To forget or not to forget, that is the question

Neuroscientist Yadin Dudai, from the Weiszmann Institute in Israel, has discovered what many would consider a miracle treatment: a substance capable of erasing memories, even those formed some time ago, which in theory would already be “consolidated” in the brain. The potentially miraculous drug is called ZIP—appropriately named after the onomatopoeia used in English for something that disappears—and blocks an enzyme involved in the cellular changes that enable memory formation. Apply ZIP to a mouse's cortex, and its old memories seem to vanish instantly—like a reformatted hard drive. A thousand and one uses for ZIP immediately come to mind. Want to forget a childhood trauma? ZIP it. Forget an ex-boyfriend? The nausea associated with your pregnancy clothes? ZIP that, too.

There are obvious practical obstacles to consider, of course. First, the substance must be applied directly to the cortex, which requires, at best, drilling a hole in your head. Second, the drug's “removing” effects appear to be vast, and it is not yet known how many memories are lost beyond the one that was tested (one of the problems with using mice in laboratories is that they do not respond directly to your questions).

But the issue that really matters to me seems to be something else. I remember an extremely lucid lecture by Thomas Murray, an ethics expert who served on the US Olympic Anti-Doping Committee, on the ethics of using substances to modify performance and memory. Murray spoke of the pressure athletes face to use drugs in competition, and illustrated his views with stories from his experience with elite athletes—when he suddenly began to comment on a personal experience, the most painful possible: the loss of his 16-year-old daughter, murdered by her sociopathic boyfriend.

At the time, ZIP was a theoretical possibility. But would he use a substance like that, which could erase the painful memories associated with his daughter? No. The pain of losing her was an integral part of what remained of his daughter: her memory. To forget that pain would be a dishonor to his daughter's short life and the mark she left on her father.

Perhaps some pain should indeed be left behind—which is, in fact, the goal of so many therapies: to reframe pain. On the other hand, if we are the sum of our memories, resorting to ZIP would be like erasing part of our essence: ZIP!

Excerpted from Suzana Herculano-Houzel (2025) Neuroscience of Everyday Life, originally published in Folha de São Paulo in April 2009.