Analysis of individual differences in neurofeedback training illuminates successful self-regulation of the dopaminergic midbrain

The dopaminergic midbrain is associated with reinforcement learning, motivation and decision-making – functions often disturbed in neuropsychiatric disorders. Previous research has shown that dopaminergic midbrain activity can be endogenously modulated via neurofeedback. However, the robustness of endogenous modulation, a requirement for clinical translation, is unclear. Here, we examine whether the activation of particular brain regions associates with successful regulation transfer when feedback is no longer available. Moreover, to elucidate mechanisms underlying effective self-regulation, we study the relation of successful transfer with learning (temporal difference coding) outside the midbrain during neurofeedback training and with individual reward sensitivity in a monetary incentive delay (MID) task. Fifty-nine participants underwent neurofeedback training either in standard (Study 1 N = 15, Study 2 N = 28) or control feedback group (Study 1, N = 16). We find that successful self-regulation is associated with prefrontal reward sensitivity in the MID task (N = 25), with a decreasing relation between prefrontal activity and midbrain learning signals during neurofeedback training and with increased activity within cognitive control areas during transfer. The association between midbrain self-regulation and prefrontal temporal difference and reward sensitivity suggests that reinforcement learning contributes to successful self-regulation. Our findings provide insights in the control of midbrain activity and may facilitate individually tailoring neurofeedback training

Self-regulation of the dopaminergic reward circuit in cocaine users with mental imagery and neurofeedback

BACKGROUND Enhanced drug-related reward sensitivity accompanied by impaired sensitivity to non-drug related rewards in the mesolimbic dopamine system are thought to underlie the broad motivational deficits and dysfunctional decision-making frequently observed in cocaine use disorder (CUD). Effective approaches to modify this imbalance and reinstate non-drug reward responsiveness are urgently needed. Here, we examined whether cocaine users (CU) can use mental imagery of non-drug rewards to self-regulate the ventral tegmental area and substantia nigra (VTA/SN). We expected that obsessive and compulsive thoughts about cocaine consumption would hamper the ability to self-regulate the VTA/SN activity and tested if real-time fMRI (rtfMRI) neurofeedback (NFB) can improve self-regulation of the VTA/SN. METHODS Twenty-two CU and 28 healthy controls (HC) were asked to voluntarily up-regulate VTA/SN activity with non-drug reward imagery alone, or combined with rtfMRI NFB. RESULTS On a group level, HC and CU were able to activate the dopaminergic midbrain and other reward regions with reward imagery. In CU, the individual ability to self-regulate the VTA/SN was reduced in those with more severe obsessive-compulsive drug use. NFB enhanced the effect of reward imagery but did not result in transfer effects at the end of the session. CONCLUSION CU can voluntary activate their reward system with non-drug reward imagery and improve this ability with rtfMRI NFB. Combining mental imagery and rtFMRI NFB has great potential for modifying the maladapted reward sensitivity and reinstating non-drug reward responsiveness. This motivates further work to examine the use of rtfMRI NFB in the treatment of CUD

The Nachtlichter app: a citizen science tool for documenting outdoor light sources in public space

The relationship between satellite based measurements of city radiance at night and the numbers and types of physical lights installed on the ground is not well understood. Here we present the "Nachtlichter app", which was developed to enable citizen scientists to classify and count light sources along street segments over large spatial scales. The project and app were co-designed: citizen scientists played key roles in the app development, testing, and recruitment, as well as in analysis of the data. In addition to describing the app itself and the data format, we provide a general overview of the project, including training materials, data cleaning, and the result of some basic data consistency checks

Individual differences in the mechnistic control of the dopaminergic midbrain

The dopaminergic midbrain is associated with elementary brain functions, such as reward processing, reinforcement learning, motivation and decision-making that are often disturbed in neuropsychiatric disease. Previous research has shown that activity in the dopaminergic midbrain can be endogenously modulated via neurofeedback, suggesting potential for non-pharmacological interventions. However, the robustness of endogenous modulation, a requirement for clinical translation, is unclear. Here, we used non-invasive modulation of the dopaminergic midbrain activity by real-time neurofeedback to examine how self-modulation capability affects transfer and correlated activation across the brain. In addition, to further elucidate potential mechanisms underlying successful self-regulation, we studied individual prediction error coding during neurofeedback training, and, during a completely independent monetary incentive delay (MID) task, individual reward sensitivity. Fifty-nine participants underwent neurofeedback training either in a veridical or inverted feedback group. Post-training activity within the cognitive control network was increased only in those individuals with successful self-regulation of the dopaminergic midbrain during neurofeedback training. Successful learning to regulate was accompanied by decreasing prefrontal prediction error signals and increased prefrontal reward sensitivity in the MID task. Our findings suggest that the cognitive control network contributes to successful transfer of the capability to upregulate the dopaminergic midbrain. The link of dopaminergic self-regulation with individual differences in prefrontal prediction error and reward sensitivity indicates that reinforcement learning contributes to successful top-down control of the midbrain. Our findings therefore provide new insights in the cognitive control of dopaminergic midbrain activity and pave the way to improving neurofeedback training in neuropsychiatric patients

Mobiliário escolar francês e os projetos vanguardistas de Jean Prouvé e André Lurçat na primeira metade do século XX

O objetivo deste artigo é investigar a história do mobiliário escolar enquanto componente de uma modernidade que tem como um dos seus focos de discussão os discursos e os projetos idealizados pelos arquitetos. Esta é a uma tentativa de tentar enxergá-los como autênticas peças de investigação que facilitam a compreensão de uma das faces da cultura material escolar. Com o presente tema coloco em cena a valorização do papel desses profissionais, muitos deles desconhecidos da historiografia da educação, que juntos com educadores e médicos pensaram caminhos possíveis para uma escola que almejava ser moderna. Assim, concentrarei minhas análises na realidade do ocidente europeu da primeira metade do século XX e o papel que desempenharam alguns arquitetos franceses como protagonistas na configuração de um mobiliário que procurava alcançar demandas que favorecessem a saúde e a aprendizagem dos alunos em sala de aula

Synthesis of (-)-Hennoxazole A: Integrating Batch and Flow Chemistry Methods

A new total synthesis of (–)-hennoxazole A is reported. The synthetic approach is based on the preparation of three similarly sized fragments resulting in a fast and convergent assembly of the natural product. The three key reactions of the synthesis include a highly stereoselective 1,5-anti aldol coupling, a gold-catalyzed alkoxycyclization reaction, and a stereocontrolled diene cross-meta­thesis. The synthesis involves integrated batch and flow chemistry methods leading to the natural product in 16 steps longest linear ­sequence and 2.8% overall yield

Self-regulation of the dopaminergic reward circuit in cocaine users with mental imagery and neurofeedbackResearch in Context

Background: Enhanced drug-related reward sensitivity accompanied by impaired sensitivity to non-drug related rewards in the mesolimbic dopamine system are thought to underlie the broad motivational deficits and dysfunctional decision-making frequently observed in cocaine use disorder (CUD). Effective approaches to modify this imbalance and reinstate non-drug reward responsiveness are urgently needed. Here, we examined whether cocaine users (CU) can use mental imagery of non-drug rewards to self-regulate the ventral tegmental area and substantia nigra (VTA/SN). We expected that obsessive and compulsive thoughts about cocaine consumption would hamper the ability to self-regulate the VTA/SN activity and tested if real-time fMRI (rtfMRI) neurofeedback (NFB) can improve self-regulation of the VTA/SN. Methods: Twenty-two CU and 28 healthy controls (HC) were asked to voluntarily up-regulate VTA/SN activity with non-drug reward imagery alone, or combined with rtfMRI NFB. Results: On a group level, HC and CU were able to activate the dopaminergic midbrain and other reward regions with reward imagery. In CU, the individual ability to self-regulate the VTA/SN was reduced in those with more severe obsessive-compulsive drug use. NFB enhanced the effect of reward imagery but did not result in transfer effects at the end of the session. Conclusion: CU can voluntary activate their reward system with non-drug reward imagery and improve this ability with rtfMRI NFB. Combining mental imagery and rtFMRI NFB has great potential for modifying the maladapted reward sensitivity and reinstating non-drug reward responsiveness. This motivates further work to examine the use of rtfMRI NFB in the treatment of CUD. Keywords: Cocaine use disorder, Dopamine, Mental imagery, Neurofeedback, Real-time fMRI, Reward sensitivity, Treatmen