Can an fMRI tell if you are lying?

Can an fMRI tell if you are lying?What is an fMRI?

fMRI stands for Functional Magnetic Resonance Imaging and it’s a technique used for measuring brain activity. This brain imaging technology has many advantages as it doesn’t involve radiation, making it safe and easy to use for experimental practice.

Since its development in 1990, it has been used in neuroscience, clinical psychiatry and for presurgical planning. Nowadays, fMRI is commonly used to monitor certain therapies and diseases.

fMRI can also be used to monitor the growth of brain tumours and determine brain functioning after a stroke or Alzheimer’s diagnosis. Over the last decade, the fMRI has provided insight into memories, pain, language and emotions.

How does it work?

In simple words, fMRI can detect blood oxygenation and flow. When neuronal activity increases, there is a demand for more oxygen and the response is an increase in blood flow in the regions of increased neural activity.

Blood oxygenation can vary according to the levels of neural activity and these differences can be used to detect brain activity. This form of MRI is known as Blood Oxygenation Level Dependent  (BOLD) imaging. In other words, oxygen-rich blood and oxygen-poor blood have a different magnetic resonance.

How is it done?

An fMRI scan is usually performed just like an MRI scan, during the test you lie on a table and then you are slid headfirst into the MRI scanner. While the fMRI is scanning your brain, you will be asked to perform some tasks in order to increase oxygen blood flow.

Can an fMRI tell if you are lying?

In a recent study, people were given two playing cards and were asked to lie about the one and acknowledge the possession of the other. The subjects underwent fMRI scanning while they viewed a series of cards including the two that had been given to them earlier.

When the subjects lied, the decision-making areas of the brain “lit up” and demonstrated compelling evidence that the fMRI scan could pick up the false statements and could also show a comparison between the truth and lie.

In a very similar test, subjects were asked to pick a number between three and eight. They were then shown a series of numbers on a screen and they had to deny having picked a number (lie) and also deny picking any other numbers (tell the truth). While undergoing fMRI, activity was clearly displayed when the participant lied and when he/she said the truth.

What emotions have been recorded using fMRI?

Several successful experiments have been conducted using fMRI with the goal of displaying different emotions.  In one of the very first studies conducted, ten method actors were asked to experience multiple emotions such as anger, envy, fear, happiness, pride, sadness and shame through script-driven imagery.

The results were incredible: the fMRI scan displayed all emotions at 84% accuracy when testing with the same subject and 70% accuracy when testing was performed on independent subjects.

In another study, participants were asked to view certain images which would stimulate multiple emotions, have a look below:

Recently, virtual reality has also been used to provide new insights into brain activity during emotional complex states:

We do not currently offer fMRI scanning, but open MRI scanning can provide detailed images of the brain and nerve tissues. An open MRI scan of the brain can diagnose many diseases that affect the brain. If you are interested in learning more please contact us today.