Social stimuli increase physiological reactivity but not defensive responses

Emotional reactions are crucial in survival because they provide approach and withdrawal behaviors. However, an unsolved question is whether the social content of the affective stimuli has a specific effect on emotional responses. We studied whether the social content of affective pictures influenced the defensive response and response mobilization. For this purpose, we recorded startle blink reflex (a defensive response) and skin conductance responses (a measure of unspecific physiological reactivity or arousal) in 73 participants while they viewed a series of 81 pictures of varying affective valence and social content. Our results revealed that defense response, as indicated by increases in the magnitude of the startle blink reflex, was mainly dependent on threatening or unpleasant cues, but was unrelated to the social content of the pictures. The social content, however, had an influence on pleasant stimuli, provoking an increase in resource mobilization, as reflected by changes in electrodermal activity. Hence, the social content of the affective stimuli may increase the physiological arousal elicited by pleasant stimuli, and it appears to be unrelated to the defense reactivity provoked by unpleasant stimuli.     

Integrating Dimensional and Discrete Theories of Emotions: A New Set of Anger- and Fear-Eliciting Stimuli for Children

The selection of appropriate stimuli for inducing specific emotional states has become one of the most challenging topics in psychological research. In the literature there is a lack of affective picture database specifically suited to investigate emotional response in children. Here the authors present the methodology that led us to create a new database (called Anger- and Fear-Eliciting Stimuli for Children) of affective stimuli inducing experiences of 3 target emotions (neutral, anger, and fear) to use in experimental session involving children. A total of 84 children were asked to (a) indicate the perceived emotion and its intensity and (b) rate the three affective dimensions of the Self-Assessment Manikin (SAM). Based on concordance between labeled and expected target emotion, the authors decided to select 15 stimuli to be included in Multivariate modeling techniques were applied to evaluate the association between expected target emotion and SAM ratings. The authors found that the hit rate for the neutral pictures was good (greater than 81%), for fear-eliciting pictures it was greater than 64%, and for anger-eliciting pictures it was moderate (between 45% and 56%). The study results reveal also an age effect only in the arousal scale. However, the authors did not find significant gender-related differences in SAM ratings.     

Enhanced memory for emotional pictures: A product of increased attention to affective stimuli?

The current experiment addressed the question, is enhanced memory for emotional pictures due to increased attention to affective stimuli? Participants viewed pairs of pictures (emotional-neutral or neutral-neutral) whilst their eye movements were recorded; participants had to decide which picture out of each pair they preferred. There was increased attention to positive pictures and decreased attention to negative images during picture viewing. Despite this, when a recognition test was given 1 week later, memory enhancements were found for negative pictures only. Moreover, although there was a general correlation between total inspection time and memory performance, this reliability was clear only for neutral pictures, and not for emotional images. The results suggest that memory advantages for emotional pictures can occur without increased attention to such images.     

记忆编码中目标与背景的情绪一致性对记忆提取的影响

摘 要 本研究将经典情绪启动范式和学习-再认范式相结合,探讨学习时启动与目标的情绪一致性对目标再认的影响。在记忆编码阶段,以情绪面孔图片为启动刺激、一般情绪图片为目标刺激,要求被试对目标图片的效价进行判断;在提取阶段向被试呈现一般情绪图片,要求被试判断是否在前一阶段见过。结果表明,编码阶段的加工背景对记忆提取产生了显著影响。一致启动促进了认知加工与记忆编码,提高了再认正确率。ERP结果也表明,在目标刺激呈现后300-500ms,编码时的情绪一致性对再认阶段消极目标诱发的ERP产生了显著影响。     

Emotional processing and emotional memory are modulated by interoceptive awareness

The ability to perceive interoceptive signals plays a central role in many theories of emotions. The present study was designed to investigate the relationship between interoceptive awareness and the conscious processing and memory of emotional information. Heart-rate changes were recorded during baseline and affective picture presentation in two groups of participants, differing in cardiac awareness. After a 60-minute break, a recognition task was conducted. Statistical analyses revealed significantly stronger heart-rate deceleration to pleasant and unpleasant stimuli in participants with high interoceptive awareness. In the subsequent picture recognition task, participants with high interoceptive awareness demonstrated a superior recall of pleasant and unpleasant pictures, while no differences were found between interoceptive awareness groups for pictures of neutral content. Our results demonstrate a strong relationship between the perception of cardiac signals and both the processing as well as the recognition of emotional stimuli. High interoceptive awareness was related to increased physiological responses to emotional stimuli and is therefore an important mediating variable when investigating cardiovascular reactivity both in healthy subjects as well as in clinical populations.     

Electrophysiological differences in the processing of affective information in words and pictures

It is generally assumed that affective picture viewing is related to higher levels of physiological arousal than is the reading of emotional words. However, this assertion is based mainly on studies in which the processing of either words or pictures has been investigated under heterogenic conditions. Positive, negative, relaxing, neutral, and background (stimulus fragments) words and pictures were presented to subjects in two experiments under equivalent experimental conditions. In Experiment 1, neutral words elicited an enhanced late positive component (LPC) that was associated with an increased difficulty in discriminating neutral from background stimuli. In Experiment 2, high-arousing pictures elicited an enhanced early negativity and LPC that were related to a facilitated processing for these stimuli. Thus, it seems that under some circumstances, the processing of affective information captures attention only with more biologically relevant stimuli. Also, these data might be better interpreted on the basis of those models that postulate a different access to affective information for words and pictures.     

Cross-modal attention capture by affective stimuli: Evidence from event-related potentials

The P3 component of the event-related potential (ERP) to an acoustic startle probe is modulated during picture viewing, with reduced P3 amplitude when participants view either pleasant or unpleasant, as opposed to neutral, pictures. We have interpreted this as reflecting capture of attentional resources by affective pictures, with fewer resources available for processing the secondary startle probe. In the present study, we tested this resource allocation hypothesis by presenting either pictures or sounds as foreground stimuli, with the prediction that P3 amplitude in response to secondary startle probes would be reduced for affectively engaging foregrounds regardless of modality. Using dense-array electroencephalography and a source estimation procedure, we observed that P3 amplitude was indeed smaller when startle probes were presented during emotional, as opposed to neutral, stimuli for both sound and picture foregrounds. Source modeling indicated a common frontocentral maximum of P3 modulation by affect. The data support the notion that emotionally arousing stimuli transmodally attract resources, leading to optimized processing of the affective stimuli at the cost of the processing of concurrent stimuli.     

Affective stimuli capture attention regardless of categorical distinctiveness: An emotion-induced blindness study

Affective stimuli capture attention, whether their affective value stems from emotional content or a history of reward. The uniqueness of such stimuli within their experimental contexts might imbue them with an enhanced categorical distinctiveness that accounts for their impact on attention. Indeed, in emotion-induced blindness, categorically distinctive neutral pictures disrupt target perception, albeit to a lesser degree than do emotional pictures. Here, we manipulated the categorical distinctiveness of distractors in an emotion-induced blindness task. Participants searched within RSVP streams for a target that followed an emotional or a neutral distractor picture. In a categorically homogenous condition, all non-distractor items were exemplars from a uniform category, thus enhancing the distractor's categorical distinctiveness. In a categorically heterogeneous condition, each non-distractor item represented a distinct category. Neutral distractors disrupted target perception only in the homogenous condition, but emotional distractors did so regardless of their categorical distinctiveness.     

The Karolinska Directed Emotional Faces: A validation study

Although affective facial pictures are widely used in emotion research, standardised affective stimuli sets are rather scarce, and the existing sets have several limitations. We therefore conducted a validation study of 490 pictures of human facial expressions from the Karolinska Directed Emotional Faces database (KDEF). Pictures were evaluated on emotional content and were rated on an intensity and arousal scale. Results indicate that the database contains a valid set of affective facial pictures. Hit rates, intensity, and arousal of the 20 best KDEF pictures for each basic emotion are provided in an appendix.     

Effects of social and affective content on exogenous attention as revealed by event-related potentials

The social content of affective stimuli has been proposed as having an influence on cognitive processing and behaviour. This research was aimed, therefore, at studying whether automatic exogenous attention demanded by affective pictures was related to their social value. We hypothesised that affective social pictures would capture attention to a greater extent than non-social affective stimuli. For this purpose, we recorded event-related potentials in a sample of 24 participants engaged in a digit categorisation task. Distracters were affective pictures varying in social content, in addition to affective valence and arousal, which appeared in the background during the task. Our data revealed that pictures depicting high social content captured greater automatic attention than other pictures, as reflected by the greater amplitude and shorter latency of anterior P2, and anterior and posterior N2 components of the ERPs. In addition, social content also provoked greater allocation of processing resources as manifested by P3 amplitude, likely related to the high arousal they elicited. These results extend data from previous research by showing the relevance of the social value of the affective stimuli on automatic attentional processing.     

Affective picture processing is modulated by emotion word type in masked priming paradigm: an event-related potential study

ABSTRACT

Although a large body of research demonstrates the role of language in emotion processing (e.g. emotional facial expressions), how emotion-laden words (e.g. poison, reward) and emotion-label words (e.g. fear, satisfaction) differently impact affective picture processing is not clear. Emotion-label words label affective states straightforwardly, whereas emotion-laden words engender emotion via reflection. The current study adopted the masked priming paradigm to examine how Chinese emotion-laden words and emotion-label words distinctively influence affective picture processing. Twenty Chinese speakers decided the valence of the pictures with their cortical responses recorded. Emotion-label words facilitated affective picture evaluation behaviourally. Moreover, pictures that were preceded by emotion-laden words generated larger electrophysiological activation than those preceded by emotion-label words. Combined behavioural and ERP evidence revealed that emotion word type modulated affective picture processing, suggesting different roles of emotion-laden and emotion-label words in how emotion is shaped by language.     

Fuzzy picture processing: effects of size reduction and blurring on emotional processing

Previous studies have suggested that picture size reduction affects emotional reactions, possibly because scenes subtending a small visual angle are perceived as being more distant and less relevant compared to larger stimuli. However, pictures that subtend a small visual angle also contain few fine-grained details, which may determine less vivid representations and responses compared to larger and more detailed images. Critically, the present study compared two different types of manipulations, namely size reduction and low-pass spatial filtering, which determined similar detail loss but affected visual angles differently. Affective modulation was assessed using an evaluative task and a behavioral interference task. Results showed that the availability of fine-grained details, independently of visual angle, modulated emotional evaluation. Moreover, interference in an unrelated task was unaffected by either size reduction or low-pass spatial filtering. These findings suggest that high spatial frequencies affect subjective emotional response whereas attentional capture by affective stimuli seems to rely on information that is sufficient to allow a categorization of picture content.     

Early modulation of visual perception by emotional arousal: Evidence from steady-state visual evoked brain potentials

Allocation of processing resources to emotional picture stimuli was examined using steady-state visual evoked brain potentials (ssVEPs). Participants viewed a set of 60 colored affective pictures from the International Affective Picture System, presented in a flickering mode at 10 Hz in order to elicit ssVEPs. Phase and amplitude of the 10-Hz ssVEP were examined for six picture categories: threat and mutilation (unpleasant), families and erotica (pleasant), and household objects and persons (neutral). Self-reported affective arousal and hedonic valence of the picture stimuli were assessed by means of subjective ratings. Viewing affectively arousing (unpleasant and pleasant) pictures was associated with enhanced ssVEP amplitude at parieto-occipital recording sites, as compared with neutral stimuli. Phase information suggested increased coactivation of right occipitotemporal and frontotemporal sources during processing of affectively arousing stimuli. These findings are consistent with reentrant modulation of early visual processing by distributed networks including subcortical and neocortical structures according to a stimulus's motivational relevance.     

Affective stimulus properties influence size perception and the Ebbinghaus illusion

In the New Look literature of the 1950s, it has been suggested that size judgments are dependent on the affective content of stimuli. This suggestion, however, has been 'discredited' due to contradictory findings and methodological problems. In the present study, we revisited this forgotten issue in two experiments. The first experiment investigated the influence of affective content on size perception by examining judgments of the size of target circles with and without affectively loaded (i.e., positive, neutral, and negative) pictures. Circles with a picture were estimated to be smaller than circles without a picture, and circles with a negative picture were estimated to be larger than circles with a positive or a neutral picture confirming the suggestion from the 1950s that size perception is influenced by affective content, an effect notably confined to negatively loaded stimuli. In a second experiment, we examined whether affective content influenced the Ebbinghaus illusion. Participants judged the size of a target circle whereby target and flanker circles differed in affective loading. The results replicated the first experiment. Additionally, the Ebbinghaus illusion was shown to be weakest for a negatively loaded target with positively loaded and blank flankers. A plausible explanation for both sets of experimental findings is that negatively loaded stimuli are more attention demanding than positively loaded or neutral stimuli.     

Flexible emotional responsiveness in trait resilience

Field studies and laboratory experiments have documented that a key component of resilience is emotional flexibility--the ability to respond flexibly to changing emotional circumstances. In the present study we tested the hypotheses that resilient people exhibit emotional flexibility: (a) in response to frequently changing emotional stimuli and (b) across multiple modalities of emotional responding. As participants viewed a series of emotional pictures, we assessed their self-reported affect, facial muscle activity, and startle reflexes. Higher trait resilience predicted more divergent affective and facial responses (corrugator and zygomatic) to positive versus negative pictures. Thus, compared with their low-resilient counterparts, resilient people appear to be able to more flexibly match their emotional responses to the frequently changing emotional stimuli. Moreover, whereas high-trait-resilient participants exhibited divergent startle responses to positive versus negative pictures regardless of the valence of the preceding trial, low-trait-resilient participants did not exhibit divergent startle responses when the preceding picture was negative. High-trait-resilient individuals, therefore, appear to be better able than are their low-resilient counterparts to either switch or maintain their emotional responses depending on whether the emotional context changes. The present findings broaden our understanding of the mechanisms underlying resilience by demonstrating that resilient people are able to flexibly change their affective and physiological responses to match the demands of frequently changing environmental circumstances.     

Fear of Failure Biases Affective and Attentional Responses to Lexical and Pictorial Stimuli

The purpose of this investigation was to examine whether attentional biases would be noticed among individuals differing in levels of fear of failure (FF) as they viewed pictorial and lexical stimuli depicting various affective content. Indices of natural selective attention, namely, viewing time and self-reported affect, were assessed in 137 college students during free viewing picture and word presentation conditions. As hypothesized, FF was (a) negatively associated with self-reported dominance and valence for failure- and unpleasant-themed stimuli, and (b) positively associated with arousal ratings for unpleasant pictures. Although initially suppressed by neuroticism, partial correlation coefficients revealed a significant positive relationship between FF and viewing time for failure pictures. Results are discussed in the context of current theories of emotional reactivity and attentional biases pertaining to the nature of FF. Recommendations are provided for future research to elaborate the mechanisms involved in detrimental effects of FF.     

Rapid picture presentation and affective engagement

Emotional reactions were assessed to pictorial stimuli presented in a continuous stream at rapid speeds that compromise conceptual memory and the processing of specific picture content. Blocks of unpleasant, neutral, or pleasant pictures were presented at the rate of either three pictures per second or seven pictures per second. Even with rapid presentation rates, startle reflexes, corrugator muscle activity, and skin conductance responses were heightened when viewing unpleasant pictures. These effects were stronger later in the aversive block, suggesting that cumulative exposure increasingly activates the defense system. The findings suggest that, despite conceptual masking inherent in rapid serial visual presentation, affective pictures prompt measurable emotional engagement.     

Attentional bias during emotional processing: evidence from an emotional flanker task using IAPS

Attention is biased towards threat-related stimuli. In three experiments, we investigated the mechanisms, processes, and time course of this processing bias. An emotional flanker task simultaneously presented affective or neutral pictures from the international affective picture system database either as central response-relevant stimuli or surrounding response-uninformative flankers. Participants’ response times to central stimuli was measured. The attentional bias was observed when stimuli were presented either for 1500?ms (Experiment 1) or 500?ms (Experiment 2). The threat-related attentional bias held regardless of the stimuli competing for attention even when presentation time was further reduced to 200?ms (Experiment 3). The results indicate that automatic and controlled mechanisms may interact to modulate the orientation of attention to threat. The data presented here shed new light on the mechanisms, processes, and time course of this long investigated by still largely unknown processing bias.     

Sex differences in the time course of emotion

Conventional wisdom holds that women are more "emotional" than men. However, research evidence suggests that sex differences in emotion are considerably more complex. The authors tested hypotheses about sex differences in the engagement of the approach and avoidance motivational systems thought to underpin emotional responses. The authors measured reported emotional experience and startle response magnitude both during the presentation and after the offset of emotional stimuli that engage these motivational systems to assess whether men and women differ in their patterns of immediate response to emotional stimuli and in their patterns of recovery from these responses. Our findings indicated that women were more experientially reactive to negative, but not positive, emotional pictures compared to men, and that women scored higher than men on measure of aversive motivational system sensitivity. Although both men and women exhibited potentiation of the startle response during the presentation of negative pictures relative to neutral pictures, only women continued to show this relative potentiation during the recovery period, indicating that women were continuing to engage the aversive motivational system after the offset of negative emotional pictures.     

Visual complexity attenuates emotional processing in psychopathy: Implications for fear-potentiated startle deficits

A long-standing debate is the extent to which psychopathy is characterized by fundamental deficits in attention or emotion. We tested the hypothesis that the interplay of emotional and attentional systems is critical for understanding processing deficits in psychopathy. A group of 63 offenders were assessed using the Psychopathy Checklist: Screening Version. Event-related brain potentials (ERPs) and fear-potentiated startle (FPS) reflexes were collected while participants viewed pictures selected to disentangle an existing confound between perceptual complexity and emotional content in the pictures typically used to study fear deficits in psychopathy. As predicted, picture complexity moderated the emotional processing deficits. Specifically, the affective–interpersonal features of psychopathy were associated with greater allocation of attentional resources to processing emotional stimuli at initial perception (visual N1), but only when the picture stimuli were visually complex. Despite this, results for the late positive potential indicated that emotional pictures were less attentionally engaging and held less motivational significance for individuals high in affective–interpersonal traits. This deficient negative emotional processing was observed later in their reduced defensive fear reactivity (FPS) to high-complexity unpleasant pictures. In contrast, the impulsive–antisocial features of psychopathy were associated with decreased sensitivity to picture complexity (visual N1) and were unrelated to emotional processing, as assessed by both ERPs and FPS. These findings are the first to demonstrate that picture complexity moderates FPS deficits, and they implicate the interplay of attention and emotional systems as deficient in psychopathy.