A Halifax student has used lies and deception to earn herself a spot in a high-profile thesis competition in Montreal. 

But Nicole Adams-Quackenbush won't be telling any fibs. She's earning her master's of applied science at Saint Mary's University by studying techniques for detecting lies.

Many of us think we can spot a liar, but the truth is we're mostly lying to ourselves. 

Police officers, for example, often feel they instinctively know when they're being lied to. But like most of us, sometimes they're right, and sometimes they're wrong. 

Nicole Adams-Quackenbush will lay out her thesis in three minutes this week.

Nicole Adams-Quackenbush will lay out her thesis in three minutes this week. (Submitted )

In fact, Adams-Quackenbush says laboratory studies reveal that police officers are generally no better than 50 per cent accurate when asked to determine truth from lies. 

That's a problem. It can lead to people telling the police the truth, and getting grilled for a long, intense interrogation to extract the "truth."

Even worse, it can lead to false confessions. On the other side, those who successfully lie avoid closer scrutiny. 

No sweat? They may still be lying

Adams-Quackenbush says most lie detecting techniques are rooted in an outdated belief that liars are nervous, feel shame or guilt. 

But she says deception is not an emotion, and not all liars show signs of anxiety. Her research instead looks at how busying the brain can be used as a technique to detect lies.

She's following historic footsteps. A Nova Scotian man named John Augustus Larson earned a reputation as a police officer who excelled at hunting liars. Born in 1892, he moved to the U.S. and invented the polygraph lie detector.

Adams-Quackenbush says lying, especially by falsification, takes a lot of mental energy. If you make the person work their memory, that should make it harder to lie. "In fact, the lie may even break down if the amount of cognitive load is great enough," she says. 

That technique was first investigated by Dr. Aldert Vrij at Portsmouth University in the United Kingdom.

Adams-Quackenbush says her own research is purely experimental at this point. Down the road, her findings may lead to improved questioning and interrogation techniques for law enforcement officers. 

She hopes that eventually her research will create new techniques police can use as a reliable tool to accurately detect deception through behavioural cues.

"Right now there are some police agencies in Canada that actually use certain kinds of cognitive load-inducing tasks in interrogations with good anecdotal results, but there's no scientific support," she said.

"If somebody were to contest it in court or use it as a grounds of appeal, it would be nice to have some support to say this has been tested in the lab, we know it works, and it's humane and it's ethical and it's good."

Three-minute thesis

Adams-Quackenbush will present her research at the Three Minute Thesis eastern region finals Thursday at Concordia University. 

She'll be up against seven competitors, including two other students from Nova Scotia: Dayna Bell of Mount Saint Vincent University and Justine McMillan of Dalhousie University.

Three Minute Thesis is an international competition where grad students are challenged to present their research in easy-to-understand terms. 

Presenters have only three minutes, one slide and no props.