Performance monitoring and empathy during active and observational learning in patients with major depression

Attenuated Doors-Locked P300 Amplitude and Elevated Depressive Symptoms: Effects of Age and Sex in Two Independent Samples of Youth

Deficits in cognitive and reward-related functions, measured via reductions in the P300 and reward positivity (RewP) event-related potential (ERP) components, are commonly observed in adults suffering with depression. Considering higher risk for depression emerges among females in adolescence, examination of the neurological underpinnings of depression during this critical developmental period can help further elucidate our overall understanding of the etiology of depressive disorders. Therefore, the present study sought to first examine associations between doors-locked P300 amplitude, RewP amplitude, current depression symptoms, and age in an all-female youth sample (sample 1: n = 296; age, 8 to 14). Next, we examined these same associations, as well as sex, in a second independent sample consisting of male and female youths (sample 2: n = 605; age, 11 to 14). Blunted doors-locked P300 was associated with higher depressive symptoms in both samples. Moreover, the association between P300 and depression was stronger among older youths in both samples. Sex further moderated this relationship in sample 2 such that smaller P300 related to greater depression only in females. There were no consistent associations between RewP amplitude and depressive symptoms in either youth sample. These findings suggest that the doors-locked P300 component is a reliable neural correlate of depression in youth that might specifically relate to pathways linked to increased risk for depression among adolescent females.

Therapeutic Efficacy of Reward Circuit‐Targeted Transcranial Magnetic Stimulation (TMS) on Suicidal Ideation in Depressed Patients: A Sham‐Controlled Trial of Two TMS Protocols

Background: Suicide is one of the leading causes of premature death, and dysfunctional reward processing may serve as a potential mechanism. However, effective treatment targeting reward circuits is rarely reported.

Objective: The present study investigated the therapeutic efficacy of two individualized protocols, repetitive transcranial magnetic stimulation (rTMS) and intermittent theta burst stimulation (iTBS), targeting the left dorsolateral prefrontal cortex (lDLPFC)–nucleus accumbens (NAcc) circuit on suicidal ideation among patients with major depressive disorder (MDD).

Methods: Here, 40 healthy controls (HCs) and 70 MDD patients (MDDs) were recruited for this double‐blinded, sham‐controlled clinical trial. The reward learning process during the Iowa gambling task (IGT) was initially measured at the baseline. Further, 62 MDDs were assigned to receive 15 daily sessions of individualized rTMS (n = 25), iTBS (n = 15), or sham treatment (n = 22) to the site of strongest lDLPFC–NAcc connectivity.

Results: We found MDDs demonstrated abnormalities in both IGT performance and reward‐associated event‐related potential (ERP) components compared to HCs. MDDs in the rTMS and iTBS groups showed significant improvements in suicidal ideation and anhedonia symptoms compared to the sham group. The rTMS group also exhibited a more negative‐going N170 and feedback‐related negativity (FRN) after treatment, and the increase in N170 absolute amplitude posttreatment showed a trend of correlation with improved Temporal Experience Pleasure Scales (TEPSs) and TEPS‐anticipatory (TEPS‐ant) scores.

Conclusion: The current study indicates that reward circuit‐based rTMS and iTBS showed comparable antisuicidal effects in depressive patients, suggesting that the lDLPFC–NAcc pathway may serve as a potential treatment target.

Trial Registration: ClinicalTrials.gov identifier: NCT03991572

Feedback negativity and feedback-related P3 in individuals at risk for depression: Comparing surface potentials and current source densities

Blunted responses to reward feedback have been linked to major depressive disorder (MDD) and depression risk. Using a monetary incentive delay task (win, loss, break-even), we investigated the impact of family risk for depression and lifetime history of MDD and anxiety disorder with 72-channel electroencephalograms (EEG) recorded from 29 high-risk and 32 low-risk individuals (15-58 years, 30 male). Linked-mastoid surface potentials (ERPs) and their corresponding reference-free current source densities (CSDs) were quantified by temporal principal components analysis (PCA). Each PCA solution revealed a midfrontal feedback negativity (FN; peak around 310 ms) and a posterior feedback-P3 (fb-P3; 380 ms) as two distinct reward processing stages. Unbiased permutation tests and multilevel modeling of component scores revealed greater FN to loss than win and neutral for all stratification groups, confirming FN sensitivity to valence. Likewise, all groups had greater fb-P3 to win and loss than neutral, confirming that fb-P3 indexes motivational salience and allocation of attention. By contrast, group effects were subtle, dependent on data transformation (ERP, CSD), and did not confirm reduced FN or fb-P3 for at-risk individuals. Instead, CSD-based fb-P3 was overall reduced in individuals with than without MDD history, whereas ERP-based fb-P3 was greater for high-risk individuals than for low-risk individuals for monetary, but not neutral outcomes. While the present findings do not support blunted reward processing in depression and depression risk, our side-by-side comparison underscores how the EEG reference choice affects the characterization of subtle group differences, strongly advocating the use of reference-free techniques.

Effort and Appetitive Responding in Depression: Examining Deficits in Motivational and Consummatory Stages of Reward Processing Using the Effort-Doors Task

Background

Reward sensitivity is a dimensional construct central to understanding the nature of depression. Psychophysiological research on this construct has primarily focused on the reward positivity, an event-related potential (ERP) that indexes consummatory reward sensitivity. This study extended prior research by focusing on ERPs that index the motivational component of reward.

Methods

A novel effort-for-reward task was used to elicit motivational and consummatory ERPs. Groups consisting of 34 participants with depression and 32 participants without depression were compared across a range of reward-related ERPs.

Results

Participants with depression exhibited reduced responsivity to effort completion cues following high effort expenditure, reduced anticipation of rewards after low effort expenditure (i.e., the stimulus preceding negativity), and reduced reward positivity following high effort expenditure. ERPs occurring prior to reward receipt accounted for unique variance in depression status and differentiated between subgroups of depressed individuals.

Conclusions

Findings support the utility of leveraging multiple ERPs that index separate reward processing deficits to better characterize depression and depressive subtypes.

Deficits in doors P300 amplitude during adolescence associated with preschool-onset depression

The psychophysiological underpinnings of preschool-onset depression (PO-MDD) remain underexplored. Moreover, there is currently a limited understanding of the potential impact that PO-MDD might have on neurobiological functions later in development such as general cognitive domains and reward processing. Thus, the current study sought to examine potential neurophysiological differences, measured via electroencephalography (EEG), in adolescents with and without a history of PO-MDD. Participants and their caregivers (N = 138) from a large longitudinal study completed semi-structured clinical interviews at a baseline visit (ages 3-7) to determine PO-MDD status. At a follow-up visit approximately 11 years later, adolescents (ages 13-19) completed the doors gambling task while EEG was recorded to measure event-related potentials (ERPs) elicited by both the doors and feedback stimuli, to index cognitive and reward processing functions (i.e., doors-P300, gain/loss feedback-P300, and RewP). Adolescents with a history of PO-MDD exhibited significantly smaller doors-P300 compared with adolescents with no history of PO-MDD, whereas there were no group differences in gain/loss feedback-P300 or RewP. Additionally, reduced doors-P300 was independently associated with lower baseline income-to-needs ratio, older age, and female gender. The current study suggests that reduced doors-P300 amplitude during adolescence might reflect impaired neurophysiological development related to PO-MDD. Thus, the P300 derived from the doors stimuli might be a valuable neural measure to further our understanding of potential neurophysiological differences associated with early-onset childhood depression.

Sensitivity to intrinsic rewards is domain general and related to mental health

Humans frequently engage in intrinsically rewarding activities (for example, consuming art, reading). Despite such activities seeming diverse, we show that sensitivity to intrinsic rewards is domain general and associated with mental health. In this cross-sectional study, participants online (N = 483) were presented with putative visual, cognitive and social intrinsic rewards as well as monetary rewards and neutral stimuli. All rewards elicited positive feelings (were 'liked'), generated consummatory behaviour (were 'wanted') and increased the likelihood of the action leading to them (were 'reinforcing'). Factor analysis revealed that ~40% of response variance across stimuli was explained by a general sensitivity to all rewards, but not to neutral stimuli. Affective aspects of mental health were associated with sensitivity to intrinsic, but not monetary, rewards. These results may help explain thriving and suffering: individuals with high reward sensitivity will engage in a variety of intrinsically rewarding activities, eventually finding those they excel at, whereas low sensitivity individuals will not.

A, Srivastava P. Empathic Accuracy Task: Indian Adaptation and Validation

Background

The Empathic Accuracy Task (EAT) is an objective measure to assess empathic accuracy. Due to the variability in the number and linked emotions of the narrated events, we adapted EAT for the Indian sociocultural setting as Indian EAT (I-EAT).

Methods

Eight videos were adapted in three languages (English, Hindi, and Kannada), narrating emotional events with a uniform representation of age groups, different emotions, and sex. The adapted I-EAT was then validated by cross-sectional comparison with different tests similar to EAT and those that assessed concepts different from or similar to empathy, in 29 healthy young adults, 23 healthy older adults (aged ≥60 years) along with clinical groups of 15 young people with depression, 15 older people with depression, and 15 young people with schizophrenia.

Results

We selected eight videos with good content validity and internal consistency (Cronbach's alpha = 0.73. We obtained satisfactory concurrent validity of the EAT scores with the self-reported empathic assessments using the Questionnaire of Cognitive and Affective Empathy (Cognitive empathy score = 0.29, p = .034; Total score = 0.29, p = .035) and Interpersonal Reactivity Index (Empathic concern score = 0.45, p = .001). Good divergent validity was revealed in the high inverse correlation recorded with the Apathy Evaluation Scale ( = -0.67, p < .001). I-EAT did not correlate significantly with measures of social cognition. Known-groups validity was adequate in young adults with the significantly lower EAT scores (Cohen's d: 0.77 to 1.15) in the Schizophrenia group and higher EAT-N scores (Cohen's d: 0.51) in the Depression group, compared to the Healthy group. The Healthy group of the geriatric population also achieved significantly higher EAT scores (Cohen's d: 0.71 to 0.85) than the Depression group.

Conclusion

With a good validity and internal consistency, I-EAT can be used in the Indian population to assess empathic accuracy without compromising performance of the original EAT.

Belief updating in psychosis, depression and anxiety disorders: A systematic review across computational modelling approaches

Alterations in belief updating are proposed to underpin symptoms of psychiatric illness, including psychosis, depression, and anxiety. Key parameters underlying belief updating can be captured using computational modelling techniques, aiding the identification of unique and shared deficits, and improving diagnosis and treatment. We systematically reviewed research that applied computational modelling to probabilistic tasks measuring belief updating in stable and volatile (changing) environments, across clinical and subclinical psychosis (n = 17), anxiety (n = 9), depression (n = 9) and transdiagnostic samples (n = 9). Depression disorders related to abnormal belief updating in response to the valence of rewards, evidenced in both stable and volatile environments. Whereas psychosis and anxiety disorders were associated with difficulties adapting to changing contingencies specifically, indicating an inflexibility and/or insensitivity to environmental volatility. Higher-order learning models revealed additional difficulties in the estimation of overall environmental volatility across psychosis disorders, showing increased updating to irrelevant information. These findings stress the importance of investigating belief updating in transdiagnostic samples, using homogeneous experimental and computational modelling approaches.

Pleasure, Reward Value, Prediction Error and Anhedonia

In order to develop effective treatments for anhedonia we need to understand its underlying neurobiological mechanisms. Anhedonia is conceptually strongly linked to reward processing, which involves a variety of cognitive and neural operations. This chapter reviews the evidence for impairments in experiencing hedonic response (pleasure), reward valuation and reward learning based on outcomes (commonly conceptualised in terms of "reward prediction error"). Synthesising behavioural and neuroimaging findings, we examine case-control studies of patients with depression and schizophrenia, including those focusing specifically on anhedonia. Overall, there is reliable evidence that depression and schizophrenia are associated with disrupted reward processing. In contrast to the historical definition of anhedonia, there is surprisingly limited evidence for impairment in the ability to experience pleasure in depression and schizophrenia. There is some evidence that learning about reward and reward prediction error signals are impaired in depression and schizophrenia, but the literature is inconsistent. The strongest evidence is for impairments in the representation of reward value and how this is used to guide action. Future studies would benefit from focusing on impairments in reward processing specifically in anhedonic samples, including transdiagnostically, and from using designs separating different components of reward processing, formulating them in computational terms, and moving beyond cross-sectional designs to provide an assessment of causality.

A biomarker of maternal vicarious reward processing and its association with parenting behavior

Parenting styles play a critical role in child well-being, yet the neural bases of parenting behaviors remain nebulous. Understanding the neural processes associated with parenting styles can both clarify etiological mechanisms underlying parenting behaviors and point us toward new targets for intervention. A novel electrocortical biomarker called the observational reward positivity (oRewP) that occurs in response to observing another receive a reward has been linked to self-reported authoritarian parenting behavior. The current study sought to replicate associations between the oRewP and self-reported and observationally-coded parenting in a sample of mothers selected to be at elevated risk for problematic parenting. Self-reported authoritarian parenting was associated with observationally-coded problematic discipline, while no other self-reported parenting scales were associated with observationally-coded scores. We replicated the previously reported association between a blunted oRewP and increased self-reported authoritarian parenting. We additionally found that an attenuated oRewP was associated with greater permissive parenting, and that only the relationship with permissive parenting was conserved after adjusting for other parenting styles and other relevant covariates. We did not find significant associations between the oRewP and observationally-coded parenting. The current findings suggest that the neural process indexed by the oRewP are relevant to parenting behavior. Further research is needed to better understand the discrepancy between self-reported and observed parenting.

Direct feedback and social conformity promote behavioral change via mechanisms indexed by centroparietal positivity: Electrophysiological evidence from a role-swapping ultimatum game

Our behavior is shaped by multiple factors, including direct feedback (seeing the outcomes of our past actions) and social observation (in part, via a drive to conform to other peoples' behaviors). However, it remains unclear how these two processes are linked in the context of behavioral change. This is important to investigate, as behavioral change is associated with distinct neural correlates that reflect specific aspects of processing, such as information integration and rule updating. To clarify whether these processes characterize both direct learning and conformity, we elicited the two within the same task, using a role-swapping version of the Ultimatum Game-a fairness paradigm where subjects decide how to share a pot of money with other players-while electroencephalography (EEG) data were recorded. Behavioral results showed that subjects decided how to divide the pot based on both direct feedback (seeing whether their past proposals were accepted or rejected) and social observation (copying the splits that others just proposed). Converging EEG evidence revealed that increased centroparietal positivity (P2, P3b, and late positivity) indexed behavioral changes motivated by direct feedback and those motivated by drives to conform. However, exploratory analyses also suggest that these two motivating factors may also be dissociable, and that frontal midline theta oscillations may predict behavioral changes linked to direct feedback but not conformity. Overall, this study provides novel electrophysiological evidence regarding the different forms of behavioral change. These findings are also relevant for understanding the mechanisms of social information processing that underlie successful cooperation.

Doors P300 moderates the relationship between reward positivity and current depression status in adults

BACKGROUND

Previous research has found deficits in both the reward positivity (RewP) and P300 components of the event-related potential (ERP) in relation to depression. The current study examined whether the P300, elicited from imperative stimuli in a gambling task, relates to depression - and can be utilized in tandem with the RewP to better account for individual differences in depression.

METHODS

In the current study, 80 adults with current depression (M_age = 39.65, 79% female) and 43 healthy controls (M_age = 37.02, 81% female) completed clinical interviews, self-report questionnaires, and the doors gambling task while EEG was recorded.

RESULTS

Results indicated a reduced P300 to doors stimuli (i.e., doors P300) in depression, especially among depressed individuals reporting heightened anhedonia. Gain and loss feedback P300s did not differ between groups. Moreover, the doors P300 moderated the association between RewP and depression status: individuals with relatively intact reward processing (i.e., larger RewP) were more likely to be currently depressed if they exhibited a reduced P300.

LIMITATIONS

The majority of the sample identified as Caucasian which reduces generalizability of current results. Additionally, the current study is cross sectional design which limits insight into how these ERPs coincide with changes in the disorder.

CONCLUSIONS

The current study demonstrates that a novel P300 component to the doors stimulus appears to be blunted in currently depressed individuals, and that using the doors P300 in combination with the RewP accounts for significantly more variance in depression.

The role of trait empathy in the processing of observed actions in a false-belief task

Empathic brain responses are characterized by overlapping activations between active experience and observation of an emotion in another person, with the pattern for observation being modulated by trait empathy. Also for self-performed and observed errors, similar brain activity has been described, but findings concerning the role of empathy are mixed. We hypothesized that trait empathy modulates the processing of observed responses if expectations concerning the response are based on the beliefs of the observed person. In the present study, we utilized a false-belief task in which observed person’s and observer’s task-related knowledge were dissociated and errors and correct responses could be expected or unexpected. While theta power was generally modulated by the expectancy of the observed response, a negative mediofrontal event-related potential (ERP) component was more pronounced for unexpected observed actions only in participants with higher trait empathy (assessed by the Empathy Quotient), as revealed by linear mixed effects analyses. Cognitive and affective empathy, assessed by the Interpersonal Reactivity Index, were not significantly related to the ERP component. The results suggest that trait empathy can facilitate the generation of predictions and thereby modulate specific aspects of the processing of observed actions, while the contributions of specific empathy components remain unclear.

Reward-Processing Behavior in Depressed Participants Relative to Healthy Volunteers: A Systematic Review and Meta-analysis

IMPORTANCE

Dysfunctional reward processing is a leading candidate mechanism for the development of certain depressive symptoms, such as anhedonia. However, to our knowledge, there has not yet been a systematic assessment of whether and to what extent depression is associated with impairments on behavioral reward-processing tasks.

OBJECTIVE

To determine whether depression is associated with impairments in reward-processing behavior.

DATA SOURCES

The MEDLINE/PubMed, Embase, and PsycInfo databases were searched for studies that investigated reward processing using performance on behavioral tasks by individuals with depression and nondepressed control groups, published between January 1, 1946, and August 16, 2019.

STUDY SELECTION

Studies that contained data regarding performance by depressed and healthy control groups on reward-processing tasks were included in the systematic review and meta-analysis.

DATA EXTRACTION AND SYNTHESIS

Summary statistics comparing performance between depressed and healthy groups on reward-processing tasks were converted to standardized mean difference (SMD) scores, from which summary effect sizes for overall impairment in reward processing and 4 subcomponent categories were calculated. Study quality, heterogeneity, replicability-index, and publication bias were also assessed.

MAIN OUTCOME AND MEASURES

Performance on reward-processing tasks.

RESULTS

The final data set comprised 48 case-control studies (1387 healthy control individuals and 1767 individuals with major depressive disorder). The mean age was 37.85 years and 58% of the participants were women. These studies used tasks assessing option valuation (n = 9), reward bias (n = 6), reward response vigor (n = 12), reinforcement learning (n = 20), and grip force (n = 1). Across all tasks, depression was associated with small to medium impairments in reward-processing behavior (SMD = 0.345; 95% CI, 0.209-0.480). When examining reward-processing subcomponent categories, impairment was associated with tasks assessing option valuation (SMD = 0.309; 95% CI, 0.147-0.471), reward bias (SMD = 0.644; 95% CI, 0.270-1.017), and reinforcement learning (SMD = 0.352; 95% CI, 0.115-0.588) but not reward response vigor (SMD = 0.083; 95% CI, -0.144 to 0.309). The medication status of the major depressive disorder sample did not explain any of the variance in the overall effect size. There was significant between-study heterogeneity overall and in all subcomponent categories other than option valuation. Significant publication bias was identified overall and in the reinforcement learning category.

CONCLUSIONS AND RELEVANCE

Relative to healthy control individuals, individuals with depression exhibit reward-processing impairments, particularly for tests of reward bias, option valuation, and reinforcement learning. Understanding the neural mechanisms driving these associations may assist in designing novel interventions.

Momentary subjective well-being depends on learning and not reward

Subjective well-being or happiness is often associated with wealth. Recent studies suggest that momentary happiness is associated with reward prediction error, the difference between experienced and predicted reward, a key component of adaptive behaviour. We tested subjects in a reinforcement learning task in which reward size and probability were uncorrelated, allowing us to dissociate between the contributions of reward and learning to happiness. Using computational modelling, we found convergent evidence across stable and volatile learning tasks that happiness, like behaviour, is sensitive to learning-relevant variables (i.e. probability prediction error). Unlike behaviour, happiness is not sensitive to learning-irrelevant variables (i.e. reward prediction error). Increasing volatility reduces how many past trials influence behaviour but not happiness. Finally, depressive symptoms reduce happiness more in volatile than stable environments. Our results suggest that how we learn about our world may be more important for how we feel than the rewards we actually receive.

Many people believe they would be happier if only they had more money. And events such as winning the lottery or receiving a large pay rise do make people happy, at least temporarily. But recent studies suggest that the main factor driving happiness on such occasions is not the size of the reward received. Instead, it is how well that reward matches up with expectations. Receiving a 10% pay rise when you were expecting 1% will make you feel happier than receiving 10% when you had been expecting 20%.

This difference between an expected and an actual reward is referred to as a reward prediction error. Reward prediction errors have a key role in learning. They motivate people to repeat behaviours that led to unexpectedly large rewards. But they also enable people to update their beliefs about the world, which is rewarding in itself. Could it be that reward prediction errors are associated with happiness mainly because they help us understand the world a little better than before?

To test this idea, Blain and Rutledge designed a task in which the likelihood of receiving a reward was unrelated to the size of the reward. This study design makes it possible to separate out the contributions of learning versus reward to moment-by-moment happiness.

In the task, volunteers had to decide which of two cars would win a race. In the ‘stable’ condition, one of the cars always had an 80% chance of winning. In the ‘volatile’ condition, one car had an 80% chance of winning for the first 20 trials. The other car then had an 80% chance of winning for the next 20 trials. The volunteers were not told these probabilities in advance, but had to work them out by playing the game. However, on every trial, the volunteers were shown the reward they would receive if they chose either of the cars and that car went on to win. The size of the rewards varied at random and was unrelated to the likelihood of a car winning.

Every few trials, the volunteers were asked to indicate their current level of happiness on a scale. The results showed that volunteers were happier after winning than after losing. On average they were also happier in the stable condition than in the volatile condition. This was especially true for volunteers with pre-existing symptoms of depression. Moreover, happiness after wins did not depend on how large the reward they got was, but instead simply on how surprised they were to win.

These results suggest that how we learn about the world around us can be more important for how we feel than rewards we receive directly. Measuring happiness in various types of environment could help us understand factors affecting mental health. The current results suggest, for example, that uncertain environments may be especially unpleasant for people with depression. Further research is needed to understand why this might be the case. In the real world, rewards are often uncertain and infrequent, but learning may nevertheless have the potential to boost happiness.

Understanding psychiatric disorder by capturing ecologically relevant features of learning and decision-making

Recent research in cognitive neuroscience has begun to uncover the processes underlying increasingly complex voluntary behaviours, including learning and decision-making. Partly this success has been possible by progressing from simple experimental tasks to paradigms that incorporate more ecological features. More specifically, the premise is that to understand cognitions and brain functions relevant for real life, we need to introduce some of the ecological challenges that we have evolved to solve. This often entails an increase in task complexity, which can be managed by using computational models to help parse complex behaviours into specific component mechanisms. Here we propose that using computational models with tasks that capture ecologically relevant learning and decision-making processes may provide a critical advantage for capturing the mechanisms underlying symptoms of disorders in psychiatry. As a result, it may help develop mechanistic approaches towards diagnosis and treatment. We begin this review by mapping out the basic concepts and models of learning and decision-making. We then move on to consider specific challenges that emerge in realistic environments and describe how they can be captured by tasks. These include changes of context, uncertainty, reflexive/emotional biases, cost-benefit decision-making, and balancing exploration and exploitation. Where appropriate we highlight future or current links to psychiatry. We particularly draw examples from research on clinical depression, a disorder that greatly compromises motivated behaviours in real-life, but where simpler paradigms have yielded mixed results. Finally, we highlight several paradigms that could be used to help provide new insights into the mechanisms of psychiatric disorders.

Emotional reactivity and perspective-taking in individuals with and without severe depressive symptoms

The perspective-taking ability to imagine another person's feelings and thoughts is paramount for successful communication. This study pursued two questions regarding the link between perspective-taking and depressive symptomatology in a task where participants provided responses to words ranging in their positivity. First, we examined in a between-participants experimental manipulation how the presence of depressive symptoms influenced participants' emotional reactivity. Second, we measured within-participants, how their responses change as a function of the perspective they are assigned to take, that of a depressed or a non-depressed person. Our main interest is in the interaction of the two effects: we examine how one's emotional state determines the ability to engender someone else's responses. Our central finding is that depressive symptoms lead to emotional insensitivity, i.e., weaker responses to extremely positive and negative words. Furthermore, depressive symptoms come with a much weaker ability to take a non-depressed perspective. Finally, non-depressed participants demonstrated an excellent ability to mimic the blunt affect of depression when responding for the other group, suggesting that the outlook of a depressed individual is available to people throughout the range of depressive symptomatology. We discuss the implications of these findings for quantifying emotional reactivity during depression, as well as the diagnosis and prognosis of depression.

Effects of feedback delay on learning from positive and negative feedback in patients with Parkinson's disease off medication

Phasic dopamine (DA) signals conveyed from the substantia nigra to the striatum and the prefrontal cortex crucially affect learning from feedback, with DA bursts facilitating learning from positive feedback and DA dips facilitating learning from negative feedback. Consequently, diminished nigro-striatal dopamine levels as in unmedicated patients suffering from Parkinson's Disease (PD) have been shown to lead to a negative learning bias. Recent studies suggested a diminished striatal contribution to feedback processing when the outcome of an action is temporally delayed. This study investigated whether the bias towards negative feedback learning induced by a lack of DA in PD patients OFF medication is modulated by feedback delay. To this end, PD patients OFF medication and healthy controls completed a probabilistic selection task, in which feedback was given immediately (after 800 ms) or delayed (after 6800 ms). PD patients were impaired in immediate but not delayed feedback learning. However, differences in the preference for positive/negative learning between patients and controls were seen for both learning from immediate and delayed feedback, with evidence of stronger negative learning in patients than controls. A Bayesian analysis of the data supports the conclusion that feedback timing did not affect the learning bias in the patients. These results hint at reduced, but still relevant nigro-striatal contribution to feedback learning, when feedback is delayed.

Interfering with activity in the dorsomedial prefrontal cortex via TMS affects social impressions updating

In our everyday social interactions we often need to deal with others' unpredictable behaviors. Integrating unexpected information in a consistent representation of another agent is a cognitively demanding process. Several neuroimaging studies point to the medial prefrontal cortex (mPFC) as a critical structure in mediating social evaluations. Our aim here was to shed light on the possible causal role of the mPFC in the dynamic process of forming and updating social impressions about others. We addressed this issue by suppressing activity in the mPFC by means of 1 Hz offline transcranial magnetic stimulation (TMS) prior to a task requiring participants to evaluate other agents' trustworthiness after reading about their social behavior. In two different experiments, we found that inhibiting activity in the mPFC increased perceived trustworthiness when inconsistent information about one agent's behavior was provided. In turn, when only negative or positive behaviors of a person were described, TMS over the mPFC did not affect judgments. Our results indicate that the mPFC is causally involved in mediating social impressions updating-at least in cases in which judgment is uncertain due to conflicting information to be processed.

Authoritarian parenting predicts reduced electrocortical response to observed adolescent offspring rewards

Parenting styles are robust predictors of offspring outcomes, yet little is known about their neural underpinnings. In this study, 44 parent-adolescent dyads (Mage of adolescent = 12.9) completed a laboratory guessing task while EEG was continuously recorded. In the task, each pair member received feedback about their own monetary wins and losses and also observed the monetary wins and losses of the other member of the pair. We examined the association between self-reported parenting style and parents' electrophysiological responses to watching their adolescent winning and losing money, dubbed the observational Reward Positivity (RewP) and observational feedback negativity (FN), respectively. Self-reported authoritarian parenting predicted reductions in parents' observational RewP but not FN. This predictive relationship remained after adjusting for sex of both participants, parents' responsiveness to their own wins, and parental psychopathology. 'Exploratory analyses found that permissive parenting was associated with a blunting of the adolescents' response to their parents' losses'. These findings suggest that parents' rapid neural responses to their child's successes may relate to the harsh parenting behaviors associated with authoritarian parenting.