Once the realm of science fiction, advances in technology, neurochemistry, and cognitive science are redefining what memory is, enabling us to erase old memories and implant new ones.

The Nova documentary Memory Hackers, premiering tonight on PBS, recounts the scientific breakthroughs over the last 70 years that have lead to our current understanding of where and how long-term memories are formed, stored, and recalled.

Hausler in a DOT scanner at Washington University

“The purpose of memory is not to be a recording device, but a much more creative act,” says Michael Bicks, Memory Hackers‘ writer, director, and producer. “It changes the way we look at the brain.” He adds: “It’s built to be flexible and quickly rearrange and incorporate new information. So a lot of the things that we think are bad about memory, like forgetting things or false memories, are byproducts of the system. It’s not designed to be perfect, so people shouldn’t expect it to be.”

Michael Bicks Photo: Rahoul Ghose , courtesy of PBS

The hour-long film shows how the advent of imaging tools—PET scans, TMS, fMRIs—and psychopharmacology are facilitating new ways to chart memory and pave the way for radical treatments of disorders such as addiction, phobias, and PTSD. It also glimpses the future with cutting-edge research such as optogenetics, which allows researchers to map a specific memory in genetically modified rats and manipulate it with lasers.

In tackling the film, which took a year to complete, “the biggest challenge is that memory is a huge field, and you don’t want to say, ‘Here are some interesting things about memory,'” says Bicks. “You want to build a narrative.”

A participant in professor Merel Kindt‘s study at the University of Amsterdam erasing spider phobias by utilizing therapy based on reconsolidation.

To do that, Bicks focused on the researchers and subjects behind some of the field’s most provocative discoveries. One is Jake Hausler, an 11-year-old boy who has near total recall of every day of his life since age 8. Another is University of Amsterdam professor Merel Kindt, who succeeded in erasing spider phobias in patients. And, most unnerving, is a false memories study in which London South Bank University psychology professor Julia Shaw convinced subjects to remember doing things they hadn’t actually done in incidents that had never occurred.