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

Approach and withdrawal tendencies during written word processing: 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 behaviour (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 towards 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 labelled 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

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

Hemagglutinin sequence conservation guided stem immunogen design from influenza A H3 subtype

Seasonal epidemics caused by influenza A (H1 and H3 subtypes) and B viruses are a major global health threat. The traditional, trivalent influenza vaccines have limited efficacy because of rapid antigenic evolution of the circulating viruses. This antigenic variability mediates viral escape from the host immune responses, necessitating annual vaccine updates. Influenza vaccines elicit a protective antibody response, primarily targeting the viral surface glycoprotein hemagglutinin (HA). However, the predominant humoral response is against the hypervariable head domain of HA, thereby restricting the breadth of protection. In contrast, the conserved, subdominant stem domain of HA is a potential ‘universal’ vaccine candidate. We designed an HA stem-fragment immunogen from the 1968 pandemic H3N2 strain (A/Hong Kong/1/68) guided by a comprehensive H3 HA sequence conservation analysis. The biophysical properties of the designed immunogen were further improved by C-terminal fusion of a trimerization motif, ‘isoleucine-zipper’ or ‘foldon’. These immunogens elicited cross-reactive, antiviral antibodies and conferred partial protection against a lethal, homologous HK68 virus challenge in vivo. Furthermore, bacterial expression of these immunogens is economical and facilitates rapid scale-up

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

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