Reduced functional connectivity when processing threatening faces in childhood trauma people

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Abstract Submission 

Xia Liu¹, Huiyuan Huang², Liwei Tan¹, Yidan Qiu¹, Yihe Zhang¹, Yanxuan Du¹, Ruiwang Huang¹

¹School of Psychology, Key Laboratory of Brain, South China Normal University, Guangzhou, Guangdong, ²School of Public Health and Management, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong

Xia Liu  
School of Psychology, Key Laboratory of Brain, South China Normal University
Guangzhou, Guangdong

Huiyuan Huang  
School of Public Health and Management, Guangzhou University of Chinese Medicine
Guangzhou, Guangdong

Liwei Tan  
School of Psychology, Key Laboratory of Brain, South China Normal University
Guangzhou, Guangdong

Yidan Qiu  
School of Psychology, Key Laboratory of Brain, South China Normal University
Guangzhou, Guangdong

Yihe Zhang  
School of Psychology, Key Laboratory of Brain, South China Normal University
Guangzhou, Guangdong

Yanxuan Du  
School of Psychology, Key Laboratory of Brain, South China Normal University
Guangzhou, Guangdong

Ruiwang Huang  
School of Psychology, Key Laboratory of Brain, South China Normal University
Guangzhou, Guangdong

Childhood trauma, consisting of abuse (physical, emotional, and sexual abuse) and neglect (physical and emotional neglect), can affect an individual's brain structure and a general pattern of emotional response^[1,2]. Previous studies indicated that the hippocampus (HP) is one of the most obvious brain regions that were affected by childhood traumatic experiences^[3,4]. However, it remains unclear whether the functional network of HP is affected by childhood traumatic experiences when encountering threats. Thus, we recruited subjects with or without childhood trauma, presented them with threatening faces during fMRI scanning, and used a generalized psychophysiological interaction (gPPI) to analyze differences in the functional connectivity patterns of the HP between the two groups.

Subjects
We enrolled 45 adult subjects and measured their degrees of childhood trauma by using the Childhood Trauma Questionnaire-Short Form (CTQ-SF). The subjects included a childhood trauma group (22 subjects) and a healthy group (23 subjects) according to their CTQ-SF scores.
Experiment design
Fig. 1 shows the matching task and the BOLD-fMRI data were acquired while the subjects were performing the task. The study was approved by the Institutional Research Board (IRB) of South China Normal University. Written informed consent was obtained from each subject before the experiment.
Data acquisition
All imaging data were acquired on a Siemens Trio Tim 3T MRI scanner with the 8-channel phased-array head coil. The BOLD-fMRI data were acquired using a gradient echo EPI sequence (GE-EPI) with the following parameters, TR = 2,000ms, TE = 30ms, FA = 90°, FOV = 224 mm × 224 mm, data matrix = 64 × 64, voxel-size = (3.5mm)3, 32 transversal interleaved slices with interslice gap = 0.4mm, and 300 volume acquired in about 10 mins. The high-resolution brain structural images were acquired using a T1-weighed 3D MP-RAGE sequence with the following parameters, TR = 2,300ms, TE = 3.24ms, FA = 90°, FOV = 256 mm × 256 mm, matrix = 64 × 64, voxel-size = (1mm)3, and 176 sagittal slices covering the whole brain. The brain structural and fMRI data were obtained in the same session for each subject.
Data preprocessing
Functional and structural data were preprocessed using the CONN toolbox, including head motion correction, distortion correction, slice timing correction, outlier detection, segmentation, and normalization to the MNI space. The preprocessed functional data were spatial smoothed using a Gaussian kernel of 6 mm full-width half maximum (FWHM).
fMRI data analysis
We selected the bilateral HP as seeds and performed a gPPI analysis by using CONN to estimate the voxel-wise functional connectivity (FC) of the HP in the whole brain. For each seed, a two-sample t-test was used to examine the differences in functional connectivity patterns between the two groups for the contrast of (face condition > shape condition). The mean PPI beta value for each subject was then extracted from each significance cluster to estimate the Pearson correlation coefficient with the CTQ scores.

Fig. 2a shows our selection of seeds. Fig. 2b shows significant negative FC between the seed at the left HP and the posterior cingulate gyrus in childhood trauma. We also estimated the FC for the seed at the right HP and found no significant difference between the two groups. Additionally, Fig. 2c shows a significant negative correlation between PPI beta values and CTQ scores (r = -0.521, p < 0.01).

This study showed that individuals who experienced childhood trauma had lower functional connectivity between the left HP and right PCC in response to the threatening faces. This result suggested that the degree of early trauma may be associated with abnormal functional connectivity patterns. This finding may contribute to our understanding of the effects of early trauma on the brain's reactivity to emotions.

Non-Invasive Stimulation Methods Other ²

BOLD fMRI ¹

FUNCTIONAL MRI