Lie Detection

For the fifth blog, I decided to write about something somewhat irrelevant to the current topics in lecture--lie detection and interrogation. I got the idea when thinking about how eye-witness testimony can be manipulated with incredible ease due to the ways that our memories function. There are several methods employed by investigators, such as electroencephalography, cognitive chronometry, fMRI, and observing nonverbal behavior. These are just four of the more common methods. No method is 100% accurate or comprehensive.

Electroencephalography measures changes in brain waves of the subject. An investigator will ask control questions to gauge a baseline for brain activity. When the subject answers a question with a lie, the machine will usually indicate a change in brainwave activity, which indicates to the investigator that the subject is lying.

Cognitive chronometry is the measurement of the time it takes to perform cognitive activities. We actually spent a fair bit of time on this in my communication theory class. We talked about how it requires much more brain power to tell a lie and that when lying, a person will often hesitate momentary. We went on to discuss how being able to construct logical and comprehensive lies on the stop is truly an art, albeit a usually undesirable one!

Another method for detecting lies is the use of an fMRI (functional magnetic resonance imaging). This method is rather new and has yet to been refined. The TV show Mythbusters actually tested an fMRI lie detection machine. Two of the testers were unsuccessful in fooling it, but one of them managed to fool the machine, indicating the need for further refinement.

A final method for lie detection is the observation of nonverbal behavior. We spent a lot of time on this in my nonverbal communication class. Some behaviors that may indicate a lie are placing objects between yourself and the investigator, trying to make yourself smaller, looking to the left, blushing, and restlessness. Sometimes it can be difficult to attribute specific behaviors to lying. For example, the subject may be experiencing anxiety from the interrogation and thus is restless in the first place.