Study On The Cognitive Resources Consumed For Lie-Detection With A Dual-Tasking Paradigm

Lying is a normal phenomenon in our daily life. In order to prevent the occurrence of lying phenomenon, exploration into lie detection has important research significance and practical values. Lying is a kind of cognitive process with cognitive resources consumed and people are inferior at multi-tasking. Individual-cognitive intervention may cast light on lie detection in the process of task completion. In the present study, we adopted "Follow Me" dual-tasking to test the cognitive resources consumed between lying and truth-telling in employment interview. For the purpose of authenticity of the interview, we used job advertisement that was paid to recruite colledge students who could be competent for Psychological laboratory assistant. Interview questions consist of Eysenck lie questions and self-edited questions by experimenters. During the dual-tasking in the employment interview, interviewees needed to finish the "Follow Me" task that following the dot moving with the mouse to test personal hand-eye coordination and answered the questions that asked by the interviewers. Subjects were asked to try their best to track the randomly-moving dot on the computer screen with continuous adjustment of hand-movement direction. The dot was set to move at 20 steps per second,20 pixels. The experimental results are presented by the mean speed of the mouse, percent of pause time, hand-shaking frequency, the de-noised averaged dominant frequency as lie-detection indexes.First, through the pre-test to explore the strength of cognitive load in Follow Me task that influence the cognitive resources consumed between lying and truth-telling. The result of pre-test showed that there is no big difference between indexes when individual just clicked mouse. Considering that the task is too simple and lead to "ceiling effect’", we increase the cognitive load in the next experiments. Then we explored the better indexes of lie-detection by two experiments. In study 1, we explored the cognitive resources consumed between lying and truth-telling under subjects’high motivation and high cognitive load condition. We supposed that lying would consume more cognitive resources than true-telling whether subjects answered Eysenck lie questions or self-edited questions (Hypothesis 1) and people who answered self-edited questions would consume more cognitive resources than answered Eysenck lie questions (Hypothesis 2) under high motivation and high cognitive load condition. In study 2, we reserched the cognitive resources consumed between lying and truth-telling under subjects’low motivation and high cognitive load condition. The assumption is that lying would consume more cognitive resources than true-telling whether subjects answered Eysenck lie questions or self-edited questions (Hypothesis 3) under low motivation and high cognitive load condition.The results revealed that:(1) Eysenck lie questions compared with self-edited questions can better detect the difference between the lying cognitive resources consumed and the truth-telling cognitive resources consumed during the interview process;(2) In high motivation and high cognitive load condition, the mean speed of the mouse and the de-noised averaged dominant frequency are better indexes of lie-detection on self-edited questions;(3) In low motivation and high cognitive load condition, the mean speed of the mouse is the better index of lie-detection on self-edited questions;...