Effects of task-relevant incentives on the electrophysiological correlates of error processing in major depressive disorder

Probabilistic reward learning in adults with Attention Deficit Hyperactivity Disorder--an electrophysiological study

Attention Deficit Hyperactivity Disorder (ADHD) is hypothesized to be characterized by altered reinforcement sensitivity. The main aim of the present study was to assess alterations in the electrophysiological correlates of monetary reward processing in adult patients with ADHD of the combined subtype. Fourteen adults with ADHD of the combined subtype and 14 healthy control participants performed an active and an observational probabilistic reward-based learning task while an electroencephalogramm (EEG) was recorded. Regardless of feedback valence, there was a general feedback-related negativity (FRN) enhancement in combination with reduced learning performance during both active and observational reward learning in patients with ADHD relative to healthy controls. Other feedback-locked potentials such as the P200 and P300 and response-locked potentials were unaltered in the patients. There were no significant correlations between learning performance, FRN amplitudes and clinical symptoms, neither in the overall group involving all participants, nor in patients or controls considered separately. This pattern of findings might reflect generally impaired reward prediction in adults with ADHD of the combined subtype. We demonstrated for the first time that patients with ADHD of the combined subtype show not only deficient active reward learning but are also impaired when learning by observing other people׳s outcomes.

Active and observational reward learning in adults with autism spectrum disorder: relationship with empathy in an atypical sample

INTRODUCTION

Autism spectrum disorders (ASDs) are characterised by disturbances in social behaviour. A prevailing hypothesis suggests that these problems are related to deficits in assigning rewarding value to social stimuli. The present study aimed to examine monetary reward processing in adults with ASDs by means of event-related potentials (ERPs).

METHODS

Ten individuals with mild ASDs (Asperger's syndrome and high-functioning autism) and 12 healthy control subjects performed an active and an observational probabilistic reward-learning task.

RESULTS

Both groups showed similar overall learning performance. With respect to reward processing, subjects with ASDs exhibited a general reduction in feedback-related negativity (FRN) amplitude, irrespective of feedback valence and type of learning (active or observational). Individuals with ASDs showed lower scores for cognitive empathy, while affective empathy did not differ between groups. Correlation analyses revealed that higher empathy (both cognitive and affective) negatively affected performance in observational learning in controls and in active learning in ASDs (only cognitive empathy). No relationships were seen between empathy and ERPs.

CONCLUSIONS

Reduced FRN amplitudes are discussed in terms of a deficit in fast reward processing in ASDs, which may indicate altered reward system functioning.

Alpha suppression following performance errors is correlated with depression, affect, and coping behaviors

This study tested the hypothesis that enhanced neural arousal in response to performance errors would predict poor affect and coping behaviors in everyday life. Participants were preselected as either low-depressed (LD) or high-depressed (HD) based on a screening questionnaire, and they then completed a laboratory Stroop task while EEG was recorded, followed by a 2-week period of daily reports of affect and coping behaviors. The EEG measure of arousal response to errors was the degree of error-related alpha suppression (ERAS) in the intertrial interval, that is the reduction in alpha power following errors compared with correct responses. ERAS was relatively heightened at frontal sites for the HD versus the LD group, and frontal ERAS predicted lower positive affect, higher negative affect, and less adaptive coping behaviors in the daily reports. Together, the results imply that heightened arousal following mistakes is associated with suboptimal emotion and coping with stressors.

Increased error-related brain activity distinguishes generalized anxiety disorder with and without comorbid major depressive disorder

Generalized anxiety disorder (GAD) and major depressive disorder (MDD) are so frequently comorbid that some have suggested that the 2 should be collapsed into a single overarching "distress" disorder. Yet there is also increasing evidence that the 2 categories are not redundant. Neurobehavioral markers that differentiate GAD and MDD would be helpful in ongoing efforts to refine classification schemes based on neurobiological measures. The error-related negativity (ERN) may be one such marker. The ERN is an event-related potential component presenting as a negative deflection approximately 50 ms following an erroneous response and reflects activity of the anterior cingulate cortex. There is evidence for an enhanced ERN in individuals with GAD, but the literature in MDD is mixed. The present study measured the ERN in 26 GAD, 23 comorbid GAD and MDD, and 36 control participants, all of whom were female and medication-free. Consistent with previous research, the GAD group was characterized by a larger ERN and an increased difference between error and correct trials than controls. No such enhancement was evident in the comorbid group, suggesting comorbid depression may moderate the relationship between the ERN and anxiety. The present study further suggests that the ERN is a potentially useful neurobiological marker for future studies that consider the pathophysiology of multiple disorders in order to construct or refine neurobiologically based diagnostic phenotypes.

Clarifying domains of internalizing psychopathology using neurophysiology

Current initiatives such as the National Institute of Mental Health's Research Domain Criteria project aim to reorganize classification of mental disorders along neurobiological lines. Here, we describe how consideration of findings from psychiatric research employing two physiological measures with distinct neural substrates--the startle blink reflex and the error-related negativity (ERN)--can help to clarify relations among disorders entailing salient anxiety or depressive symptomatology. Specifically, findings across various studies and reviews reveal distinct patterns of association for both the startle blink reflex and the ERN with three key domains of psychopathology: (1) Fear (or phobic) disorders (distinguished by increased startle to unpleasant stimuli, but normal-range ERN). (2) Non-phobic anxiety disorders and negative affect (associated with increased ERN, increased startle across all types of emotional stimuli and increased baseline startle) and, more tentatively (3) Major depression (for which patterns of response for both startle and ERN appear to vary, as a function of severity and distinct symptomatology). Findings from this review point to distinct neurobiological indicators of key psychopathology domains that have been previously demarcated using personality and diagnostic data. Notably, these indicators exhibit more specificity in their relations with these three domains than has been seen in quantitative-dimensional models. Implications of these findings are discussed.

Altered error-related brain activity in youth with major depression

Depression is associated with impairments in cognitive control including action monitoring processes, which involve the detection and processing of erroneous responses in order to adjust behavior. Although numerous studies have reported altered error-related brain activity in depressed adults, relatively little is known about age-related changes in error-related brain activity in depressed youth. This study focuses on the error-related negativity (ERN), a negative deflection in the event-related potential (ERP) that is maximal approximately 50ms following errors. High-density ERPs were examined following responses on a flanker task in 24 youth diagnosed with MDD and 14 low-risk healthy controls (HC). Results indicate that compared to HC, MDD youth had significantly smaller ERN amplitudes and did not exhibit the normative increases in ERN amplitudes as a function of age. Also, ERN amplitudes were similar in depressed youth with and without comorbid anxiety. These results suggest that depressed youth exhibit different age-related changes in brain activity associated with action monitoring processes. Findings are discussed in terms of existing work on the neural correlates of action monitoring and depression and the need for longitudinal research studies investigating the development of neural systems underlying action monitoring in youth diagnosed with and at risk for depression.

Drug-free patients with major depression show an increased electrophysiological response to valid and invalid feedback

BACKGROUND

Depressed patients are biased in their response to negative information. They have been found to show a maladaptive behavioral and aberrant electrophysiological response to negative feedback. The aim of this study was to investigate the behavioral and electrophysiological response to feedback validity in drug-free depressed patients.

METHOD

Fifteen drug-free in-patients with unipolar major depression disorder (MDD) and 30 demographically matched controls performed a time-estimation task in which they received valid and invalid (i.e. related and unrelated to performance) positive and negative feedback. The number of behavioral adjustments to the feedback and the feedback-related negativity (FRN) were measured.

RESULTS

Patients made fewer correct adjustments after valid negative feedback than controls, and their FRNs were larger. Neither patients nor controls adjusted their time estimates following invalid negative feedback.

CONCLUSIONS

The FRN results suggest that depressed drug-free in-patients have an atypical rostral anterior cingulate response to feedback that is independent of feedback validity. Their behavioral response to invalid negative feedback, however, is not impaired. This study confirms the notion that the behavioral responses of depressed individuals to negative feedback are context dependent.

Larger Error Signals in Major Depression are Associated with Better Avoidance Learning

The medial prefrontal cortex (mPFC) is particularly reactive to signals of error, punishment, and conflict in the service of behavioral adaptation and it is consistently implicated in the etiology of major depressive disorder (MDD). This association makes conceptual sense, given that MDD has been associated with hyper-reactivity in neural systems associated with punishment processing. Yet in practice, depression-related variance in measures of mPFC functioning often fails to relate to performance. For example, neuroelectric reflections of mediofrontal error signals are often found to be larger in MDD, but a deficit in post-error performance suggests that these error signals are not being used to rapidly adapt behavior. Thus, it remains unknown if depression-related variance in error signals reflects a meaningful alteration in the use of error or punishment information. However, larger mediofrontal error signals have also been related to another behavioral tendency: increased accuracy in avoidance learning. The integrity of this error-avoidance system remains untested in MDD. In this study, EEG was recorded as 21 symptomatic, drug-free participants with current or past MDD and 24 control participants performed a probabilistic reinforcement learning task. Depressed participants had larger mid-frontal EEG responses to error feedback than controls. The direct relationship between error signal amplitudes and avoidance learning accuracy was replicated. Crucially, this relationship was stronger in depressed participants for high conflict “lose–lose” situations, demonstrating a selective alteration of avoidance learning. This investigation provided evidence that larger error signal amplitudes in depression are associated with increased avoidance learning, identifying a candidate mechanistic model for hypersensitivity to negative outcomes in depression.

Neural responses to negative feedback are related to negative emotionality in healthy adults

Prior neuroimaging and electrophysiological evidence suggests that potentiated responses in the anterior cingulate cortex (ACC), particularly the rostral ACC, may contribute to abnormal responses to negative feedback in individuals with elevated negative affect and depressive symptoms. The feedback-related negativity (FRN) represents an electrophysiological index of ACC-related activation in response to performance feedback. The purpose of the present study was to examine the FRN and underlying ACC activation using low resolution electromagnetic tomography source estimation techniques in relation to negative emotionality (a composite index including negative affect and subclinical depressive symptoms). To this end, 29 healthy adults performed a monetary incentive delay task while 128-channel event-related potentials were recorded. We found that enhanced FRNs and increased rostral ACC activation in response to negative--but not positive--feedback was related to greater negative emotionality. These results indicate that individual differences in negative emotionality--a putative risk factor for emotional disorders--modulate ACC-related processes critically implicated in assessing the motivational impact and/or salience of environmental feedback.

Impaired decision making and feedback evaluation in borderline personality disorder

BACKGROUND

Increased impulsivity is considered to be a core characteristic of borderline personality disorder (BPD) and has been shown to play a significant role in decision making and planning. Neuropsychological studies in BPD revealed impairments of executive functions, and it is assumed that these deficits are related to altered feedback processing. However, research on executive functions in BPD is still limited and the underlying deficits remain an open question. The present study, therefore, explored whether decision-making deficits are related to altered feedback evaluation in BPD.

METHOD

A total of 18 BPD patients and 18 matched healthy controls underwent a modified version of the Iowa Gambling Task while an electroencephalogram was recorded. Feedback processing was examined by measuring the feedback-related negativity (FRN) and the P300 as electrophysiological correlates of feedback evaluation.

RESULTS

Behavioural results revealed that BPD patients, relative to controls, made more risky choices and did not improve their performance. With regard to the FRN, amplitudes in BPD patients did not discriminate between positive and negative feedback information. Further, BPD patients showed reduced FRN amplitudes, which were associated with enhanced impulsivity and enhanced risk taking. In contrast, the P300 amplitudes following negative feedback were increased in BPD patients, relative to controls.

CONCLUSIONS

This study indicates that BPD patients are impaired in decision making, which might be related to a dysfunctional use of feedback information. Specifically, BPD patients did not learn to avoid disadvantageous selections, even though they attended to negative consequences.

The error-related negativity relates to sadness following mood induction among individuals with high neuroticism

The error-related negativity (ERN) is an event-related potential (ERP) that indexes error monitoring. Research suggests that the ERN is increased in internalizing disorders, such as depression and anxiety. Although studies indicate that the ERN is insensitive to state-related fluctuations in anxiety, few studies have carefully examined the effect of state-related changes in sadness on the ERN. In the current study, we sought to determine whether the ERN would be altered by a sad mood induction using a between-subjects design. Additionally, we explored if this relationship would be moderated by individual differences in neuroticism-a personality trait related to both anxiety and depression. Forty-seven undergraduate participants were randomly assigned to either a sad or neutral mood induction prior to performing an arrow version of the flanker task. Participants reported greater sadness following the sad than neutral mood induction; there were no significant group differences on behavioral or ERP measures. Across the entire sample, however, participants with a larger increase in sad mood from baseline to post-induction had a larger (i.e. more negative) ERN. Furthermore, this effect was larger among individuals reporting higher neuroticism. These data indicate that neuroticism moderates the relationship between the ERN and changes in sad mood.

Depression symptom severity and error-related brain activity

The present study examined the relationship between depression and neural correlates of response monitoring using event-related potentials (ERPs). The error-related negativity (ERN) and correct response negativity (CRN) are ERPs that present as a negative deflection approximately 50 ms following an erroneous and correct response, respectively; the error positivity (Pe) is a positive deflection approximately 200 ms following an erroneous response. Some studies have reported an increased ERN in individuals with major depressive disorder (MDD), but others have failed to find such differences. Results on the Pe in MDD have also been mixed. In the current study, unmedicated individuals with MDD (N=22) and healthy controls (N=22) performed an arrow version of the flanker task. Although these groups did not differ on the ERN or CRN overall, depression severity related to the CRN and the differentiation between the ERN and CRN (DeltaERN) in the MDD group: more severe depression was associated with an increased CRN and a reduced DeltaERN. Additionally, the difference between the Pe on error and correct trials (DeltaPe) was reduced among individuals with MDD compared to healthy controls. These data suggest that individuals with severe depression have a reduced differentiation between error and correct trials on ERPs that index error monitoring and awareness.

Attentional control in depression: A translational affective neuroscience approach

Translational research refers to the application of basic science to address clinical problems and acquire knowledge that can be used to guide and refine clinical practice. This special issue of Cognitive, Affective, & Behavioral Neuroscience seeks to explore and integrate some of the most promising findings offered by recent cognitive and affective neuroscience studies in hopes of filling the gap between basic and applied research, thereby heightening our understanding of vulnerability for depression. The studies presented in this special issue focus specifically on attentional processes. We solicited contributions from leading researchers involved in basic cognitive and neuroscience research investigating processes underlying depression-related disturbances in emotion processing. In this introductory article, we present an integrative overview to demonstrate how these specific contributions might be valuable for translational research.