Personality effects on attentional shifts to emotional charged cues: ERP, behavioural and HR data

Examining the impact of schizotypal personality traits on event-related potential (ERP) indexes of sensory gating in a healthy population

The aim of this study was to better understand the relation of schizotypy traits with sensory gating ability in a sample of community-dwelling individuals with high and low schizotypy traits. Sensory gating was assessed through the paired click paradigm and mid-latency evoked responses (i.e., P50, N100, P200), while schizotypy traits were assessed through the SPQ-BR which was used to classify participants into "high" and "low" schizotypy groups. Based on prior work, we hypothesized that those with the highest schizotypy scores would have reduced sensory gating ability. While this study does not show differences between relatively low and high schizotypy groups on sensory gating ability, it does suggest that our participants may have been experiencing deficits in attention allocation, a downstream cognitive processing measure. Scores on the SPQ-BR suggest that our sample was not close to the high end of the schizotypy traits which may help explain why no differences were found. This research shows the importance of including all levels of schizotypy ratings in clinical research as we can gain a clearer view of the impact of schizotypy on the brain and cognitive functioning in those with "high" levels of schizotypy. Additionally, this work highlights the importance of including measures of important factors such as impulsivity and sensation-seeking to better understand what aspects of schizotypy may be driving these sensory gating alterations reported in the literature.

Interdependent Neural Correlates of Reward and Punishment Sensitivity During Rewarded Action and Inhibition of Action

Imaging studies have distinguished the brain correlates of approach and avoidance behaviors and suggested the influence of individual differences in trait sensitivity to reward (SR) and punishment (SP) on these neural processes. Theoretical work of reinforcement sensitivity postulates that SR and SP may interdependently regulate behavior. Here, we examined the distinct and interrelated neural substrates underlying rewarded action versus inhibition of action in relation to SR and SP as evaluated by the Sensitivity to Punishment and Sensitivity to Reward Questionnaire. Forty-nine healthy adults performed a reward go/no-go task with approximately 2/3 go and 1/3 no-go trials. Correct go and no-go responses were rewarded and incorrect responses were penalized. The results showed that SR and SP modulated rewarded go and no-go, respectively, both by recruiting the rostral anterior cingulate cortex and left middle frontal gyrus (rACC/left MFG). Importantly, SR and SP influenced these regional activations in opposite directions, thus exhibiting an antagonistic relationship as suggested by the reinforcement sensitivity theory. Furthermore, mediation analysis revealed that heightened SR contributed to higher rewarded go success rate via enhanced rACC/left MFG activity. The findings demonstrate interrelated neural correlates of SR and SP to support the diametric processes of behavioral approach and avoidance.

Neuroticism and extraversion as predictors of negative and positive emotional information processing: comparing Eysenck's, Gray's, and Newman's theories

This study compared how extraversion, neuroticism, and extraversion × neuroticism are related to processing of pleasant and unpleasant emotional information as predicted by Eysenck's, Gray's, and Newman's theories. Initially, the participants' levels of extraversion (as measured by the sociability subscale) and neuroticism were assessed with Eysenck's Personality Inventory. They were then tested individually. After completing a questionnaire of current positive and negative moods, they completed three tasks measuring processing of pleasant, unpleasant, and also neutral information. The results showed that extraversion was associated positively with the processing of pleasant information, while neuroticism was associated positively with the processing of unpleasant information. These findings support predictions from Eysenck's theory. Copyright © 2002 John Wiley & Sons, Ltd.

Trait BIS predicts alpha asymmetry and P300 in a Go/No‐Go task

Inspired by the revised Behavioural Inhibition System (BIS) theory the present study probed the association between individual differences in Trait BIS and electroencephalogram indicators of conflict processing/inhibition. Sixty‐nine male participants either high or low in Trait BIS completed a Go/No‐Go task while the electroencephalogram was recorded. As expected, Trait BIS was associated with the No‐Go‐anteriorisation of the P300 event‐related potential (i.e. an index of response inhibition presumably generated in the dorsal anterior cingulate—an area implicated in conflict processing) and with No‐ Go‐related changes towards left frontal alpha activity (i.e. presumably more activity in right prefrontal cortex—an area implicated in response inhibition). These findings support the role of conflict processing attributed to BIS functioning in the revised theory. Copyright © 2009 John Wiley & Sons, Ltd.

A Neuroimaging Study of Personality Traits and Self-Reflection

This study examines the blood-oxygen level dependent (BOLD) activation of the brain associated with the four distinctive thinking styles associated with the four personality orientations of the Gountas Personality Orientations (GPO) survey: Emotion/Feeling-Action, Material/Pragmatic, Intuitive/Imaginative, and Thinking/Logical. The theoretical postulation is that each of the four personality orientations has a dominant (primary) thinking style and a shadow (secondary) thinking style/trait. The participants (N = 40) were initially surveyed to determine their dominant (primary) and secondary thinking styles. Based on participant responses, equal numbers of each dominant thinking style were selected for neuroimaging using a unique fMRI cognitive activation paradigm. The neuroimaging data support the general theoretical hypothesis of the existence of four different BOLD activation patterns, associated with each of the four thinking styles. The fMRI data analysis suggests that each thinking style may have its own cognitive activation system, involving the frontal ventromedial, posterior medial, parietal, motor, and orbitofrontal cortex. The data also suggest that there is a left hemisphere relationship for the Material/Pragmatic and Thinking/Logical styles and a right activation relationship for Emotional/Feeling and Intuitive/Imaginative styles. Additionally, the unique self-reflection paradigm demonstrated that perception of self or self-image, may be influenced by personality type; a finding of potentially far-reaching implications.

An EEG Study on Emotional Intelligence and Advertising Message Effectiveness

Some electroencephalography (EEG) studies have investigated emotional intelligence (EI), but none have examined the relationships between EI and commercial advertising messages and related consumer behaviors. This study combines brain (EEG) techniques with an EI psychometric to explore the brain responses associated with a range of advertisements. A group of 45 participants (23 females, 22 males) had their EEG recorded while watching a series of advertisements selected from various marketing categories such as community interests, celebrities, food/drink, and social issues. Participants were also categorized as high or low in emotional intelligence (n = 34). The EEG data analysis was centered on rating decision-making in order to measure brain responses associated with advertising information processing for both groups. The findings suggest that participants with high and low emotional intelligence (EI) were attentive to different types of advertising messages. The two EI groups demonstrated preferences for “people” or “object,” related advertising information. This suggests that differences in consumer perception and emotions may suggest why certain advertising material or marketing strategies are effective or not.

Extraversion and behavioural approach system in stimulus analysis and motor response initiation

In this study, we attempt to validate previous findings on extraversion-related differences in speed of sensorimotor processing and to extend them into Behavioural Approach System (BAS) subtraits within the framework of the revised Reinforcement Sensitivity Theory (rRST) of personality. Here, we assessed psychological traits of extraversion (E), four BAS facets (Goal-Drive Persistence, BAS-GDP; Reward Interest, BAS-RI; Reward Reactivity, BAS-RR; Impulsivity, BAS-I), Behavioural Inhibition System (BIS), and Fight-Flight-Freeze System (FFFS) in 51 volunteers (28 women). Stimulus-locked lateralized readiness potential (S-LRP), response-locked LRP (R-LRP), stimulus-locked and response-locked forearm electromyogram (S-EMG and R-EMG), and P3 components of the event-related potentials (ERPs), were recorded during the performance of a two-choice Go/NoGo visual letter-digit discrimination task varying in task difficulty. High extraverts, relative to introverts and individuals high relative to low on BAS-RI, were more likely to exhibit shorter S-LRP latencies and stimulus- and response-locked EMG latencies. Additionally, high BAS-I had a shorter R-RLP latency than low BAS-I participants for the difficult task. High FFFS levels were associated with longer S-LRP and S-EMG latencies, while high BIS levels had larger response accuracy. Extraverts, relative to introverts, along with those high relative to low on BAS-RR and BAS-I, exhibited smaller P3 amplitudes. The faster cortical premotor initiation, found in individuals high on extraversion, BAS-RI and low on FFFS, may account for their faster peripheral motor response initiation and execution. Smaller P3 amplitudes in extraverts and individuals high on BAS-RR and BAS-I may indicate reduced perceptual processing capacity in these individuals.

Minho Affective Sentences (MAS): Probing the roles of sex, mood, and empathy in affective ratings of verbal stimuli

During social communication, words and sentences play a critical role in the expression of emotional meaning. The Minho Affective Sentences (MAS) were developed to respond to the lack of a standardized sentence battery with normative affective ratings: 192 neutral, positive, and negative declarative sentences were strictly controlled for psycholinguistic variables such as numbers of words and letters and per-million word frequency. The sentences were designed to represent examples of each of the five basic emotions (anger, sadness, disgust, fear, and happiness) and of neutral situations. These sentences were presented to 536 participants who rated the stimuli using both dimensional and categorical measures of emotions. Sex differences were also explored. Additionally, we probed how personality, empathy, and mood from a subset of 40 participants modulated the affective ratings. Our results confirmed that the MAS affective norms are valid measures to guide the selection of stimuli for experimental studies of emotion. The combination of dimensional and categorical ratings provided a more fine-grained characterization of the affective properties of the sentences. Moreover, the affective ratings of positive and negative sentences were not only modulated by participants' sex, but also by individual differences in empathy and mood state. Together, our results indicate that, in their quest to reveal the neurofunctional underpinnings of verbal emotional processing, researchers should consider not only the role of sex, but also of interindividual differences in empathy and mood states, in responses to the emotional meaning of sentences.

Personality and emotional processing: A relationship between extraversion and the late positive potential in adolescence

Neuroticism and extraversion are multifaceted affective-laden personality traits that have been associated with major depressive disorder (MDD). Research and theory have argued that extraversion, and particularly its facet positive emotionality, is specific to MDD, while neuroticism is common across internalizing disorders. Converging evidence has suggested that MDD is associated with reduced engagement with emotional stimuli, but it remains unclear whether either extraversion, neuroticism, or both modulate reactivity to emotional cues. The late positive potential (LPP) is an event-related brain potential that is uniquely suited to assess engagement with emotional stimuli because it reflects sustained attention toward emotional content. The current study examined the LPP in relation to personality traits that may confer risk for depression by examining the relationship between the LPP and both neuroticism and extraversion in never-depressed adolescent girls. Specifically, 550 girls aged 13.5-15.5 with no lifetime history of depression completed an emotional picture-viewing task, and the LPP was measured in response to neutral, pleasant, and unpleasant pictures. Personality traits were gathered via self- and informant report. Results indicated that high extraversion was associated with a potentiated LPP to emotional pictures-and this effect was accounted for by positive emotionality in particular. In contrast, there was no association between the LPP and neuroticism or its facets. The present study is one of the first to demonstrate that extraversion is associated with variation in neural indices of emotional picture processing, similar to what has been observed among individuals with depression and at high risk for depression.

Personality and Skin Conductance Responses to Reward and Punishment

For several years now, the somatic aspect of emotions has been regarded as a major factor in the decision-making process. A large body of literature has investigated this issue, within the somatic marker hypothesis perspective, using the classical Iowa Gambling Task (IGT). Many studies reported an influence of clinical and differential factors, including personality, on IGT performance. On the other hand, personality appears to modulate the emotional responses as a function of valence (i.e., responses to rewards vs. punishments). The present study investigated whether the influence of personality on the decision-making process might be mediated by differential emotional responsiveness. Skin conductance levels were recorded in 32 subjects while performing the IGT. The results showed that novelty seeking (NS) modulated the skin conductance responses to feedback, and both NS and harm avoidance (HA) influenced anticipative response development. We also found that NS tended to modulate the final score, beyond the influence of beneficial anticipative autonomic responses. The present data partially support the hypothesis that personality-related differential emotional responsiveness may modulate somatic marker development in a decision-making situation. On the other hand, personality influence on the performance was not entirely explained by these emotional differences.

EEG oscillatory activity associated to monetary gain and loss signals in a learning task: effects of attentional impulsivity and learning ability

This study investigated the influence of individual differences in attentional impulsivity (Att-Imp), learning ability, and learning practice on oscillatory activity and phase synchrony responses to monetary gain and loss signals during an instrumental-learning task in healthy women. We used a trial-by-trial wavelet-based time-frequency analysis of the electroencephalographic (EEG) signal to provide amplitude and inter-site phase synchrony measures from 30 electrodes in theta (4-8 Hz, 350-500 ms), alpha (8-12 Hz, 100-200 ms), beta (13-25 Hz, 100-200 ms), and gamma (30-40 Hz, 350-450 ms) time-frequency ranges. Oscillatory amplitude and inter-site phase synchrony were both greater following loss signals as compared to gain signals in theta, beta, and gamma frequency bands. Low Att-Imp subjects had higher theta activity within a 350-500 ms time window over frontocentral, and centroparietal sites than high Att-Imp subjects. Monetary gain signals elicited higher theta and gamma activities in high Att-Imp individuals and loss signals elicited higher activities to loss signals in low Att-Imp individuals. Good learners showed enhanced intrahemispheric theta synchrony between frontoparietal, and fronto-occipital sites to monetary loss compared to gain signals. In good learners, monetary loss produced an increase of gamma synchrony that enhanced in the second stage of learning. In low Att-Imp individuals, there was a reduction of theta synchrony during the second stage, as compared with the first stage of learning, between temporal, parietal and fronto-parietal brain regions. These findings may offer valuable clues to understand outcome processing, attentional impulsivity, and learning ability. We propose that the punishment-related theta and gamma waves play a leading role in learning process.

Does Personality Modulate Skin Conductance Responses to Emotional Stimuli?

Several studies showed that personality modulates emotional responsiveness, though most of them used subjective ratings as the measure of emotion. The present study extends personality-emotion relationship findings to psychophysiological methods, more precisely to skin conductance responses (SCRs). SCRs were recorded in 54 normal subjects following the presentation of neutral and emotional pictures. Results showed that half-recovery time was modulated by harm avoidance (HA) as a function of emotional valence: Low-HA subjects showed longer half-recovery time following the presentation of pleasant pictures relative to neutral ones, whereas high-HA subjects showed no extended half-recovery time. These results support the hypothesis that personality modulates some aspects of somatic emotional reactivity, and together with previous results, they suggest that this phenomenon is highly dependent upon the characteristics of the emotional material.

Do Personality Traits Modulate the Effect of Emotional Visual Stimuli on Auditory Information Processing?

Several lines of evidence attest robust relationships between personality dimensions and emotions, including cognitive aspect of emotion. More particularly, many studies reported strong relationships between extraversion, the behavioral activation system (BAS), and the cognitive processing of positive information, on the one hand, and between neuroticism, the behavioral inhibition system (BIS), and the processing of negative information, on the other hand. Recently, DePascalis, Awari, Matteucci, and Mazzocco (2005 ) reported that personality traits modulated the effect of the emotional visual stimuli on the mismatch negativity (MMN). The aim of the present study was to replicate these data and extend them to other personality dimensions. Auditory MMN was recorded in normal subjects simultaneously to the presentation of emotional pictures selected as neutral, positive, or negative from the International Affective Picture System, and presented in randomized order. The results support the recent finding that personality (namely, BIS and harm avoidance) modulates the influence of emotional (negative) context on auditory information processing. The present findings suggest that the modulation by personality of change detection in the unattended environment as a function of context valence is limited to unpleasant context.

Impulsivity and semantic/emotional processing: an examination of the N400 wave

OBJECTIVE

The study investigated (a) to what extent semantic/emotional processing modulates the N400 wave of the event-related potentials (ERPs) during reading, (b) the influence of impulsivity trait on neurocognitive systems underlying semantic/emotional processing related to the generation of the N400 wave.

METHODS

A canonical semantic sentence processing paradigm, known to selectively elicit the N400 wave was used. The ERPs were elicited to emotionally valenced (neutral, positive and negative) sentence final words that were either semantically congruent or semantically incongruent with the previous sentence context.

RESULTS

Congruent negatively valenced words produced longer reaction times (RTs) than congruent positive and neutral words. Incongruent words elicited more pronounced N400 peak amplitudes than congruent ones, while, for the congruent trials, the N400 amplitude was greater for negative words as compared to positive and neutral words. High impulsive participants, compared to low impulsive ones, (a) made more errors and longer reaction times in identifying incongruent words, (b) displayed more pronounced N400 peak amplitudes over fronto-central midline scalp sites.

CONCLUSIONS

This pattern of results indicated that the activity of fronto-central system may account for individual differences of impulsivity with high impulsive individuals showing more difficulty in integrating incongruent final words into a sentence context.

SIGNIFICANCE

Results open up new perspectives for future investigations on language disorders characterized by substantial impulsivity.

A meta-analysis of reinforcement sensitivity theory: on performance parameters in reinforcement tasks

J. A. Gray's Reinforcement Sensitivity Theory (RST) has produced a wealth of quasi-experimental studies in more than 35 years of research on personality and reinforcement sensitivity. The present meta-analysis builds on this literature by investigating RST in conflict and nonconflict reinforcement tasks in humans. Based on random-effects meta-analysis, we confirmed RST predictions of performance parameters (e.g., number of responses, reaction time) in reinforcement tasks for impulsivity- and anxiety-related traits. In studies on anxiety-related traits, the effect size variance was smaller for conflict tasks than for nonconflict tasks. A larger mean effect size and a larger variability of effect sizes were found for conflict compared to nonconflict tasks in studies on impulsivity-related traits. Our results suggest that problems with RST confirmation in reinforcement tasks are at least partly caused by insufficient statistical power of primary studies, and thus, encourage future research on RST.

ERP correlates of error monitoring in 10-year olds are related to socialization

Research suggests that the anterior cingulate cortex (ACC) generates the error-related negativity (ERN or Ne), an event-related potential component that reflects response monitoring and is influenced by individual differences in personality. The present study examined the relation between personality as indexed by the Junior Eysenck Personality Questionnaire (Extraversion, Neuroticism, Psychoticism, and Lie scale) and the ERN in 10-year-old children. High scores on the Psychoticism and low scores on the Lie scale, which are taken to reflect low socialization in children, were associated with smaller ERNs. Results lend support to previous studies finding this association in adults. We argue that the ERN may be an indirect measure of ACC activity and is affected by one's concern with task performance. The results of the present study extend findings previously reported in adults to a population of normally developing children and show that similar mechanisms of performance monitoring may underlie individual differences in personality across development.

Are there common mechanisms in sensation seeking and reality distortion in schizophrenia? A study using memory event-related potentials

A growing literature suggests that the characteristics of sensation seeking and reality distortion expressed in schizophrenia share several mechanisms. In a previous study, the comparison of patients with high vs. low reality distortion using event-related potentials (ERPs) recorded in a recognition memory task for unfamiliar faces identified neural and cognitive anomalies specifically related to the expression of these symptoms. As a follow-up, this study investigated the ERP correlates of sensation seeking in schizophrenia using the same recognition memory protocol. ERPs have been recorded in controls (N=21) and schizophrenia patients separated into high (HSS; N=13) and low (LSS; N=17) scorers according to Zuckerman's Sensation Seeking Scale. The results show a reduced P2a that was found unrelated to reality distortion in the previous study of reality distortion. It identifies interference inhibition impairment as being specifically related to sensation seeking. On the other hand, HSS scorers display enhanced fronto-central and normal P600 effects also found in high reality distortion patients. These results indicate inappropriate context processing and mnemonic binding common to sensation seeking and reality distortion. LSS scorers also display a reduced temporal N300 similar to that found in low reality distortion patients. This anomaly could reflect the lower reactivity to emotionally significant stimuli that underlies anhedonia symptoms. Finally, the N400 effect and a late frontal effect are found in both HSS and LSS. Since they were unrelated to reality distortion, these indices have been related to basic aspects of schizophrenia, e.g., deficient knowledge integration, or other mechanisms, e.g. anxiety or impulsivity. In summary, the present study examines the strategy of investigating variables, such as temperamental characteristics, in addition to symptoms, to show how discrete impairments may contribute to the expression of the illness.

Preliminary study: Psychological effects of muscle relaxation on Juvenile delinquents

The purpose of this study is to test our hypothesis that muscle relaxation is effective on the psychological well-being of juvenile delinquents. Subjects were 16 juvenile delinquents who had entered a reform school. Subjects were divided into two groups. The muscle relaxation group received muscle relaxation therapy once a week for a total of 4 times. The control group spent an ordinary daily life in the reformatory. Psychological questionnaires used were the Rosenzweig Picture Frustration Study (P-F study), the Psychological Stress Response Scale (PSRS), and the Eysenck Personality Questionnaire (EPQ). There was a significant Group Time interaction of the Group Conformity Rating (GCR) of the P-F study (F [1,14] =10.1, P=0.007). There were no significant interactions in the other psychological subscales. Thus, muscle relaxation therapy may improve frustration tolerance among juvenile delinquents.

Extraversion and emotional reactivity

Six mood induction studies and a meta-analysis were conducted to test 2 models of the extraversion-pleasant affect relation. The affect-level model suggests that extraverts should be happier than introverts in both neutral and positive mood conditions. The reactivity model posits that extraverts react particularly strongly to pleasant stimuli and that they should be happier than introverts only in positive conditions. In all studies, extraverts failed to exhibit greater emotional reactivity when pleasantness items were analyzed. When activated positive affect items were analyzed, results were mixed. The meta-analysis confirmed that there is only a slight reactivity effect overall, and this effect emerges only in activated positive affect items. Furthermore, the meta-analysis showed that the correlation in neutral conditions is strong enough to support the affect-level model.

Reinforcement sensitivity theory and personality

A fully fledged neuroscience of personality is beginning to emerge, shaped and guided in large measure by the seminal work of Jeffrey A. Gray over a period of 40 years. In this Festschrift, I trace the theoretical development of Gray's approach--now known as Reinforcement Sensitivity Theory (RST)--out of the Eysenckian tradition to its most recent articulation. Experimental attempts to test RST are reviewed and the theoretical problems raised by this literature discussed. Also presented are data relating to a recent clarification of RST, viz. the joint subsystems hypothesis, which postulates a fundamental interdependence of appetitive and aversive systems in the typical human laboratory. The value of Gray's general approach to building behavioural theories on the bases of both the conceptual nervous system and the real nervous system is validated in personality, which has long been thought a philosophical mystery rather than a standard problem to be tackled by scientific method.

Somatosensory event-related potential and autonomic activity to varying pain reduction cognitive strategies in hypnosis

OBJECTIVES

The issues of differential effects among cognitive strategies during hypnosis in the control of human pain are under active debate. This study, which employs measures of pain perception, electrocortical and autonomic responses, was aimed at determining these pain-related modulations.

METHODS

Somatosensory event-related potentials (SERPs) to noxious stimuli under an odd-ball paradigm were recorded at the frontal, temporal and parietal regions in 10 high, 9 mid, and 10 low hypnotizable right-handed young women, at waking baseline, varying cognitive strategies (deep relaxation, dissociative imagery, focused analgesia) in hypnosis and placebo conditions. The phasic heart rate (HR) and skin conductance response were also recorded. The analysis was focused on the frequent standard trials of the odd-ball SERPs. Repeated measures analysis of variance was conducted to examine the experimental effects.

RESULTS

Focused analgesia induced the largest reduction in pain rating, more in the high than low hypnotizable subjects. In high hypnotizable subjects, the N2 amplitude was greater over frontal and temporal scalp sites than over parietal and central sites, whereas in moderately and low hypnotizable subjects, N2 was greater over temporal sites than over frontal, parietal, and central sites. These subjects also displayed a larger N2 peak over temporal sites during focused analgesia than in the other conditions. The P3 amplitude was smaller under deep relaxation, dissociative imagery and focused analgesia in the high hypnotizable subjects. For these subjects, the smallest P3 peaks were obtained for dissociated imagery and focused analgesia over frontal and temporal sites. In contrast, for the P3 peak, low hypnotizable subjects failed to show significant condition effects. In all of the subjects, the skin conductance and HR were smaller during hypnotic suggestions than in the waking state.

CONCLUSIONS

The effect of pain modulation is limited to high hypnotizable subjects rather than low hypnotizable ones. Higher frontal-temporal N2 and smaller posterior parietal P3 may indicate active inhibitory processes during cognitive strategies in hypnotic analgesia. These inhibitory processes also regulate the autonomic activities in pain perception.