Dollhouse

Memory erasure might seem like pure sci-fi, but it’s actually on the cutting edge of science. PM’s Digital Hollywood speaks with three memory experts to separate what’s fact from what’s fiction on Fox’s new show, Dollhouse, premiering tonight at 9 pm.

Imagine a clandestine organization whose members can complete any assignment, whether it requires a deadly assassin or an adept hostage negotiator. Imagine that afterwards, the members of the organization will have no memory of what they’ve done, who they’ve done it with, or even who they were before joined the secret club.

Welcome to the Dollhouse, where Actives—people who have had their personalities wholly erased and are, essentially, human embodiments of tabula rasa—are implanted with memories and personalities that allow them to become anything a client desires. After the assignment is complete, technicians use high-tech equipment t o erase all memory of the event, leaving the Active a blank slate until the next assignment.

Dollhouse creator Joss Whedon, whose credits also include cult television hits Buffy the Vampire Slayer and Firefly, told PM’s Digital Hollywood that he did, in fact, consider science as he was writing the show, though he readily admits "not as much, probably, as I should have." He drew mostly from research he did for Afterlife, a film he wrote a few years ago, "where I had to study a lot of memory-replacement brain stuff." But when it came to Dollhouse, ideas came first, then the science. "We did it in a slightly haphazard fashion," Whedon says, "if we wanted to back something up or make something sound good."

Memory erasure is far from science fiction; in fact, it’s the subject of ongoing research. "Experiments are being done to erase memory as part of the general effort to understand the molecular basis of memory," confirms Brandeis University professor Dr. John Lisman. Understanding how memories are stored will help scientists understand memory disorders like Alzheimer’s disease.

Lisman and his colleagues have experimented with memory erasure at the cellular level with a molecule called CaMKII. "It is thought that neurons store memories at synapses by a process called long-term potentiation (LTP)," he explains. "We can induce LTP in the brain slice. The experiment we have done is see if we can erase LTP by attacking CaMKII." The team was able to erase LTP with an inhibitor of CaMKII.

Dr. Todd Sacktor at State University of New York–Brooklyn has gone one step further. He has hypothesized that some synapses in the brain contain a special enzyme called protein kinase M zeta (PKM zeta), which allows them to store long-term memories. It works, essentially, like a computer’s hard disk. "The patterns of the 0s and 1s store the memory," says Sacktor. "If a synapse has PKMZ it’s twice as strong as one that does not. And it’s the pattern of whether this enzyme is in the synapses that stores long term memories." Enzymes can be inhibited with drugs injected into particular areas of the brain, Sacktor says. In his experiments, Sacktor taught rats how to run a maze, then used drugs to inhibit the enzyme in their brains—thereby erasing their memories of the maze (a related lab will soon test the enzymes on nonhuman primates). Within a few minutes of the drug wearing off, the rats were able to store new memories on the synapses, so no damage was done to the brain.

Humans have this same enzyme, Sacktor says, so theoretically, the memory-erasure part of Dollhouse is possible, though, unlike the show, no fancy-looking equipment is needed to do it. But using the drugs doesn’t selectively erase memories; it will erase all memories from the area of the brain where it is injected—injecting into the hippocampus, for example, will remove all episodic memories about a person’s life, but leave them with a general knowledge about the world. If taken orally, however, the drugs will erase all memories, leaving the subject like a baby, unable to speak or walk. "I think it’s quite possible that you would simply have to re-teach somebody everything," says Sacktor. "You might as well just be a [normal] spy. Why erase someone’s memory and replant it if it’s going to take years to restore all the basic knowledge?"

Joe Z. Tsien at the Medical College of Georgia School of Medicine, however, has selectively—and safely—removed memories from the brains of mice. Over-expressing a protein critical to brain-cell communication while a memory was being recalled led to the elimination of that memory. If the treatment could be translated to human memory, it could help sufferers of phobia or post-traumatic stress disorder. But, Tsien says, the same approach can’t be used in humans. "The memory mechanism could be more complicated in humans, obviously, so you may not be able to translate what you learned from mice to humans directly," he says.

Clearly, memory erasure has scientific basis, even if it’s not possible in humans yet. But what about implanting memories? What’s shown on Dollhouse—personalities and memories stored on hard drives and downloaded into Actives’ heads—is complete science fiction. "Implanting and taking people’s memories out and putting them in some other media, forget that," Sacktor says. "That’s nuts." Still, memory implantation isn’t completely unheard of. "In a very kind of weak way, people have already done that," he says. "Psychologists have found that you can implant false memories into people. But you don’t have to erase a memory ahead of time." Because memories are constantly rewritten as they are recalled, Sacktor explains, an experimenter can introduce incorrect knowledge, which gets incorporated into canon memory.

The verdict, according to our scientists, is that while Dollhouse is pretty far out there, the show gets at least a little of the science right—even if what’s being shown isn’t morally sound. "Some of it is possible," Sacktor says. "But all of it is unethical."