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Neurofeedback (NFB) is a brain-based training method that enables users to control their own cortical oscillations using real-time feedback from the electroencephalogram (EEG). Importantly, no investigations to date have directly explored the potential impact of NFB on the brain's key neuromodulatory systems. Our study's objective was to assess the capacity of NFB to induce dopamine release as revealed by positron emission tomography (PET). Thirty-two healthy volunteers were randomized to either EEG-neurofeedback (NFB) or EEG-electromyography (EMG), and scanned while performing self-regulation during a single session of dynamic PET brain imaging using the high affinity D 2/3 receptor radiotracer, [ 18 F]Fallypride. NFB and EMG groups down-regulated cortical alpha power and facial muscle tone, respectively. Task-induced effects on endogenous dopamine release were estimated in the frontal cortex, anterior cingulate cortex, and thalamus, using the linearized simplified reference region model (LSRRM), which accounts for time-dependent changes in radiotracer binding following task initiation. Contrary to our hypothesis of a differential effect for NFB vs. EMG training, significant dopamine release was observed in both training groups in the frontal and anterior cingulate cortex, but not in thalamus. Interestingly, a significant negative correlation was observed between dopamine release in frontal cortex and pre-to-post NFB change in spontaneous alpha power, suggesting that intra-individual changes in brain state (i.e., alpha power) could partly result from changes in neuromodulatory tone. Overall, our findings constitute the first direct investigation of neurofeedback's effect on the endogenous release of a key neuromodulator, demonstrating its feasibility and paving the way for future studies using this methodology., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Ros, Kwiek, Andriot, Michela, Vuilleumier, Garibotto and Ginovart.)

Background: Human immunodeficiency virus (HIV) status awareness is important for preventing onward HIV transmission, and is one of the Joint United Nations Programme on HIV and AIDS (UNAIDS) 90-90-90 goals. Efforts to scale up HIV testing have generally been successful, but identifying at-risk individuals who have never tested for HIV-a population necessary to reach improved HIV status awareness-remains challenging., Methods: Using data from a community-based cohort of people living in rural central Malawi, we identified demographic, socioeconomic, and sexual health correlates of never having tested for HIV. Correlates were assigned values from the logistic regression model to develop a risk score that identified who had never tested for HIV., Results: Among 1310 ever sexually active participants, 7% of the women and 13% of the men had never tested for HIV. Of those who had tested for HIV, about 30% had tested more than 12 months ago. For women, younger age and poorer sexual health knowledge were correlated with never having tested for HIV, and the c-statistic for the risk score was 0.83. For men, their partner having not tested for HIV, low socioeconomic status, and poor sexual health knowledge were correlated with never testing for HIV (c-statistic, 0.81). Among those with a score of 3 or greater, the sensitivity and specificity for never having tested for HIV were 81% and 77% for women, and 82% and 66% for men, respectively., Conclusions: About 10% of participants had never tested for HIV. This risk score could help health professionals to identify never testers to increase HIV status awareness in line with 90-90-90 goals.