Animal approach-avoidance conflict paradigms have been used extensively to operationalize anxiety, quantify the effects of anxiolytic agents, and probe the neural basis of fear and anxiety. Results from human neuroimaging studies support that a frontal-striatal-amygdala neural circuitry is important for approach-avoidance learning. However, the neural basis of decision-making is much less clear in this context. Thus, we combined a recently developed human approach-avoidance paradigm with functional magnetic resonance imaging (fMRI) to identify neural substrates underlying approach-avoidance conflict decision-making. Fifteen healthy adults completed the approach-avoidance conflict (AAC) paradigm during fMRI. Analyses of variance were used to compare conflict to non-conflict (avoid-threat and approach-reward) conditions and to compare level of reward points offered during the decision phase. Trial-by-trial amplitude modulation analyses were used to delineate brain areas underlying decision-making in the context of approach/avoidance behavior. Conflict trials as compared to the non-conflict trials elicited greater activation within bilateral anterior cingulate cortex (ACC), anterior insula, and caudate, as well as right dorsolateral prefrontal cortex. Right caudate and lateral PFC activation was modulated by level of reward offered. Individuals who showed greater caudate activation exhibited less approach behavior. On a trial-by-trial basis, greater right lateral PFC activation related to less approach behavior. Taken together, results suggest that the degree of activation within prefrontal-striatal-insula circuitry determines the degree of approach versus avoidance decision-making. Moreover, the degree of caudate and lateral PFC activation is related to individual differences in approach-avoidance decision-making. Therefore, the AAC paradigm is ideally suited to probe anxiety-related processing differences during approach-avoidance decision-making.

Background Posttraumatic stress disorder (PTSD) is associated with reduced executive functioning and verbal memory performance, as well as abnormal task-specific activity in prefrontal (PFC) and anterior cingulate cortices (ACC). The current study examined how PTSD symptoms and neuropsychological performance in combat veterans relates to 1) medial PFC and ACC activity during cognitive inhibition, and 2) task-independent PFC functional connectivity. Methods Thirty-nine male combat veterans with varying levels of PTSD symptoms completed the multisource interference task during functional magnetic resonance imaging. Robust regression analyses were used to assess relationships between percent signal change (PSC: Incongruent-Congruent) and both PTSD severity and neuropsychological performance. Analyses were conducted voxel-wise and for PSC extracted from medial PFC and ACC regions of interest. Resting state scans were available for veterans with PTSD. Regions identified via task-based analyses were used as seeds for resting state connectivity analyses. Results Worse PTSD severity and neuropsychological performance related to less medial PFC and rostral ACC activity during interference processing, driven partly by increased activation to congruent trials. Worse PTSD severity related to reduced functional connectivity between these regions and bilateral, lateral PFC (Brodmann area 10). Worse neuropsychological performance related to reduced functional connectivity between these regions and the inferior frontal gyrus. Conclusions PTSD and associated neuropsychological deficits may result from difficulties regulating medial PFC regions associated with “default mode”, or self-referential processing. Further clarification of functional coupling deficits between default mode and executive control networks in PTSD may enhance understanding of neuropsychological and emotional symptoms and provide novel treatment targets.

OBJECTIVEWe previously reported changes in food-cue neural reactivity associated with behavioral and surgical weight loss interventions. Resting functional connectivity represents tonic neural activity that may contribute to weight loss success. Here we explore whether intervention type is associated with differences in functional connectivity after weight loss.METHODSFifteen obese participants were recruited prior to adjustable gastric banding surgery. Thirteen demographically matched obese participants were selected from a separate behavioral diet intervention. Resting state fMRI was collected three months after surgery/behavioral intervention. ANOVA was used to examine post-weight loss differences between the two groups in connectivity to seed regions previously identified as showing differential cue-reactivity after weight loss.RESULTSFollowing weight loss, behavioral dieters exhibited increased connectivity between left precuneus/superior parietal lobule (SPL) and bilateral insula pre- to post-meal and bariatric patients exhibited decreased connectivity between these regions pre- to post-meal (pcorrected<.05).CONCLUSIONSBehavioral dieters showed increased connectivity pre- to post-meal between a region associated with processing of self-referent information (precuneus/SPL) and a region associated with interoception (insula) whereas bariatric patients showed decreased connectivity between these regions. This may reflect increased attention to hunger signals following surgical procedures, and increased attention to satiety signals following behavioral diet interventions.

Background: While evidence-based PTSD treatments are often efficacious, 20–50% of individuals continue to experience significant symptoms following treatment. Further, these treatments do not directly target associated neuropsychological deficits. Here, we describe the methods and feasibility for computer-based executive function training (EFT), a potential alternative or adjunctive PTSD treatment. Methods: Male combat veterans with full or partial PTSD ( n = 20) and combat-exposed controls (used for normative comparison; n = 20) completed clinical, neuropsychological and functional neuroimaging assessments. Those with PTSD were assigned to EFT ( n = 13) or placebo training (word games; n = 7) at home for 6 weeks, followed by repeat assessment. Baseline predictors of treatment completion were explored using logistic regressions. Individual feedback and changes in clinical symptoms, neuropsychological function, and neural activation patterns are described. Results: Dropout rates for EFT and placebo training were 38.5 and 57.1%, respectively. Baseline clinical severity and brain activation (i.e., prefrontal-insula-amygdala networks) during an emotional anticipation task were predictive of treatment completion. Decreases in clinical symptoms were observed following treatment in both groups. EFT participants improved on training tasks but not on traditional neuropsychological assessments. All training completers indicated liking EFT, and indicated they would engage in EFT (alone or as adjunctive treatment) if offered. Conclusion: Results provide an initial framework to explore the feasibility of placebo-controlled, computerized, home-based executive function training (EFT) on psychological and neuropsychological function and brain activation in combat veterans with PTSD. Clinical severity and neural reactivity to emotional stimuli may indicate which veterans will complete home-based computerized interventions. While EFT may serve as a potential alternative or adjunctive PTSD treatment, further research is warranted to address compliance and determine whether EFT may benefit functioning above and beyond placebo interventions.

Despite vaccines' consistently demonstrated effectiveness, vaccination rates remain suboptimal due to vaccine refusal. Low vaccination rates are particularly problematic for individuals who cannot be vaccinated for medical reasons and thus must rely on herd immunity (i.e., protection of vulnerable individuals due to the high rate of vaccination of other-often socially distant-individuals). The current study uses a novel decision-making task to examine how three variables impacted participants' highest acceptable probability of side effects to their children: 1) the severity of the side effects their children experience, 2) the social distance to the beneficiary of the vaccination, and 3) the probability that the vaccine will prevent disease for that designated beneficiary. Participants' willingness to risk potential side effects of vaccination systematically decreased as the 1) effectiveness of the vaccination decreased, 2) the beneficiary of the vaccination became more socially distant, and 3) the severity of side effects increased. These data were well-described by behavioral economic models used to examine the discounting of other health behavior.