Applying eye-fixation-related brain potentials for a concealed information test

Abstract

Abstract A concealed information test (CIT) is a memory detection technique that is commonly used in criminal investigations. Although event-related brain potentials (ERPs) have been used as a measure in CIT studies, they are not typically measured in criminal investigations due to their susceptibility to noise resulting from eye movement. The present study focused on eye-fixation-related brain potentials (EFRPs), which are a type of brain potentials that are time-locked to the onset of eye-fixations, in order to avoid contamination from eye movement, and investigated whether EFRPs could be a useful measure for CIT. Nineteen participants selected a photograph of one person out of five and created a fictional story about a crime they committed with the person in the selected photograph. The participants provided information about the selected photograph to an experimenter in a no-secret condition, but they did not disclose any information about it in a concealed condition. After the story was created a photograph of a person and a target were presented continuously on alternating sides of the monitor and participants were asked to follow them with their eyes and to press a button when their eyes fixed on the target. The amplitude of P1 elicited by the selected photograph was significantly larger than that elicited by unselected ones only in the concealed condition. The result demonstrates that spatial attention to incoming visual information was modulated by the intent to conceal and indicates that EFRPs are a useful measure in CIT.