Abnormal proactive and reactive cognitive control during conflict processing in major depression.

According to the Dual Mechanisms of Control framework, cognitive control consists of two complementary components: proactive control refers to anticipatory maintenance of goal-relevant information, whereas reactive control acts as a correction mechanism that is activated when a conflict occurs. Possibly, the well-known diminished inhibitory control in response to negative stimuli in Major Depressive Disorder (MDD) patients stems from a breakdown in proactive control, and/or anomalies in reactive cognitive control. In our study, MDD patients specifically showed increased response latencies when actively inhibiting a dominant response to a sad compared with a happy face. This condition was associated with a longer duration of a dominant ERP topography (800-900 ms poststimulus onset) and a stronger activity in the bilateral dorsal anterior cingulate cortex, reflecting abnormal reactive control when inhibiting attention to a negative stimulus. Moreover, MDD patients showed abnormalities in proactive cognitive control when preparing for the upcoming imperative stimulus (abnormal modulation of the contingent negative variation component), accompanied by more activity in brain regions belonging to the default mode network. All together, deficits to inhibit attention to negative information in MDD might originate from an abnormal use of both proactive resources and reactive control processes.

Electrical brain imaging reveals the expression and timing of altered error monitoring functions in major depression.

Major depressive disorder (MDD) is characterized by disturbances in affect, motivation, and cognitive control processes, including error detection. However, the expression and timing of the impairments during error monitoring remain unclear in MDD. The behavior and event-related brain responses (ERPs) of 20 patients with MDD were compared with those of 20 healthy controls (HCs), while they performed a Go/noGo task. Errors during this task were associated with 2 ERP components, the error-related negativity (ERN/Ne) and the error positivity (Pe). Results show that the ERN/Ne-correct-related negativity (CRN) amplitude difference was significantly larger in MDD patients (after controlling for speed), compared with HCs, although MDD patients exhibited overactive medial frontal cortex (MFC) activation. By comparison, the subsequent Pe component was smaller in MDD patients compared with HCs and this effect was accompanied by a reduced activation of ventral anterior cingulate cortex (ACC) regions. These results suggest that MDD has multiple cascade effects on early error monitoring brain mechanisms.

Erroneous and correct actions have a different affective valence: evidence from ERPs.

The accuracy of actions is swiftly determined through specific monitoring brain systems. Event-related potential (ERP) studies have shown that error commission is associated with the generation of the error-related negativity (ERN/Ne), whereas correct actions are associated with the correct-related negativity (CRN). Although the exact functional meaning of the ERN/Ne (and CRN) component remains debated, some authors have suggested that it reflects the processing of the emotional significance of actions. However, no study to date has directly linked amplitude changes at the level of the ERN/Ne-CRN to the affective processing of actions. To decode the emotional valence of actions performed during a go/no-go task, the authors used an evaluative priming method in this study. After each action following the go/no-go stimulus, participants had to categorize an evaluative word as either positive or negative. Behavioral results showed that response errors (i.e., false alarms, FAs) performed during the go/no-go task led to a faster categorization of negative than positive words. Remarkably, this evaluative priming effect was related to the magnitude of the ERN/Ne component generated during the go/no-go task. Moreover, ERP results showed that the processing of evaluative words following FAs was influenced early on after word onset (early posterior negativity-EPN effect), while it was influenced later following correct as well as incorrect actions (late positive potential-LPP effect). Altogether, these ERP results suggest that the action-related ERN-CRN component encodes the perceived emotional significance of actions, such that early stages of evaluative word processing following these actions are influenced by this automatic process.

Evidence for the automatic evaluation of self-generated actions.

The accuracy of simple actions is swiftly determined through specific monitoring brain systems. However, it remains unclear whether this evaluation is accompanied by a rapid and compatible emotional appraisal of the action that allows to mark incorrect actions as negative/bad and conversely correct actions as positive/good. In this study, we used a new method to decode the affective value of simple actions generated by participants during a standard Go/noGo task. Immediately after each Go/noGo action, participants responded to the valence of either a positive or a negative word. Results showed that False Alarms performed during the Go/noGo task led to a faster evaluative categorization of negative words relative to positive words. This action-word evaluative priming effect occurred when the interval between these two events was set to either 300 or 600ms, but not 1000ms. Finally, higher levels of trait anxiety were associated with a reduction of the evaluative priming effect. Our results suggest that simple actions are rapidly evaluated as positive or negative depending on the automatic monitoring of their perceived accuracy.

Anxiety disrupts the evaluative component of performance monitoring: An ERP study.

Thirty low and 30 high anxious participants performed a speeded Go/noGo task during which they had to rely on evaluative feedback to infer whether their actions were timely (correct) or not. We focused on FRN, an ERP component that is sensitive to the valence of feedback. Depending on the context, neutral faces served either as positive or negative feedback. Whereas the FRN of low anxious individuals did discriminate between neutral faces when used either as positive or negative feedback, the FRN of high anxious individuals did not. However, before the FRN, we also found evidence for a differential perceptual effect at the level of the N170 face-specific component between the two feedback conditions, equally so in low and high anxious individuals. These results suggest that anxiety disrupts selectively the evaluative component of performance monitoring, which presumably allows to ascribe a given value (either positive or negative) to actions.

Anxiety not only increases, but also alters early error-monitoring functions.

Anxiety has profound influences on a wide range of cognitive processes, including action monitoring. Event-related brain potential (ERP) studies have shown that anxiety can boost early error detection mechanisms, as reflected by an enhanced error-related negativity (ERN) following errors in high-anxious, as compared with low-anxious, participants. This observation is consistent with the assumption of a gain control mechanism exerted by anxiety onto error-related brain responses within the dorsal anterior cingulate cortex (ACC). However, whether anxiety simply enhances or, rather, alters early error detection mechanisms remains unsolved. In this study, we compared the performance of low- versus high-trait-anxious participants during a go/no-go task while high-density EEG was recorded. The two groups showed comparable behavioral performance, although levels of state anxiety increased following the task for high-anxious participants only. ERP results confirmed that the ERN/Ne to errors was enhanced for high-anxious, relative to low-anxious, participants. However, complementary topographic analyses revealed that the scalp map of the ERN/Ne was not identical between the two groups, suggesting that anxiety did not merely increase early error detection mechanisms, but also led to a qualitative change in the early appraisal of errors. Inverse solution results confirmed a shift within the ACC for the localization of neural generators underlying the ERN/Ne scalp map in high-anxious participants, corroborating the assumption of an early effect of anxiety on early error-monitoring functions. These results shed new light on the dynamic interplay between anxiety and error-monitoring functions in the human brain.