Stimulus-preceding Negativity Research Articles

EEG Negativity in Fixations Used for Gaze-Based Control: Toward Converting Intentions into Actions with an Eye-Brain-Computer Interface.

We usually look at an object when we are going to manipulate it. Thus, eye tracking can be used to communicate intended actions. An effective human-machine interface, however, should be able to differentiate intentional and spontaneous eye movements. We report an electroencephalogram (EEG) marker that differentiates gaze fixations used for control from spontaneous fixations involved in visual exploration. Eight healthy participants played a game with their eye movements only. Their gaze-synchronized EEG data (fixation-related potentials, FRPs) were collected during game's control-on and control-off conditions. A slow negative wave with a maximum in the parietooccipital region was present in each participant's averaged FRPs in the control-on conditions and was absent or had much lower amplitude in the control-off condition. This wave was similar but not identical to stimulus-preceding negativity, a slow negative wave that can be observed during feedback expectation. Classification of intentional vs. spontaneous fixations was based on amplitude features from 13 EEG channels using 300 ms length segments free from electrooculogram contamination (200–500 ms relative to the fixation onset). For the first fixations in the fixation triplets required to make moves in the game, classified against control-off data, a committee of greedy classifiers provided 0.90 ± 0.07 specificity and 0.38 ± 0.14 sensitivity. Similar (slightly lower) results were obtained for the shrinkage Linear Discriminate Analysis (LDA) classifier. The second and third fixations in the triplets were classified at lower rate. We expect that, with improved feature sets and classifiers, a hybrid dwell-based Eye-Brain-Computer Interface (EBCI) can be built using the FRP difference between the intended and spontaneous fixations. If this direction of BCI development will be successful, such a multimodal interface may improve the fluency of interaction and can possibly become the basis for a new input device for paralyzed and healthy users, the EBCI “Wish Mouse.”

Perceived control increases the reward positivity and stimulus preceding negativity.

The reward positivity (RewP) and the stimulus preceding negativity (SPN), two ERPs associated with reward delivery and reward anticipation, are modulated by motivational intensity. Motivational intensity is the effort organisms would make to exert behaviors, and it varies with the difficulty of exerting that behavior. If a task is perceived as impossible, which means that one does not have control over own outcomes, motivational intensity is low. In the current study, we tested the prediction that perceiving control over one's outcomes increases both the RewP to feedback and the SPN prior to feedback compared to perceiving no control. We also examined whether P300 and LPP amplitudes to reward and nonreward images were similarly modulated. Twenty-five female participants completed a gambling task in which correct choices were followed by pictures of attractive men and incorrect choices were followed by pictures of rocks. To manipulate perceived control, participants were told that, in one block of trials, they could learn a mouse-click rule in order to see only pictures of men (high perceived control condition), while in the other block, the pictures would appear randomly (low perceived control condition). However, in both conditions, feedback appeared randomly. Although the RewP was elicited in both blocks, the RewP and SPN were higher in the high perceived control condition (i.e., when participants thought that they could influence their outcomes). Perceived control did not modulate the P300 and LPP to pictures. The results suggest that approach motivation and its intensity modulate the processing of performance feedback.

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.

What do we expect from a beauty? Facial attractiveness of the opposite sex gives rise to discrepancies in males' anticipation and demand.

Facial attractiveness plays a significant role in social interactions and the effect of beauty premium is frequently observed. Previous studies showed that observing attractive counterparts would alleviate one's sense of unfairness. However, the mechanism underlying this phenomenon remained to be clarified. In this study, male participants were engaged in a modified Dictator game as recipients and their electroencephalograms were recorded. They were convinced that anonymous females who vary in facial attractiveness played as dictators. An outcome anticipation stage was implemented before proposed offers were presented and we focused on the cognitive process of subjective anticipation. A less negative Stimulus-preceding negativity was observed in the attractive face condition, suggesting that subjects paid less anticipatory attention toward proposed offers, and subjective expectation toward fair ones was weakened when beauties played as dictators. Thus, this study provides additional neural evidences for the beauty premium effect and suggests a reasonable explanation for this commonly reported phenomenon.

Behavioural and neural modulation of win-stay but not lose-shift strategies as a function of outcome value in Rock, Paper, Scissors.

Competitive environments in which individuals compete for mutually-exclusive outcomes require rational decision making in order to maximize gains but often result in poor quality heuristics. Reasons for the greater reliance on lose-shift relative to win-stay behaviour shown in previous studies were explored using the game of Rock, Paper, Scissors and by manipulating the value of winning and losing. Decision-making following a loss was characterized as relatively fast and relatively inflexible both in terms of the failure to modulate the magnitude of lose-shift strategy and the lack of significant neural modulation. In contrast, decision-making following a win was characterized as relatively slow and relatively flexible both in terms of a behavioural increase in the magnitude of win-stay strategy and a neural modulation of feedback-related negativity (FRN) and stimulus-preceding negativity (SPN) following outcome value modulation. The win-stay/lose-shift heuristic appears not to be a unified mechanism, with the former relying on System 2 processes and the latter relying on System 1 processes. Our ability to play rationally appears more likely when the outcome is positive and when the value of wins are low, highlighting how vulnerable we can be when trying to succeed during competition.

Adaptive behaviour and feedback processing integrate experience and instruction in reinforcement learning

In any non-deterministic environment, unexpected events can indicate true changes in the world (and require behavioural adaptation) or reflect chance occurrence (and must be discounted). Adaptive behaviour requires distinguishing these possibilities. We investigated how humans achieve this by integrating high-level information from instruction and experience. In a series of EEG experiments, instructions modulated the perceived informativeness of feedback: Participants performed a novel probabilistic reinforcement learning task, receiving instructions about reliability of feedback or volatility of the environment. Importantly, our designs de-confound informativeness from surprise, which typically co-vary. Behavioural results indicate that participants used instructions to adapt their behaviour faster to changes in the environment when instructions indicated that negative feedback was more informative, even if it was simultaneously less surprising. This study is the first to show that neural markers of feedback anticipation (stimulus-preceding negativity) and of feedback processing (feedback-related negativity; FRN) reflect informativeness of unexpected feedback. Meanwhile, changes in P3 amplitude indicated imminent adjustments in behaviour. Collectively, our findings provide new evidence that high-level information interacts with experience-driven learning in a flexible manner, enabling human learners to make informed decisions about whether to persevere or explore new options, a pivotal ability in our complex environment.

An Integrative Approach to Delta and Theta Oscillatory Activity: Cognitive Correlates, Aging and Applications to Neuropsychiatric Disorders

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.

Headstart for speech segmentation: a neural signature for the anchor word effect

Learning a new language is an incremental process that builds upon previously acquired information. To shed light on the mechanisms of this incremental process, we studied the on-line neurophysiological correlates of the so-called anchor word effect where newly learned words facilitate segmentation of novel words from continuous speech. Higher segmentation performance was observed for speech streams embedded with newly learned anchor words. The anchor words elicited an enhanced Stimulus-preceding negativity (SPN) component considered to be an index of expectation for incoming relevant information. Moreover, we confirmed a previously reported N400 amplitude increase for the to-be-segmented novel words, indicating a bottom-up learning process whereby new memory representations for the novel words emerge. We propose that the anchor word effect indexed by SPN reflects an expectation for an incoming novel word at the offset of the anchor word, thus facilitating the segmentation process.

Stimulus-preceding negativity represents a conservative response tendency

Humans tend to be conservative and typically will retain their initial decision even if an option to change is provided. We investigated whether the stimulus-preceding negativity (SPN), an event-related potential associated with the affective-motivational anticipation of feedback in gambling tasks, represents the strong response tendency to retain an initial decision. We compared SPNs in three different card-gambling tasks wherein the participants were given the opportunity to change their initial decision after they chose one of three cards. In two of these tasks, the winning probability was equiprobable (1/3 and 1/2, respectively) whether or not the participants changed their initial decision. However, in the Monty Hall dilemma task, changing the initial decision stochastically doubled the probability of winning (2/3) compared with retaining (1/3). In this counterintuitive probabilistic dilemma task, after the participant chose an option among three cards, a nonreward (losing) option is revealed. Then, the participants are offered a chance to change their mind and asked to make their final decision: to retain their initial choice or change to the alternate option. In all tasks, maintenance of previous behaviors was observed, although the rate of retaining earlier choices tended to be lower in the Monty Hall dilemma task than in the other two tasks. The SPNs were larger on retain trials than on change trials irrespective of task. These results suggest that underlying brain activities associated with the strong tendency to retain the initial decision can be observed by the SPN and thus it reflects expectancy of outcomes in terms of self-chosen behaviors.

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.

Single-Trial Event-Related Potential Correlates of Belief Updating(1,2,3).

Belief updating—the process by which an agent alters an internal model of its environment—is a core function of the CNS. Recent theory has proposed broad principles by which belief updating might operate, but more precise details of its implementation in the human brain remain unclear. In order to address this question, we studied how two components of the human event-related potential encoded different aspects of belief updating. Participants completed a novel perceptual learning task while electroencephalography was recorded. Participants learned the mapping between the contrast of a dynamic visual stimulus and a monetary reward and updated their beliefs about a target contrast on each trial. A Bayesian computational model was formulated to estimate belief states at each trial and was used to quantify the following two variables: belief update size and belief uncertainty. Robust single-trial regression was used to assess how these model-derived variables were related to the amplitudes of the P3 and the stimulus-preceding negativity (SPN), respectively. Results showed a positive relationship between belief update size and P3 amplitude at one fronto-central electrode, and a negative relationship between SPN amplitude and belief uncertainty at a left central and a right parietal electrode. These results provide evidence that belief update size and belief uncertainty have distinct neural signatures that can be tracked in single trials in specific ERP components. This, in turn, provides evidence that the cognitive mechanisms underlying belief updating in humans can be described well within a Bayesian framework.

Source analysis of stimulus-preceding negativity constrained by functional magnetic resonance imaging

The stimulus-preceding negativity (SPN) is an event-related potential (ERP) reflecting anticipation. The anterior insular cortex is assumed to be one of the physiological sources of the SPN. However, the precise neural substrates of the SPN have yet to be confirmed. We therefore performed separate functional magnetic resonance imaging (fMRI) and ERP studies using the same time estimation task, followed by fMRI-constrained ERP source analysis. Dipole locations were determined by the fMRI results, while the time courses of dipole activities were modeled by the ERP data. Analysis revealed that the right anterior insula was significantly activated before delivery of the feedback stimulus, whereas the left anterior insula was not, and that the SPN mainly arose from four groups of brain regions related to, respectively: (1) the salience network, (2) reward expectation, (3) perceptual anticipation, and (4) arousal. The results suggest that the SPN pertains to multiple brain functions with complex interactions.

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.

Blunted neural responses to monetary risk in high sensation seekers

The sensation-seeking trait is a valid predictor of various risk-taking behaviors. However, the neural underpinnings of risk processing in sensation seeking are yet unclear. The present event-related potential (ERP) study examined electrophysiological correlates associated with different stages of risky reward processing in sensation seeking. Twenty-one high sensation seekers (HSS) and 22 low sensation seekers (LSS) performed a simple two-choice gambling task. Behaviorally, whereas LSS exhibited a risk-averse pattern, HSS showed a risk-neutral pattern. During the anticipation stage, an increased stimulus-preceding negativity was elicited by high-risk compared to low-risk choices in LSS but not in HSS. During the outcome-appraisal stage, the feedback-related negativity, when calculated as the difference between losses and gains, was enhanced in response to the high-risk versus low-risk outcomes, which appeared for LSS but not for HSS. Further, HSS as compared to LSS exhibited a diminished P300 to both gains and losses. These findings suggest that risk-taking behavior in sensation seeking is expressed as blunted neural responses to risk in the anticipation stage and in the outcome-appraisal stage, which represents a candidate target for drug prevention.

Emotional intensity influences pre-implementation and implementation of distraction and reappraisal.

Although emotional intensity powerfully challenges regulatory strategies, its influence remains largely unexplored in affective-neuroscience. Accordingly, the present study addressed the moderating role of emotional intensity in two regulatory stages--implementation (during regulation) and pre-implementation (prior to regulation), of two major cognitive regulatory strategies--distraction and reappraisal. According to our framework, because distraction implementation involves early attentional disengagement from emotional information before it gathers force, in high-intensity it should be more effective in the short-term, relative to reappraisal, which modulates emotional processing only at a late semantic meaning phase. Supporting findings showed that in high (but not low) intensity, distraction implementation resulted in stronger modulation of negative experience, reduced neural emotional processing (centro-parietal late positive potential, LPP), with suggestive evidence for less cognitive effort (frontal-LPP), relative to reappraisal. Related pre-implementation findings confirmed that anticipating regulation of high-intensity stimuli resulted in distraction (over reappraisal) preference. In contrast, anticipating regulation of low-intensity stimuli resulted in reappraisal (over distraction) preference, which is most beneficial for long-term adaptation. Furthermore, anticipating cognitively demanding regulation, either in cases of regulating counter to these preferences or via the more effortful strategy of reappraisal, enhanced neural attentional resource allocation (Stimulus Preceding Negativity). Broad implications are discussed.

Contextual valence modulates the neural dynamics of risk processing.

A well-known bias in risky decision making is that most people tend to be risk averse when gains are salient but risk seeking when losses are salient. The present study addressed the neural dynamics of this process by recording ERPs during a gambling task in a gain and a loss context. Behaviorally, participants were found to be risk averse in the gain context but risk neutral in the loss context. During the anticipation stage, an increased stimulus-preceding negativity was elicited by high- versus low-risk choices in the gain but not the loss context. During the outcome-appraisal stage, the feedback-related negativity was larger after high- versus low-risk choices in the gain instead of the loss context. For the P300, an outcome valence effect (a larger P300 for gain vs. loss outcomes) emerged following the high- versus low-risk decisions in the gain but not the loss context. Our findings suggest that risk processing can be modulated by the context of valence during the anticipation stage and by both the contextual valence and the outcome valence during the outcome-appraisal stage, which may be driven by the motivational salience imposed by the context of valence.

Brain dynamics of visual attention during anticipation and encoding of threat- and safe-cues in spider-phobic individuals.

This study systematically investigated the sensitivity of the phobic attention system by measuring event-related potentials (ERPs) in spider-phobic and non-phobic volunteers in a context where spider and neutral pictures were presented (phobic threat condition) and in contexts where no phobic but unpleasant and neutral or only neutral pictures were displayed (phobia-irrelevant conditions). In a between-group study, participants were assigned to phobia-irrelevant conditions either before or after the exposure to spider pictures (pre-exposure vs post-exposure participants). Additionally, each picture was preceded by a fixation cross presented in one of three different colors that were informative about the category of an upcoming picture. In the phobic threat condition, spider-phobic participants showed a larger P1 than controls for all pictures and signal cues. Moreover, individuals with spider phobia who were sensitized by the exposure to phobic stimuli (i.e. post-exposure participants) responded with an increased P1 also in phobia-irrelevant conditions. In contrast, no group differences between spider-phobic and non-phobic individuals were observed in the P1-amplitudes during viewing of phobia-irrelevant stimuli in the pre-exposure group. In addition, cues signaling neutral pictures elicited decreased stimulus-preceding negativity (SPN) compared with cues signaling emotional pictures. Moreover, emotional pictures and cues signaling emotional pictures evoked larger early posterior negativity (EPN) and late positive potential (LPP) than neutral stimuli. Spider phobics showed greater selective attention effects than controls for phobia-relevant pictures (increased EPN and LPP) and cues (increased LPP and SPN). Increased sensitization of the attention system observed in spider-phobic individuals might facilitate fear conditioning and promote generalization of fear playing an important role in the maintenance of anxiety disorders.

78. Neurophysiological markers of disrupted anticipatory expectancy in the adult ADHD disease

The assessment of the Attention Deficit/Hyperactivity Disorder (ADHD) in adults is often challenging, particularly due to the absence of specific diagnostic criteria. We applied a non-motor triplet protocol in a ADHD population to study the anticipatory attention as reflected by the slow cortical potential named Stimulus Preceding Negativity(SPN). We recorded 26 ADHD patients and 26 control subjects who did not receive any task instructions. We delivered trains of three stimuli belonging to the acoustic or the electric modality. In the first session(Triplet Same) the three stimuli belong to the same modality. In the second session(Triplet Different) the third stimulus belongs to the alternative modality. Grand-average waveforms were analyzed to evaluate the presence of the SPN in the interval time preceding the 1st, 2nd and 3rd stimulus. The ADHD group showed a significant N1 amplitude reduction in response to S1 and also a significant attenuation of the SPN before electric stimuli. We hypothesized that an abnormal attention processing combined with a dysfunction in emotional awareness may impair the anticipatory expectancy to the upcoming salient stimuli. We think that our findings may reflect an atypical attentional processing in the ADHD group, providing an additional level of analysis to the clinical psychiatric evaluation.

Physiological sources of stimulus-preceding negativity: Source analysis using fMRI and ERP

Physiological sources of stimulus-preceding negativity: Source analysis using fMRI and ERP