Aversive Counterconditioning Attenuates Reward Signaling in the Ventral Striatum

Appetitive conditioning refers to the process of learning cue-reward associations and is mediated by the mesocorticolimbic system. Appetitive conditioned responses are difficult to extinguish, especially for highly salient reward such as food and drugs. We investigate whether aversive counterconditioning can alter reward reinstatement in the ventral striatum in healthy volunteers using functional magnetic resonance imaging (fMRI). In the initial conditioning phase, two different stimuli were reinforced with a monetary reward. In the subsequent counterconditioning phase, one of these stimuli was paired with an aversive shock to the wrist. In the following extinction phase, none of the stimuli were reinforced. In the final reinstatement phase, reward was reinstated by informing the participants that the monetary gain could be doubled. Our fMRI data revealed that reward signaling in the ventral striatum and ventral tegmental area following reinstatement was smaller for the stimulus that was counterconditioned with an electrical shock, compared to the non-counterconditioned stimulus. A functional connectivity analysis showed that aversive counterconditioning strengthened striatal connectivity with the hippocampus and insula. These results suggest that reward signaling in the ventral striatum can be attenuated through aversive counterconditioning, possibly by concurrent retrieval of the aversive association through enhanced connectivity with hippocampus and insula

A synthesis of evidence for policy from behavioural science during COVID-19

Scientific evidence regularly guides policy decisions1, with behavioural science increasingly part of this process2. In April 2020, an influential paper3 proposed 19 policy recommendations (‘claims’) detailing how evidence from behavioural science could contribute to efforts to reduce impacts and end the COVID-19 pandemic. Here we assess 747 pandemic-related research articles that empirically investigated those claims. We report the scale of evidence and whether evidence supports them to indicate applicability for policymaking. Two independent teams, involving 72 reviewers, found evidence for 18 of 19 claims, with both teams finding evidence supporting 16 (89%) of those 18 claims. The strongest evidence supported claims that anticipated culture, polarization and misinformation would be associated with policy effectiveness. Claims suggesting trusted leaders and positive social norms increased adherence to behavioural interventions also had strong empirical support, as did appealing to social consensus or bipartisan agreement. Targeted language in messaging yielded mixed effects and there were no effects for highlighting individual benefits or protecting others. No available evidence existed to assess any distinct differences in effects between using the terms ‘physical distancing’ and ‘social distancing’. Analysis of 463 papers containing data showed generally large samples; 418 involved human participants with a mean of 16,848 (median of 1,699). That statistical power underscored improved suitability of behavioural science research for informing policy decisions. Furthermore, by implementing a standardized approach to evidence selection and synthesis, we amplify broader implications for advancing scientific evidence in policy formulation and prioritization

Dorsomedial prefrontal cortex mediates the impact of serotonin transporter linked polymorphic region genotype on anticipatory threat reactions

Background Excessive anticipatory reactions to potential future adversity are observed across a range of anxiety disorders, but the neurogenetic mechanisms driving interindividual differences are largely unknown. We aimed to discover and validate a gene-brain-behavior pathway by linking presumed genetic risk for anxiety-related psychopathology, key neural activity involved in anxious anticipation, and resulting aversive emotional states. Methods The functional neuroanatomy of aversive anticipation was probed through functional magnetic resonance imaging in two independent samples of healthy subjects (n = 99 and n = 69), and we studied the influence of genetic variance in the serotonin transporter linked polymorphic region (5-HTTLPR). Skin conductance and startle data served as objective psychophysiological indices of the intensity of individuals’ anticipatory responses to potential threat. Results Threat cues signaling risk of future electrical shock activated the dorsomedial prefrontal cortex (dmPFC), anterior insula, bed nucleus of the stria terminalis, thalamus, and midbrain consistently across both samples. Threat-related dmPFC activation was enhanced in 5-HTTLPR short allele carriers in sample 1 and this effect was validated in sample 2. Critically, we show that this region mediates the increase in anticipatory psychophysiological reactions in short allele carriers indexed by skin conductance (experiment 1) and startle reactions (experiment 2). Conclusions The converging results from these experiments demonstrate that innate 5-HTTLPR linked variation in dmPFC activity predicts psychophysiological responsivity to pending threats. Our results reveal a neurogenetic pathway mediating interindividual variability in anticipatory responses to threat and yield a novel mechanistic account for previously reported associations between genetic variability in serotonin transporter function and stress-related psychopathology