Emotional words facilitate lexical but not early visual processing

An EPR study of the cognitive processes underlying the impact of self-relevant information on emotional word processing

Using the event-related potentials (ERPs) technique, this study successively presented names (in either a supra- or subthreshold manner) and emotional words to examine how self-relevant cue (self-name) affects emotional word processing in word class judgment task (to determine whether an emotional word is a noun or adjective) and valence judgment task (to determine whether an emotional word is positive or negative). At the suprathreshold condition, self-relevant positive words elicited a more significant Early posterior negativity (EPN) than negative words only in the valence judgment task. In contrast, at the subthreshold condition, self-relevant negative words elicited an enhanced Late positive potential (LPP) than positive words only in the word class judgment task. These results indicate that self-relevant cue affects emotional word processing at both suprathreshold and subthreshold conditions; nevertheless, the effect manifests as self-positive bias at the suprathreshold condition and self-negative bias at the subthreshold condition. The experimental task modulates these dynamics.

Cursed Concepts: New insights on combinatorial processing from ERP correlates of swearing in context

Expressives (damn) convey speaker attitude and when used in context (Tom lost the damn dog) can be flexibly applied locally to the noun (dog) or globally to the whole sentence (the situation). We used ERPs to explore brain responses to expressives in sentences. Participants read expressive, descriptive, and pseudoword adjectives followed by nouns in sentences (The damn/black/flerg dog peed on the couch). At the adjective late-positivity-component (LPC), expressives and descriptives showed no difference, suggesting reduced social threat and that readers employ a 'wait-and-see' strategy to interpret expressives. Nouns preceded by expressives elicited a larger frontal P200, as well as reduced N400 and LPC than nouns preceded by descriptives. We associated the frontal P200 with emotional salience, the frontal N400 with mental imagery, and the LPC with cognitive load for combinatorics. We suggest that expressive adjectives are not bound to conceptual integration and conclude that parsers wait-and-see what is being damned.

Emotional responses to mortality salience: Behavioral and ERPs evidence

Terror Management Theory (TMT) suggests that death-related thoughts activate proximal defense which allows people to suppress or rationalize death awareness. So far there is no direct evidence to support the emotional response in the proximal defense process. The current research aimed to address this issue by examining behavioral (e.g., accuracy and reaction time) and neural responses (e.g., P1 and N400 amplitude) related to emotional arousal following death-related thoughts during proximal defense. Before engaged in emotional words (e.g., anxiety, fear and neutral) judgment task, participants answered questions that referred to emotional and physical changes about death to induce mortality salience (MS). In the control condition, participants received similar instructions concerning the experience of watching TV. Behavioral results showed that longer reaction time of words was seen in control group than MS group. The ERPs results showed that after reminders of death-related thoughts, in condition of MS, fear words elicited larger P1 ERP amplitudes, while the control group did not have this effect, which might reflect that emotional words caused different early attention patterns between MS group and control group. Moreover, compared with control group, larger N400 ERP amplitudes were elicited in condition of MS, suggesting larger cognitive inhibition of words processing caused by emotional reaction. The above results indicate that the early stages after mortality salience will induce fear and anxiety, but soon these negative emotions are suppressed and are at a lower level of accessibility. This result provides electrophysiological evidence for the proximal defense hypothesis of terror management theory.

The mental representation and social aspect of expressives

Despite increased focus on emotional language, research lacks for the most emotional language: Swearing. We used event-related potentials (ERPs) to investigate whether swear words have content distinct from function words, and if so, whether this content is emotional or social in nature. Stimuli included swear (e.g. shit, damn), negative but non-swear (e.g. kill, sick), open-class neutral (e.g. wood, lend), and closed-class neutral words (e.g. while, whom). Behaviourally, swears were recognised slower than valence- and arousal- matched negative words, meaning that there is more to the expressive dimension than merely a heightened emotional state. In ERPs, both swears and negative words elicited a larger positivity (250-550 ms) than open-class neutral words. Later, swears elicited a larger late positivity (550-750 ms) than negative words. We associate the earlier positivity effect with attention due to negative valence, and the later positivity effect with pragmatics due to social tabooness. Our findings suggest a view in which expressives are not merely function words or emotional words. Rather, expressives are emotionally and socially significant. Swears are more than what is indicated by valence ore arousal alone.

Personality Traits and Emotional Word Recognition: An ERP Study

Recent research has investigated how personality trait differences influence the processing of emotion conveyed by pictures, but limited research has examined the emotion conveyed by words. The present study investigated whether extraversion (extroverts vs. introverts) and neuroticism (high neurotics vs. low neurotics) influence the processing of positive, neutral, and negative words that were matched for arousal. Electroencephalography (EEG) was recorded from healthy participants while they performed a lexical decision task. We found that personality traits influenced emotional word recognition at N400 (300-450 ms) and LPC (450-800 ms). At the earlier (N400) stage, the more extraverted and neurotic a participant was, the more reduced the N400s for the positive words relative to neutral words were. This suggests that the extroverts and high neurotics (i.e., high impulsivity) identified positive content in words during lexical feature retrieval, which facilitated such retrieval. At the later (LPC) stage, both the introverts and high neurotics (i.e., high anxiety) showed greater LPCs to negative than neutral words, indicating their sustained attention and elaborative processing of negative information. These results suggest that extraversion and neuroticism collectively influence different stages of emotional word recognition in a way that is consistent with Gray's biopsychological theory of personality.

Expectation Gates Neural Facilitation of Emotional Words in Early Visual Areas

The current study examined whether emotional expectations gate attention to emotional words in early visual cortex. Color cues informed about word valence and onset latency. We observed a stimulus-preceding negativity prior to the onset of cued words that was larger for negative than for neutral words. This indicates that in anticipation of emotional words more attention was allocated to them than to neutral words before target onset. During stimulus presentation the steady-state visual evoked potential (SSVEP), elicited by flickering words, was attenuated for cued compared to uncued words, indicating sharpened sensory activity, i.e., expectation suppression. Most importantly, the SSVEP was more enhanced for negative than neutral words when these were cued. Uncued conditions did not differ in SSVEP amplitudes, paralleling previous studies reporting lexico-semantic but not early visual effects of emotional words. We suggest that cueing mediates re-entrant engagement of visual resources by providing an early “affective gist” of an upcoming word. Consequently, visual single-word studies may have underestimated attentional effects of emotional words and their anticipation during reading.

Steady state visual evoked potentials in reading aloud: Effects of lexicality, frequency and orthographic familiarity

The present study explored the possibility to use Steady-State Visual Evoked Potentials (SSVEPs) as a tool to investigate the core mechanisms in visual word recognition. In particular, we investigated three benchmark effects of reading aloud: lexicality (words vs. pseudowords), frequency (high-frequency vs. low-frequency words), and orthographic familiarity ('familiar' versus 'unfamiliar' pseudowords). We found that words and pseudowords elicited robust SSVEPs. Words showed larger SSVEPs than pseudowords and high-frequency words showed larger SSVEPs than low-frequency words. SSVEPs were not sensitive to orthographic familiarity. We further localized the neural generators of the SSVEP effects. The lexicality effect was located in areas associated with early level of visual processing, i.e. in the right occipital lobe and in the right precuneus. Pseudowords produced more activation than words in left sensorimotor areas, rolandic operculum, insula, supramarginal gyrus and in the right temporal gyrus. These areas are devoted to speech processing and/or spelling-to-sound conversion. The frequency effect involved the left temporal pole and orbitofrontal cortex, areas previously implicated in semantic processing and stimulus-response associations respectively, and the right postcentral and parietal inferior gyri, possibly indicating the involvement of the right attentional network.

The role of experience for abstract concepts: Expertise modulates the electrophysiological correlates of mathematical word processing

Embodied theories assign experience a crucial role in shaping conceptual representations. Supporting evidence comes mostly from studies on concrete concepts, where e.g., motor expertise facilitated action concept processing. This study examined experience-dependent effects on abstract concept processing. We asked participants with high and low mathematical expertise to perform a lexical decision task on mathematical and nonmathematical abstract words, while acquiring event-related potentials. Analyses revealed an interaction of expertise and word type on the amplitude of a fronto-central N400 and a centro-parietal late positive component (LPC). For mathematical words, we found a trend for a lower N400 and a significantly higher LPC amplitude in experts compared to nonexperts. No differences between groups were found for nonmathematical words. The results suggest that expertise affects the processing stages of semantic integration and memory retrieval specifically for expertise-related concepts. This study supports the generalization of experience-dependent conceptual processing mechanisms to the abstract domain.

Concurrent emotional response and semantic unification: An event-related potential study

Using event-related potentials, in this study we examined how implied emotion is derived from sentences. In the same sentential context, different emotionally neutral words rendered the whole sentence emotionally neutral and semantically congruent, emotionally negative and semantically congruent, or emotionally neutral and semantically incongruent. Relative to the words in the neutral-congruent condition, the words in the neutral-incongruent condition elicited a larger N400, indicating increased semantic processing, whereas the words in the negative-congruent condition elicited a long-lasting positivity between 300 and 1,000 ms, indicating an emotional response. The overlapping time windows of semantic processing and the emotional response suggest that the construction of emotional meaning operates concurrently with semantic unification. The results indicate that the implied emotional processing of sentences may be a result of unification operations but does not necessarily involve causal appraisal of a sentence's mental representation.

Automatic Lexical Access in Visual Modality: Eye-Tracking Evidence

Language processing has been suggested to be partially automatic, with some studies suggesting full automaticity and attention independence of at least early neural stages of language comprehension, in particular, lexical access. Existing neurophysiological evidence has demonstrated early lexically specific brain responses (enhanced activation for real words) to orthographic stimuli presented parafoveally even under the condition of withdrawn attention. These studies, however, did not control participants’ eye movements leaving a possibility that they may have foveated the stimuli, leading to overt processing. To address this caveat, we recorded eye movements to words, pseudowords, and non-words presented parafoveally for a short duration while participants performed a dual non-linguistic feature detection task (color combination) foveally, in the focus of their visual attention. Our results revealed very few saccades to the orthographic stimuli or even to their previous locations. However, analysis of post-experimental recall and recognition performance showed above-chance memory performance for the linguistic stimuli. These results suggest that partial lexical access may indeed take place in the presence of an unrelated demanding task and in the absence of overt attention to the linguistic stimuli. As such, our data further inform automatic and largely attention-independent theories of lexical access.

An evil face? Verbal evaluative multi-CS conditioning enhances face-evoked mid-latency magnetoencephalographic responses

Humans have a remarkable capacity for rapid affective learning. For instance, using first-order US such as odors or electric shocks, magnetoencephalography (MEG) studies of multi-CS conditioning demonstrate enhanced early (<150 ms) and mid-latency (150–300 ms) visual evoked responses to affectively conditioned faces, together with changes in stimulus evaluation. However, particularly in social contexts, human affective learning is often mediated by language, a class of complex higher-order US. To elucidate mechanisms of this type of learning, we investigate how face processing changes following verbal evaluative multi-CS conditioning. Sixty neutral expression male faces were paired with phrases about aversive crimes (30) or neutral occupations (30). Post conditioning, aversively associated faces evoked stronger magnetic fields in a mid-latency interval between 220 and 320 ms, localized primarily in left visual cortex. Aversively paired faces were also rated as more arousing and more unpleasant, evaluative changes occurring both with and without contingency awareness. However, no early MEG effects were found, implying that verbal evaluative conditioning may require conceptual processing and does not engage rapid, possibly sub-cortical, pathways. Results demonstrate the efficacy of verbal evaluative multi-CS conditioning and indicate both common and distinct neural mechanisms of first- and higher-order multi-CS conditioning, thereby informing theories of associative learning.

Auditory attention enhances processing of positive and negative words in inferior and superior prefrontal cortex

Visually presented emotional words are processed preferentially and effects of emotional content are similar to those of explicit attention deployment in that both amplify visual processing. However, auditory processing of emotional words is less well characterized and interactions between emotional content and task-induced attention have not been fully understood. Here, we investigate auditory processing of emotional words, focussing on how auditory attention to positive and negative words impacts their cerebral processing. A Functional magnetic resonance imaging (fMRI) study manipulating word valence and attention allocation was performed. Participants heard negative, positive and neutral words to which they either listened passively or attended by counting negative or positive words, respectively. Regardless of valence, active processing compared to passive listening increased activity in primary auditory cortex, left intraparietal sulcus, and right superior frontal gyrus (SFG). The attended valence elicited stronger activity in left inferior frontal gyrus (IFG) and left SFG, in line with these regions' role in semantic retrieval and evaluative processing. No evidence for valence-specific attentional modulation in auditory regions or distinct valence-specific regional activations (i.e., negative > positive or positive > negative) was obtained. Thus, allocation of auditory attention to positive and negative words can substantially increase their processing in higher-order language and evaluative brain areas without modulating early stages of auditory processing. Inferior and superior frontal brain structures mediate interactions between emotional content, attention, and working memory when prosodically neutral speech is processed.

Selective visual attention to emotional words: Early parallel frontal and visual activations followed by interactive effects in visual cortex

Human brains spontaneously differentiate between various emotional and neutral stimuli, including written words whose emotional quality is symbolic. In the electroencephalogram (EEG), emotional-neutral processing differences are typically reflected in the early posterior negativity (EPN, 200-300 ms) and the late positive potential (LPP, 400-700 ms). These components are also enlarged by task-driven visual attention, supporting the assumption that emotional content naturally drives attention. Still, the spatio-temporal dynamics of interactions between emotional stimulus content and task-driven attention remain to be specified. Here, we examine this issue in visual word processing. Participants attended to negative, neutral, or positive nouns while high-density EEG was recorded. Emotional content and top-down attention both amplified the EPN component in parallel. On the LPP, by contrast, emotion and attention interacted: Explicit attention to emotional words led to a substantially larger amplitude increase than did explicit attention to neutral words. Source analysis revealed early parallel effects of emotion and attention in bilateral visual cortex and a later interaction of both in right visual cortex. Distinct effects of attention were found in inferior, middle and superior frontal, paracentral, and parietal areas, as well as in the anterior cingulate cortex (ACC). Results specify separate and shared mechanisms of emotion and attention at distinct processing stages. Hum Brain Mapp 37:3575-3587, 2016. © 2016 Wiley Periodicals, Inc.