Impact of hypomanic personality traits on brain functional connectivity during a dynamic theory-of-mind task.

Hypomanic personality traits are present in the general population and represent a risk factor for developing bipolar disorder. This personality style, notably its social component, is linked to difficulties in theory of mind (i.e., ability to infer mental states). Exploring the neural correlates of mental states' inference in individuals with these personality traits can provide meaningful insights into the development of bipolar disorder. The aim of the present study was therefore to investigate the potential impact of hypomanic traits on brain activation and task-based connectivity strength during a dynamic theory of mind task in a nonclinical population. A total of 52 nonclinical participants were recruited, and hypomanic traits were assessed with the Hypomanic Personality Scale. The severity of hypomanic traits was positively associated with right middle and inferior frontal gyri activations (in high vs. low inference in nonemotional condition and emotion vs. no emotion in high inference, respectively). It was also associated with stronger connectivity between the salience network (i.e., bilateral putamen and pallidum) and bilateral superior temporal gyri (high inference in nonemotional condition), and between cerebellar and temporal areas (high inference in emotional condition). These changes may either reflect adaptations or differential processing, and further studies are therefore mandatory.

Activation of the left medial temporal gyrus and adjacent brain areas during affective theory of mind processing correlates with trait schizotypy in a nonclinical population.

Schizophrenia, a severe psychiatric disorder, is associated with abnormal brain activation during theory of mind (ToM) processing. Researchers recently suggested that there is a continuum running from subclinical schizotypal personality traits to fully expressed schizophrenia symptoms. Nevertheless, it remains unclear whether schizotypal personality traits in a nonclinical population are associated with atypical brain activation during ToM tasks. Our aim was to investigate correlations between fMRI brain activation during affective ToM (ToMA) and cognitive ToM (ToMC) tasks and scores on the Schizotypal Personality Questionnaire (SPQ) and the Basic Empathy Scale in 39 healthy individuals. The total SPQ score positively correlated with brain activation during ToMA processing in clusters extending from the left medial temporal gyrus (MTG), lingual gyrus and fusiform gyrus to the parahippocampal gyrus (Brodmann area: 19). During ToMA processing, the right inferior occipital gyrus, right MTG, precuneus and posterior cingulate cortex negatively correlated with the emotional disconnection subscore and the total score of self-reported empathy. These posterior brain regions are known to be involved in memory and language, as well as in creative reasoning, in nonclinical individuals. Our findings highlight changes in brain processing associated with trait schizotypy in nonclinical individuals during ToMA but not ToMC processing.

The Influence of Negative Orthographic Neighborhood in the Lexical Decision Task: Valence and Arousal Contributions.

This study investigated whether the visual recognition of neutral words might be influenced by the emotional dimensions (i.e., valence and arousal) of orthographically similar lexical representations, and whether this might also depend on emotional-related traits of participants (i.e., alexithymia). To this end, 108 participants performed a lexical decision task with 80 neutral words with a higher frequency orthographic neighbor that varied in valence (from neutral to negative) and arousal (from low to high). The main finding was the expected interaction effect between the valence and arousal of the neighbor on the lexical decision times of neutral stimulus words. Longer reaction times were found when the valence score of the neighbor decreased from neutral to negative for words with a low-arousal orthographic neighbor while this emotional neighbor effect was reversed for words with a high-arousal negative neighbor. This combined influence of the valence and arousal of the neighbor was interpreted in terms of increased lexical competition processes and direct influence of the affective system on the participant's response. Moreover, this interaction effect was smaller when the level of alexithymia of the participants increased, suggesting that people with a higher level of alexithymia are less sensitive to the emotional content of the neighbor. The results are discussed within an interactive activation model of visual word recognition incorporating an affective system with valence and arousal dimensions, with regard to the role of the alexithymia level of participants.

Investigation of the neural correlates of mentalizing through the Dynamic Inference Task, a new naturalistic task of social cognition.

Understanding others' intentions requires both the identification of social cues (e.g., emotional facial expressions, gaze direction) and the attribution of a mental state to another. The neural substrates of these processes have often been studied separately, and results are heterogeneous, in part attributable to the variety of paradigms used. The aim of the present study was to explore the neural regions underlying these sociocognitive processes, using a novel naturalistic task in which participants engage with human protagonists featured in videos. A total of 51 right-handed volunteers underwent functional magnetic resonance imaging while performing the Dynamic Inference Task (DIT), manipulating the degree of inference (high vs. low), the presence of emotion (emotional vs. nonemotional), and gaze direction (direct vs. averted). High nonemotional inference elicited neural activation in temporal regions encompassing the right posterior superior temporal sulcus. The presence (vs. absence) of emotion in the high-inference condition elicited a bilateral pattern of activation in internal temporal areas around the amygdala and orbitofrontal structures, as well as activation in the right dorsomedial part of the superior frontal gyrus and the left precuneus. On account of its dynamic, naturalistic approach, the DIT seems a suitable task for exploring social interactions and the way we interact with others, both in nonclinical and clinical populations.

Component process analysis of verbal memory in a sample of students with a binge drinking pattern.

BACKGROUND: Many studies have emphasized the harmful impact of binge drinking on several cognitive functions, including memory. However, the exact nature of the memory processes involved is still unknown. The present study was designed to assess verbal working memory and verbal episodic memory, especially its encoding, storage and retrieval processes, in binge drinking to identify the processes impacted by this behavior. METHODS: Participants were 48 community-recruited college students aged 18-25 years and categorized as either binge drinkers (BDs) or social drinkers (SDs). They were assessed with (a) subtests of the Wechsler scale (digit span, letter-number sequencing) measuring verbal working memory, and (b) a modified version of the Free and Cued Selective Reminding Test (FCSRT), which measures verbal episodic memory functioning in various conditions of encoding (controlled) and recollection (free recall, cued recall, and recognition). RESULTS: Verbal working memory was unaffected by binge drinking, whereas verbal episodic memory performances were reduced. In particular, analysis of the modified FCSRT scores suggested that BDs had less proficient storage and retrieval processes. Furthermore, correlational analyses indicated that the proficiency of these memory components was negatively correlated with several indicators of binge drinking behavior. CONCLUSIONS: Results suggest that binge drinking behavior affects the storage and recollection processes of verbal episodic memory. The academic failure described in binge drinkers could be partly related to this harmful effect. Our results on the negative impact of binge drinking on memory should be used to develop information campaigns targeting students.

Modulation of the N400 component in relation to hypomanic personality traits in a word meaning ambiguity resolution task.

AIM: High levels of hypomanic personality traits have been associated with an increased risk of developing bipolar disorder (BD). Changes in semantic content, impaired verbal associations, abnormal prosody, and abnormal speed of language are core features of BD, and are thought to be related to semantic processing abnormalities. In the present study, we used event-related potentials to investigate the relation between semantic processing (N400 component) and hypomanic personality traits. METHODS: We assessed 65 healthy young adults on the Hypomanic Personality Scale (HPS). Event-related potentials were recorded during a semantic ambiguity resolution task exploring semantic ambiguity (polysemous word ending a sentence) and congruency (target word semantically related to the sentence). RESULTS: As expected, semantic ambiguity and congruency both elicited an N400 effect across our sample. Correlation analyses showed a significant positive relationship between the Social Vitality subscore of the HPS and N400 modulation in the frontal region of interest in the incongruent unambiguous condition, and in the frontocentral region of interest in the incongruent ambiguous condition. CONCLUSION: We found differences in semantic processing (i.e., detection of incongruence and semantic inhibition) in individuals with higher Social Vitality subscores. In the light of the literature, we discuss the notion that a semantic processing impairment could be a potential marker of vulnerability to BD, and one that needs to be explored further in this clinical population.

Electrophysiological correlates of emotional meaning in context in relation to facets of schizotypal personality traits: A dimensional study.

AIMS: The aim of this study was to investigate the neurocognitive processes mediating the processing of emotional information during the integration of contextual and social information in a schizotypal population. METHODS: One hundred and thirty-one healthy participants were evaluated using the Schizotypal Personality Questionnaire and event-related potentials were recorded during a linguistic task in which participants read sentence pairs describing short social situations to themselves. The first sentence implicitly conveyed the positive or negative emotional state of a character. The second sentence was emotionally congruent or incongruent with the first sentence. RESULTS: Across our overall sample, our results revealed a greater N400 effect at right sites than left sites, whereas the late positive component effect was only observed at left sites. Concerning the correlation results, we observed a negative link between positive and global schizotypy and N400 modulation in response to congruent targets for positive context sentences. Results also showed a positive correlation between negative schizotypy and late positive component modulation in response to congruent targets for negative context sentences. CONCLUSIONS: These results suggest that the different facets of the schizotypal personality traits influenced the integration of emotional context at the level of both early and later-mobilized neurocognitive processes.

Emotional Meaning in Context in Relation to Hypomanic Personality Traits: An ERP Study.

The ability to integrate contextual information is important for the comprehension of emotional and social situations. While some studies have shown that emotional processes and social cognition are impaired in people with hypomanic personality trait, no results have been reported concerning the neurophysiological processes mediating the processing of emotional information during the integration of contextual social information in this population. We therefore chose to conduct an ERP study dealing with the integration of emotional information in a population with hypomanic personality trait. Healthy participants were evaluated using the Hypomanic Personality Scale (HPS), and ERPs were recorded during a linguistic task in which participants silently read sentence pairs describing short social situations. The first sentence implicitly conveyed the positive or negative emotional state of a character. The second sentence was emotionally congruent or incongruent with the first sentence. We analyzed the difference in the modulation of two components (N400 and LPC) in response to the emotional word present at the end of the "target" sentences as a function of the HPS score and the emotional valence of the context. Our results showed a possible modulation of the N400 component in response to both positive and negative context among the participants who scored high on the Mood Volatility subscale of the Hypomanic Personality Scale. These results seem to indicate that the participants with hypomanic personality traits exhibited specificities in the integration of emotions at the level of the early-mobilized neurocognitive processes (N400). Participants with hypomanic personality traits found it difficult to integrate negative emotional contexts, while simultaneously exhibiting an enhanced integration of positive emotional contexts.

Event-related potential correlates of emotional orthographic priming.

Event-related potentials were used to explore the underlying mechanisms of masked orthographic priming and to determine whether the emotional valence of a word neighbor prime affects target processing in a lexical decision task. The results showed that the N200 and N400 amplitudes were modified by orthographic priming, which also varied with the emotional valence of the neighbors. These findings provide new evidence that the N400 component is sensitive to orthographic priming and further suggest that the affective content of the neighbor influences target word processing.