The Characteristics Of Executive Function And Brain Mechanism Among Poly-victimized Vocational College Students

BackgroundChildhood victimization as a common public health problem, now gradually attracts the focus of researchers due to its negative clinical outcomes. Recent researches have mostly focused on prevalence or influencing factors of single type victimization. Neuropsychological and neuroimaging findings of single type victimization were also emerging while researches concerning multiple victimization were relatively few. As individuals who were exposed to one form of victimization during childhood were at an increasing risk for experiencing additional forms of victimization, it was of practical significance to extend our study to multiple victimization. Victimization experience may damage one’s executive function (EF). The present study examined the differences of EF among poly-victims with or without posttraumatic stress symptom, non poly-victims and controls using ecological and neuropsychological assessment tools, and investigated the characteristics of regional homogeneity, functional connectivity in resting state, and response inhibition brain activations map by GO STOP paradigm by using functional magnetic resonance imaging (fMRI).Part IEcological and Neuropsychological Characteristics of Excutive Function among Poly-victimized Vocational College StudentsObjectiveTo explore the characteristics of executive function among poly-victims in a vocational college. MethodsTwo hundred and ninety-nine subjects were selected from those who participated the survey of poly-victimation in a vocational college and grouped by two questionnaires (Juvenile Victimization Questionnaire and Posttraumatic Stress Disorder Checklist). Finally, two hundred and seventy students participated in the present study. All of them completed General Information Questionnare, Behavior Rating Inventory of Executive Function-Adult version (BRIEF-A) and Raven Standard Progressive Matrices Test (RSPM). Final sample had259valid data after excluding those who got higher score than the cut-off score of validity subscale of BRIEF-A. There were53subjects in poly-victimized with posttraumatic stress symptoms group (PV with PTSS, Group A),64in poly-victimized without posttraumatic stress symptoms group (PV without PTSS, Group B),68in non poly-victimized group (Group C) and44in control group (Group D).164subjects from the total sample participated executive function related tests selected from Cambridge Neuropsychological Test Automated Battery (CANTAB) voluntarily. There were32in poly-victimized with posttraumatic stress symptoms (PV with PTSS, Group A’),49in poly-victimized without posttraumatic stress symptoms (PV without PTSS, Group B’),41in non poly-victimized group (Group C’) and42in control group (Group D’).Results1. There were significant differences among four groups on the eight subscales of BRIEF-A (P<0.01). Post hoc test (Scheffe test) showed that compared with control group, PV with PTSS group obtained higher scores on seven subscales of executive function and PV without PTSS group got higher scores on five subscales. Compared with non poly-victimized group, PV with PTSS group obtained higher scores on five subscales of executive function and PV without PTSS group got higher scores on one subscale (P<0.05). There was no difference between PV with PTSS and PV without PTSS, and also there was no difference between control group and non poly-victimized group (P<0.05) on BRIEF-A.2. Neuropsychological tests results showed that there were significant differences among four groups on go trial mean reaction time, stop signal delay and proportion of successful stops of Stop Signal Test (SST), and mean initial thinking time of the Stockings of Cambridge (SOC)(P<0.05). There were no differences among four groups in the other indexes of the above two tests and also no differences on indexes of Intra-Extra Dimensional Set Shift Test (IED), Spatial Span Test (SSP) and Spatial Working Memory Test (SWM).Conclusions1. Poly-victimized students had a higher score on ecological executive function scale, and those who were more highly victimized had poorer executive function. Posttraumatic stress symptoms may not yet have effect on executive function.2. Poly-victimized students showed poorer performance on the SST and SOC tests, which indicated that poly-victimized students may have poorer ability of response inhibition and planning.3. Ecological and neuropsychological tests all showed that PV experience was correlated to the damage of executive function. Part ⅡA Functional Magnetic Resonace Imaging Study among Poly-victimized Vocational College Girls in Resting State and Task StateObjectiveUsing fMRI, this paper explored the characteristics of brain activity of poly-victimized vocational college girls in resting state and task state.MethodsThe imaging was carried out on a3.0T Siemens Verio scanner (Siemens, Erlangen, Germany).15poly-victimized girls without PTSS,15poly-victimized girls with PTSS and15controls completed the fixed position scanning, resting-state fMRI scanning and task state fMRI scaning, in order. The three groups were matched in age, intelligence and education level.The resting-state data preprocessing and analysis were performed by Statistical Parametric Mapping (SPM8) and Resting-State fMRI Data Analysis Toolkit (REST1.6),fMRI data were analysed in two ways:regional homogeneity (ReHo) method and regional of interest correlation analysis. An independent two-sample t-test was used to examine the difference of ReHo or functional connectivity between the PV without PTSS group and control group or PV with PTSS group (P<0.005, voxel size≥10). Then we transformed MNI coordinates into Talairach coordinates in order to get the associated brain regions in Talairach Daemon (TD) software.The stimulus task, GO STOP impulsivity paradigm software was used in block design fMRI. The data preprocessing and analysis were performed by Statistical Parametric Mapping (SPM8). One sample t-test and independent two-sample t-test were performed to examine the differences between the PV without PTSS group and control group or PV with PTSS group (P<0.001, voxel size≥100for one sample t-test and P<0.001, voxel size≥10for independent two-sample t-test). Then we got the associated brain regions in xjView software.Results1. Compared with control group, the PV without PTSS group showed significantly decreased ReHo in the left inferior frontal gyrus, bilateral medial frontal gyrus, right postcentral gyrus, left fusiform gyrus, bilateral parahippocampus, right cingulate gyrus, bilateral lenticular nucleus and right insula, and increased ReHo in the bilateral superior, middle and inferior frontal gyrus, bilateral inferior parietal lobe, bilateral precuneus, bilateral superior temporal gyrus, left transverse temporal gyrus, bilateral middle temporal gyrus, right lingual gyrus and right posterior cingulate gyrus. Compared with PV with PTSS group, PV without PTSS group showed significantly decreased ReHo in the right middle and inferior frontal gyrus, left precuneus, left lingual gyrus, bilateral parahippocampus, left cingulate gyrus, left lenticular nucleus and left insula, and increased ReHo in the bilateral superior and middle frontal gyrus, left medial frontal gyrus, right postcentral gyrus, left supramarginal gyrus, bilateral inferior parietal lobe, left fusiform gyrus, and left the caudate nuclei and left insula.2. Compared with control group, the dorsal-lateral prefrontal cortex of PV without PTSS group showed significantly increased functional connectivity in right superior frontal gyrus, bilateral middle frontal gyrus, bilateral medial frontal gyrus, right precuneus and right postcingulate gyrus. Compared with PV with PTSS group, PV without PTSS group showed significantly increased functional connectivity in the left middle frontal gyrus and left cingulate gyrus, and decreased functional connectivity in the bilateral frontal gyrus, right insula and right superior temporal gyrus.3. When performing GO STOP paradigm, the control group, PV without PTSS group, PV with PTSS group all showed activity in frontal, temporal, parietal and occipital lobe, the control group showed high and centralized activity while the other two groups, especially the PV with PTSS group showed relatively smaller and more dispersive areas in the above active regions. Compared with control group, PV without PTSS group showed increased activity in right superior frontal gyrus, right superior parietal lobe and bilateral insula,etc. Compared with PV with PTSS group, PV without PTSS group showed decreased activity in right precuneus, bilateral cuneus, right middle occipital gyrus and right parahippocampus gyrus etc.Conclusions1. Abnormal spontaneous activity was found in the default mode network, insula, basal ganglia and parahippocampus among poly-victimized vocational college girls.2. Compared with the control group, the PV without PTSS group showed increased functional connectivity in frontal lobe,precuneus and cingulate gyrus, which may be either a kind of complementary mechanism related to cognition or just higher in base line level. Damage of cingulate gyrus was related to PTSS, and damage of cingulate gyrus caused by PV may in the stage of compensatory period.There was relationship between PTSS and the dysfuction of superior temporal gyrus, the relationship between PV and the function of superior temporal gyrus need to be verified in the future.3. When performing GO STOP paradigm, the control group, PV without PTSS group, PV with PTSS group all showed increase activity in right middle and inferior frontal cortex, and the activated areas are gradually dispersed with exposure to victimization and PTSS. Taking no account of PTSS, PFC network dysfunction existed in individuals who were poly-victimized,which would lead to executive dysfunction.