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6. Social feedback processing deficits in individuals with depression

Author

He, Zhenhong, Elliott, Rebecca, and Muhlert, Nils

Subjects
616.85
Abstract

Background: Social feedback, i.e., receiving social rewards like approval, acceptance, interest, or praise or conversely, receiving social punishments like being excluded, rejected or criticised in social interactions, is a critical source of social information. There is abundant evidence suggesting that, compared to healthy controls, individuals with depression show more negative experience of social feedback, have a more negative expectation of social feedback, and potentially show dysregulation of negative emotions evoked by negative social feedback. The brain structural and functional alterations associated with changes in anticipation and response to social feedback in these groups is however unclear. The aims of this PhD thesis were to address multiple aspects of social feedback processing in depression: (1) Anticipating and consuming social feedbacks; (2) Processing the expectancy violation of social feedbacks. (3) Emotion regulation of social feedbacks. Methods: Multi-modal approaches, including fMRI, non-invasive brain stimulation, EEG, eye-tracker recording and cognitive testing were employed as research tools for my project. The large-scale MRI analysis of the existing neuroimaging data such as UK biobank were also used. Paper one. This study provides evidence that depression is characterized by distinct neural alteration in processing monetary and social incentives. Paper two. This study highlights an important role of expectancy violation in the brain dysfunction of social feedback perception and evaluation in depression. Paper three. This study suggests a causal role for rVLPFC in down-regulation of negative emotions produced by social exclusion. Paper four. This study highlights a more specific causal relationship between rVLPFC rTMS and reappraisal success of social pain compared to physical pain. Paper five. This study found that the tDCS-activated rVLPFC could improve emotion regulation capacity on social exclusion. However the findings do not suggest that individuals with high depressive mood benefit from a single-tDCS session on the emotion regulation of social exclusion. Paper six. This study demonstrates cultural differences in emotional reaction to and emotion regulation of social exclusion. Paper seven. This study provides evidence linking loneliness to grey matter volume changes in ACC and VLPFC in depression. Conclusions: Taken together these papers show neural deficits contributing to abnormal social feedback processing (anticipation, experience, expectancy violation, and emotion regulation) in individuals with depression. These results may have potential implications for clinical practice on how abnormal brain could be normalized in certain targeted interventions, and highlight the importance of protecting individuals with depression from specific social risk factors such as the negative social feedback.

Published
2020

25. Invisible Electromagnetic Huygens’ Metasurface Operational in Wide Frequency Band and Its Experimental Validation

Author

Xiaodong Cheng, Xujin Yuan, Daining Fang, Ying Li, Yixing Huang, Xiuzhu Ye, Cunxi Liu, Rui Zhang, Mingji Chen, He Zhenhong, and Weiduan Li

Subjects
Physics, Electromagnetics, Frequency band, Acoustics, Cloak, Metamaterial, 020206 networking & telecommunications, 02 engineering and technology, Electromagnetic metasurface, Narrowband, 0202 electrical engineering, electronic engineering, information engineering, Reflection (physics), Electrical and Electronic Engineering, Wideband
Abstract

Wideband operation ability becomes an obstacle for many metamaterial applications since they are generally based on effective material (medium) hypothesis, which is intrinsically functional on single frequency or narrowband. Effective biological camouflage strategies involve concealment under sunlight with multiple frequency (color) components, for example, a shark could fuse itself into sea water environment for better invisibility and hunting effectiveness. A wideband 3-D metasurface ground cloak in gigahertz frequency order is proposed and realized in the experiment with a hemispherical profile. A complex unit structure to broaden the operational frequency range for a phase-preserved electromagnetic metasurface based on the difference of elevation is also proposed. Comparison between the wideband and its contrast narrowband metasurface clearly indicates the scattering improvement effect that demonstrates the proposed metasurface’s significance. Both instantaneous electric field scanning and reflection cross section shrinking quantitatively give strong evidence of the wideband operational functions. Comparison between simulation and experiment validated each other. These results indicate that the proposed metasurface conceals itself into a background inside a wide frequency spectrum of 7.0–9.5 GHz. This structure has a great application value for object security under wave package illumination and in landscape fusion. This mechanism also demonstrates the possibility to change other effective material properties in a wide frequency band.

Published
2021
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30. Neural substrates of expectancy violation associated with social feedback in individuals with subthreshold depression.

Author

He, Zhenhong, Ao, Xiang, Muhlert, Nils, Elliott, Rebecca, and Zhang, Dandan

Subjects
*NEURAL physiology, *MENTAL depression risk factors, *AFFINITY groups, *PREFRONTAL cortex, *NEURAL pathways, *BRAIN mapping, *COGNITION, *SOCIAL status, *DESCRIPTIVE statistics, *SOCIAL skills
Abstract

Background: Abnormal processing of social feedback is an important contributor to social dysfunction in depression, however the exact mechanisms remain unclear. One important factor may be the extent to which social processing depends on expectations, in particular whether social feedback confirms or violates expectations. Methods: To answer this question, we studied behavioral and brain responses during the evaluative processing of social feedback in 25 individuals with subthreshold depression (SD) and 25 healthy controls (HCs). Participants completed a Social Judgment Task in which they first indicated expectation about whether a peer would like them or not, and then received peer's feedback indicating acceptance or rejection. Results: Individuals with SD who reported greater depressive symptoms gave fewer positive expectations. Compared to HCs, individuals with SD showed reduced activation in the medial prefrontal cortex when expecting positive feedback. They also exhibited increased dorsal anterior cingulate cortex after receipt of unexpected social rejection, and reduced ventral striatum activity after receipt of unexpected social acceptance. Conclusions: The observed alternations are specific to unexpected social feedback processing and highlight an important role of expectancy violation in the brain dysfunction of social feedback perception and evaluation in individuals at risk for depression. [ABSTRACT FROM AUTHOR]

Published
2022
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35. Bromide promoted hydrogenation of CO2 to higher alcohols using Ru–Co homogeneous catalyst† †Electronic supplementary information (ESI) available: GC-MS and GC data. See DOI: 10.1039/c6sc01314g

Author

Cui, Meng, Qian, Qingli, He, Zhenhong, Zhang, Zhaofu, Ma, Jun, Wu, Tianbin, Yang, Guanying, and Han, Buxing

Subjects
Chemistry
Abstract

Higher alcohols can be synthesized efficiently by CO2 hydrogenation over Ru3(CO)12–Co4(CO)12 bimetallic catalyst with bis(triphenylphosphoranylidene)ammonium chloride (PPNCl) as the cocatalyst and LiBr as the promoter., Iodides are commonly used promoters in C2+OH synthesis from CO2/CO hydrogenation. Here we report the highly efficient synthesis of C2+OH from CO2 hydrogenation over a Ru3(CO)12–Co4(CO)12 bimetallic catalyst with bis(triphenylphosphoranylidene)ammonium chloride (PPNCl) as the cocatalyst and LiBr as the promoter. Methanol, ethanol, propanol and isobutanol were formed at milder conditions. The catalytic system had a much better overall performance than those of reported iodide promoted systems because PPNCl and LiBr cooperated very well in accelerating the reaction. LiBr enhanced the activity and PPNCl improved the selectivity, and thus both the activity and selectivity were very high when both of them were used simultaneously. In addition, the catalyst could be reused for at least five cycles without an obvious change of catalytic performance.

Published
2016

40. Highly selective hydrogenation of CO2 into C2+ alcohols by homogeneous catalysis† †Electronic supplementary information (ESI) available: Supplementary figures and tables. See DOI: 10.1039/c5sc02000j

Author

Qian, Qingli, Cui, Meng, He, Zhenhong, Wu, Congyi, Zhu, Qinggong, Zhang, Zhaofu, Ma, Jun, Yang, Guanying, Zhang, Jingjing, and Han, Buxing

Subjects
Chemistry, integumentary system, organic chemicals, bacteria, lipids (amino acids, peptides, and proteins), equipment and supplies
Abstract

Methanol, ethanol, propanol, 2-methyl propanol, butanol, and 2-methyl butanol were produced in homogeneous CO2 hydrogenation with a selectivity for C2+ alcohols of 96.4%., The hydrogenation of CO2 to produce alcohols with two or more carbons (C2+ alcohols) is of great importance, but is challenging. In this work, we found that a Ru3(CO)12/Rh2(CO)4Cl2–LiI system could catalyze the reaction effectively in 1,3-dimethyl-2-imidazolidinone (DMI) under mild conditions. Methanol, ethanol, propanol, 2-methyl propanol, butanol, and 2-methyl butanol were produced in the homogeneous catalytic reaction. The C2+ alcohols could be generated at 160 °C, which is the lowest temperature reported so far for producing C2+ alcohols via CO2 hydrogenation. The selectivity for the C2+ alcohols could be as high as 96.4% at the optimized conditions, which is higher than those reported in the literature. In addition, the catalytic system could be easily recycled. The route of the reaction for forming the C2+ alcohols was discussed on the basis of control experiments.

Published
2015

42. Improving emotion regulation of social exclusion in depression-prone individuals: a tDCS study targeting right VLPFC.

Author

He, Zhenhong, Liu, Zhenli, Zhao, Jun, Elliott, Rebecca, and Zhang, Dandan

Subjects
*ANALYSIS of variance, *MENTAL depression, *EMOTIONS, *FRONTAL lobe, *REGRESSION analysis, *SELF-management (Psychology), *SOCIAL isolation, *DATA analysis software, *DESCRIPTIVE statistics, *TRANSCRANIAL direct current stimulation
Abstract

Background: Growing evidence has indicated that right ventrolateral prefrontal cortex (RVLPFC) is critical in down-regulating emotional responses to social exclusion, and that depression is accompanied by social emotional dysregulation associated with reduced lateral prefrontal engagement. This study used anodal transcranial direct current stimulation (tDCS) to examine whether stimulating RVLPFC could improve emotional down-regulation of social exclusion in individuals with high depressive mood (DM). Methods: A total of 96 high and 94 low DM individuals received active or sham tDCS while viewing social exclusion or individual negative pictures under no-reappraisal (passive viewing) and reappraisal conditions. Participants rate their negative emotional experience following the presentation of each image. Pupil diameter and visual fixation duration were also recorded during the task. Results: It was found that tDCS-activated RVLPFC induced a stronger regulation effect on social exclusion than individual negative emotions. The effect of tDCS on regulation of social exclusion was more pronounced in low v. high DM individuals. Conclusions: These findings demonstrate the specific role of RVLPFC on social emotion regulation, which has implications for refining target areas for the treatment of social emotion dysregulation in depression. However the findings do not suggest that high DM individuals benefit from a single-tDCS session on the emotion regulation of social exclusion. Thus we suggest to use multiple tDCS sessions or transcranial magnetic stimulation to further explore the therapeutic proposal in the future. [ABSTRACT FROM AUTHOR]

Published
2020
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43. The right VLPFC and downregulation of social pain: A TMS study.

Author

He, Zhenhong, Zhao, Jun, Shen, Junshi, Muhlert, Nils, Elliott, Rebecca, and Zhang, Dandan

Subjects
*TRANSCRANIAL magnetic stimulation, *PREFRONTAL cortex, *PAIN, *DOWNREGULATION, *ANALGESIA
Abstract

Previous studies have demonstrated that the right ventrolateral prefrontal cortex (RVLPFC) is crucially involved in downregulating physical and social pain. However, it remains unclear whether the RVLPFC is more specific to either physical or social pain. The present study compares the role of RVLPFC in emotion regulation in physical‐ and social‐pain conditions using repetitive transcranial magnetic stimulation (rTMS). A total of 60 healthy participants underwent active (n = 30) or sham (n = 30) rTMS over the RVLPFC. Following each TMS session, participants performed a non‐reappraisal and then a reappraisal task to downregulate imagined physical or social pain evoked by pictures. Self‐reported negative emotional ratings and electroencephalogram data were recorded during the emotion regulation task. Participants were then required to rate the valence and arousal of those pictures 30 min after the task. It is found that rTMS‐activated RVLPFC led to reductions in subjective negative feelings and amplitudes of the late positive potential during reappraisal; however, these effects were found exclusively in the social‐pain condition. Participants also reported higher positive valence for socially, compared to physically, painful pictures after 30 min of the task. Behavioral and electrophysiological evidence both supported the functional specificity of RVLPFC in regulation of social pain. The prominent delayed effect of rTMS makes it possible to consider the potential application of rTMS‐VLPFC in clinical practice for social pain relief. [ABSTRACT FROM AUTHOR]

Published
2020
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