Brain Wave Scanners

The term brain wave scanners, in the context of law enforcement, particularly concerning forensic investigations, encompasses an array of research and technological developments that seek to electronically determine whether a statement is true or false.

It has been demonstrated that brain patterns are altered when a lie is being told. Moreover, using a technique called magnetic resonance imaging (MRI), the alteration can be visualized as a lie occurs (commonly referred to as "real-time"). Simply put, a lie can be seen.

The concept of a brain wave scanner is not unlike that of a polygraph. Whereas a polygraph measures fluctuations in heart rate and breathing, a scanner measures brain responses to stimuli. It could be more effective, because a person adept a telling a lie may experience little excitement in the circulatory system. However, even this individual would be required to expend extra energy on the thought necessary to tell a lie, and it is this energy that a brain wave scanner may be able to measure.

When one is asked a question to which one knows the true answer, that answer comes first to mind automatically. Even if the individual has already prepared and rehearsed a lie, it is still necessary to think past the true answer and access the lie. This extra activity is easily measured on a brain scan.

After the September 11, 2001, terrorist attacks, a number of government agencies began to take a new look at brain scanning technology as a means of security screening. In 2002, officials of the National Aeronautics and Space Administration reportedly informed airline officials that they were developing brain-monitoring technology for use in screening airline passengers. Such activity, along with an increase of interest in brain-wave scanning by the Federal Bureau of Investigation, has raised concerns among civil-libertarians, who view brain-wave scanning as a particularly objectionable invasion of privacy in the service of public security.