A novel Dual Probe Complex Trial Protocol for detection of concealed information

Area of Science:

• Neuroscience
• Psychology
• Forensic Science

Background:

• Concealed information testing is crucial for forensic science.
• Previous P300-based protocols have limitations in efficiency.
• The P300 event-related potential is a reliable indicator of cognitive processing.

Purpose of the Study:

• To evaluate a novel P300-based concealed information test, the Dual Probe Complex Trial Protocol.
• To assess the protocol's efficiency in detecting mock crime information.
• To determine the protocol's accuracy and discriminability between guilty and innocent subjects.

Main Methods:

• A mock crime scenario was used with three subject groups: simply guilty (SG), countermeasure-using guilty (CM), and innocent (IN).
• The Dual Probe Complex Trial Protocol, integrating two or three stimuli (probe, irrelevant, target) per trial, was administered.
• P300 amplitudes and signal detection theory measures (AUC) were analyzed.

Main Results:

• The protocol significantly differentiated guilty (SG and CM) from innocent (IN) subjects based on P300 amplitudes.
• High accuracy (94.7%) was achieved in detecting concealed information.
• The area under the curve (AUC) for discriminability averaged 0.92, indicating strong performance.
• Countermeasures in the CM group influenced irrelevant P300s.

Conclusions:

• The Dual Probe Complex Trial Protocol is an effective and efficient method for concealed information testing.
• The protocol demonstrates high accuracy and discriminability, even with countermeasures.
• This advanced protocol enhances the detection of deception in forensic contexts.