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.     

Human content in affect-inducing stimuli: A secondary analysis of the international affective picture system

We report a secondary analysis of the international affective picture system (IAPS), the broadest available standardized sample of emotional stimuli, which confirmed our prediction that the distribution of slides across the valence and arousal dimensions would be related to human versus inanimate slide content. Pictures depicting humans are over-represented in the high arousal/positive and high arousal/negative areas of affective space as compared to inanimate pictures, which are especially frequent in the low arousal/neutral valence area. Results pertaining to dominance ratings and gender differences in valence and arousal ratings further suggest that there are qualitative differences between emotional reactions to animal or human slide content and responses to nonsocial still photos. Researchers need to be mindful of this distinction when selecting affect-inducing stimuli.

Personality effects and sex differences on the International Affective Picture System (IAPS): A Spanish and Swiss study

The present study analyses the relationship between Anxiety and Impulsivity personality factors and emotions, by controlling for country and sex effects in a sample of Spanish and Swiss university students. Emotions were assessed through the International Affective Picture System (IAPS) of pictures (valence/arousal) using the Self-Assessment Manikin (SAM) procedure. The mixed valence/arousal groups’ pictures were formed according to Tok, Koyuncu, Dural and Catikkas procedure (2010). Results showed that females scored significantly higher in Anxiety factor and men in Impulsivity factor in both countries. The effect of sex was highly significant for Anxiety (ŋ²: 0.12), but there was no significant effect of the country. Also, females obtained higher scores in the four valence/arousal pictures groups. The sex effect was particularly robust for negative valence–high arousal (ŋ²: 0.13). Impulsivity correlated with high ratings of positive valence–high arousal while Anxiety correlated with high ratings of negative valence–high arousal and with high ratings of negative valence–low arousal in both sexes, although scores were higher for females. Structural Equation Modelling confirmed these relationships. Nevertheless, Anxiety and Impulsivity explained only a small amount of the accounted variance of the self-reported valence and arousal of the pictures.     

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/.     

Differences in adult and adolescent listeners’ ratings of valence and arousal in emotional prosody

ABSTRACT

Judgments of emotional stimuli’s valence and arousal can differ based on the perceiver’s age. With most of the existing literature on age-related changes in such ratings based on perceptions of visually-presented pictures or words, less is known about how youth and adults perceive and rate the affective information contained in auditory emotional stimuli. The current study examined age-related differences in adolescent (n?=?31; 45% female; aged 12–17, M?=?14.35, SD?=?1.68) and adult listeners’ (n?=?30; 53% female; aged 21–30, M?=?26.20 years, SD?=?2.98) ratings of the valence and arousal of spoken words conveying happiness, anger, and a neutral expression. We also fitted closed curves to the average ratings for each emotional expression to determine their relative position on the valence-arousal plane of an affective circumplex. Compared to adults, adolescents’ ratings of emotional prosody were generally higher in valence, but more constricted in range for both valence and arousal. This pattern of ratings is suggestive of lesser differentiation amongst emotional categories’ holistic properties, which may have implications for the successful recognition and appropriate response to vocal emotional cues in adolescents’ social environments.     

Relationships between hostility, affective ratings of pictures, and state affects during task-induced stress

The authors examined the relationship of hostility with (a) affective ratings of pictures and (b) state affects evoked by task-induced stress in 95 healthy men and women 22-37 years of age. Pictures were from the International Affective Picture System (IAPS; P. J. Lang, M. M. Bradley, & B. N. Cuthbert, 1999). Stressors included a startle task, mental arithmetic task, and choice-deadline reaction time task. The circumplex model of affect was used to structure the self-reported state affects. The authors found that hostility was associated with displeasure, high arousal, and low dominance ratings of IAPS pictures. Hostility was related to unpleasant affect and unactivated unpleasant affect during the experiment, and subscale paranoia was related to activated unpleasant affect. Findings suggest that participants scoring high on hostility are prone to negative emotional reactions.     

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.     

Introducing the Open Affective Standardized Image Set (OASIS)

We introduce the Open Affective Standardized Image Set (OASIS), an open-access online stimulus set containing 900 color images depicting a broad spectrum of themes, including humans, animals, objects, and scenes, along with normative ratings on two affective dimensions—valence (i.e., the degree of positive or negative affective response that the image evokes) and arousal (i.e., the intensity of the affective response that the image evokes). The OASIS images were collected from online sources, and valence and arousal ratings were obtained in an online study (total N = 822). The valence and arousal ratings covered much of the circumplex space and were highly reliable and consistent across gender groups. OASIS has four advantages: (a) the stimulus set contains a large number of images in four categories; (b) the data were collected in 2015, and thus OASIS features more current images and reflects more current ratings of valence and arousal than do existing stimulus sets; (c) the OASIS database affords users the ability to interactively explore images by category and ratings; and, most critically, (d) OASIS allows for free use of the images in online and offline research studies, as they are not subject to the copyright restrictions that apply to the International Affective Picture System. The OASIS images, along with normative valence and arousal ratings, are available for download from www.benedekkurdi.com/#oasis or https://db.tt/yYTZYCga.     

The insula and evaluative processes

The insula has been implicated as a component of central networks subserving evaluative and affective processes. This study examined evaluative valence and arousal ratings in response to picture stimuli in patients with lesions of the insula and two contrast groups: a control-lesion group (the primary contrast group) and an amygdala-lesion group. Patients rated the positivity and negativity of picture stimuli (from very unpleasant to very pleasant) and how emotionally arousing they found the pictures to be. Compared with patients in the control-lesion group, patients with insular lesions reported reduced arousal in response to both unpleasant and pleasant stimuli, as well as marked attenuation of valence ratings. In contrast, the arousal ratings of patients with amygdala lesions were selectively attenuated for unpleasant stimuli, and these patients' positive and negative valence ratings did not differ from those of the control-lesion group. Results support the view that the insular cortex may play a broad role in integrating affective and cognitive processes, whereas the amygdala may have a more selective role in affective arousal, especially for negative stimuli.     

The effect of content and physical properties of affective pictures on emotional responses

The aim of this research was to study the influence of both the emotional content and the physical characteristics of affective stimuli on the psychophysiological, behavioral and cognitive indexes of the emotional response. We selected 54 pictures from the IAPS, depicting unpleasant, neutral, and pleasant contents, and used two picture sizes as experimental conditions (120 x 90 cm and 52 x 42 cm). Sixty-one subjects were randomly assigned to each experimental condition. We recorded the startle blink reflex, skin conductance response, heart rate, free viewing time, and picture valence and arousal ratings. In line with previous research (e.g., Bradley, Codispoti, Cuthbert, and Lang, 2001), our data showed an effect of the affective content on all the measurements recorded. Importantly, effects of the size of the affective pictures on emotional responses were not found, indicating that the emotional content is more important than the formal properties of the stimuli in evoking the emotional response.     

Distinct brain systems underlie the processing of valence and arousal of affective pictures

Valence and arousal are thought to be the primary dimensions of human emotion. However, the degree to which valence and arousal interact in determining brain responses to emotional pictures is still elusive. This functional MRI study aimed to delineate neural systems responding to valence and arousal, and their interaction. We measured neural activation in healthy females (N = 23) to affective pictures using a 2 (Valence) × 2 (Arousal) design. Results show that arousal was preferentially processed by middle temporal gyrus, hippocampus and ventrolateral prefrontal cortex. Regions responding to negative valence included visual and lateral prefrontal regions, positive valence activated middle temporal and orbitofrontal areas. Importantly, distinct arousal-by-valence interactions were present in anterior insula (negative pictures), and in occipital cortex, parahippocampal gyrus and posterior cingulate (positive pictures). These data demonstrate that the brain not only differentiates between valence and arousal but also responds to specific combinations of these two, thereby highlighting the sophisticated nature of emotion processing in (female) human subjects.     

Distinct brain systems underlie the processing of valence and arousal of affective pictures

Valence and arousal are thought to be the primary dimensions of human emotion. However, the degree to which valence and arousal interact in determining brain responses to emotional pictures is still elusive. This functional MRI study aimed to delineate neural systems responding to valence and arousal, and their interaction. We measured neural activation in healthy females (N = 23) to affective pictures using a 2 (Valence) × 2 (Arousal) design. Results show that arousal was preferentially processed by middle temporal gyrus, hippocampus and ventrolateral prefrontal cortex. Regions responding to negative valence included visual and lateral prefrontal regions, positive valence activated middle temporal and orbitofrontal areas. Importantly, distinct arousal-by-valence interactions were present in anterior insula (negative pictures), and in occipital cortex, parahippocampal gyrus and posterior cingulate (positive pictures). These data demonstrate that the brain not only differentiates between valence and arousal but also responds to specific combinations of these two, thereby highlighting the sophisticated nature of emotion processing in (female) human subjects.     

The adaptation of the Affective Norms for English Words (ANEW) for European Portuguese

This study presents the adaptation of the Affective Norms for English Words (ANEW; Bradley & Lang, 1999a) for European Portuguese (EP). The EP adaptation of the ANEW was based on the affective ratings made by 958 college students who were EP native speakers. Subjects assessed about 60 words by considering the affective dimensions of valence, arousal, and dominance, using the Self-Assessment Manikin (SAM) in either a paper-and-pencil or a Web survey procedure. Results of the adaptation of the ANEW for EP are presented. Furthermore, the differences between EP, American (Bradley & Lang, 1999a), and Spanish (Redondo, Fraga, Padrón, & Comesa?a, Behavior Research Methods, 39, 600–605, 2007) standardizations were explored. Results showed that the ANEW words were understood in a similar way by EP, American, and Spanish subjects, although some sex and cross-cultural differences were observed. The EP adaptation of the ANEW is shown to be a valid and useful tool that will allow researchers to control and/or manipulate the affective properties of stimuli, as well as to develop cross-linguistic studies. The normative values of EP adaptation of the ANEW can be downloaded at .     

Crossmodal transfer of arousal, but not pleasantness, from the musical to the visual domain

Arousal and valence (pleasantness) are considered primary dimensions of emotion. However, the degree to which these dimensions interact in emotional processing across sensory modalities is poorly understood. We addressed this issue by applying a crossmodal priming paradigm in which auditory primes (Romantic piano solo music) varying in arousal and/or pleasantness were sequentially paired with visual targets (IAPS pictures). In Experiment 1, the emotion spaces of 120 primes and 120 targets were explored separately in addition to the effects of musical training and gender. Thirty-two participants rated their felt pleasantness and arousal in response to primes and targets on equivalent rating scales as well as their familiarity with the stimuli. Musical training was associated with elevated familiarity ratings for high-arousing music and a trend for elevated arousal ratings, especially in response to unpleasant musical stimuli. Males reported higher arousal than females for pleasant visual stimuli. In Experiment 2, 40 nonmusicians rated their felt arousal and pleasantness in response to 20 visual targets after listening to 80 musical primes. Arousal associated with the musical primes modulated felt arousal in response to visual targets, yet no such transfer of pleasantness was observed between the two modalities. Experiment 3 sought to rule out the possibility of any order effect of the subjective ratings, and responses of 14 nonmusicians replicated results of Experiment 2. This study demonstrates the effectiveness of the crossmodal priming paradigm in basic research on musical emotions.     

Reproducing affective norms with lexical co-occurrence statistics: Predicting valence,arousal, and dominance

Human ratings of valence, arousal, and dominance are frequently used to study the cognitive mechanisms of emotional attention, word recognition, and numerous other phenomena in which emotions are hypothesized to play an important role. Collecting such norms from human raters is expensive and time consuming. As a result, affective norms are available for only a small number of English words, are not available for proper nouns in English, and are sparse in other languages. This paper investigated whether affective ratings can be predicted from length, contextual diversity, co-occurrences with words of known valence, and orthographic similarity to words of known valence, providing an algorithm for estimating affective ratings for larger and different datasets. Our bootstrapped ratings achieved correlations with human ratings on valence, arousal, and dominance that are on par with previously reported correlations across gender, age, education and language boundaries. We release these bootstrapped norms for 23,495 English words.     

Emotional Responses to Pictures of Oneself in Healthy College Age Females

Emotional responses related to self-perceptions were investigated in healthy college-aged females using a picture-viewing paradigm that consisted of four categories of pictures (pleasant, neutral, unpleasant, and full body pictures of themselves). The startle eye-blink reflex, facial EMG, and self-reported valence, arousal, and dominance measures were recorded for each picture. Startle reflex and facial EMG measures exhibited decreased activation for self-pictures compared to the other affective categories. Self-reports indicated self-pictures were rated as moderately pleasant, low arousing, and moderately dominant relative to the other affective picture categories. The findings of reduced startle blink reflex coupled with decreased activation for all facial EMG measures and the moderate self-report ratings suggest increased attentional processing for self-pictures. These findings provide an understanding of emotional responses to self-perceptions in healthy young females.     

Affective auditory stimuli: Adaptation of the International Affective Digitized Sounds (IADS-2) for European Portuguese

In this study, we present the normative values of the adaptation of the International Affective Digitized Sounds (IADS-2; Bradley & Lang, 2007a) for European Portuguese (EP). The IADS-2 is a standardized database of 167 naturally occurring sounds that is widely used in the study of emotions. The sounds were rated by 300 college students who were native speakers of EP, in the three affective dimensions of valence, arousal, and dominance, by using the Self-Assessment Manikin (SAM). The aims of this adaptation were threefold: (1)?to provide researchers with standardized and normatively rated affective sounds to be used with an EP population; (2)?to investigate sex and cultural differences in the ratings of affective dimensions of auditory stimuli between EP and the American (Bradley & Lang, 2007a) and Spanish (Fernández-Abascal et al., Psicothema 20:104–113 2008; Redondo, Fraga, Padrón, & Piñeiro, Behavior Research Methods 40:784–790 2008) standardizations; and (3)?to promote research on auditory affective processing in Portugal. Our results indicated that the IADS-2 is a valid and useful database of digitized sounds for the study of emotions in a Portuguese context, allowing for comparisons of its results with those of other international studies that have used the same database for stimulus selection. The normative values of the EP adaptation of the IADS-2 database can be downloaded along with the online version of this article.     

Psychophysiological, behavioral, and cognitive indices of the emotional response: a factor-analytic study

Previous research on the components of the emotional response employing factor analytic studies has yielded a two-factor structure (Lang, Greenwald, Bradley, & Hamm, 1993; Cuthbert, Schupp, Bradley, Birbaumer, & Lang, 2000). However, the startle blink reflex, a widely employed measure of the emotional response, has not been considered to date. We decided to include two parameters of the startle reflex (magnitude and latency) in order to explore further how this response fits into the two-factor model of emotion. We recorded the acoustic startle blink response, skin conductance response, heart rate, free viewing time, and picture valence and arousal ratings of 45 subjects while viewing 54 pictures from the International Affective Picture System (IAPS; 18 unpleasant, 18 neutral, and 18 pleasant). Factorizations of all measures gave a two-factor solution (valence and arousal) that accounted for 70% of the variance. Although some measurements, including heart rate change, did not behave as predicted, our results reinforce the two-dimension model of the emotion, and show that startle fits into the model.