppression has many good uses,” Dunbar said in front of the bioethics committee. “Think of the soldier who is at war and sees unspeakable things. When they come back, they have posttraumatic syndrome or PTSD. If we could effectively suppress the memory that is causing the trauma, the individual could regain a more normal life."
The bioethics committee had their own opinions.
"The trouble with memory suppression or memory enhancement is the fact that the misuse of such knowledge can have devastating effects on the individual. If a person were to have certain memories suppressed, never to be retrieved, that would be akin to brainwashing. This leaves the door open for mass behavioral modification."
The drug was not approved.
Memory, Inc., folded up shop but appealed the ruling. Eventually, they would have their memory enhancement drug.
After his failure at Memory, Inc., Dunbar went back to teaching at McGill.
He was amazed by the passage of time. By how a place could have so many memories pressed over it. A simple walk down a certain street could bring to mind moments in his life at twenty-two, thirty-six, forty-five, or sixty walking down that same street. The time he found that nice table in the trash. The time he picked up a bottle to recycle. The time he got a parking ticket. The time he slipped on the ice.
And on top of those memories, Dunbar knew with certainty that every single time he walked down St. Laurent street, the memory that he wanted to forget got stronger. Even if he walked one street over, sometimes the wind would still blow the smell of the smoked meat from Shwartz's, and like anyone would tell you, smell is one of the biggest triggers of memories that there is.
Two steps.
Four steps.
Six steps.
And then the smell would be left behind him, but the memory was always there.
Why would smoked meat remind him of the moon?
It was a mystery.
Dunbar had turned sixty-eight earlier that year.
He was here to get an award. The lifetime achievement award for the IAAS (the International Association for the Advancement of Science).
Why they held the party on the moon was anybody's guess. Perhaps the association felt that the moon was more international.
3. Third Memory
It was the middle of February. The days had been bitter cold and relentlessly gray for weeks. The night before had dumped another ten inches of snow.
But that day, it was sunny.
Dunbar watched his students as they sat at their stations in the lab dissecting
Aplysia
s and running their experiments. He noticed that they never looked out the window at Mount Royal, which was shining bright with the pure untouched snow. It was the kind of day that Dunbar had loved as a child.
Dunbar made a decision.
"OK, everyone, lunchtime. Put your coats on,” he said. “We're going out."
He marched his entire lab to the mountain, buying some toboggans on the way.
Dunbar went sliding down the toboggan run successfully five times before the snow got so packed down that it exposed a root from a tree. The root made his red plastic sled crack in half, which sent Dunbar flying into the air and smashing straight into a tree.
His students laid him on the other toboggan and slid him down the mountain so that the ambulance could take him away.
He had broken his leg in three places.
Sometimes during his lecture, he reminded his students that time had passed. That day-to-day lives were lived differently.
"Imagine,” he said. “How much life was changed when these things were introduced."
The push-button phone.
The remote control.
Cellular technology.
The portable personal computer.
The Internet.
Nanotechnology.
Retinal ID chips.
Gene therapy.
Civilian space travel.
Dunbar believed in the collective memories of generations who had useless skills in their old age.
In his youth, for an undergrad experiment, he had brought in groups of people at different ages and left them with old technology and new technology.
Mostly, the old people could figure out the new technology, but the young people could not figure out how to use old technology.
It was not a part of their collective memory.
When he said this, the students did not look up from their desks. They just kept taking notes. He had meant to say these things to excite the students. To give them some pause. To make a big change in the synaptic pathways in their brains. To jog something loose.
Nothing.
They didn't even read scientific papers that were published over ten years ago. They thought old science was useless.
Dunbar turned back to his Powerpoint presentation and clicked to the next slide.
Slide 3: The Hippocampus
Patient HM
The hippocampus is the place in the brain where some types of memory begin to be formed and consolidated. Consolidation is the switching from short-term memory to long-term memory which happens when synaptic connections between neurons are made more permanent. In some diseases of the memory, the important step of passing from short-term to long-term is impaired. There is an inability to form any new long-term change of synaptic connections.
Dunbar told his students about the case of the famous patient HM.
His hippocampus had been removed to cure the recurrence of large seizures. The seizures stopped, but the brain operation resulted in a total collapse of the ability to store new information. Patient HM experienced every day, every moment as a completely new one. Patient HM could remember things that occurred in long-term memory, his childhood, how to read, how to make conversation, how to drive, but HM could not store any new information in the brain. The endless loop of meeting people for the first time happened every single day, even with the doctors who had cared for him for decades.
Dunbar wondered if it would be better to be senile in order to forget. He wondered if it would be better to be like his mother. Or patient HM? Or Heidi?
Heidi had remembered Dunbar's lecture on patient HM and did something terrible to herself. She reasoned that if she damaged her hippocampal structure she could block the storing of new information and stop accumulating new details of her life. She flew down to a hospital and had her hippocampus severed.
Dunbar went every Wednesday to lunch with her at the hospital.
DUNBAR: Heidi. How are you today?
HEIDI: Dunbar! It's so nice to see you.
DUNBAR: Heidi. How are you today?
HEIDI: Dunbar! It's so nice to see you.
DUNBAR: Heidi. How are you today?
HEIDI: Dunbar! It's so nice to see you.
After a few years, he stopped.
Heidi did not notice.
He had been a young man the first time he had come to the moon, and here he was again.
"Are you ready, sir?” asked the young man who had been assigned as his handler.
"One minute,” Dunbar said.
He needed to look out the window for a little bit longer. He was now dressed, except for his shoes. He could not bear to put them on. They were a little too tight, because of the difference in gravity.
He was being rewarded for all of the work he had done on memory techniques. And here he was, standing in the one place he wanted to forget.
4. Fourth Memory
Dunbar and Gertie had come to the moon for a romantic weekend. It was expensive and decadent, but they felt that they were more the type of couple that would go to the moon than to a tropical island. So when the prices came down low enough for civilian space travel to be affordable, they jumped at the chance to go.
"We are going to the moon!” they said.
They kissed the whole space flight up. They marveled at the architecture of the space station. They enjoyed the free shampoos in the bathroom of the hotel.
"Newlyweds?” the bellhop had asked.
Gertie blushed. Dunbar had wanted to ask her, but he was slow and shy.
Once in the room, they made love with the window shade open so that they could see the earth rise. There were three hurricanes on the Atlantic.