Can we edit memories?

Memory is such an everyday thing
that we almost take it for granted.

We all remember what we had
for breakfast this morning,

or what we did last weekend.

It's only when memory starts to fail

that we appreciate just how amazing it is,

and how much we allow
our past experiences to define us.

But memory is not always a good thing.

As the American poet and clergyman
John Lancaster Spalding once said,

"As memory may be a paradise
from which we cannot be driven,

it may also be a hell
from which we cannot escape."

Many of us experience
chapters of our lives

that we would prefer
to never have happened.

It is estimated that
nearly 90 percent of us

will experience some sort of
traumatic event during our lifetimes.

Many of us will suffer acutely
following these events, and then recover,

maybe even become better people
because of those experiences.

But some events are so extreme

that many, up to half of those
who survive sexual violence, for example,

will go on to develop
post-traumatic stress disorder,

or PTSD.

PTSD is a debilitating
mental health condition

characterized by symptoms
such as intense fear and anxiety

and flashbacks of the traumatic event.

These symptoms have a huge impact
on a person's quality of life

and are often triggered
by particular situations

or cues in that person's environment.

The responses to those cues may have been
adaptive when they were first learned --

fear and diving for cover
in a war zone, for example --

but in PTSD,

they continue to control behavior
when it's no longer appropriate.

If a combat veteran returns home
and is diving for cover

when he or she hears a car backfiring,
or can't leave their own home

because of intense anxiety,
then the response to those cues,

those memories,

have become what we
would refer to as maladaptive.