Neural correlates of emotion word processing: the interaction between emotional valence and arousal

Emotion is characterised by two-dimensions: emotional valence describes the extent to which an emotion is positive or negative, and arousal represents its intensity. Emotional content of verbal material affects cognitive processing, although research on word recognition has only recently taken emotion into account, primarily focusing on valence, while neglecting arousal. The present work aimed to disentangle the effects of valence and arousal during a lexical decision task, using reaction times (RTs), event-related potentials (ERPs) and BOLD responses in an event-related fMRI design. These methods were chosen to determine when affective features have an effect, and which neural systems are involved. The material for three experiments was based on a word corpus created by collecting ratings for emotional and lexico-semantic features. A first and novel finding was that arousal interacted with valence. Specifically, lexical decision times were slower for high-arousal positive stimuli (PH) and low-arousal negative ones (NL) compared to low-arousal positive (PL) and high arousal negative (NH) stimuli. ERPs also showed an interaction between 200-300 ms on the early posterior negativity (EPN), a component which is sensitive to emotional stimuli. At this processing stage people access their mental lexicon. Its amplitude was greater for PH and NL words, suggesting a higher processing load for conflicting stimuli. Positive valence and low arousal elicit an approach schema, whereas negative valence and high arousal elicit an avoidance schema (Robinson, Storbeck, Meier & Kirkeby, 2004). BOLD responses showed a similar interaction in the insula bilaterally, with increased activation for PH and NL words. This region is associated with integration of information on visceral states with higher-order cognitive and emotional processing, suggesting higher difficulty in integrating conflicting stimuli. Taken together, these studies indicate that emotion affects word processing during lexical access, and models of word recognition need to take into account both valence and arousal

Social context modulates the effect of physical warmth on perceived interpersonal kindness:a study of embodied metaphors

Physical contact with hot vs. iced coffee has been shown to affect evaluation of the personal warmth or kindness of a hypothetical person (Williams & Bargh, 2008). In 3 studies, we investigated whether the manipulation of social context can modulate the activation of the metaphorical mapping, KINDNESS as WARMTH. After priming participants with warm vs. cold temperature, we asked them to evaluate a hypothetical ad-hoc ally or adversary on the kindness dimension, as well as on other qualities used as a control. We expected more extreme evaluations of kindness in the adversary than in the ally condition, and no effects on other ratings. We thus replicated the classical effect of physical warmth on kindness ratings and generalized it to a German-speaking population. In addition, when the two German studies were combined, we found evidence suggesting a contextual modulation of the temperature effect: only out-group members, namely adversaries, were judged as more kind when participants had experienced physical warmth; the effect was not evident in the ally (i.e., in-group) condition. These studies suggest that context can modulate metaphorical activation; they therefore represent an initial attempt to add nuance to our understanding of when embodied metaphors affect our decisions

Effects of Task, Emotional Valence, and Emotional Arousal

The affective dimensions of emotional valence and emotional arousal affect processing of verbal and pictorial stimuli. Traditional emotional theories assume a linear relationship between these dimensions, with valence determining the direction of a behavior (approach vs. withdrawal) and arousal its intensity or strength. In contrast, according to the valence-arousal conflict theory, both dimensions are interactively related: positive valence and low arousal (PL) are associated with an implicit tendency to approach a stimulus, whereas negative valence and high arousal (NH) are associated with withdrawal. Hence, positive, high-arousal (PH) and negative, low-arousal (NL) stimuli elicit conflicting action tendencies. By extending previous research that used several tasks and methods, the present study investigated whether and how emotional valence and arousal affect subjective approach vs. withdrawal tendencies toward emotional words during two novel tasks. In Study 1, participants had to decide whether they would approach or withdraw from concepts expressed by written words. In Studies 2 and 3 participants had to respond to each word by pressing one of two keys labeled with an arrow pointing upward or downward. Across experiments, positive and negative words, high or low in arousal, were presented. In Study 1 (explicit task), in line with the valence-arousal conflict theory, PH and NL words were responded to more slowly than PL and NH words. In addition, participants decided to approach positive words more often than negative words. In Studies 2 and 3, participants responded faster to positive than negative words, irrespective of their level of arousal. Furthermore, positive words were significantly more often associated with “up” responses than negative words, thus supporting the existence of implicit associations between stimulus valence and response coding (positive is up and negative is down). Hence, in contexts in which participants' spontaneous responses are based on implicit associations between stimulus valence and response, there is no influence of arousal. In line with the valence-arousal conflict theory, arousal seems to affect participants' approach-withdrawal tendencies only when such tendencies are made explicit by the task, and a minimal degree of processing depth is required

Neural correlates of written emotion word processing:a review of recent electrophysiological and hemodynamic neuroimaging studies

A growing body of literature investigating the neural correlates of emotion word processing has emerged in recent years. Written words have been shown to represent a suitable means to study emotion processing and most importantly to address the distinct and interactive contributions of the two dimensions of emotion: valence and arousal. The aim of the present review is to integrate findings from electrophysiological (ERP) and hemodynamic neuroimaging (fMRI) studies in order to provide a better understanding of emotion word processing. It provides an up-to-date review of recent ERP studies since the review by Kissler et al. (2006) as well as the first review of hemodynamic brain imaging studies in the field. A discussion of theoretical and methodological issues is also presented, along with suggestions for future research

Effects of valence and arousal on written word recognition:Time course and ERP correlates

Models of affect assume a two-dimensional framework, composed of emotional valence and arousal. Although neuroimaging evidence supports a neuro-functional distinction of their effects during single word processing, electrophysiological studies have not yet compared the effects of arousal within the same category of valence (positive and negative). Here we investigate effects of arousal and valence on written lexical decision. Amplitude differences between emotion and neutral words were seen in the early posterior negativity (EPN), the late positive complex and in a sustained slow positivity. In addition, trends towards interactive effects of valence and arousal were observed in the EPN, showing larger amplitude for positive, high-arousal and negative, low-arousal words. The results provide initial evidence for interactions between arousal and valence during processing of positive words and highlight the importance of both variables in studies of emotional stimulus processing. Crown Copyright (C) 2012 Published by Elsevier Ireland Ltd. All rights reserved

How are affective word ratings related to lexicosemantic properties?:evidence from the Sussex Affective Word List

Emotional content of verbal material affects the speed of visual word recognition in various cognitive tasks, independently of lexicosemantic variables. However, little is known about how the dimensions of emotional arousal and valence interact with the lexicosemantic properties of words such as age of acquisition, familiarity, and imageability, that determine word recognition performance. This study aimed to examine these relationships using English ratings for affective and lexicosemantic features. Eighty-two native English speakers rated 300 words for emotional valence, arousal, familiarity, age of acquisition, and imageability. Although both dimensions of emotion were correlated with lexicosemantic variables, a unique emotion cluster produced the strongest quadratic relationship. This finding suggests that emotion should be included in models of word recognition as it is likely to make an independent contribution

Arousal and emotional valence interact in written word recognition

Behavioural, psychophysiological and neuroimaging studies reveal a prioritisation for emotional material in a variety of cognitive tasks. Although emotion is comprised of two dimensions (valence and arousal), previous research using verbal materials has mostly focused on valence, while controlling level of arousal. The aim of the present study is to investigate the effects of valence and arousal on lexical decision (LD) by manipulating both dimensions while controlling correlated psycholinguistic variables (e.g., word length, frequency, imageability). Results showed that valence and arousal affect word recognition in an interactive way: LD latencies are slower for positive high-arousal and negative low-arousal words compared to positive low-arousal and negative high-arousal words, in line with an approach-withdrawal tendency model. Furthermore, principal component analysis (PCA) on the latencies revealed a unique contribution of a distinct cluster of emotion variables, independent of lexico-semantic variables, to explaining written word recognition. We conclude that the dimensions of valence and arousal both need to be taken into account in studies of emotion word processing as they have an interactive relationship

The emotion potential of words and passages in reading Harry Potter:an fMRI study

Previous studies suggested that the emotional connotation of single words automatically recruits attention. We investigated the potential of words to induce emotional engagement when reading texts. In an fMRI experiment, we presented 120 text passages from the Harry Potter book series. Results showed significant correlations between affective word (lexical) ratings and passage ratings. Furthermore, affective lexical ratings correlated with activity in regions associated with emotion, situation model building, multi-modal semantic integration, and Theory of Mind. We distinguished differential influences of affective lexical, inter-lexical, and supra-lexical variables: differential effects of lexical valence were significant in the left amygdala, while effects of arousal-span (the dynamic range of arousal across a passage) were significant in the left amygdala and insula. However, we found no differential effect of passage ratings in emotion-associated regions. Our results support the hypothesis that the emotion potential of short texts can be predicted by lexical and inter-lexical affective variables

Metaphorical sentences are more emotionally engaging than their literal counterparts

Why do people so often use metaphorical expressions when literal paraphrases are readily available? This study focuses on a comparison of metaphorical statements involving the source domain of taste (e.g., She looked at him sweetly) and their literal paraphrases (e.g., She looked at him kindly). Metaphorical and literal sentences differed only in one word and were normed for length, familiarity, imageability, emotional valence, and arousal. Our findings indicate that conventional metaphorical expressions are more emotionally evocative than literal expressions, as the amygdala and the anterior portion of the hippocampus were more active in the metaphorical sentences. They also support the idea that even conventional metaphors can be grounded in sensorimotor and perceptual representations in that primary and secondary gustatory areas (lateral OFC, frontal operculum, anterior insula) were more active as well. A comparison of the individual words that distinguished the metaphorical and literal sentences revealed greater activation in the lateral OFC and the frontal operculum for the taste-related words, supporting the claim that these areas are relevant to taste

When emotions are expressed figuratively:psycholinguistic and affective norms of 619 idioms for German (PANIG)

Despite flourishing research on the relationship between emotion and literal language, and despite the pervasiveness of figurative expressions in communication, the role of figurative language in conveying affect has been under-investigated. This study provides affective and psycholinguistic norms for 619 German idiomatic expressions and explores the relationships between affective and psycholinguistic idiom properties. German native speakers rated each idiom for emotional valence, arousal, familiarity, semantic transparency, figurativeness, and concreteness. They also described the figurative meaning of each idiom, and rated how confident they were on the attributed meaning. Results showed that idioms rated high in valence were also rated high in arousal. Negative idioms were rated as more arousing than positive ones, in line with results on single words. Furthermore, arousal correlated positively with figurativeness (supporting the idea that figurative expressions are more emotionally engaging than literal expressions) and with concreteness and semantic transparency. This suggests that idioms may convey a more direct reference to sensory representations, mediated by the meaning of their constituting words. Arousal correlated positively with familiarity. In addition, positive idioms were rated as more familiar than negative idioms. Finally, idioms without a literal counterpart were rated as more emotionally valenced and arousing than idioms with a literal counterpart. Although the meaning of ambiguous idioms was less correctly defined than that of unambiguous idioms, ambiguous idioms were rated as more concrete than unambiguous ones. We also discuss the relationships between the various psycholinguistic variables characterising idioms, with reference to the literature on idiom structure and processing