The interplay of childhood maltreatment and maternal depression in relation to the reward positivity in youth

Guided by developmental psychopathology and dual-risk frameworks, the present study examined the interplay between childhood maltreatment and maternal major depression history in relation to neural reward responsiveness in youth. The sample consisted of 96 youth (ages 9–16; M = 12.29 years, SD = 2.20; 68.8% female) drawn from a large metropolitan city. Youth were recruited based on whether their mothers had a history of major depressive disorder (MDD) and were categorized into two groups: youth with mothers with a history of MDD (high risk; HR; n = 56) and youth with mothers with no history of psychiatric disorders (low risk; LR; n = 40). The reward positivity (RewP), an event-related potential component, was utilized to measure reward responsiveness and the Childhood Trauma Questionnaire measured childhood maltreatment. We found a significant two-way interaction between childhood maltreatment and risk group in relation to RewP. Simple slope analysis revealed that in the HR group, greater childhood maltreatment was significantly associated with reduced RewP. The relationship between childhood maltreatment and RewP was not significant among the LR youth. The present findings demonstrate that the association between childhood maltreatment and blunted reward responsiveness is dependent on whether offspring have mothers with histories of MDD.

Decision Making Under Chronic Stress and Anxiety: State and Trait Anxiety Impact Contextual Updating but not Feedback Learning

Stress may alter executive functioning by causing structural and functional changes to the brain. Sub-optimal decisions made under high levels of stress and anxiety may act as a mediator for stress-related health effects. We examined the effect of three personality traits–chronic stress, state anxiety, and trait anxiety–on updating working memory and feedback learning across 330 participants, using electroencephalography (EEG). We hypothesized a decrease in P300 (updating working memory) and reward positivity (feedback learning) amplitudes with increasing chronic stress and anxiety scores. The three personality traits were not correlated with reward positivity amplitudes. Additionally, chronic stress had no effect on P300 amplitudes. However, state and trait anxiety were negatively correlated with P300 amplitudes. Anxiety appears to impact working memory processes, and this effect was amplified with decreasing anxiety score quantiles to reflect the tails of the distribution. Our results are evidence of the beginnings of a correlation between anxiety and the neural correlates of decision-making, offering insight into anxiety-related adverse health outcomes.

Neural Response to Rewards in Youths with Insomnia

Study Objectives Insomnia and depression are common comorbid conditions in youths. Emerging evidence suggests that disrupted reward processing may be implicated in the association between insomnia and the increased risk for depression. Reduced reward positivity (RewP) as measured by event-related potential (ERP) has been linked to depression, but has not been tested in youths with insomnia. Methods Twenty-eight participants with insomnia disorder and without any comorbid psychiatric disorders and 29 healthy sleepers aged between 15-24 completed a monetary reward task, the Cued Door task, whilst electroencephalographic activity was recorded. RewP (reward minus non-reward difference waves) was calculated as the mean amplitudes within 200ms to 300ms time window at FCz. Two analyses of covariance (ANCOVAs) were conducted with age as a covariate on RewP amplitude and latency, respectively. Results Participants with insomnia had a significantly lower RewP amplitude regardless of cue types (Gain, Control, and Loss) than healthy sleepers, F (1, 51) = 4.95, p = .031, indicating blunted reward processing. On the behavioural level, healthy sleepers were more prudential (slower reaction time) in decision making towards Loss/Gain cues than their insomnia counterparts. Trial-by-trial behavioural adjustment analyses showed that, compared with healthy sleepers, participants with insomnia were less likely to dynamically change their choices in response to Loss cues. Conclusions Dysfunctional reward processing, coupled with inflexibility of behavioural adjustment in decision-making, is associated with insomnia disorder among youth, independent of mood disorders. Future studies with long-term follow-up are needed to further delineate the developmental trajectory of insomnia-related reward dysfunctions in youth.

Task-level value affects trial-level reward processing and control

Despite disagreement about how anterior cingulate cortex (ACC) supports decision making, a recent hypothesis suggests that activity in this region is best understood in the context of a task or series of tasks. One important task-level variable is average reward because it is both a known driver of effortful behaviour and an important determiner of the tasks in which we choose to engage. Here we asked how average task value affects reward-related ACC activity. To answer this question, we measured a reward-related signal said to be generated in ACC called the reward positivity (RewP) while participants gambled in three tasks of differing average value. The RewP was reduced in the high-value task, an effect that was not explainable by either reward magnitude or outcome expectancy. Average task value also affected cue-locked frontal midline theta (FMT), an ACC signal linked to cognitive control: FMT was enhanced for low-value cues relative to high-value cues. This effect was related to behaviour, as the more FMT a participant exhibited, the better they performed. These results suggest that ACC does not evaluate outcomes and cues in isolation, but in the context of the value of the current task.

Differences in Reward Sensitivity between High and Low Problematic Smartphone Use Adolescents: An ERP Study

Background: Problematic smartphone use is highly prevalent in adolescent populations compared to other age groups (e.g., adults and young children). Previous studies suggested that higher levels of reward sensitivity were associated with problematic smartphone use. Therefore, the current study investigated the neural processing of monetary and social reward and punishment feedbacks between high and low problematic smartphone use adolescents. Methods: 46 adolescents participated in the current study and they were categorized into two groups based on their level of problematic smartphone use: those who obtained low scores on the measure of problematic smartphone use were categorized as Low Problematic Smartphone Use (LPSU), and those who obtained high scores on the measure of problematic smartphone use were categorized as High Problematic Smartphone Use (HPSU). Electrocortical activities were recorded during the processing of monetary and social reward and punishment feedback. Results: (1) LPSUs evoked larger P3 in the social punishment condition than in the monetary punishment condition. HPSUs evoked larger P3 in the social reward condition than in the monetary condition. (2) The feedback-related negativity (FRN) amplitudes in the reward condition were significantly larger than those in the punishment condition. (3) HPSUs induced larger reward positivity in social feedback conditions than in monetary feedback conditions, while there were no significant differences between the two types of conditions in the LPSUs. Discussion: The results provide neural underpinning evidence that high sensitivity to social rewards may be related to problematic smartphone use in adolescence.

Amphetamine alters the Reward Positivity in humans and mice

The development of pro-cognitive therapeutics for psychiatric disorders has been beset with difficulties. This is in part due to the absence of pharmacologically-sensitive cognitive biomarkers common to humans and rodents. Here, we describe a cross-species translational measure of reward processing that is sensitive to the dopamine agonist, d-amphetamine. Motivated by human electroencephalographic (EEG) findings, we recently reported that frontal midline delta-band power is also an electrophysiological biomarker of reward surprise in mice. Here, we determined the impact on this reward-related EEG response from humans (n=23) and mice (n=28) performing a probabilistic learning task under parametric doses of d-amphetamine (human: placebo, 10 mg, 20 mg; mice: placebo, 0.1 mg/kg, 0.3 mg.kg, 1.0 mg/kg). In humans, d-amphetamine boosted the Reward Positivity event-related potential (ERP) component as well as the spectral delta-band representation of this signal. In mice, only the Reward Positivity ERP component was significantly boosted by d-amphetamine. In sum, the present results confirm the role of dopamine in the generation of the Reward Positivity, and support the first pharmacologically valid biomarker of reward sensitivity across species.