Electrophysiological correlates of anticipating improbable but desired events

Effects and neural correlates of tDCS on anhedonia in MDD: A randomized clinical trial

OBJECTIVE

Transcranial direct current stimulation (tDCS) targeting the left dorsolateral prefrontal cortex (DLPFC) has been explored as a potential add-on therapy for anhedonia in major depressive disorder (MDD), a condition often resistant to conventional antidepressants. This study aimed to further evaluate the effects and neural correlates of adjunctive tDCS on anhedonia in MDD.

METHODS

This randomized, double-blind, sham-controlled study recruited 70 MDD patients, of whom 56 completed the protocol. Assessments were conducted at baseline and after two weeks of intervention, utilizing clinical evaluations for depression and anhedonia, alongside task- and resting-state EEG measurements.

RESULTS

Our results demonstrated that adjunctive tDCS significantly improved overall depressive symptoms and anhedonia. Notably, we observed a more pronounced negative-going shift in Feedback-Related Negativity amplitude during the Guessing-Door Task and enhanced occipital alpha power spectral density in resting-state EEG. Moreover, increases in alpha activity were inversely correlated with subjective anhedonia severity, as measured by the Snaith-Hamilton Pleasure Scale.

CONCLUSIONS

These findings suggest that adjunctive tDCS applied to the left DLPFC can effectively reduce symptoms of anhedonia in MDD patients, potentially through specific alterations in brain activity.

Differential Insular Cortex Activation During Reward Anticipation in Major Depressive Disorder With and Without Anxiety

BACKGROUND

Anticipation involves preparatory resource allocation to optimize upcoming responses, linked to insular cortex function. Although individuals with major depressive disorder (MDD) show impairments in anticipatory processing and blunted insula activation, it is unclear whether this pattern holds across MDD with comorbid anxiety disorders (MDD+ANX) and MDD without comorbid anxiety disorders. The monetary incentive delay (MID) task, combined with magnetic resonance imaging (MRI)-guided electroencephalography (EEG) source localization, offers a robust approach to study anticipatory mechanisms in MDD subtypes.

METHODS

Participants with MDD (n = 53) or MDD+ANX (n = 108) and healthy control participants (CTLs; n = 38) completed the MID task during simultaneous EEG-MRI recording. Stimulus-preceding negativity event-related potentials were source localized to identify insular cortical activity differences across groups (MDD, MDD+ANX, CTL), sex (male, female), MID task conditions (gain, loss), hemisphere (left, right), and 6 insular subregions.

RESULTS

Behavioral performance revealed that the CTL group reacted faster than the MDD+ANX group in both gain and loss conditions (p = .03). Insular source analysis showed lower activity in the MDD+ANX (p < .001) and MDD (p = .06) groups than in the CTL group during gain anticipation and lower activity in the MDD+ANX group than in both CTL (p = .003) and MDD (p < .001) groups during loss anticipation.

CONCLUSIONS

Results highlight potential intervention targets for improving anticipatory deficits in MDD+ANX. The MDD+ANX group exhibited distinctive patterns of insular cortical activity, with lower activity during the anticipation of both gain and loss feedback than the CTL and MDD groups, suggesting significant neural alterations. Moreover, in the MDD+ANX group, higher anxiety severity was linked to increased insula activity during loss anticipation, indicating a specific neural correlate of anxiety in this comorbid condition.

The effect of unilateral hand muscle contraction on frontal alpha asymmetry and inhibitory control in intrinsic reward contexts, a randomized controlled trial

Challenged inhibitory control has been implicated in various disorders, including addiction. Previous research suggests that asymmetry of frontal brain activity, indexed by frontal alpha asymmetry (FAA), is associated with inhibitory control and could be a target for neuromodulatory intervention. Some evidence suggests that unilateral muscle contraction (UMC) can modulate FAA; however, experimental evidence is scarce. We conducted a randomized controlled trial, with 65 participants (Mage = 26.6; SD = 7.4), 37 of whom were females. We collected EEG data to calculate FAA and assessed inhibitory performance using the Stop Signal Task (SST) in neutral and intrinsic reward (palatable food) conditions, both before and after a unilateral left-hand muscle contraction task aimed at enhancing right relative to left frontal activity. We found a significant main effect of group on FAA. Specifically, UMC group was associated with higher right relative to left frontal activity, associated with resting state inhibitory activity. Event-related potential analyses revealed a significant dissociation between the stop N2 and stop P3 components as a function of time. More specifically, as time progressed, the stop N2 was enhanced, while the stop P3 was reduced. These results did not lead to observable changes in the behavioral index of stopping. In conclusion, UMC did not affect any behavioral and brain activity indices. There is some indication of a potential effect on FAA. However, this effect could reflect coincidental differences in trait FAA. Our findings provide new insights into the temporal dynamics of brain activity indices of inhibitory control.

Neural dynamics underlying the illusion of control during reward processing

The illusion of control refers to a behavioral bias in which people believe they have greater control over completely stochastic events than they actually do, leading to an inflated estimate of reward probability than objective probability warrants. In this study, we examined how reward system is modulated by the illusion of control through the lens of neural dynamics. Participants in a behavioral task exhibited a classical illusion of control, assigning a higher value to the gambling wheels they picked themselves than to those given randomly. An event-related potential study of the same task revealed that this behavioral bias is associated with reduced reward anticipation, as indexed by the stimulus-preceding negativity, diminished positive prediction error signals, as reflected by the reward positivity, and enhanced motivational salience, as revealed by the P300. Our findings offer a mechanistic understanding of the illusion of control in terms of reward dynamics.

Blunted stimulus-preceding negativity during reward anticipation in major depressive disorder

BACKGROUND

Reward processing dysfunction is a core characteristic of major depressive disorder (MDD), yet event-related potential (ERP) research in MDD has predominantly focused on reward receipt as opposed to anticipation. The stimulus-preceding negativity (SPN) ERP reflects anticipatory brain processing. This study examines whether individuals with MDD exhibit deficits during reward anticipation as evidenced by altered SPN amplitude.

METHODS

We assessed prefeedback-SPN amplitudes during a monetary incentive delay (MID) task in individuals with MDD (n = 142, 99 with comorbid anxiety disorders [MDD + ANX]) compared to Controls (n = 37). A mixed analysis of variance was performed on prefeedback-SPN amplitude and behavioral measures, with group (MDD, MDD + ANX, Control) as the between-subjects factor, and feedback (gain, loss) and electrode (F3, F4, Fz, C3, C4, Cz, P3, P4, Pz) as within-subjects factors.

RESULTS

A group main effect revealed faster reaction times for the Control group than MDD and MDD + ANX groups. A group x feedback interaction indicated that the MDD subgroup had smaller prefeedback-SPN amplitudes than MDD + ANX and Control groups when anticipating gain feedback. Additionally, individuals with current MDD, irrespective of past MDD and comorbid anxiety, exhibited smaller SPN amplitudes than Controls prior to gain feedback.

LIMITATIONS

The MID paradigm, designed for functional magnetic resonance imaging (fMRI) data acquisition, lacks optimization for ERP analysis. Moreover, the clinical groups included more females than the Control group.

CONCLUSIONS

Reduced resource allocation to reward anticipation may differentiate MDD from MDD + ANX and Control groups. Further investigation of the neural mechanisms of distinct MDD phenotypes is warranted.

Neurophysiological signatures of prediction in language: A critical review of anticipatory negativities

Recent event-related potential (ERP) studies in language comprehension converge in finding anticipatory negativities preceding words or word segments that can be pre-activated based on either sentence contexts or phonological cues. We review these findings from different paradigms in the light of evidence from other cognitive domains in which slow negative potentials have long been associated with anticipatory processes and discuss their potential underlying mechanisms. We propose that this family of anticipatory negativities captures common mechanisms associated with the pre-activation of linguistic information both within words and within sentences. Future studies could utilize these anticipatory negativities in combination with other, well-established ERPs, to simultaneously track prediction-related processes emerging at different time intervals (before and after the perception of pre-activated input) and with distinct time courses (shorter-lived and longer-lived cognitive operations).

Exploring the neural underpinnings of chord prediction uncertainty: an electroencephalography (EEG) study

Predictive processing in the brain, involving interaction between interoceptive (bodily signal) and exteroceptive (sensory) processing, is essential for understanding music as it encompasses musical temporality dynamics and affective responses. This study explores the relationship between neural correlates and subjective certainty of chord prediction, focusing on the alignment between predicted and actual chord progressions in both musically appropriate chord sequences and random chord sequences. Participants were asked to predict the final chord in sequences while their brain activity was measured using electroencephalography (EEG). We found that the stimulus preceding negativity (SPN), an EEG component associated with predictive processing of sensory stimuli, was larger for non-harmonic chord sequences than for harmonic chord progressions. Additionally, the heartbeat evoked potential (HEP), an EEG component related to interoceptive processing, was larger for random chord sequences and correlated with prediction certainty ratings. HEP also correlated with the N5 component, found while listening to the final chord. Our findings suggest that HEP more directly reflects the subjective prediction certainty than SPN. These findings offer new insights into the neural mechanisms underlying music perception and prediction, emphasizing the importance of considering auditory prediction certainty when examining the neural basis of music cognition.

Effort Expenditure Increases Risk-Taking for Improbable Rewards

Previous studies have found that exerting effort can lead people to engage in risk-taking behaviors. While effort can be either cognitive or physical, risk-taking can take place in either a risky context with known outcome probabilities or an ambiguous context with unknown outcome probabilities. The goal of the current research is to investigate how effort type and decision context influence risk-taking after effort exertion. Across three experiments, we find evidence that investing effort increases risk-taking at a short timescale. Importantly, this effect is particularly noticeable when the chance of winning is low, rather than when it is uncertain. Furthermore, the increase in risk-taking happens regardless of whether the effort is cognitive or physical. These findings suggest the existence of a cost-invariant but decision context-variant mechanism for the risk-taking after-effect of effort expenditure, which helps to bring the negative emotions caused by effort exertion back to a state of emotional homeostasis.

The neural correlates of continuous feedback processing

Feedback processing is commonly studied by analyzing the brain's response to discrete rather than continuous events. Such studies have led to the hypothesis that rapid phasic midbrain dopaminergic activity tracks reward prediction errors (RPEs), the effects of which are measurable at the scalp via electroencephalography (EEG). Although studies using continuous feedback are sparse, recent animal work suggests that moment-to-moment changes in reward are tracked by slowly ramping midbrain dopaminergic activity. Some have argued that these ramping signals index state values rather than RPEs. Our goal here was to develop an EEG measure of continuous feedback processing in humans, then test whether its behavior could be accounted for by the RPE hypothesis. Participants completed a stimulus-response learning task in which a continuous reward cue gradually increased or decreased over time. A regression-based unmixing approach revealed EEG activity with a topography and time course consistent with the stimulus-preceding negativity (SPN), a scalp potential previously linked to reward anticipation and tonic dopamine release. Importantly, this reward-related activity depended on outcome expectancy: as predicted by the RPE hypothesis, activity for expected reward cues was reduced compared to unexpected reward cues. These results demonstrate the possibility of using human scalp-recorded potentials to track continuous feedback processing, and test candidate hypotheses of this activity.

Neural Correlates of Anhedonia in Major Depressive Disorder: Insights from Concurrent Analysis of Feedback-Related Negativity and Stimulus-Preceding Negativity

Purpose

Anhedonia, a core symptom of major depressive disorder (MDD), is explored in this study, focusing on the neural underpinnings through the examination of two event-related potential (ERP) components: feedback-related negativity (FRN) and stimulus-preceding negativity (SPN).

Patients and Methods

This cross-sectional study was conducted in China from March 2022 to March 2023. It involved 35 MDD patients and 31 healthy controls (HC) participating in a modified 2-door task with simultaneous EEG recordings. Depression severity and anhedonia were assessed using the Hamilton Depression Scale (HAMD) and the Temporal Experience of Pleasure Scale (TEPS-CV), respectively. FRN and SPN metrics, along with correlations with each other and clinical assessments, were examined.

Results

In comparison to the HC group, the MDD group exhibited significantly lower scores in TEPS-CV (t = 2.854, p = 0.006) and its subscales (t = -3.596, p = 0.001 and t = 2.434, p = 0.018, respectively), along with consistently reduced amplitudes of FRN (F 1.64= 4.726, p = 0.033) and SPN (F 1.64= 4.195, p = 0.045) across all conditions. Limited correlations were observed between ERP metrics and clinical indicators, except for positive correlations between FRN amplitudes (loss minus win) and HAMD scores (r = 0.392, p = 0.020), and SPN amplitudes after losing (SPN-L) and TEPS-CV consumption subscale scores (r = 0.357, p = 0.035). Notably, while the HC group displayed no significant FRN-SPN correlations, the MDD group exhibited positive FRN-SPN correlations under distinct conditions (r = 0.376, p = 0.026 and r = 0.355, p = 0.037, respectively).

Conclusion

Our data reveal subjective and objective anhedonia in both consumption and anticipation, suggesting a shared impairment in reward feedback processing and anticipatory neural mechanisms in individuals with MDD. These findings deepen our understanding of anhedonia's neural foundations and may guide targeted interventions for this core symptom.

Adaptations of the balloon analog risk task for neuroimaging settings: a systematic review

Introduction

The Balloon Analog Risk Task (BART), a computerized behavioral paradigm, is one of the most common tools used to assess the risk-taking propensity of an individual. Since its initial behavioral version, the BART has been adapted to neuroimaging technique to explore brain networks of risk-taking behavior. However, while there are a variety of paradigms adapted to neuroimaging to date, no consensus has been reached on the best paradigm with the appropriate parameters to study the brain during risk-taking assessed by the BART. In this review of the literature, we aimed to identify the most appropriate BART parameters to adapt the initial paradigm to neuroimaging and increase the reliability of this tool.

Methods

A systematic review focused on the BART versions adapted to neuroimaging was performed in accordance with PRISMA guidelines.

Results

A total of 105 articles with 6,879 subjects identified from the PubMed database met the inclusion criteria. The BART was adapted in four neuroimaging techniques, mostly in functional magnetic resonance imaging or electroencephalography settings.

Discussion

First, to adapt the BART to neuroimaging, a delay was included between each trial, the total number of inflations was reduced between 12 and 30 pumps, and the number of trials was increased between 80 and 100 balloons, enabling us to respect the recording constraints of neuroimaging. Second, explicit feedback about the balloon burst limited the decisions under ambiguity associated with the first trials. Third, employing an outcome index that provides more informative measures than the standard average pump score, along with a model incorporating an exponential monotonic increase in explosion probability and a maximum explosion probability between 50 and 75%, can yield a reliable estimation of risk profile. Additionally, enhancing participant motivation can be achieved by increasing the reward in line with the risk level and implementing payment based on their performance in the BART. Although there is no universal adaptation of the BART to neuroimaging, and depending on the objectives of a study, an adjustment of parameters optimizes its evaluation and clinical utility in assessing risk-taking.

DeePay: deep learning decodes EEG to predict consumer's willingness to pay for neuromarketing

There is an increasing demand within consumer-neuroscience (or neuromarketing) for objective neural measures to quantify consumers' subjective valuations and predict responses to marketing campaigns. However, the properties of EEG raise difficulties for these aims: small datasets, high dimensionality, elaborate manual feature extraction, intrinsic noise, and between-subject variations. We aimed to overcome these limitations by combining unique techniques of Deep Learning Networks (DLNs), while providing interpretable results for neuroscientific and decision-making insight. In this study, we developed a DLN to predict subjects' willingness to pay (WTP) based on their EEG data. In each trial, 213 subjects observed a product's image, from 72 possible products, and then reported their WTP for the product. The DLN employed EEG recordings from product observation to predict the corresponding reported WTP values. Our results showed 0.276 test root-mean-square-error and 75.09% test accuracy in predicting high vs. low WTP, surpassing other models and a manual feature extraction approach. Network visualizations provided the predictive frequencies of neural activity, their scalp distributions, and critical timepoints, shedding light on the neural mechanisms involved with evaluation. In conclusion, we show that DLNs may be the superior method to perform EEG-based predictions, to the benefit of decision-making researchers and marketing practitioners alike.

Distinct neural dynamics underlying risk and ambiguity during valued-based decision making

Uncertainty can be fractioned into risk and ambiguity psychologically and neurobiologically. However, whether and how risk and ambiguity are dissociated in terms of neural dynamics during value-based decision making remain elusive. The present event-related potential (ERP) study addressed these issues by asking participants to perform a wheel-of-fortune task either during a risky context (Experiment 1; N = 30) where outcome probability was known or during an ambiguous context (Experiment 2; N = 30) where outcome probability was unknown. Results revealed that the cue-P3 was more enhanced for risk versus ambiguity during the anticipatory phase, whereas the RewP was more increased for ambiguity than risk during the consummatory phase. Moreover, the SPN and the fb-P3 components were further modulated by the levels of risk and ambiguity, respectively. These findings demonstrate a neural dissociation between risk and ambiguity, which unfolds from the anticipatory phase to the consummatory phase.

An EEG study on the effect of being overweight on anticipatory and consummatory reward in response to pleasant taste stimuli

Two-thirds of adults in the United Kingdom currently suffer from overweight or obesity, making it one of the biggest contributors to health problems. Within the framework of the incentive sensitisation theory, it has been hypothesised that overweight people experience heightened reward anticipation when encountering cues that signal food, such as pictures and smells of food, but that they experience less reward from consuming food compared to normal-weight people. There is, however, little evidence for this prediction. Few studies test both anticipation and consumption in the same study, and even fewer with electroencephalography (EEG). This study sought to address this gap in the literature by measuring scalp activity when overweight and normal-weight people encountered cues signalling the imminent arrival of pleasant and neutral taste stimuli, and when they received these stimuli. The behavioural data showed that there was a smaller difference in valence ratings between the pleasant and neutral taste in the overweight than normal-weight group, in accordance with our hypothesis. However, contrary to our hypothesis, the groups did not differ in their electrophysiological response to taste stimuli. Instead, there was a reduction in N1 amplitude to both taste and picture cues in overweight relative to normal-weight participants. This suggests that reduced attention to cues may be a crucial factor in risk of overweight.

Do rare emotional scenes enhance LPP modulation?

The slow wave late positive potential (LPP) is one of the most dependable measures of emotional processing in human neuroscience. While LPP positivity shows modest malleability by emotional regulation and competing tasks, its fundamental enhancement by emotional scene perception is extremely reliable. Here we assess the impact of emotional scene frequency (67%, 50% and 17%) on the strength of LPP modulation, across 3 groups of participants, using consistent presentation and analysis methods. The results demonstrate strong consistency in the strength of emotional modulation across frequent, equiprobable, and rare emotion conditions. However, a small enhancement of LPP positivity was found during unpleasant scenes in the rare emotion condition. The LPP thus appears to be largely insensitive to contextual features such as scene frequency and predictability, suggesting that strong emotional cues persistently engage orienting and evaluation processes because this tendency was selected in phylogeny.

Contextual Cueing Accelerated and Enhanced by Monetary Reward: Evidence From Event-Related Brain Potentials

The vital role of reward in guiding visual attention has been supported by previous literatures. Here, we examined the motivational impact of monetary reward feedback stimuli on visual attention selection using an event-related potential (ERP) component called stimulus-preceding negativity (SPN) and a standard contextual cueing (CC) paradigm. It has been proposed that SPN reflects affective and motivational processing. We focused on whether incidentally learned context knowledge could be affected by reward. Both behavior and brain data demonstrated that contexts followed by reward feedback not only gave rise to faster implicit learning but also obtained a larger CC effect.

Modulatory Effects of Prediction Accuracy on Electroencephalographic Brain Activity During Prediction

Prediction is essential for the efficiency of many cognitive processes; however, this process is not always perfect. Predictive coding theory suggests that the brain generates and updates a prediction to respond to an upcoming event. Although an electrophysiological index of prediction, the stimulus preceding negativity (SPN), has been reported, it remains unknown whether the SPN reflects the prediction accuracy, or whether it is associated with the prediction error, which corresponds to a mismatch between a prediction and an actual input. Thus, the present study aimed to investigate this question using electroencephalography (EEG). Participants were asked to predict the original pictures from pictures that had undergone different levels of pixelation. The SPN amplitude was affected by the level of pixelation and correlated with the subjective evaluation of the prediction accuracy. Furthermore, late positive components (LPC) were negatively correlated with SPN. These results suggest that the amplitude of SPN reflects the prediction accuracy; more accurate prediction increases the SPN and reduces the prediction error, resulting in reduced LPC amplitudes.

Neural dynamics of monetary and social reward processing in social anhedonia

Being characterized by reduced pleasure from social interaction, social anhedonia constitutes a transdiagnostic marker for various psychiatric disorders. However, the neural portrait of social anhedonia remains elusive because of heterogeneities of reward type and reward dynamics in previous studies. The present event-related potential study investigated neural dynamics in response to monetary and social rewards in social anhedonia. Event-related potential responses were examined when a high social anhedonia (HSA, N = 23) group and a low social anhedonia (LSA, N = 26) group were anticipating and consuming social and monetary rewards. LSA but not HSA participants showed an increased stimulus-preceding negativity (anticipatory phase) and and increased reward positivity (consummatory phase) for monetary as compared with social rewards. This group difference could spring from an increased relevance of social rewards or a general decline in affective responding due to a potential association between social anhedonia and depression. Our findings provide preliminary evidence for neural aberrations of the reward system in social anhedonia, which is contingent upon reward type and reward dynamics.

Distinct electrophysiological correlates between expected reward and risk processing

Expected reward and risk (reward variance) are two fundamental parameters in decision making, which may be encoded by distinct functional brain networks during the anticipatory phase of reward processing. However, whether and how anticipatory reward and risk processing are dissociable in terms of temporal dynamics remain ambiguous. The current event-related potential (ERP) study addressed this issue in a card-guessing task where participants were presented sequentially two cards from a deck of nine (numbered 1 through 9) and were instructed to bet whether the second card was higher or lower than the first one. Expected reward and risk were manipulated orthogonally (in an uncorrelated way) over a full range of reward probabilities (every 12.5% from 0% to 100%). We focused on three anticipatory ERP components: the cue-related reward positivity (cue-RewP), the cue-related P3 (cue-P3), and the stimulus-preceding negativity (SPN). During the period after presentation of the first card, the cue-RewP was sensitive to expected reward instead of risk, whereas the cue-P3 was mainly sensitive to risk and to a lesser extent to expected reward. During the waiting period for the second card, the SPN was sensitive to expected reward but not to risk. Our findings indicate a partial neural dissociation between expected reward and risk in the anticipatory phase of reward processing.

Behavioral and Neural Arguments of Motivational Influence on Decision Making During Uncertainty

The scientific world is increasingly interested in motivation, primarily due to the suspected impact on decision-making abilities, particularly in uncertain conditions. To explore this plausible relationship, 28 healthy participants were included in the study and performed decision-making and motivational tasks while their neural activity was recorded. All participants performed the Iowa Gambling Task (IGT) and were split into two groups based on their score, one favorable group with 14 participants who performed advantageously and one undecided group with 14 participants who failed to develop the correct strategy on the IGT. In addition, all participants performed the Effort Expenditure for Reward Task (EEfRT), which defines the motivational level of each participant by the effort that participants agree to do in function of reward magnitudes and probabilities to receive these reward (10, 50, and 90%). The completion of both tasks allowed for the exploration of the relationship between the motivational level and decision-making abilities. The EEfRT was adapted to electroencephalography (EEG) recordings to explore how motivation could influence reward experience. Behavioral results showed no difference in EEfRT performances on the whole task between the two groups’ performances on the IGT. However, there was a negative correlation between the difficulty to develop an optimal strategy on the IGT and the percentage of difficult choices at the 90% condition on the EEfRT. Each probability condition has been previously associated to different motivational and emotional states, with the 90% condition associated to the reward sensitivity. This behavioral result leads to the hypothesis that reward sensitivity may induce an inability to develop an optimal strategy on the IGT. Group analysis demonstrated that only the undecided group showed a P300 during the processing of the outcome, whereas the favorable group showed a blunted P300. Similarly, there was a negative correlation between the P300 amplitude and the ability to develop an optimal strategy on the IGT. In conclusion, behavioral and neuronal data provides evidence that the propensity to focus only on the immediate outcomes is related to the development of an inefficient strategy on the IGT, without influence of motivation.

Event-Related Potentials (ERP) Indices of Motivation during the Effort Expenditure for Reward Task

Dynamic and temporal facets of the various constructs that comprise motivation remain to be explored. Here, we adapted the Effort Expenditure for Reward Task, a well-known laboratory task used to evaluate motivation, to study the event-related potentials associated with reward processing. The Stimulus Preceding Negativity (SPN) and the P300 were utilized as motivation indicators with high density electroencephalography. The SPN was found to be more negative for difficult choices compared to easy choices, suggesting a greater level of motivation, at a neurophysiological level. The insula, a structure previously associated with both effort discounting and prediction error, was concomitantly activated during the generation of the SPN. Processing a gain significantly altered the amplitude of the P300 compared to an absence of gain, particularly on centroparietal electrodes. One of the generators of the P300 was located on the vmPFC, a cerebral structure involved in the choice between two positive results and their predictions, during loss processing. Both the SPN and the P300 appear to be reliable neural markers of motivation. We postulate that the SPN represents the strength of the motivational level, while the P300 represents the impact of motivation on updating memories of the feedback.

Keep calm and carry on: electrophysiological evaluation of emotional anticipation in the second language

Investigations of the so-called ‘foreign language effect’ have shown that emotional experience is language-dependent in bilingual individuals. Response to negative experiences, in particular, appears attenuated in the second language (L2). However, the human brain is not only reactive, but it also builds on past experiences to anticipate future events. Here, we investigated affective anticipation in immersed Polish–English bilinguals using a priming paradigm in which a verbal cue of controlled affective valence allowed making predictions about a subsequent picture target. As expected, native word cues with a negative valence increased the amplitude of the stimulus preceding negativity, an electrophysiological marker of affective anticipation, as compared with neutral ones. This effect was observed in Polish–English bilinguals and English monolinguals alike. The contrast was non-significant when Polish participants were tested in English, suggesting a possible reduction in affective sensitivity in L2. However, this reduction was not validated by a critical language × valence interaction in the bilingual group, possibly because they were highly fluent in English and because the affective stimuli used in the present study were particularly mild. These results, which are neither fully consistent nor inconsistent with the foreign language effect, provide initial insights into the electrophysiology of affective anticipation in bilingualism.

Reward processing in certain versus uncertain contexts in schizophrenia: An event-related potential (ERP) study

Disturbances in motivation are prominent in the clinical presentation of people with schizophrenia and might reflect a disturbance in reward processing. Recent advances in affective neuroscience have subdivided reward processing into distinct components, but there are two limitations of the prior work in schizophrenia. First, studies typically focus on only one component rather than on the unfolding of reward processing across multiple stages. Second, studies have not considered the impact of certainty effects, which represent an important contextual factor that impacts processing. We examined whether individuals with schizophrenia show the typical certainty effects across three phases of reward processing: cue evaluation, feedback anticipation, and feedback receipt. Electroencephalography from 74 healthy controls and 92 people with schizophrenia was recorded during a cued gambling task under conditions in which cues indicated forthcoming reward outcomes that were certain or uncertain. Controls demonstrated the expected certainty effects across each stage. Initial cue evaluation (cue P300) was intact in the schizophrenia group, but people with schizophrenia showed diminished certainty effects during feedback anticipation (stimulus-preceding negativity [SPN]) and receipt (feedback reward positivity [fRewP] and feedback P300). During feedback receipt, event-related potentials in people with schizophrenia were similar to controls for the uncertain context but larger than controls for the certain context. Essentially, people with schizophrenia appeared to process certain feedback as though it were uncertain. These findings show, for the first time, that the fundamental distinction between certain and uncertain contexts is altered in schizophrenia at a neural level. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Expectation Gates Neural Facilitation of Emotional Words in Early Visual Areas

The current study examined whether emotional expectations gate attention to emotional words in early visual cortex. Color cues informed about word valence and onset latency. We observed a stimulus-preceding negativity prior to the onset of cued words that was larger for negative than for neutral words. This indicates that in anticipation of emotional words more attention was allocated to them than to neutral words before target onset. During stimulus presentation the steady-state visual evoked potential (SSVEP), elicited by flickering words, was attenuated for cued compared to uncued words, indicating sharpened sensory activity, i.e., expectation suppression. Most importantly, the SSVEP was more enhanced for negative than neutral words when these were cued. Uncued conditions did not differ in SSVEP amplitudes, paralleling previous studies reporting lexico-semantic but not early visual effects of emotional words. We suggest that cueing mediates re-entrant engagement of visual resources by providing an early “affective gist” of an upcoming word. Consequently, visual single-word studies may have underestimated attentional effects of emotional words and their anticipation during reading.

Contextual valence modulates the effect of choice on incentive processing

Previous research has demonstrated that reward-related neural activity is enhanced for choice relative to no-choice opportunities in the gain context. The current event-related potential study examined whether this modulatory effect of choice can be observed in both the gain and the loss contexts across anticipatory and consummatory phases of incentive processing. Thirty-two participants performed a simple choice task during which choices were made either by themselves (a choice condition) or by a computer (a no-choice condition) during a gain context (gain vs nongain) and a loss context (nonloss vs loss). Behaviorally, participants reported a higher level of perceived control in the choice than the no-choice condition as well as in the gain than loss context. During the anticipatory phase, the choice relative to the no-choice condition elicited an increased cue-P3 in the loss context and an enhanced stimulus-preceding negativity in the gain context. During the consummatory phase, the choice condition elicited a larger reward positivity (ΔRewP) than the no-choice condition in the gain relative to the loss context but a comparable feedback P3 across contexts. These findings demonstrate that the crucial role of voluntary choice in reward processing is contingent upon contextual valence.

Elevated outcome-anticipation and outcome-evaluation ERPs associated with a greater preference for larger-but-delayed rewards

Although waiting for a reward reduces or discounts its value, some people have a stronger tendency to wait for larger rewards and forgo smaller-but-immediate rewards. This ability to delay gratification is captured by individual differences in so-called intertemporal choices in which individuals are asked to choose between larger-but-delayed versus smaller-but-immediate rewards. The current study used event-related potentials (ERPs) to examine whether enhancement in two neurocognitive processes, outcome anticipation and outcome evaluation, modulate individual variability in intertemporal responses. After completing a behavioral intertemporal choice task, 34 participants performed an ERP gambling task. From this ERP task, we separately examined individual differences in outcome anticipation (stimulus-preceding negativity; SPN), early outcome valuation (feedback-related negativity; FRN), and late outcome evaluation (P3). We observed that both elevated outcome-anticipation (SPN) and late outcome-evaluation (P3) neural processes predicted a stronger preference toward larger-but-delayed rewards. No relationship was observed between intertemporal responses and early outcome evaluation (FRN), indicating that the relationship between outcome evaluation and intertemporal responses was specific to the late outcome-evaluation processing stream. Moreover, multiple regression analyses indicated that the SPN and P3 independently modulate individual differences in intertemporal responses, suggesting separate mechanisms underlie the relationship between these two neurocognitive processes and intertemporal responses. Accordingly, we identify two potential neurocognitive modulators of individual variability in intertemporal responses. We discuss the mechanisms underlying these modulators in terms of anticipation-related processing (SPN) and a saliency bias toward gain (compared to loss) outcomes (P3).

Diminished choice effect on anticipating improbable rewards

Previous research found that the neural substrates underlying perceived control highly overlap those of reward system, especially during reward anticipation stage. The current event-related potential study examined whether the experience of choice by which individuals exercise control is modulated by reward probability during reward anticipation stage as indexed by the stimulus-preceding negativity (SPN). Thirty participants performed a cued gambling task during which choices could be made either by themselves (a choice condition) or by a computer (a no-choice condition) with three levels of reward probability (low, medium, and high) while their EEG was recording. As expected, the participants perceived higher control during the choice compared to no-choice condition. Correspondingly, the SPN was enhanced in the choice condition than the no-choice condition. Critically, the SPN choice effect was present when reward probability was high and medium, but was diminished when reward probability was low. These findings suggest that the perceived control as exercised by choice is associated with reward anticipation, which may be sensitive to the fundamental properties of reward.

Event Boundaries Trigger Rapid Memory Reinstatement of the Prior Events to Promote Their Representation in Long-Term Memory

Although everyday experiences unfold continuously over time, shifts in context, or event boundaries, can influence how those events come to be represented in memory [1-4]. Specifically, mnemonic binding across sequential representations is more challenging at context shifts, such that successful temporal associations are more likely to be formed within than across contexts [1, 2, 5-9]. However, in order to preserve a subjective sense of continuity, it is important that the memory system bridge temporally adjacent events, even if they occur in seemingly distinct contexts. Here, we used pattern similarity analysis to scalp electroencephalographic (EEG) recordings during a sequential learning task [2, 3] in humans and showed that the detection of event boundaries triggered a rapid memory reinstatement of the just-encoded sequence episode. Memory reactivation was detected rapidly (∼200-800 ms from the onset of the event boundary) and was specific to context shifts that were preceded by an event sequence with episodic content. Memory reinstatement was not observed during the sequential encoding of events within an episode, indicating that memory reactivation was induced specifically upon context shifts. Finally, the degree of neural similarity between neural responses elicited during sequence encoding and at event boundaries correlated positively with participants' ability to later link across sequences of events, suggesting a critical role in binding temporally adjacent events in long-term memory. Current results shed light onto the neural mechanisms that promote episodic encoding not only for information within the event, but also, importantly, in the ability to link across events to create a memory representation of continuous experience.

Temporal Dynamics of Proactive and Reactive Motor Inhibition

Proactive motor inhibition refers to endogenous preparatory mechanisms facilitating action inhibition, whereas reactive motor inhibition is considered to be a sudden stopping process triggered by external signals. Previous studies were inconclusive about the temporal dynamics of involved neurocognitive processes during proactive and reactive motor control. Using electroencephalography (EEG), we investigated the time-course of proactive and reactive inhibition, measuring event-related oscillations and event-related potentials (ERPs). Participants performed in a cued go/nogo paradigm with cues indicating whether the motor response might or might not have to be inhibited. Based on the dual mechanisms of control (DMC) framework by Braver, we investigated the role of attentional effects, motor preparation in the sensorimotor cortex and prefrontal cognitive control mechanisms, separating effects before and after target onset. In the cue-target interval, proactive motor inhibition was associated with increased attention, reflected in reduced visual alpha power and an increased contingent negative variation (CNV). At the same time, motor inhibition was modulated by reduced sensorimotor beta power. After target onset, proactive inhibition resulted in an increased N1, indicating allocation of attention towards relevant stimuli, increased prefrontal beta power and a modulation of sensorimotor mu activity. As in previous studies, reactive stopping of motor actions was associated with increased prefrontal beta power and increased sensorimotor beta activity. The results stress the relevance of attentional mechanisms for proactive inhibition and speak for different neurocognitive mechanisms being involved in the early preparation for and in later implementation of motor inhibition.

Neural mechanisms of reward processing associated with depression-related personality traits

OBJECTIVE

Although impaired reward processing in depression has been well-documented, the exact nature of that deficit remains poorly understood. To investigate the link between depression and the neural mechanisms of reward processing, we examined individual differences in personality.

METHODS

We recorded the electroencephalogram from healthy college students engaged in a probabilistic reinforcement learning task. Participants also completed several personality questionnaires that assessed traits related to reward sensitivity, motivation, and depression. We examined whether behavioral measures of reward learning and event-related potential components related to outcome processing and reward anticipation-namely, the cue and feedback-related reward positivity (RewP) and the stimulus preceding negativity (SPN)-would link these personality traits to depression.

RESULTS

Participants who scored high in reward sensitivity produced a relatively larger feedback-RewP. By contrast, participants who scored high in depression learned the contingencies for infrequently rewarded cue-response combinations relatively poorly, exhibited a larger SPN, and produced a smaller feedback-RewP, especially to outcomes following cue-response combinations that were frequently rewarded.

CONCLUSION

These results point to a primary deficit in reward valuation in individuals who score high in depression, with secondary consequences that impact reward learning and anticipation.

SIGNIFICANCE

Despite recent evidence arguing for an anticipatory deficit in depression, impaired reward valuation as a primary deficit should be further examined in clinical samples.

Close games versus blowouts: Optimal challenge reinforces one's intrinsic motivation to win

When immersed in intrinsically motivating activities, individuals actively seek optimal challenge, which generally brings the most satisfaction as they play hard and finally win. To better simulate real-life scenarios in the controlled laboratory setting, a two-player online StopWatch (SW) game was developed, whose format is similar to that of a badminton tournament. During the game, a male opponent played by a confederate ensured that the same-sex participant paired with him won both matches, one with a wide margin (the lack of challenge condition) and another with a narrow one (the optimal challenge condition). Electrophysiological data were recorded during the entire experiment. An enlarged Stimulus-preceding negativity (SPN) was observed in the optimal challenge condition, indicating a more concentrated anticipatory attention toward the feedback and a stronger intrinsic motivation during close games. Thus, this study provided original neural evidence for predictions of Self-determination theory (SDT) and Flow theory, and confirmed and emphasized the significant role of optimal challenge in promoting one's intrinsic motivation to win.

Motivated to win: Relationship between anticipatory and outcome reward-related neural activity

Reward-processing involves two temporal stages characterized by two distinct neural processes: reward-anticipation and reward-outcome. Intriguingly, very little research has examined the relationship between neural processes involved in reward-anticipation and reward-outcome. To investigate this, one needs to consider the heterogeneity of reward-processing within each stage. To identify different stages of reward processing, we adapted a reward time-estimation task. While EEG data were recorded, participants were instructed to button-press 3.5s after the onset of an Anticipation-Cue and received monetary reward for good time-estimation on the Reward trials, but not on No-Reward trials. We first separated reward-anticipation into event related potentials (ERPs) occurring at three sub-stages: reward/no-reward cue-evaluation, motor-preparation and feedback-anticipation. During reward/no-reward cue-evaluation, the Reward-Anticipation Cue led to a smaller N2 and larger P3. During motor-preparation, we report, for the first time, that the Reward-Anticipation Cue enhanced the Readiness Potential (RP), starting approximately 1s before movement. At the subsequent feedback-anticipation stage, the Reward-Anticipation Cue elevated the Stimulus-Preceding Negativity (SPN). We also separated reward-outcome ERPs into different components occurring at different time-windows: the Feedback-Related Negativity (FRN), Feedback-P3 (FB-P3) and Late-Positive Potentials (LPP). Lastly, we examined the relationship between reward-anticipation and reward-outcome ERPs. We report that individual-differences in specific reward-anticipation ERPs uniquely predicted specific reward-outcome ERPs. In particular, the reward-anticipation Early-RP (1-.8s before movement) predicted early reward-outcome ERPs (FRN and FB-P3), whereas, the reward-anticipation SPN most strongly predicted a later reward-outcome ERP (LPP). Results have important implications for understanding the nature of the relationship between reward-anticipation and reward-outcome neural-processes.

Live as we choose: The role of autonomy support in facilitating intrinsic motivation

According to Self-determination Theory (SDT), autonomy is a basic psychological need, satisfaction of which may lead to enhanced intrinsic motivation and related beneficial outcomes. By manipulating the opportunity to choose between tasks of equal difficulty, throughout the motivational process, the effect of autonomy support was examined both behaviorally and electrophysiologically. More negative stimulus-preceding negativity (SPN) and an enlarged FRN loss-win difference wave (d-FRN) indicated an enhanced expectation toward the positive outcome (during the anticipation stage) as well as intensified intrinsic motivation toward the task (during the outcome appraisal stage) when choice was available. Taken together, results of the present study suggest d-FRN upon feedback as a real-time electrophysiological indicator of intrinsic/autonomous motivation and illustrate the important role of autonomy-supportive job design in the workplace.

Individual differences in error tolerance in humans: Neurophysiological evidences

When interacting in error-prone environments, humans display different tolerances to changing their decisions when faced with erroneous feedback information. Here, we investigated whether these individual differences in error tolerance (ET) were reflected in neurophysiological mechanisms indexing specific motivational states related to feedback monitoring. To explore differences in ET, we examined the performance of 80 participants in a probabilistic reversal-learning task. We then compared event-related brain responses (ERPs) of two extreme groups of participants (High ET and Low ET), which showed radical differences in their propensity to maintain newly learned rules after receiving spurious negative feedback. We observed that High ET participants showed reduced anticipatory activity prior to the presentation of incoming feedback, informing them of the correctness of their performance. This was evidenced by measuring the amplitude of the stimulus-preceding negativity (SPN), an ERP component indexing attention and motivational engagement of incoming informative feedback. Postfeedback processing ERP components (the so-called Feedback-Related Negativity and the P300) also showed reduced amplitude in this group (High ET). The general decreased responsiveness of the High ET group to external feedback suggests a higher proneness to favor internal(rule)-based strategies, reducing attention to external cues and the consequent impact of negative evaluations on decision making. We believe that the present findings support the existence of specific cognitive and motivational processes underlying individual differences on error-tolerance among humans, contributing to the ongoing research focused on understanding the mental processes behind human fallibility in error-prone scenarios.

Goal-directed EEG activity evoked by discriminative stimuli in reinforcement learning

In reinforcement learning (RL), discriminative stimuli (S) allow agents to anticipate the value of a future outcome, and the response that will produce that outcome. We examined this processing by recording EEG locked to S during RL. Incentive value of outcomes and predictive value of S were manipulated, allowing us to discriminate between outcome-related and response-related activity. S predicting the correct response differed from nonpredictive S in the P2. S paired with high-value outcomes differed from those paired with low-value outcomes in a frontocentral positivity and in the P3b. A slow negativity then distinguished between predictive and nonpredictive S. These results suggest that, first, attention prioritizes detection of informative S. Activation of mental representations of these informative S then retrieves representations of outcomes, which in turn retrieve representations of responses that previously produced those outcomes.

Task preparation processes related to reward prediction precede those related to task-difficulty expectation

Recently, attempts have been made to disentangle the neural underpinnings of preparatory processes related to reward and attention. Functional magnetic resonance imaging (fMRI) research showed that neural activity related to the anticipation of reward and to attentional demands invokes neural activity patterns featuring large-scale overlap, along with some differences and interactions. Due to the limited temporal resolution of fMRI, however, the temporal dynamics of these processes remain unclear. Here, we report an event-related potentials (ERP) study in which cued attentional demands and reward prospect were combined in a factorial design. Results showed that reward prediction dominated early cue processing, as well as the early and later parts of the contingent negative variation (CNV) slow-wave ERP component that has been associated with task-preparation processes. Moreover these reward-related electrophysiological effects correlated across participants with response time speeding on reward-prospect trials. In contrast, cued attentional demands affected only the later part of the CNV, with the highest amplitudes following cues predicting high-difficulty potential-reward targets, thus suggesting maximal task preparation when the task requires it and entails reward prospect. Consequently, we suggest that task-preparation processes triggered by reward can arise earlier, and potentially more directly, than strategic top-down aspects of preparation based on attentional demands.