Exploring time- and frequency- dependent functional connectivity and brain networks during deception with single-trial event-related potentials.

Jun-Feng Gao,Sheng Ge,Ling-Yun Gu,Yong Yang,Pan Lin,Hui Zhou,Hong-Mei Zheng,Ni-Ni Rao,Wen-Tao Huang,Chen-Hong Li

doi:10.1038/srep37065

Abstract

To better characterize the cognitive processes and mechanisms that are associated with deception, wavelet coherence was employed to evaluate functional connectivity between different brain regions. Two groups of subjects were evaluated for this purpose: 32 participants were required to either tell the truth or to lie when facing certain stimuli, and their electroencephalogram signals on 12 electrodes were recorded. The experimental results revealed that deceptive responses elicited greater connectivity strength than truthful responses, particularly in the θ band on specific electrode pairs primarily involving connections between the prefrontal/frontal and central regions and between the prefrontal/frontal and left parietal regions. These results indicate that these brain regions play an important role in executing lying responses. Additionally, three time- and frequency-dependent functional connectivity networks were proposed to thoroughly reflect the functional coupling of brain regions that occurs during lying. Furthermore, the wavelet coherence values for the connections shown in the networks were extracted as features for support vector machine training. High classification accuracy suggested that the proposed network effectively characterized differences in functional connectivity between the two groups of subjects over a specific time-frequency area and hence could be a sensitive measurement for identifying deception.

Highlights

This study was conducted with the following aims: 1) to research lie detection (LD) from the perspective of functional connectivity in the brain and to test the feasibility of applying wavelet coherence (WC) in single trials for analyzing synchronization between different brain sites; 2) to verify the hypothesis that significant differences exist in WC values between specific brain sites for specific time-frequency areas; 3) to propose a lying-associated functional connectivity network (LFCN) to characterize the pattern of coupling that forms between different brain-scalp regions during lying; and 4) to use this network to propose a classification model for identifying guilty and innocent subjects
We found that event-related potential (ERP) existed from approximately 200 ms to 600 ms relative to the stimuli onset
It is worth noting that the selected lying connection for which the Δ3 value was negative was deleted from the LFCN because we focused on the selected lying connection on which there existed a significantly greater WC value in the guilty group than in the innocent group

Summary

Introduction

Most studies using fMRI-based LD methods have attempted to identify activated brain regions associated with a deceptive response[21,22,23,24]; these investigations have not performed in-depth analyses of functional connectivity across brain regions and have not answered questions regarding how activated brain regions cooperate and synchronize (e.g., they have not identified connectivity strengths). This study was conducted with the following aims: 1) to research LD from the perspective of functional connectivity in the brain and to test the feasibility of applying WC in single trials for analyzing synchronization between different brain sites; 2) to verify the hypothesis that significant differences exist in WC values between specific brain sites for specific time-frequency areas; 3) to propose a lying-associated functional connectivity network (LFCN) to characterize the pattern of coupling that forms between different brain-scalp regions during lying; and 4) to use this network to propose a classification model for identifying guilty and innocent subjects

Methods

Results

Conclusion