Auditory Cognitive Impairment Reflects Source Localization of the P300 ERP Component in MBI Patients: The sLORETA Investigation.

Abstract

Objectives: This study aimed to investigate the differences between the source localization of the P300 event-related potential (ERP) component among the healthy and mild brain injury (MBI) patient population using standardized low-resolution electromagnetic tomography (sLORETA).

Methods: Thirty-eight participants were divided into control (n = 19) and MBI (n = 19) groups. Control participants were normal, healthy people, and participants with MBI were assigned into two groups: MBI 1st Test (7 days after a road traffic accident (RTA)) and MBI 2nd Test (2-6 months after RTA with the same participants of the 1st Test group). The 128-ERP nets were used on the heads of the participants during the experiments. Under the auditory oddball paradigm, all participants silently counted the target tones, while ignoring the standard tones. This study used the sLORETA tool in the Net Station software for the source localization of the P300 ERP component. The Mann-Whitney U test was used to compare intensities between groups, while the Wilcoxon Signed-Rank test was applied for paired observations within groups.

Results: Standard stimuli evoked P300 sources in the superior frontal gyrus (BA11) of the right frontal lobe in the control group, the superior temporal gyrus (BA38) of the right temporal lobe in the MBI 1st Test group, and the inferior frontal gyrus (BA47) of the left frontal lobe in the MBI 2nd Test group. Meanwhile, target stimuli evoked P300 sources at BA11 for all groups but in different gyrus: the superior frontal gyrus, orbital gyrus, and rectal gyrus in the control, MBI 1st Test, and MBI 2nd Test groups, respectively. In addition, there were significant differences in dipole intensities between and within groups among control and MBI patients in both standard and target stimuli.

Conclusion: P300 source localization was shifted presumably due to the auditory cognitive impairment, and the dipole intensities were significantly higher in the MBI group than in the control group, indicating that the MBI group compensated for both standard and target tone stimuli, reflected in the sLORETA investigation.