Photo credited to:

Scientists are now able to observe neural activity using powerful magnets that can detect blood flow changes in the brain. This is a non-invasive BCI technology called Functional Magnetic Resonance Imaging (fMRI). Unlike the polygraph, which measures fluctuations in pulse and temperature to detect a person’s response to lying, fMRI tries to discern a person’s decision to lie. But, the one of the main differences between the two technologies lies within the person’s participation in answering questions. For a polygraph to work properly, the person receiving the test must be willing to answer the questions, but with fMRI, information can be extracted with or without the person providing an answer. For instance, an interrogator can show a picture of a murder weapon to a suspect and fMRI can detect “guilty knowledge” which would mean the suspect recognizes the weapon.

Torture and Gathering Information 


Photo credited to:

The fMRI technology has the potential to reduce or eliminate violent torture. Polygraph tests do not work in detainee situations because a polygraph requires consent. A fMRI scan could help identify information without the person being interrogated verbally answering questions. Is this eliminating torture, or just a new form of torture?

Court Cases

With regards to court rulings, polygraph tests are admissible in some states, and inadmissible in others. But, in most instances the accuracy of the tests are suspect and therefore not emphasized in the case. What would happen if fMRI became an accurate and accepted means of lie detection? How could this affect court rulings? Currently, both sides of a court case must consent to a polygraph test, but if accuracy is increased with fMRI could they become a requirement within law enforcement agencies? As of right now, fMRI results are inadmissible in court due to lack of real world individual cases where they accurately detected deception.

Questions to Ask Yourself Regarding fMRI Lie Detection

What are the differences between this technology and the polygraph?

Are these developments in lie detection a good or bad thing? Can you think of examples where it could be good and where it could be bad?

How accurate will these tests become?

Will the results of these tests ever be admissible in a court of law?

Is lie detection a form of torture?

Links to Additional Information

“fMRI 4 Newbies”

Functional Magnetic Resonance Imaging

Great expectations: What can fMRI research tell us about psychological phenomena?