Incidental learning of faces during threat: No evidence for enhanced physiological responses to former threat identities.

Remembering an unfamiliar person and the contextual conditions of that encounter is important for adaptive future behavior, especially in a potentially dangerous situation. Initiating defensive behavior in the presence of former dangerous circumstances can be crucial. Recent studies showed selective electrocortical processing of faces that were previously seen in a threat context compared to a safety context, however, this was not reflected in conscious recognition performance. Here, we investigated whether previously seen threat-faces, that could not be remembered, were capable to activate defensive psychophysiological response systems. During an encoding phase, 50 participants with low to moderate levels of anxiety viewed 40 face pictures with neutral expressions (6 s each), without an explicit learning instruction (incidental learning task). Each half of the faces were presented with contextual background colors that signaled either threat-of-shock or safety. In the recognition phase, all old and additional new faces (total of 60) were presented intermixed without context information. Participants had to decide whether a face was new or had been presented previously in a threatening or a safe context. Results show moderate face recognition independent of context conditions. Startle reflex and skin conductance responses (SCR) were more pronounced for threat compared to safety during encoding. For SCR, this differentiation was enhanced with higher levels of depression and anxiety. There were no differential startle reflex or SCR effects during recognition. From a clinical perspective, these findings do not support the notion that perceptual biases and physiological arousal directly relate to threat-associated identity recognition deficits in healthy and clinical participants with anxiety and trauma-related disorders.

A multinomial modelling approach to face identity recognition during instructed threat.

To organise future behaviour, it is important to remember both the central and contextual aspects of a situation. We examined the impact of contextual threat or safety, learned through verbal instructions, on face identity recognition. In two studies (N = 140), 72 face-context compounds were presented each once within an encoding session, and an unexpected item/source recognition task was performed afterwards (including 24 new faces). Hierarchical multinomial processing tree modelling served to estimate individual parameters of item (face identity) and source memory (threat or safety context) as well as guessing behaviour. Results show that language was highly effective in establishing threatening and safe context conditions. In Study 1, a fleeting picture stream (1 s per picture) led to poor item and source recognition. Prolonged presentation times (Study 2 with 6 s per picture) improved face memory but no contextual modulation was observed. Thus, incidental face learning was surprisingly poor and rapidly changing contextual settings might have interfered with the accurate encoding of face identity information and item-source binding.

Contextual information resolves uncertainty about ambiguous facial emotions: Behavioral and magnetoencephalographic correlates.

Environmental conditions bias our perception of other peoples' facial emotions. This becomes quite relevant in potentially threatening situations, when a fellow's facial expression might indicate potential danger. The present study tested the prediction that a threatening environment biases the recognition of facial emotions. To this end, low- and medium-expressive happy and fearful faces (morphed to 10%, 20%, 30%, or 40% emotional) were presented within a context of instructed threat-of-shock or safety. Self-reported data revealed that instructed threat led to a biased recognition of fearful, but not happy facial expressions. Magnetoencephalographic correlates revealed spatio-temporal clusters of neural network activity associated with emotion recognition and contextual threat/safety in early to mid-latency time intervals in the left parietal cortex, bilateral prefrontal cortex, and the left temporal pole regions. Early parietal activity revealed a double dissociation of face-context information as a function of the expressive level of facial emotions: When facial expressions were difficult to recognize (low-expressive), contextual threat enhanced fear processing and contextual safety enhanced processing of subtle happy faces. However, for rather easily recognizable faces (medium-expressive) the left hemisphere (parietal cortex, PFC, and temporal pole) showed enhanced activity to happy faces during contextual threat and fearful faces during safety. Thus, contextual settings reduce the salience threshold and boost early face processing of low-expressive congruent facial emotions, whereas face-context incongruity or mismatch effects drive neural activity of easier recognizable facial emotions. These results elucidate how environmental settings help recognize facial emotions, and the brain mechanisms underlying the recognition of subtle nuances of fear.

Contextual source information modulates neural face processing in the absence of conscious recognition: A threat-of-shock study.

Often the source of information is as important as the information itself. The present study examined the impact of contextual threat and safety signals (source information) on memory encoding and recognition of faces (item information). In two experimental sessions, 30 participants viewed neutral face pictures. In the encoding session, 60 faces were presented with contextual background colors (blue or green, 30 pictures each) which were verbally instructed to signal either threat-of-shock or safety. In the recognition session, the 60 old faces intermixed with 30 new faces were shown while a combined old/new recognition and source memory task was performed. During the encoding session, face processing varied as a function of contextual source information. Confirming successful threat-of-shock manipulation, threatening compared to safe face-context compounds revealed differential neural processing (early parieto-occipital and late fronto-central negativity) as well as pronounced threat ratings. During the recognition session, participants had serious problems identifying old from new faces with poor source memory. Intriguingly, however, brain activity differentiated previously seen faces from newly presented pictures (old/new ERP effect). Moreover, old faces presented within a threat context were associated with distributed late negativities compared to old safe faces. Thus, threat effects not only emerged during face encoding (incidental learning) but also during face recognition, although no valid judgements could be made regarding the threatening or safe sources. These findings support the notion that contextual source information critically modulates person perception and recognition as a form of an expectation based remembering in the absence of conscious recognition.

Space, time, and numbers in the right posterior parietal cortex: Differences between response code associations and congruency effects.

The mental representations of space, time, and number magnitude are inherently linked. The right posterior parietal cortex (PPC) has been suggested to contain a general magnitude system that underlies the overlap between various perceptual dimensions. However, comparative studies including spatial, temporal, and numerical dimensions are missing. In a unified paradigm, we compared the impact of right PPC inhibition on associations with spatial response codes (i.e., Simon, SNARC, and STARC effects) and on congruency effects between space, time, and numbers. Prolonged cortical inhibition was induced by continuous theta-burst stimulation (cTBS), a protocol for transcranial magnetic stimulation (TMS), at the right intraparietal sulcus (IPS). Our results show that congruency effects, but not response code associations, are affected by right PPC inhibition, indicating different neuronal mechanisms underlying these effects. Furthermore, the results demonstrate that interactions between space and time perception are reflected in congruency effects, but not in an association between time and spatial response codes. Taken together, these results implicate that the congruency between purely perceptual dimensions is processed in PPC areas along the IPS, while the congruency between percepts and behavioral responses is independent of this region.

A partner's smile is not per se a safety signal: Psychophysiological response patterns to instructed threat and safety.

Recent studies on fear conditioning and pain perception suggest that pictures of loved ones (e.g., a romantic partner) may serve as a prepared safety cue that is less likely to signal aversive events. Challenging this view, we examined whether pictures of smiling or angry loved ones are better safety or threat cues. To this end, 47 healthy participants were verbally instructed that specific facial expressions (e.g., happy faces) cue threat of electric shocks and others cue safety (e.g., angry faces). When facial images served as threat cues, they elicited distinct psychophysiological defensive responses (e.g., increased threat ratings, startle reflex, and skin conductance responses) compared to viewing safety cues. Interestingly, instructed threat effects occurred regardless of the person who cued shock threat (partner vs. unknown) and their facial expression (happy vs. angry). Taken together, these results demonstrate the flexible nature of facial information (i.e., facial expression and facial identity) to be easily learned as signals for threat or safety, even when showing loved ones.

Spatial navigation under threat: aversive apprehensions improve route retracing in higher versus lower trait anxious individuals.

Spatial navigation is a basic function for survival, and the ability to retrace a route has direct relevance for avoiding dangerous places. This study investigates the effects of aversive apprehensions on spatial navigation in a virtual urban environment. Healthy participants with varying degrees of trait anxiety performed a route-repetition and a route-retracing task under threatening and safe context conditions. Results reveal an interaction between the effect of threatening/safe environments and trait anxiety: while threat impairs route-retracing in lower-anxious individuals, this navigational skill is boosted in higher-anxious individuals. According to attentional control theory, this finding can be explained by an attentional shift toward information relevant for intuitive coping strategies (i.e., running away), which should be more pronounced in higher-anxious individuals. On a broader scale, our results demonstrate an often-neglected advantage of trait anxiety, namely that it promotes the processing of environmental information relevant for coping strategies and thus prepares the organism for adequate flight responses.

The mere sight of loved ones does not inhibit psychophysiological defense mechanisms when threatened.

Looking at pictures of loved ones, such as one's romantic partner or good friends, has been shown to alleviate the experience of pain and reduce defensive reactions. However, little is known about such modulatory effects on threat and safety learning and the psychophysiological processes involved. Here, we explored the hypothesis that beloved faces serve as implicit safety cues and attenuate the expression of fear responses and/or accelerate extinction learning in a threatening context. Thirty-two participants viewed pictures of their loved ones (romantic partner, parents, and best friend) as well as of unknown individuals within contextual background colors indicating threat-of-shock or safety. Focusing on the extinction of non-reinforced threat associations (no shocks were given), the experiment was repeated on two more test days while the defensive startle-EMG, SCR, and threat ratings were obtained. Results confirmed pronounced defensive responding to instructed threat-of-shock relative to safety context (e.g., threat-enhanced startle reflex and SCR). Moreover, threat-potentiated startle response slowly declined across test days indicating passive extinction learning in the absence of shocks. Importantly, neither a main effect of face category (loved vs. unknown) nor a significant interaction with threat/safety instructions was observed. Thus, a long-term learning history of beneficial relations (e.g., with supportive parents) did not interfere with verbal threat learning and aversive apprehensions. These findings reflect the effects of worries and apprehensions that persist despite the repeated experience of safety and the pictorial presence of loved ones. How to counter such aversive expectations is key to changing mal-adaptive behaviors (e.g., avoidance or stockpiling), biased risk perceptions, and stereotypes.

Social threat and safety learning in individuals with adverse childhood experiences: electrocortical evidence on face processing, recognition, and working memory.

Background: Adverse childhood experiences (ACEs) are often associated with stress and anxiety-related disorders in adulthood, and learning and memory deficits have been suggested as a potential link between ACEs and psychopathology. Objective: In this preregistered study, the impact of social threat learning on the processing, encoding, and recognition of unknown faces as well as their contextual settings was measured by recognition performance and event-related brain potentials. Method: Sixty-four individuals with ACEs encoded neutral faces within threatening or safe context conditions. During recognition, participants had to decide whether a face was new or had been previously presented in what context (item-source memory), looking at old and new faces. For visual working memory, participants had to detect changes in low and high load conditions during contextual threat or safety. Results: Results showed a successful induction of threat expectation in persons with ACEs. In terms of face and source recognition, overall recognition of safe and new faces was better compared to threatening face-compounds, with more socially anxious individuals having an advantage in remembering threatening faces. For working memory, an effect of task load was found on performance, irrespective of threat or safety context. Regarding electrocortical activity, an old/new recognition effect and threat-selective processing of face-context information was observed during both encoding and recognition. Moreover, neural activity associated with change detection was found for faces in a threatening context, but only at high task load, suggesting reduced capacity for faces in potentially harmful situations when cognitive resources are limited. Conclusion: While individuals with ACE showed intact social threat and safety learning overall, threat-selective face processing was observed for item/source memory, and a threatening context required more processing resources for visual working memory. Further research is needed to investigate the psychophysiological processes involved in functional and dysfunctional memory systems and their importance as vulnerability factors for stress-related disorders.

Antecedentes: Las experiencias adversas en la infancia (ACEs, por su sigla en inglés) estan a menudo asociadas con trastornos relacionados con el estrés y la ansiedad en la edad adulta, y los déficits de aprendizaje y memoria han sido sugeridos como un vínculo potencial entre las ACEs y la psicopatología.Objetivo: En este estudio previamente registrado, el impacto del aprendizaje de amenazas sociales en el procesamiento, la codificación y el reconocimiento de rostros desconocidos, así como sus entornos contextuales, se midió mediante el rendimiento y los potenciales cerebrales relacionados con los eventos.Método: Sesenta y cuatro personas con ACEs codificaron rostros neutrales dentro de condiciones de contextos amenazantes o seguros. Durante el reconocimiento, los participantes tenían que decidir si una cara era nueva o se había presentado previamente en qué contexto (elemento-fuente de memoria), mirando caras antiguas y nuevas. Para la memoria de trabajo visual, los participantes tenían que detectar cambios en las condiciones de carga baja y alta durante la amenaza contextual o la seguridad.Resultados: Los resultados mostraron una inducción exitosa de la expectativa de amenaza en personas con ACEs. En términos de reconocimiento de rostros y fuentes, el reconocimiento general de rostros seguros y nuevos fue mejor en comparación con los compuestos de rostros amenazantes, y las personas más ansiosas socialmente tenían una ventaja para recordar rostros amenazantes. Para la memoria de trabajo, se encontró un efecto de la carga de tareas en el rendimiento, independientemente de la amenaza o el contexto de seguridad. Con respecto a la actividad electrocortical, se observó un efecto de reconocimiento antiguo/nuevo y un procesamiento selectivo de amenazas de la información del contexto facial durante la codificación y el reconocimiento. Además, se encontró actividad neuronal asociada con la detección de cambios para rostros en un contexto amenazante, pero solo con una gran carga de tareas, lo que sugiere una capacidad reducida para rostros en situaciones potencialmente dañinas cuando los recursos cognitivos son limitados.Conclusión: Si bien las personas con ACE mostraron un aprendizaje intacto de amenazas sociales y seguridad en general, se observó un procesamiento facial selectivo de amenazas para la memoria de elementos/fuentes, y un contexto amenazante requería más recursos de procesamiento para la memoria de trabajo visual. Se necesita más investigación para investigar los procesos psicofisiológicos involucrados en los sistemas de memoria funcional y disfuncional y su importancia como factores de vulnerabilidad para los trastornos relacionados con el estrés.

Aversive anticipations modulate electrocortical correlates of decision-making and reward reversal learning, but not behavioral performance.

Predicting the consequences of one's own decisions is crucial for organizing future behavior. However, when reward contingencies vary frequently, flexible adaptation of decisions is likely to depend on the situation. We examined the effects of an instructed threat context on choice behavior (i.e., reversal learning) and its electrocortical correlates. In a probabilistic decision-making task, 30 participants had to choose between two options that were either contingent on monetary gains or losses. Reward contingencies were reversed after reaching a probabilistic threshold. Decision-making and reversal learning were examined with two contextual background colors, which were instructed as signals for threat-of-shock or safety. Self-report data confirmed the threat context as more unpleasant, arousing, and threatening relative to safety condition. However, against our expectations, behavioral performance was comparable during the threat and safety conditions (i.e., errors-to-criterion, number of reversal, error rates, and choice times). Regarding electrocortical activity, feedback processing changed throughout the visual processing stream. The feedback-related negativity (FRN) reflected expectancy-driven processing (unexpected vs. congruent losses and gains), and the threat-selective P3 component revealed non-specific discrimination of gains vs. losses. Finally, the late positive potentials (LPP) showed strongly valence-specific processing (unexpected and congruent losses vs. gains). Thus, regardless of contextual threat, early and late cortical activity reflects an attentional shift from expectation- to outcome-based feedback processing. Findings are discussed in terms of reward, threat, and reversal-learning mechanisms with implications for emotion regulation and anxiety disorders.

Verbal threat learning does not spare loved ones.

Significant others provide individuals with a sense of safety and security. However, the mechanisms that underlie attachment-induced safety are hardly understood. Recent research has shown beneficial effects when viewing pictures of the romantic partner, leading to reduced pain experience and defensive responding. Building upon this, we examined the inhibitory capacity of loved face pictures on fear learning in an instructed threat paradigm. Pictures of loved familiar or unknown individuals served as signals for either threat of electric shocks or safety, while a broad set of psychophysiological measures was recorded. We assumed that a long-term learning history of beneficial relations interferes with social threat learning. Nevertheless, results yielded a typical pattern of physiological defense activation towards threat cues, regardless of whether threat was signaled by an unknown or a loved face. These findings call into question the notion that pictures of loved individuals are shielded against becoming threat cues, with implications for attachment and trauma research.

Instructed threat enhances threat perception in faces.

Anxiety can boost the detection of potential threats in many ways. There is evidence that one and the same facial expression can be perceived differently depending on whether it is seen in a neutral or in a threatening situation. The present study investigated how aversive anticipation influences the accuracy of facial emotion recognition and the perceived emotional intensity of faces that had their objective emotional intensity manipulated. Forty-three participants categorized and rated the intensity of morphed faces (20%, 40%, 60%, and 80%) of fearful, angry, and happy expressions. Differently colored picture frames indicated either threat of electric shock or safety. Threat of shock enhanced the categorization accuracy specifically for fearful faces. During threat, 80% fearful and happy faces, and all levels of angry faces (20%-80%) were rated as more intense. In addition, we found that more trait-anxious individuals more frequently erroneously categorized neutral faces as fearful. Thus, state anxiety enhanced accurate fear categorization and boosted the perceived intensity of emotional faces, whereas trait anxiety led to a biased threat perception in nonthreatening faces. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

#EEGManyLabs: Investigating the replicability of influential EEG experiments.

There is growing awareness across the neuroscience community that the replicability of findings about the relationship between brain activity and cognitive phenomena can be improved by conducting studies with high statistical power that adhere to well-defined and standardised analysis pipelines. Inspired by recent efforts from the psychological sciences, and with the desire to examine some of the foundational findings using electroencephalography (EEG), we have launched #EEGManyLabs, a large-scale international collaborative replication effort. Since its discovery in the early 20th century, EEG has had a profound influence on our understanding of human cognition, but there is limited evidence on the replicability of some of the most highly cited discoveries. After a systematic search and selection process, we have identified 27 of the most influential and continually cited studies in the field. We plan to directly test the replicability of key findings from 20 of these studies in teams of at least three independent laboratories. The design and protocol of each replication effort will be submitted as a Registered Report and peer-reviewed prior to data collection. Prediction markets, open to all EEG researchers, will be used as a forecasting tool to examine which findings the community expects to replicate. This project will update our confidence in some of the most influential EEG findings and generate a large open access database that can be used to inform future research practices. Finally, through this international effort, we hope to create a cultural shift towards inclusive, high-powered multi-laboratory collaborations.

Attention and emotion: An integrative review of emotional face processing as a function of attention.

Paying attention to faces is of special interest for humans as well as for scientific research. The experimental manipulation of facial information offers an ecologically valid approach to investigate emotion, attention and social functioning. Humans are highly specialized in face perception and event-related brain potentials (ERP) provide insights into the temporal dynamics of involved neuronal mechanisms. Here, we summarize ERP research from the last decade, examining the processing of emotional compared to neutral facial expressions along the visual processing stream. A particular focus lies on exploring the impact of attention tasks on early (P1, N170), mid-latency (P2, EPN) and late (P3, LPP) stages of processing. This review systematizes facial emotion effects as a function of different attention tasks: 1) When faces serve as mere distractors, 2) during passive viewing designs, 3) directing attention at faces in general, and 4) paying attention to facial expressions. We find fearful and angry expressions to reliably modulate the N170, EPN, and LPP component, the latter benefiting from attention directed at the emotional facial expression.

Threat rapidly disrupts reward reversal learning.

Threat changes cognition and facilitates adaptive coping. However, when threat becomes overwhelming, it may be deleterious to mental health, especially for vulnerable individuals. Flexible decision-making was probed with a reward reversal task to investigate how well healthy participants (N = 34) can adapt to changes in reward contingency when they expect adverse events (i.e., electric shocks). In comparison to a safe control condition, the threat of shock significantly impaired reward reversal learning. Moreover, enhanced self-reported threat ratings and elevated skin conductance levels support the successful induction of stressful and aversive apprehensions. The findings are in line with literature showing the stress-induced inhibition of goal-directed behavior at the advantage of a reflexive (habitual) response style. Notably, reversal learning was rapidly restored with the omission of threat through several cycles of threat and safety contexts within one experimental session. These results extend the literature and illuminate the immediate consequence of a sustained threatening stressor (and its removal) on decision-making. Better knowledge of the immediate effects of anticipatory anxiety on behavior could improve understanding of psychopathology and may be informative for the development of effective therapy for anxiety and emotion dysregulation.

Watch out, he's dangerous! Electrocortical indicators of selective visual attention to allegedly threatening persons.

The face of a friend indicates safety, the face of a foe can indicate threat. Here, we examine the effects of verbal instructions ('beware of this person') on the perception of unknown persons. Focusing on visual attention, face identity and facial expression information is examined during instructed threat-of-shock or safety. However, shocks never occurred. Participants quickly acquired instructed threat associations, and electrocortical processing differentiated threat- from safe-identities as well as emotional and neutral facial expressions. Importantly, face encoding varied as a joint function of identity and facial expression, as revealed by pronounced N170 amplitudes to smiling threat-identities. Moreover, instructions readily reversed previously learned affective associations leading to attention allocation and memory updating as reflected by N170, EPN and P3 amplitudes toward new threat-identities displaying angry expressions. These findings demonstrate that person perception flexibly re-adjusts according to minimal information. Intriguingly, perceptual biases occur even though the anticipated aversive consequence does not occur, with implications for research on stereotyping and anxious psychopathology.

The impact of hunger on food cue processing: an event-related brain potential study.

The present study used event-related brain potentials to examine deprivation effects on visual attention to food stimuli at the level of distinct processing stages. Thirty-two healthy volunteers (16 females) were tested twice 1 week apart, either after 24 h of food deprivation or after normal food intake. Participants viewed a continuous stream of food and flower images while dense sensor ERPs were recorded. As revealed by distinct ERP modulations in relatively earlier and later time windows, deprivation affected the processing of food and flower pictures. Between 300 and 360 ms, food pictures were associated with enlarged occipito-temporal negativity and centro-parietal positivity in deprived compared to satiated state. Of main interest, in a later time window (approximately 450-600 ms), deprivation increased amplitudes of the late positive potential elicited by food pictures. Conversely, flower processing varied by motivational state with decreased positive potentials in the deprived state. Minimum-Norm analyses provided further evidence that deprivation enhanced visual attention to food cues in later processing stages. From the perspective of motivated attention, hunger may induce a heightened state of attention for food stimuli in a processing stage related to stimulus recognition and focused attention.

Reversing Threat to Safety: Incongruence of Facial Emotions and Instructed Threat Modulates Conscious Perception but Not Physiological Responding.

Facial expressions inform about other peoples' emotion and motivation and thus are central for social communication. However, the meaning of facial expressions may change depending on what we have learned about the related consequences. For instance, a smile might easily become threatening when displayed by a person who is known to be dangerous. The present study examined the malleability of emotional facial valence by means of social learning. To this end, facial expressions served as cues for verbally instructed threat-of-shock or safety (e.g., "happy faces cue shocks"). Moreover, reversal instructions tested the flexibility of threat/safety associations (e.g., "now happy faces cue safety"). Throughout the experiment, happy, neutral, and angry facial expressions were presented and auditory startle probes elicited defensive reflex activity. Results show that self-reported ratings and physiological reactions to threat/safety cues dissociate. Regarding threat and valence ratings, happy facial expressions tended to be more resistant becoming a threat cue, and angry faces remain threatening even when instructed as safety cue. For physiological response systems, however, we observed threat-potentiated startle reflex and enhanced skin conductance responses for threat compared to safety cues regardless of whether threat was cued by happy or angry faces. Thus, the incongruity of visual and verbal threat/safety information modulates conscious perception, but not the activation of physiological response systems. These results show that verbal instructions can readily overwrite the intrinsic meaning of facial emotions, with clear benefits for social communication as learning and anticipation of threat and safety readjusted to accurately track environmental changes.

Modulation of face- and emotion-selective ERPs by the three most common types of face image manipulations.

In neuroscientific studies, the naturalness of face presentation differs; a third of published studies makes use of close-up full coloured faces, a third uses close-up grey-scaled faces and another third employs cutout grey-scaled faces. Whether and how these methodological choices affect emotion-sensitive components of the event-related brain potentials (ERPs) is yet unclear. Therefore, this pre-registered study examined ERP modulations to close-up full-coloured and grey-scaled faces as well as cutout fearful and neutral facial expressions, while attention was directed to no-face oddballs. Results revealed no interaction of face naturalness and emotion for any ERP component, but showed, however, large main effects for both factors. Specifically, fearful faces and decreasing face naturalness elicited substantially enlarged N170 and early posterior negativity amplitudes and lower face naturalness also resulted in a larger P1.This pattern reversed for the LPP, showing linear increases in LPP amplitudes with increasing naturalness. We observed no interaction of emotion with face naturalness, which suggests that face naturalness and emotion are decoded in parallel at these early stages. Researchers interested in strong modulations of early components should make use of cutout grey-scaled faces, while those interested in a pronounced late positivity should use close-up coloured faces.

Visual noise effects on emotion perception: brain potentials and stimulus identification.

Event-related potential (ERP) studies revealed an early posterior negativity (EPN) for emotionally arousing pictures. Two studies explored how this effect relates to perceptual stimulus characteristics and stimulus identification. Adding various amounts of visual noise varied stimulus perceptibility of high and low arousing picture contents, which were presented as rapid and continuous stream. Measuring dense sensor event-related potentials, study I determined that noise level was linearly related to the P1 peak. Subsequently, enlarged EPNs to emotionally arousing contents were observed, however, only for pictures containing low amounts of noise, which also enabled stimulus identification as shown by study II. These data support the notion that the EPN may serve as a measure of affective stimulus evaluation at an early transitory processing period.