Wioleta Walentowska

Attention modulates emotional expression processing

To investigate the time course of emotional expression processing, we recorded ERPs to facial stimuli. The first task was to discriminate emotional expressions. Enhanced negativity of the face-specific N170 was elicited by emotional as opposed to neutral faces, followed by the occipital negativity (240-340 ms poststimulus). The second task was to classify face gender. Here, N170 was unaffected by the emotional expression. However, emotional expression effect was expressed in the anterior positivity (160-250 ms poststimulus) and subsequent occipital negativity (240-340 ms poststimulus). Results support the thesis that structural encoding relevant to gender recognition and simultaneous expression analysis are independent processes. Attention modulates facial emotion processing 140-185 ms poststimulus. Involuntary differentiation of facial expression was observed later (160-340 ms poststimulus), suggesting unintentional attention capture.

Trait anxiety and involuntary processing of facial emotions.

There is suggestion that trait anxiety influences the processing of threat-related information. To test this hypothesis we recorded ERPs in response to subliminally presented and backward masked fearful and neutral faces, and non-face objects, in the preselected low- and high-anxious individuals. The amplitude of N170 was found to be larger when elicited by faces in comparison to non-faces, however it was not found to be emotion-sensitive or modulated by anxiety level. Differences between low- and high-anxious individuals appeared in a time window of the P1 component. At later stages, within the EPN component, stronger negativity specific for fearful faces was recorded exclusively in the low-anxious participants. Our findings indicate that anxiety level modulates early stages of information processing, as reflected in the P1 component. This leads to anxiety-related differences in involuntary emotional expression detection at later stages (EPN component).

Goal relevance influences performance monitoring at the level of the FRN and P3 components.

The feedback-related negativity (FRN) provides a reliable ERP marker of performance monitoring (PM). It is usually larger for negative compared to positive feedback, and for unexpected relative to expected feedback. In two experiments, we assessed whether these effects could be modulated by goal relevance, defined as feedback informativeness (reliability) and/or impact on a persons goals. EEG (64-channel) was recorded while 30 participants (in each experiment) performed a speeded go/no-go task across blocks in which the feedback on task performance was deemed either relevant or not. At the ERP level, the FRN component was larger for (frequent) negative compared to (deviant) positive feedback exclusively when the feedback was relevant (Experiment 1). When the probability of positive and negative feedback was balanced (Experiment 2), this valence-driven FRN effect was absent. However, across these two experiments, the FRN was always larger for irrelevant than relevant feedback. Moreover, the subsequent P300 component was larger for feedback in the relevant than the irrelevant blocks. This effect was valence unspecific in Experiment 1, while in Experiment 2 larger P3 amplitudes were recorded for negative than positive (relevant) feedback. Across the two experiments, a larger correct-related negativity in the irrelevant than relevant context was also observed, suggesting that PM is flexible. These ERP findings indicate that goal relevance influences feedback (and response) processing during PM, with two nonoverlapping neurophysiological effects: It gates reward prediction error brain mechanisms (FRN effect), before enhancing subsequent motivational processes (P300 effect).

Modulatory effects of happy mood on performance monitoring : insights from error-related brain potentials

Goal-adaptive behavior requires the rapid detection of conflicts between actions and intentions or goals. Although many studies have focused in the past on the influence of negative affect on this cognitive control process (and more specifically, on error monitoring), little is known about the possible modulatory effects of positive affect on it. To address this question, we used a standard (positive) mood induction procedure (based on guided imagery) and asked participants to carry out a speeded go/no-go task while high-density electroencephalography was recorded concurrently. As a control condition, we used a group with neutral mood. Event-related potential results showed that the error-related negativity (ERN) component, reflecting early error detection within the dorsal anterior cingulate cortex, was not influenced by happy mood. In contrast, the subsequent error positivity (Pe) component, related to the appraisal of the motivational significance of errors, was reliably smaller in the happy than in the neutral mood group. Complementing source localization analyses showed that this effect was explained by decreased activation within the posterior cingulate and insular cortices. These results were obtained in the absence of group differences regarding behavioral performance and tonic arousal. These findings suggest that happy mood likely decreases and changes the motivational significance of worse-than-expected events (Pe), while leaving their earlier automatic detection (ERN) unaltered. We discuss these new results in terms of dynamic changes in the complex interplay of performance monitoring with motivation.

Goal impact influences the evaluative component of performance monitoring: Evidence from ERPs

Successful performance monitoring (PM) requires continuous assessment of context and action outcomes. Electrophysiological studies have reliably identified event-related potential (ERP) markers for evaluative feedback processing during PM: the Feedback-Related Negativity (FRN) and P3 components. The functional significance of FRN remains debated in the literature, with recent research suggesting that feedbacks goal relevance can account for FRN (amplitude) modulation, apart from its valence or expectedness alone. Extending this account, the present study assessed whether graded differentiations in feedbacks relevance or importance to ones goal (referred to as goal impact) would influence PM at the FRN (and P3) level. To this end, we ran a within-subject crossover design experiment in which 40 participants completed two standard cognitive control tasks (Go/No Go and Simon), while 64-channel electroencephalography was recorded. Critically, both tasks entailed similar reward processing but systematically varied in goal impact assignment (high vs. low), manipulated through their supposed diagnosticity for daily life functioning and activation of social comparison. ERP results showed that goal impact reliably modulated FRN in a general manner. Irrespective of feedback valence, it was overall less negative in the high compared to the low impact condition, suggesting a general decrease in feedback monitoring in the former compared to the latter condition. These findings lend support to the idea that PM is best conceived operating not solely based on motor cues, but is shaped by motivational demands.

Relevance and uncertainty jointly influence reward anticipation at the level of the SPN ERP component

The stimulus-preceding negativity (SPN) component reflects the anticipatory phase of reward processing. Its amplitude is usually larger for informative compared to uninformative upcoming stimuli, as well as for uncertain relative to predictable ones. In this study, we sought to assess whether these two effects, when combined together, produced a synergistic effect or rather independent ones on the SPN during performance monitoring. Participants performed a speeded Go/NoGo task while 64-channel EEG was recorded concurrently. We focused on the SPN activity generated in anticipation of feedback, which was either positive (for correct and fast reactions) or negative (for correct but slow responses). Further, the feedbacks informativeness about the satisfaction status of goals was alternated across blocks. When uncertainty about the action outcome was low (in conditions where positive feedback was either less or more frequent than negative feedback), the SPN amplitude (measured at fronto-central electrodes) did not vary as a function of feedbacks relevance or valence. By comparison, when positive and negative feedback were equiprobable (uncertainty was high), the SPN was more pronounced for relevant compared to irrelevant feedback. Interestingly, in this condition, it was also larger at right fronto-central sites for positive than negative feedback. These ERP results suggest that both factors-relevance and uncertainty- combine and influence reward anticipation at the SPN level.

Attention effectively modulates processing of subliminally presented facial expression

and can be modulated by individual differences. Among them, subclinical trait-anxiety is supposed to influence the processing of threat-related information. We recorded ERPs in response to subliminally (16 ms) presented fearful and neutral faces and nonface objects, followed by an abstract mask. Relying on STAI scores, pre-selected low and high-anxious individuals were compared to investigate facial emotion processing biases. We found that an amplitude of N170 was larger when elicited by faces in comparison to non-face objects. Additionally, a ‘face effect’ on N170 was modulated by the level of trait-anxiety. In high-anxious individuals, the amplitude of N170 was diminished and the effect was reduced, suggesting a different course of facial structural analysis in that group. Moreover, a negative shift specific to fearful faces was recorded over occipital and occipito-temporal locations, starting 100 ms after stimulus onset; it was more pronounced in the high-anxious group. At later stages, Early Posterior Negativity (EPN, 240–300 ms post-stimulus) was more apparent in low-anxious participants. Our findings indicate that fearful faces elicit stronger posterior negativity than neutral ones, even in a case of low awareness of the stimuli. However, the timing of the processing differs with respect to the level of traitanxiety. This work was supported by a grant from the Polish Ministry of Science and Higher Education – N N106 098338.