Affective auditory stimulus database: An expanded version of the International Affective Digitized Sounds (IADS-E)

Using appropriate stimuli to evoke emotions is especially important for researching emotion. Psychologists have provided several standardized affective stimulus databases—such as the International Affective Picture System (IAPS) and the Nencki Affective Picture System (NAPS) as visual stimulus databases, as well as the International Affective Digitized Sounds (IADS) and the Montreal Affective Voices as auditory stimulus databases for emotional experiments. However, considering the limitations of the existing auditory stimulus database studies, research using auditory stimuli is relatively limited compared with the studies using visual stimuli. First, the number of sample sounds is limited, making it difficult to equate across emotional conditions and semantic categories. Second, some artificially created materials (music or human voice) may fail to accurately drive the intended emotional processes. Our principal aim was to expand existing auditory affective sample database to sufficiently cover natural sounds. We asked 207 participants to rate 935 sounds (including the sounds from the IADS-2) using the Self-Assessment Manikin (SAM) and three basic-emotion rating scales. The results showed that emotions in sounds can be distinguished on the affective rating scales, and the stability of the evaluations of sounds revealed that we have successfully provided a larger corpus of natural, emotionally evocative auditory stimuli, covering a wide range of semantic categories. Our expanded, standardized sound sample database may promote a wide range of research in auditory systems and the possible interactions with other sensory modalities, encouraging direct reliable comparisons of outcomes from different researchers in the field of psychology.     

A cluster-based approach to selecting representative stimuli from the International Affective Picture System (IAPS) database

The International Affective Picture System (IAPS; Lang, Bradley, & Cuthbert, 2008) is a stimulus database that is frequently used to investigate various aspects of emotional processing. Despite its extensive use, selecting IAPS stimuli for a research project is not usually done according to an established strategy, but rather is tailored to individual studies. Here we propose a standard, replicable method for stimulus selection based on cluster analysis, which re-creates the group structure that is most likely to have produced the valence arousal, and dominance norms associated with the IAPS images. Our method includes screening the database for outliers, identifying a suitable clustering solution, and then extracting the desired number of stimuli on the basis of their level of certainty of belonging to the cluster they were assigned to. Our method preserves statistical power in studies by maximizing the likelihood that the stimuli belong to the cluster structure fitted to them, and by filtering stimuli according to their certainty of cluster membership. In addition, although our cluster-based method is illustrated using the IAPS, it can be extended to other stimulus databases.     

Cross-modal validation of the Leipzig Affective Norms for German (LANG)

Affective stimuli are increasingly used in emotion research. Typically, stimuli are selected from databases providing affective norms. The validity of these norms is a critical factor with regard to the applicability of the stimuli for emotion research. We therefore probed the validity of the Leipzig Affective Norms for German (LANG) by correlating valence and arousal ratings across different sensory modalities. A sample of 120 words was selected from the LANG database, and auditory recordings of these words were obtained from two professional actors. The auditory stimuli were then rated again for valence and arousal. This cross-modal validation approach yielded very high correlations between auditory and visual ratings (>.95). These data confirm the strong validity of the Leipzig Affective Norms for German and encourage their use in emotion research.     

Emotional pictures predominate in binocular rivalry

This study used binocular rivalry to examine whether emotionally relevant pictures are processed preferentially in the visual system. Binocular rivalry occurs when two incompatible pictures are presented to both eyes. If the pictures cannot be merged to a single unambiguous percept, binocular rivalry results in an alternation of the two percepts. However, it has been controversial whether emotional picture content can influence a picture's relative predominance. Twenty pairs of emotional and neutral pictures from the International Affective Picture System (IAPS) were presented to 45 healthy participants. As hypothesised, emotional pictures significantly predominated over neutral pictures, both with respect to the first percept and the total viewing time across each trial. We conclude that the relative predominance of emotional pictures in binocular rivalry provides further support for the preferential processing of emotional stimuli in the visual system.     

What determines a feeling's position in affective space? A case for appraisal

The location of verbally reported feelings in a three-dimensional affective space is determined by the results of appraisal processes that elicit the respective states. One group of participants rated their evaluation of 59 pictures from the International Affective Picture System (IAPS) on a profile of nine appraisal criteria. Another group rated their affective reactions to the same pictures on the classic dimensions of affective meaning (valence, arousal, potency). The ratings on the affect dimensions correlate differentially with specific appraisal ratings. These results can be interpreted as showing that the reactions to the IAPS pictures are predictably produced through appraisal of picture content. The relevance of the findings for emotion induction paradigms and for emotion theory in general is discussed.     

Affective valence and P300 when stimulus arousal level is controlled

Visual stimuli from the International Affective Picture System (IAPS) were employed in a modified oddball paradigm to elicit the P300 event-related brain potential (ERP) in young adult females (N=12). The pictures varied on valence (negative, neutral, positive) ratings but had the same medium arousal level ratings. The images were presented as targets with a standard stimulus composed of red/white triangles designed to mimic the spatial frequency of the pictures. P300 amplitude from negative relative to neutral stimuli was smaller over frontal areas, whereas amplitude from positive relative to neutral stimuli did not differ. P300 amplitude differences among valence categories were consistent across the midline electrodes, and did not change over the parietal area where arousal effects are typically observed. The findings suggest that valence affects P300 frontal amplitude, and arousal level should be controlled when using emotional stimuli to elicit ERPs. Theoretical implications are discussed.     

个体神经质水平对情绪加工的影响 ——事件相关电位研究

采用事件相关电位方法探讨个体神经质水平对情绪加工的影响,测量并比较了神经质高水平个体和神经质低水平个体观看三类图片（积极、中性和消极）时的事件相关电位。结果发现,P120、N130、P230和N250成分的刺激效价主效应显著,积极、消极情绪刺激与中性刺激诱发的ERP差异最早开始于刺激呈现后的120ms左右。其次,在额叶和额中央部位的晚正电位上,神经质水平与刺激效价交互作用显著,神经质高分组与低分组对消极情绪刺激的反应有明显差异,而两组被试对积极、中性刺激的反应没有表现出差异。结果支持神经质与消极情绪相关,个体的神经质水平主要影响额叶和额中央叶的晚期负性情绪加工     

Emotional time distortions: the fundamental role of arousal

An emotion-based lengthening effect on the perception of durations of emotional pictures has been assumed to result from an arousal-based mechanism, involving the activation of an internal clock system. The aim of this study was to systematically examine the arousal effect on time perception when different discrete emotions were considered. The participants were asked to verbally estimate the duration of emotional pictures from the International Affective Picture System (IAPS). The pictures varied either in arousal level, i.e., high/low-arousal, for the same discrete emotion (disgust or sadness) or in the depicted emotion, e.g., disgust/fear for pictures matched for arousal (high-arousal). The results systematically revealed a lengthening effect on the perception of the duration of the emotional compared to the neutral pictures and indicated that the magnitude of this effect increased with arousal level. Nevertheless, variations in time perception were observed for one and the same arousal level, with the duration of disgust-inducing pictures (e.g., body mutilation) being judged longer than that of fear-inducing pictures (e.g., snake). These results suggest that arousal is a fundamental mechanism mediating the effect of emotion on time perception. However, the effect cannot be reduced to arousal, since the impact of the content of pictures also plays a critical role.     

Priming the activation of fear and disgust: evidence for semantic processing

Given that semantic processes mediate early processes in the elicitation of emotions, we expect that already activated emotion-specific information can influence the elicitation of an emotion. In Experiment 1, participants were exposed to masked International Affective Picture System (IAPS) pictures that elicited either disgust or fear. Following the presentation of the primes, other IAPS pictures were presented as targets that elicited either disgust or fear. The participants' task was to classify the target picture as either disgust or fear evoking. In Experiment 2, we substituted the IAPS primes with facial expressions of either disgust or fear. In Experiment 3, we substituted the IAPS primes with the words disgust or fear. In all three experiments, we found that prime-target combinations of the same emotion were responded to faster than prime-target combinations of different emotions. Our findings suggest that the influence of primes on the elicitation of emotion is mediated by activated schemata or appraisal processes.     

Reaction time normative data for the IAPS as a function of display time, gender, and picture content

This study aimed to extend the International Affective Picture System (IAPS; Lang, Bradley, & Cuthbert, 2005) norms by obtaining reaction time (RT) normative data for 308 selected photographs. Pictures were presented one at a time for 33, 100, or 250 msec, or under free-time display, to 96 women and 48 men. The participants’ task involved assessing the emotional valence of each picture and responding as quickly as possible as to whether it was unpleasant, neutral, or pleasant. RTs provided an index of processing efficiency. The manipulation of display time served to estimate the time course in the valence identification of each picture. Some categories of depicted scenes (e.g., erotica and mutilations) were classified more consistently and efficiently than were others as pleasant or unpleasant. There were minimal differences between men and women. Overall, the present data provide researchers investigating cognition/emotion relationships with an objective criterion to select pictorial stimuli on the basis of RTs. Data for all pictures may be downloaded from brm.psychonomic-journals.org/content/supplemental.     

中等强度情绪性图片的神经机制——一项fMRI研究

采用修订后的中等唤起度的国际情绪图片为刺激材料,以12名女性大学生为被试,考察情绪性图片引起的脑激活模式。结果发现,与中性条件相比,消极情绪图片激活了枕叶、杏仁核、海马旁回和壳核。积极情绪图片引起枕叶、内侧眶额、额中回等脑区的激活,研究结果再次验证了杏仁核与消极情绪的密切关系,同时推测,内侧眶额可能是中等唤起度的趋近性积极情绪的一个脑功能区。     

Emotional time distortions: The fundamental role of arousal

An emotion-based lengthening effect on the perception of durations of emotional pictures has been assumed to result from an arousal-based mechanism, involving the activation of an internal clock system. The aim of this study was to systematically examine the arousal effect on time perception when different discrete emotions were considered. The participants were asked to verbally estimate the duration of emotional pictures from the International Affective Picture System (IAPS). The pictures varied either in arousal level, i.e., high/low-arousal, for the same discrete emotion (disgust or sadness) or in the depicted emotion, e.g., disgust/fear for pictures matched for arousal (high-arousal). The results systematically revealed a lengthening effect on the perception of the duration of the emotional compared to the neutral pictures and indicated that the magnitude of this effect increased with arousal level. Nevertheless, variations in time perception were observed for one and the same arousal level, with the duration of disgust-inducing pictures (e.g., body mutilation) being judged longer than that of fear-inducing pictures (e.g., snake). These results suggest that arousal is a fundamental mechanism mediating the effect of emotion on time perception. However, the effect cannot be reduced to arousal, since the impact of the content of pictures also plays a critical role.     

Working memory load reduces the late positive potential and this effect is attenuated with increasing anxiety

Emotion regulation decreases the processing of arousing stimuli, as indexed by the late positive potential (LPP), an electrocortical component that varies in amplitude with emotional arousal. Emotion regulation increases activity in the prefrontal areas associated with cognitive control, including the dosolateral prefrontal cortex (DLPFC). The present study manipulated working memory load, known to activate the DLPFC, and recorded the LPP elicited by aversive and neutral IAPS pictures presented during the retention interval. The LPP was larger on low-load compared to high-load trials, and on trials with aversive compared to neutral pictures. These LPP data suggest that emotional content and working memory load have opposing effects on attention to distracting stimuli. State anxiety was associated with reduced modulation of the LPP by working memory load. Results are discussed in terms of competition for attention between emotion and cognition and suggest a relationship between DLPFC activation and the allocation of attentional resources to distracting visual stimuli–a relationship that may be disrupted with increasing anxiety.     

Impact of negative affectively charged stimuli and response style on cognitive-control-related neural activation: An ERP study

The canonical AX-CPT task measures two forms of cognitive control: sustained goal-oriented control (“proactive” control) and transient changes in cognitive control following unexpected events (“reactive” control). We modified this task by adding negative and neutral International Affective Picture System (IAPS) pictures to assess the effects of negative emotion on these two forms of cognitive control. Proactive and reactive control styles were assessed based on measures of behavior and electrophysiology, including the N2 event-related potential component and source space activation (Low Resolution Tomography [LORETA]). We found slower reaction-times and greater DLPFC activation for negative relative to neutral stimuli. Additionally, we found that a proactive style of responding was related to less prefrontal activation (interpreted to reflect increased efficiency of processing) during actively maintained previously cued information and that a reactive style of responding was related to less prefrontal activation (interpreted to reflect increased efficiency of processing) during just-in-time environmentally triggered information. This pattern of results was evident in relatively neutral contexts, but in the face of negative emotion, these associations were not found, suggesting potential response style-by-emotion interaction effects on prefrontal neural activation.     

The Nencki Affective Picture System (NAPS): Introduction to a novel,standardized, wide-range,high-quality,realistic picture database

Selecting appropriate stimuli to induce emotional states is essential in affective research. Only a few standardized affective stimulus databases have been created for auditory, language, and visual materials. Numerous studies have extensively employed these databases using both behavioral and neuroimaging methods. However, some limitations of the existing databases have recently been reported, including limited numbers of stimuli in specific categories or poor picture quality of the visual stimuli. In the present article, we introduce the Nencki Affective Picture System (NAPS), which consists of 1,356 realistic, high-quality photographs that are divided into five categories (people, faces, animals, objects, and landscapes). Affective ratings were collected from 204 mostly European participants. The pictures were rated according to the valence, arousal, and approach–avoidance dimensions using computerized bipolar semantic slider scales. Normative ratings for the categories are presented for each dimension. Validation of the ratings was obtained by comparing them to ratings generated using the Self-Assessment Manikin and the International Affective Picture System. In addition, the physical properties of the photographs are reported, including luminance, contrast, and entropy. The new database, with accompanying ratings and image parameters, allows researchers to select a variety of visual stimulus materials specific to their experimental questions of interest. The NAPS system is freely accessible to the scientific community for noncommercial use by request at http://naps.nencki.gov.pl.     

Emotion and recognition memory: the discrimination of negative information as an adaptive process

We studied the effect of emotion generated by IAPS (International Affective Picture System) pictures on incidental recognition of these pictures for short retention periods (15 min). Memorization distraction tasks and reaction time tasks were used together with short exposure times (2 seconds per picture) in order to prevent a high recognition rate that would impede testing for the effect of emotion on discrimination parameters (A′) and response bias (B′′D) (ceiling effect). We used 80 pictures representing the medium and high levels of two-dimensional emotional space. The results showed greater discrimination and a more conservative response style to unpleasant and medium arousal level pictures. These pictures produced higher confidence and lower response times in the recognition phase. The results can be explained by the negative content of the pictures and activation level effects on attentional processing and memory, and can be interpreted as a phenomenon that is evolutionarily adaptive.     

不同注意资源水平上核心厌恶和道德厌恶刺激加工分离效应的ERPs研究

厌恶帮助人类避免接触生物病菌、社会道德威胁物。本研究采用“线索—靶”范式考察不同注意资源水平上核心和道德厌恶刺激的认知加工特征。结果发现,核心厌恶刺激诱发的P2波幅显著大于道德厌恶和中性刺激;有效线索下核心厌恶刺激的P3波幅与道德厌恶刺激间差异不显著,而无效线索下核心厌恶刺激的P3波幅显著大于道德厌恶。结果表明两类厌恶刺激在不同注意资源水平上存在加工分离效应,支持了厌恶情绪“异质性”的观点。     

Disturbed prefrontal and temporal brain function during emotion and cognition interaction in criminal psychopathy

Impaired emotional responsiveness has been revealed as a hallmark of psychopathy. In spite of an increasing database on emotion processing, studies on cognitive function and in particular on the impact of emotion on cognition in psychopathy are rare. We used pictures from the International Affective Picture Set (IAPS) and a Simon Paradigm to address emotion-cognition interaction while functional and structural imaging data were obtained in 12 healthy controls and 10 psychopaths. We found an impaired emotion-cognition interaction in psychopaths that correlated with a changed prefrontal and temporal brain activation. With regard to the temporal cortex, it is shown that structure and function of the right superior temporal gyrus is disturbed in psychopathy, supporting a neurobiological approach to psychopathy, in which structure and function of the right STG may be important.     

记忆编码之后的情绪对中性词语记忆巩固现象的影响

在被试记忆中性词语之后加入情绪图片,人为地诱发被试的正中负三种情绪,旨在考察情绪通过影响记忆的巩固过程对记忆中性词语的影响。实验结果发现,再认时与正负情绪图片配对的词语再认率显著高于与中性情绪图片配对的词语,且正负两种条件下的再认率差异不显著;性别主效应和交互作用都不显著,即在所有被试中都发现了类似的情绪记忆优势效应。