Perceptual processing of natural scenes at rapid rates: Effects of complexity, content, and emotional arousal

During rapid serial visual presentation (RSVP), the perceptual system is confronted with a rapidly changing array of sensory information demanding resolution. At rapid rates of presentation, previous studies have found an early (e.g., 150–280 ms) negativity over occipital sensors that is enhanced when emotional, as compared with neutral, pictures are viewed, suggesting facilitated perception. In the present study, we explored how picture composition and the presence of people in the image affect perceptual processing of pictures of natural scenes. Using RSVP, pictures that differed in perceptual composition (figure–ground or scenes), content (presence of people or not), and emotional content (emotionally arousing or neutral) were presented in a continuous stream for 330 ms each with no intertrial interval. In both subject and picture analyses, all three variables affected the amplitude of occipital negativity, with the greatest enhancement for figure–ground compositions (as compared with scenes), irrespective of content and emotional arousal, supporting an interpretation that ease of perceptual processing is associated with enhanced occipital negativity. Viewing emotional pictures prompted enhanced negativity only for pictures that depicted people, suggesting that specific features of emotionally arousing images are associated with facilitated perceptual processing, rather than all emotional content.     

双加工再认提取中的情绪记忆增强效应

根据双加工理论, 再认提取可以划分为两种不同的加工：熟悉性与回想。以往的研究普遍认为情绪对再认提取具有增强效应, 但是情绪对再认记忆中两种不同加工方式(熟悉性与回想)的增强效应的神经机制尚存争议。本研究以ERP作为测量手段, 采用修正的“记得/知道”范式对情绪图片进行再认测验, 旨在探究在学习?测验间隔较长的条件下, 情绪信息如何对熟悉性与回想产生增强效应。在行为结果中, 对于知道判断, 情绪图片的记忆表现显著高于中性图片, 情绪效价间没有差异; 对于记得判断, 负性情绪图片的记忆表现要显著高于正性与中性图片。在ERP数据上, 对于知道判断, 情绪图片的FN400新旧效应有增强作用。对于记得判断, 负性图片的LPC的新旧效应波幅显著高于中性与负性图片; 而正性图片的LPC新旧效应增强作用不显著。以上证据表明：学习?测验间隔较长的情况下, 熟悉性再认提取中, 情绪记忆增强效应主要体现在情绪唤醒对记忆强度的提高, 而不仅仅体现在情绪效价对熟悉判断反应倾向的影响。在回想的再认提取中, 情绪效价的调节占据主导地位, 负性情绪图片有显著的情绪记忆增强效应; 正性情绪图片则不具有增强效应。     

Emotional state affects the initiation of forward gait

The aim of the current study was to determine the extent to which pleasant and unpleasant emotional states impact the initiation of forward gait. Participants initiated gait and walked for several steps following the presentation of low arousing pleasant, high arousing pleasant, low arousing unpleasant, high arousing unpleasant, and neutral pictures. Reaction time, displacement, and velocity of the center of pressure (COP) trajectory, and length and velocity of the first and second steps were calculated. Exposure to the highly arousing unpleasant pictures reduced reaction times compared to all other affective conditions. Compared to the low arousing unpleasant pictures, exposure to the high and low arousing pleasant pictures increased the displacement of the COP movement during the anticipatory postural adjustment phase of gait initiation. Additionally, exposure to the low arousing pleasant pictures increased the velocity of the COP movement during the anticipatory postural adjustment phase, compared to the high and low arousing unpleasant pictures. Exposure to the high and low arousing pleasant pictures increased the velocity of the first step relative to the low arousing unpleasant pictures. These findings demonstrate that highly arousing unpleasant emotional states accelerate the initial motor response, but pleasant emotional states generally facilitate the initiation of forward gait due to the approach-oriented directional salience of the movement. These findings extend the scope of the motivational direction hypothesis by demonstrating the effects of emotional reactivity on the initiation of gait.     

Emotionally arousing pictures increase blood glucose levels and enhance recall

Arousal enhances memory in human participants and this enhancing effect is likely due to the release of peripheral epinephrine. As epinephrine does not readily enter the brain, one way that peripheral epinephrine may enhance memory is by increasing circulating blood glucose levels. The present study investigated the possibility that emotionally arousing color pictures would improve memory and elevate blood glucose levels in human participants. Blood glucose levels were measured before, 15 min, and 30 min after male university students viewed 60 emotionally arousing or relatively neutral pictures. Participants viewed each picture for 6 s and then had 10 s to rate the arousal (emotional intensity) and valence (pleasantness) of each picture. A free-recall memory test was given 30 min after the last picture was viewed. Although the emotionally arousing and neutral picture sets were given comparable valence ratings, participants who viewed the emotionally arousing pictures rated the pictures as being more arousing, recalled more pictures, and had higher blood glucose levels after viewing the pictures than did participants who viewed the neutral pictures. These findings indicate that emotionally arousing pictures increase blood glucose levels and enhance memory, and that this effect is not due to differences in the degree of pleasantness of the stimuli. These findings support the possibility that increases in circulating blood glucose levels in response to emotional arousal may be part of the biological mechanism that allows emotional arousal to enhance memory.     

Age-related differences in valence and arousal ratings of pictures from the International Affective Picture System (IAPS): Do ratings become more extreme with age?

The International Affective Picture System (IAPS) has been widely used in aging-oriented research on emotion. However, no ratings for older adults are available. The aim of the present study was to close this gap by providing ratings of valence and arousal for 504 IAPS pictures by 53 young and 53 older adults. Both age groups rated positive pictures as less arousing, resulting in a stronger linear association between valence and arousal, than has been found in previous studies. This association was even stronger in older than in young adults. Older adults perceived negative pictures as more negative and more arousing and positive pictures as more positive and less arousing than young adults did. This might indicate a dedifferentiation of emotional processing in old age. On the basis of a picture recognition task, we also report memorability scores for individual pictures and how they relate to valence and arousal ratings. Data for all the pictures are archived at www.psychonomic.org/archive/.     

The role of age on reactivity and memory for emotional pictures

The purpose of this study was to investigate subjects' reactivity to emotional pictures and their recollection of these pictures, and to examine these two factors as they relate to age. Adolescents and young adults were shown emotionally arousing scenic pictures for long (4-s) and very brief (50-ms) durations. Recognition of the pictures and recall and recognition of words presented along with the pictures were assessed both immediately after the presentation and six weeks later. The results showed that very negative pictures are retained better than neutral or even positive pictures, and that very negative pictures reduce memory for associated information. It was also found that adolescents show a somewhat lower reactivity to very negative pictures and a higher degree of retention of these pictures than adults. The results are discussed in relation to (a) habituation effects, (b) strategies that subjects might develop to block emotional involvement, and (c) the notion that watching violence might serve as a powerful prime to socially undesirable behaviour.     

Effect of negative emotional pictures on associative memory for peripheral information

We investigated the influence of negative emotional pictures on associative memory. A visual object was embedded in the periphery of negative emotional or neutral pictures. Memory was assessed for central item (pictorial) information, peripheral (object) information, and the association between item and peripheral information. On tests of item information, negative emotional pictures were remembered better than neutral pictures. However, associative memory between item and peripheral information was less accurate when the pictures were negative compared to neutral. This occurred despite equivalent recall (Experiments 1 and 2) and recognition (Experiment 2) for the peripheral objects themselves. Further experiments confirmed that performance on the associative test was not influenced by testing order (Experiment 3). These findings suggest that negative emotional arousal can particularly disrupt the associative binding of peripheral information to a central emotional event.     

The tenacious nature of memory binding for arousing negative items

In two experiments, we investigated whether people are better or worse at updating memory for the location of emotional pictures than of neutral pictures. We measured participants’ memories for the locations of both arousing negative pictures and neutral pictures while manipulating practice (encountering the same event repeatedly) and interference (encountering the same picture in a different location). Memory for the context of emotional items was less likely to be corrected when erroneous and was less likely to be correctly updated when the context changed. These results suggest that initial item-context binding is more tenacious for emotional items than for neutral items, even when such binding is incorrect.     

Paying attention to emotional images with impact

Emotional stimuli receive high processing priority in attention and memory. This processing "advantage" is generally thought to be predominantly mediated by arousal. However, recent data suggest that ratings of an image's affective "impact" may be a better predictor of recollection than arousal or valence. One interpretation of these findings is that high-impact images may draw an individual's attention, thus facilitating subsequent processing. We investigated the allocation of visual attention to negative emotional images that differed in impact but were matched for valence, arousal, and other characteristics. Participants viewed a central image flanked by 2 neutral indoor or outdoor scenes and made speeded judgments about whether the neutral scenes matched. In Experiment 1, responses were slower on high-impact relative to low-impact or neutral trials. In Experiment 2, responses on high-arousal relative to low-arousal trials did not differ significantly. These data provide evidence for differential allocation of attention to distinct sets of negative, equally arousing images, and argue against the prevailing view that heightened attention to and processing of emotional stimuli relate simply to arousal or valence.     

Effects of aging and encoding instructions on emotion-induced memory trade-offs

The effects of emotion on memory are often described in terms of trade-offs: People often remember central, emotional information at the expense of background details. The present experiment examined the effects of aging and encoding instructions on participants' ability to remember the details of central emotional objects and the backgrounds on which those objects were placed. When young and older adults passively viewed scenes, both age groups showed strong emotion-induced trade-offs. They were able to remember the visual details as well as the general theme of the emotional object, but they had difficulties remembering the visual specifics of the scene background. Age differences emerged, however, when participants were given encoding instructions that emphasized elaborative encoding of the entire scene. With these instructions, young adults overcame the trade-offs (i.e., they no longer showed impairing effects of emotion), whereas older adults continued to show good memory for the emotional object but poor memory for its background. These results suggest that aging impairs the ability to flexibly disengage attention from the negative arousing elements of scenes, preventing the successful encoding of nonemotional aspects of the environment.     

Attentional interference effects of emotional pictures: threat, negativity, or arousal?

Attentional interference arising from emotional pictures was examined. Participants had to ignore emotional pictures while solving math problems (Study 1, N = 126) or detecting the location of a line (Study 2, N = 60). Data analyses tested predictions of 3 theories. Evolutionary threat theory predicts interference by snake pictures. Categorical negativity theory predicts interference by negative pictures regardless of their intensity. According to arousal theory, arousal level predicts interference effects. The results supported arousal theory, with the most arousing pictures (strong unpleasant pictures, oppositesex models) producing the strongest interference. The findings are interpreted in the context of process models of emotions that postulate an initial relevance check before further processing of valence and other appraisal dimensions.     

Encoding details: positive emotion leads to memory broadening

In the current experiment we tested the hypothesis that unlike negative arousal, which leads to memory narrowing effects whereby an increase in memory for the central details is accompanied by a decrease in memory for the peripheral details, positive arousing events might lead to a memory broadening effect such that positive arousal would increase memory for both central and peripheral details. This was assessed by testing recognition for central and peripheral details of pictures that were selected to vary in a continuous manner across a wide range of arousal for both positive and negative items. The results indicated that increases in both positive and negative stimulus arousal levels led to gradual increases in memory for the central aspects of the photos. In contrast, negative arousal first increased then decreased memory for peripheral detail as arousal levels increased, whereas positive arousal led to a continuous increase in memory for peripheral details. Thus, arousing negative materials lead to memory narrowing, whereas arousing positive materials can lead to memory broadening.     

Endogenous cortisol level interacts with noradrenergic activation in the human amygdala

Animal studies show that high cortisol levels exert their effect on stressful task performance via modulation of the amygdala. Availability of noradrenaline in this brain region appears to be a critical prerequisite for this effect. This relationship between noradrenaline and cortisol is explained by an animal model where the amygdala constitutes a crucial region for this interaction. In humans this model has not been extensively tested so far. In a previously reported study human subjects (aged 20.93+/-2.38) were scanned using fMRI when watching sets of emotional and neutral pictures after taking the beta-adrenergic antagonist propranolol or placebo. Stimulus sets consisted of 92 pictures, divided in four emotional categories that ranged from neutral scenes of domestic objects (CAT1) to extremely negative scenes of mutilation or accidents (CAT4). Confrontation with arousing emotional pictures, accompanied by increased noradrenaline levels, evoked increased amygdala activation under placebo but not under betablocker condition. This new and additional analysis of this data set was carried out to determine the effect of differential endogenous cortisol levels on amygdala activation. Cortisol levels during scanning were determined using salivary samples and subjects were post hoc divided in a High (n=14) and Low cortisol group (n=14). When subjects were watching emotional stimuli, presumably associated with enhanced noradrenaline (NA) levels, amygdala activation was contrasted between the two cortisol groups. We hypothesized that emotional stimuli would elicit more amygdala activation in the High than in the Low cortisol group. Here we demonstrate indeed a significant interaction effect of the endogenous cortisol level with increasing activation in the amygdala under placebo but not under betablocker condition, thereby extending the rodent based model of a synergistic effect of the two stress hormones to the human.     

Encoding details: Positive emotion leads to memory broadening

In the current experiment we tested the hypothesis that unlike negative arousal, which leads to memory narrowing effects whereby an increase in memory for the central details is accompanied by a decrease in memory for the peripheral details, positive arousing events might lead to a memory broadening effect such that positive arousal would increase memory for both central and peripheral details. This was assessed by testing recognition for central and peripheral details of pictures that were selected to vary in a continuous manner across a wide range of arousal for both positive and negative items. The results indicated that increases in both positive and negative stimulus arousal levels led to gradual increases in memory for the central aspects of the photos. In contrast, negative arousal first increased then decreased memory for peripheral detail as arousal levels increased, whereas positive arousal led to a continuous increase in memory for peripheral details. Thus, arousing negative materials lead to memory narrowing, whereas arousing positive materials can lead to memory broadening.     

不同延时条件下的情绪记忆鲜活性

大量研究表明,情绪在一定程度上提高了记忆的准确性,但是情绪对记忆鲜活性的影响更大,该文关注延时条件下情绪记忆鲜活性的研究。研究采用记得/知道范式,操控图片情绪性和测验延时变量,结果发现情绪记忆的记得成绩好于中性记忆,且在不同延时测验下,正性高唤醒图片的记得成绩下降由慢到快再到慢的变化,负性高唤醒图片的记得下降由快到慢变化,而中性则快速下降。说明情绪记忆更具鲜活性,且是效价在高唤醒下起的作用。     

The Presence of a Weapon Shrinks the Functional Field of View

This study examined whether the functional field of view shrinks by the presence of a weapon or the increase of emotional arousal. In Experiment 1, participants viewed two types of pictures depicting scenes involving weapons or control objects and were asked to identify digits presented at the periphery when the pictures disappeared. The results showed that the presence of a weapon impaired identification of the peripheral digits, even when the pictures were equal with respect to emotional arousal level. In Experiment 2, participants viewed emotionally arousing pictures or neutral pictures, neither of which included weapons, and they were asked to identify digits presented at the periphery when the pictures disappeared. The results revealed that the increased emotional arousal did not impair identification of the peripheral digits. These results indicate that the functional field of view shrinks because of the presence of a weapon but not because of increased emotional arousal.Copyright © 2015 John Wiley & Sons, Ltd.     

情绪场景图片的注意偏向：眼动研究

注意实验中,与不带情绪色彩的刺激相比,具有情绪意义的刺激可引起注意偏向。本研究以情绪场景图片为材料,通过眼动技术分别记录被试在反向眼跳任务和Go/No-go任务中的眼动数据,考察了情绪图片的注意偏向。结果发现：反向眼跳任务中,对情绪图片的眼跳潜伏期比中性图片更长,眼跳错误率也更高;在Go任务中,相对于呈现在中央的中性图片,情绪图片引起的对靶子的眼跳潜伏期更长;在No-go任务中,相对于呈现在中央的中性图片,情绪图片引起的眼跳错误率更低。实验结果说明,情绪图片可引起注意偏向,表现为更快的捕获注意并且注意更难从情绪图片上转移。     

Age-related affective modulation of the startle eyeblink response: older adults startle most when viewing positive pictures

Previous studies reveal age by valence interactions in attention and memory, such that older adults focus relatively more on positive and relatively less on negative stimuli than younger adults. In the current study, eyeblink startle response was used to measure differences in emotional reactivity to images that were equally arousing to both age groups. Viewing positive and negative pictures from the International Affective Picture System had opposite effects on startle modulation for older and younger adults. Younger adults showed the typical startle blink pattern, with potentiated startle when viewing negative pictures compared to positive pictures. Older adults, on the other hand, showed the opposite pattern, with potentiated startle when viewing positive pictures compared to viewing negative and neutral pictures. Potential underlying mechanisms for this interaction are evaluated. This pattern suggests that, compared with younger adults, older adults are more likely to spontaneously suppress responses to negative stimuli and process positive stimuli more deeply.     

人类情绪记忆的行为遗传学与神经遗传学研究进展述评

情绪记忆及其增强效应存在广泛的个体差异,这种个体差异可能有其神经与遗传基础。近来的行为遗传学与神经遗传学证实人类ADRA2B基因缺失突变以及BDNF Val66Met基因的多态性与情绪记忆增强及其神经机制的个体差异相联系。本文重点介绍与人类情绪记忆相关的这两种基因,梳理了行为与神经遗传学研究的最新进展,指出未来应关注更多候选基因,并重视多个脑区之间的交互作用;还应使用情绪面孔刺激探索BDNF Val66Met基因多态性对情绪记忆编码和提取的影响等。     

The naked truth: Positive,arousing distractors impair rapid target perception

Emotional stimuli tend to capture and hold attention more than non-emotional stimuli do. Aversive pictures have been found to impair perception of visual targets even after the emotional information has disappeared. The benefits of such interlinked emotion and attention systems have sometimes been discussed within an evolutionary framework, with a survival advantage attributed to early detection of threatening stimuli. However, consistent with recent suggestions that attention is drawn to arousing stimuli regardless of whether they are positive or negative, the current investigation found that erotic distractors—generally rated as both pleasing and arousing—consistently elicited a transient “emotion-induced blindness” similar to that caused by aversive distractors (Experiment 1). This effect persisted despite performance-based monetary incentives to ignore the distractors (Experiment 2), and following attentional manipulations that reduced interference from aversive images (Experiment 3). The findings indicate that positively arousing stimuli can spontaneously cause emotion-induced deficits in visual processing, just as aversive stimuli can.