Scientific Methods of Extraction of Information from Suspects: An Analysis of the Current Trends

This paper discusses critical issues related to extraction of information from the brain of a person, without his behavioral or oral outputs. Information extraction has become an important forensic/security need, and newer non invasive methods of investigation of suspects are being adopted for this purpose. Two paradigms that have been used extensively so far are that of detection of deception, and remembrance of experiences (memory of autobiographic episodes). A Third paradigm- recognition of concealed information (known only to the guilty) was considered unsuccessfully in the past. Both lie detection and recognition of concealed information paradigms usually require responses from the subjects to the stimuli presented, whereas remembrance of experiences is achieved through verbal/visual cueing, which does not need any response from the subject. Lie detection is primarily used in a forensic context, whereas the use of remembrance is only incidental in Forensics. It is important to note that none of the methods available today can indicate the contents of thoughts. A Large spectrum of personal activities or episodic details can be tested using the remembrance paradigm, which involves several neurocognitive stages linked to attention of internal processing, accessing memory, semantic processing, and recreation of sensory and motor imageries, which occur during remembrance. Changes associated with these neurocognitive processes are recorded using the electrical oscillations from the brain, they are analyzed in the frequency and time domains for eliciting a signature of remembrance, triggered by the verbal probes used for cueing the individual.