Can you trust your own memories or can we be persuaded to remember things that never happened?

Elizabeth Loftus believe false memories are relatively easy to implant in many people's minds. Photo / Getty Images

Elizabeth Loftus can make you see people that never existed, remember events that never happened and vividly recall life changing experiences that never occurred.

She can persuade you of that time when you were a kid, terrified, lost in a shopping centre, or that unhappy memory of strawberry ice cream that put you off eating it ever again.

This, despite the fact you have never been lost while out shopping and love strawberry ice cream.

So convinced will you be, you'll swear - despite all evidence to the contrary - that your memory is entirely trustworthy.

She can take control of your brain. But she is not a conjurer, a hypnotist or a con artist. She is a university professor.

"I have spent 15 years distorting peoples' memories," Associate Professor Loftus tells news.com.au. "Either I, or other scientists, have implanted false memories of being attacked by animals, demonically possessed or even crimes committed so serious the police came."

Prof Loftus, a psychological scientist at the University of California Irvine, will give a talk at the University of Sydney on Tuesday on the fallibility of memory and how easily what we recall can be manipulated.

"I don't study what people forget. I study the opposite: when they remember things that didn't happen or were different from the way they really were. I study false memory," she said at a TED talk in 2013.

She will pose the question, could tinkering with our minds have positive outcomes or is it an "abuse of memory".

Her curiosity in memory came about due to the case of Seattle restaurant manager Steve Titus who was wrongly convicted of rape in 1980.

The 31-year-old had been out for dinner with his fiance when the police pulled him over. A woman had recently been raped and Mr Titus' car resembled the one described by the victim as having been driven by the perpetrator.

The police took a photo of Mr Titus and in a subsequent line up the victim said he was the most similar to the attacker. But by the time it came to trial the victim was convinced he was, without a shadow of the doubt, the man who raped her.

Mr Titus was jailed. However, the real attacker was later found and, anyhow, it was established it would have been physically impossible for Mr Titus to have committed the crime.

"How did that victim go from 'that's the closest' to 'I'm absolutely positive that's the guy," Prof Loftus said

To find out, she devised a series of experiments to see how easily peoples' recollections of events could be clouded by suggestion.

One experiment involved subjects being shown footage of a car crash. Those that were then asked to estimate how fast the cars were going before they "hit" one another invariably thought they were travelling at a lower speed than those who were asked the speed when they "smashed" into one another.

Subjects who were asked questions about the more leading "smashed" cars also had a higher incidence of describing broken glass on the road - even though there was none in the images.

In another experiment, US soldiers were put through a mock interrogation.

Later, they were fed misinformation and when asked to describe the main perpetrator at the interrogation many pinpointed a bald man. When, in fact, the lead interrogator was a quite different man with curly hair.

But perhaps Prof Loftus' most famous experiment is what has become known as the "lost in the mall" technique.

"In this technique, I have got people to believe that when they were five or six they were lost in a mall. They were frightened and crying and were rescued by an elderly person."

She would talk to a subject's mother about some true incidents in shopping centres when they were young. Discussing these with the subject, they would then introduce the entirely made-up situation.

"We suggestively interviewed them, feeding them with false information that supposedly came from a trusted relative and by the time we were done about a quarter of people would remember this experience.

The "lost in the mall" experiment showed how easy it was for people to create memories of events that never happened. Photo / Steven McNichol

"I remember a great sense of excitement when I listened to the first tape recording of an individual remembering being lost in a mall and I thought, whoa, this is amazing," she said.

"This individual was describing the person who rescued him, he had a flannel shirt and he had glasses, and we would ultimately establish that they really believed what they're reporting and yet the person didn't exist."

Prof Loftus said her interest in memory cranked up in the 1990s when people began being convicted of horrific sexual abuse based on supposedly suppressed memories that had been "recovered" during psychotherapy sessions.

Some of the recovered memories were incredibly vivid and disturbing, of women forced into pregnancy and then being ritualistically abused and having the babies cut from their belly. And yet, there was no scarring.

"Every now and then we would find somebody would remember something biologically, geographically or psychologically impossible, so I wondered how people develop these rich false memories?" she said.

Would implanting an unhappy memory about strawberry ice cream in your mind help you give up fattening foods? Photo / Babiche Martens

There were concerns some psychotherapists were using techniques that led their patients to believe in things that were more grotesque flights of fancy than reality.

Every day we are spoon fed misinformation, Prof Loftus said, that can skew our understanding of an event even those witnessed by our own eyes.

Other people and the media might tell us - inadvertently or otherwise - erroneous details that change our own recollections.

"When you feed people misinformation, you can distort their memory," she said.

Soon Prof Loftus discovered you didn't even need a trusted person to back up false claims.

"We get a whole load of information about you and your personality, and we tell you we submitted your data into a real smart computer and that determined certain things happened to you, such as you got sick on strawberry ice cream once. We implant that memory," she said.

"One of the signs they really have accepted the story is the embellishment. You can let time pass, expose them to the food, and they won't want the food so much."

Prof Loftus' research hasn't gone down well with everyone. Psychotherapists weren't impressed when she cast doubt on their methods, neither were some people who truly believed they had been abused. She also received criticism when she asked whether false memory techniques could help improve people's health.

"If I plant a false memory saying you could get sick eating fattening food, yes it's a negative memory but it could help you.

"If I can make a dent in the obesity problem by planting a few bits of misinformation into memories that are already full of misinformation, why not try to help people? That is an issue worth discussing."

Can we trust what's going on in our heads? Photo / 123RF

Prof Loftus said she will be raising some of the issues with "mind technology" at the Sydney University talk and whether it should be regulated or even banned outright? Or can it be used for good?

In the end, she asks, can anyone fully trust their own memories if there is no else around to corroborate them?

"Just because somebody tells you something and they say it with confidence, emotion and lots of detail, it doesn't mean that it really happened.

"We can't reliably distinguish true memories from false memories."