Working memory impairment in children orphaned by parental HIV/AIDS: An event-related potentials study

Age-related changes in brain oscillatory patterns during an n-back task in children and adolescents

The development of brain oscillatory responses and their possible role in the working memory (WM) performance of children, adolescents and young adults was investigated. A set of 0- and 1-back tasks with letter stimuli were administered to a final sample of 131 subjects (between 6 and 20 years of age). A decrease in response times (RTs) and an increase of the sensitivity index d-prime (d') were seen with increased age. RTs increased and d' decreased with load, indicating higher difficulty for higher loads. Event-related synchronization (ERS) and event-related desynchronization (ERD) were obtained by the convolution of Morlet wavelets on the recorded EEG. Statistical analyses were performed of the absolute and relative power of brain oscillations defined by topography, frequency and latency. Posterior alpha and beta ERD, and frontocentral theta ERS, were induced by the stimuli presented during the n-back task. While relative theta ERS increased with age, absolute theta ERS, absolute and relative alpha and, absolute beta ERD, decreased with age. Age-related improvement in behavioral performance was mediated by relative theta. Alpha and beta ERD were more pronounced for the most difficult task (1-back) and for the target condition. Globally, there was high consistency of the effects of target type and task load across development. Theta ERS maturation is a crucial step for improving WM performance during development, while alpha and beta ERD maturation seem to be less critical for behavioral performance improvement with age, possibly due to a sufficient level of alpha-beta ERD for good performance in young children.

The mediating role of executive function in the relationship between self-stigma and self-injury or suicidal ideation among men who have sex with men living with HIV

Background

Men who have sex with men (MSM) living with HIV suffer from psychosocial pressures and marginalization as a result of being HIV-positive and belonging to a sexual minority group, and self-injury or suicidal ideation are prevalent among this group. Studies have found that both perceived self-stigma and altered executive function is related to self-injury or suicidal ideation. However, the combined contribution of self-stigma and executive function to self-injury or suicidal ideation remains unclear, especially in MSM living with HIV. Therefore, this study is conducted to explore the mechanism of self-injury or suicidal ideation by hypothesizing that executive function plays a mediating role in the relationship between self-stigma and self-injury or suicidal ideation.

Methods

We conducted a cross-sectional survey among 448 MSM living with HIV who were recruited in the HIV clinic of a tertiary general hospital in Changsha, China, from November 2021 to February 2022. A questionnaires survey was adopted to collect sociodemographic and disease-related information and data related to executive function (including working memory, inhibition, and task monitoring), self-stigma, and self-injury or suicidal ideation. Structural equation modeling and bootstrap testing were used to investigate the potential mediating role of executive function in the relationship between self-stigma and suicidal ideation.

Results

The participants were aged 18-76 years. Those who had ever had self-injury or suicidal ideation accounted for 32.8% of the total. A higher level of self-stigma and poorer executive function were associated with more frequent self-injury or suicidal ideation (p < 0.01). The mediation model analysis showed a good fit (x ²/df = 1.07, p = 0.381). The direct effect of self-stigma on self-injury or suicidal ideation (β = 0.346, p < 0.001) and the indirect effect of self-stigma via executive function (β = 0.132, p < 0.001) were significant, with the indirect effect accounting for 27.6% of the total effect.

Conclusions

This study demonstrates that executive function mediates the relationship between self-stigma and self-injury or suicidal ideation among MSM living with HIV. It suggests that future studies targeting enhancing executive function and decreasing self-stigma may reduce self-injury or suicidal ideation among MSM living with HIV.

EEG Evidence of Altered Functional Connectivity and Microstate in Children Orphaned by HIV/AIDS

Children orphaned by HIV/AIDS ("AIDS orphans") suffer numerous early-life adverse events which have a long-lasting effect on brain function. Although previous studies found altered electroencephalography (EEG) oscillation during resting state in children orphaned by HIV/AIDS, data are limited regarding the alterations in connectivity and microstate. The current study aimed to investigate the functional connectivity (FC) and microstate in children orphaned by HIV/AIDS with resting-state EEG data. Data were recorded from 63 children orphaned by HIV/AIDS and 65 non-orphan controls during a close-eyes resting state. The differences in phase-locking value (PLV) of global average FC and temporal dynamics of microstate were compared between groups. For functional connectivity, children orphaned by HIV/AIDS showed decreased connectivity in alpha, beta, theta, and delta band compared with non-orphan controls. For microstate, EEG results demonstrated that children orphaned by HIV/AIDS show increased duration and coverage of microstate C, decreased occurrence and coverage of microstate B, and decreased occurrence of microstate D than non-orphan controls. These findings suggest that the microstate and functional connectivity has altered in children orphaned by HIV/AIDS compared with non-orphan controls and provide additional evidence that early life stress (ELS) would alter the structure and function of the brain and increase the risk of psychiatric disorders.

Facial Expression Processing of Children Orphaned by Parental HIV/AIDS: A Cross-Sectional ERP Study with Rapid Serial Visual Presentation

Existing behavioral studies have suggested that individuals with early life stress usually show abnormal emotional processing. However, limited event-related brain potentials (ERPs) evidence was available to explore the emotional processes in children orphaned by parental HIV/AIDS ("AIDS orphans"). The current study aims to investigate whether there are behavioral and neurological obstacles in the recognition of emotional faces in AIDS orphans and also to further explore the processing stage at which the difference in facial emotion recognition exists. A total of 81 AIDS orphans and 60 non-orphan children were recruited through the local communities and school systems in Henan, China. Participants completed a computer version of the rapid serial visual presentation (RSVP) task while recording ERPs. Behavioral results showed that orphans displayed higher response accuracy and shorter reaction time than the control (p_s < 0.05). As for the ERPs analysis, the attenuated amplitude of N170 (i.e., an early component sensitive to facial configuration) was observed in AIDS orphans compared to the non-orphan control with happy and neutral faces; P300 (i.e., an endogenous component for affective valence evaluation in emotional processing) also showed significant differences in parietal lobe between groups, the non-orphan control group produced larger P300 amplitudes than orphans (p < 0.05). The results suggested that compared to the control group, AIDS orphans showed impaired facial emotion recognition ability with reduced brain activation.