Psychophysiological correlates of the NEO PI-R openness, agreeableness and conscientiousness: preliminary results

Binaural sound therapy for tinnitus treatment: A psychometric and neurophysiological evaluation

INTRODUCTION

Tinnitus is an annoying buzz that manifests itself in many ways. In addition, it can provoke anxiety, stress, depression, and fatigue. The acoustic therapies have become the most commonly applied treatment for tinnitus, either self-administered or clinically prescribed. Binaural Sound Therapy (BST) and Music Therapy (MT) aim to reverse the neuroplasticity phenomenon related to tinnitus by adequately stimulating the auditory path-way. The goal of this research is to evaluate the feasibility of applying BST for tinnitus treatment by comparing its effect with MT effect.

MATERIALS AND METHODS

34 patients with tinnitus from 29 to 60 years were informed about the experimental procedure and consented their participation. Patients were divided into two groups: 1) MT and 2) BST. They applied their sound-based treatment for one hour every day along eight weeks. Each treatment was adjusted to Hearing Loss (HL) and tinnitus characteristics of each participant. To record EEG data, a bio-signal amplifier with sixteen EEG channels was used. The system recorded data at a sampling frequency of 256 Hz within a bandwidth between 0.1 and 100 Hz.

RESULTS

The questionnaire-monitoring reported that MT increased tinnitus perception in 30% of the patients, and increased anxiety and stress in 8% of them. Regarding EEG-monitoring, major neural synchronicity over the frontal lobe was found after the treatment. In the case of BST reduced stress in 23% of patients. Additionally, BST reduced tinnitus perception similar to MT (15% of patients). With respect to EEG-monitoring, slightly major neural synchronicity over the right frontal lobe was found after the treatment.

CONCLUSIONS

MT should be applied with caution since it could be worsening the tinnitus sufferer condition. On the other hand, BST is recommended for tinnitus sufferers who have side effects concerning stress but no anxiety.

Success of Hand Movement Imagination Depends on Personality Traits, Brain Asymmetry, and Degree of Handedness

Brain-computer interfaces (BCIs), based on motor imagery, are increasingly used in neurorehabilitation. However, some people cannot control BCI, predictors of this are the features of brain activity and personality traits. It is not known whether the success of BCI control is related to interhemispheric asymmetry. The study was conducted on 44 BCI-naive subjects and included one BCI session, EEG-analysis, 16PF Cattell Questionnaire, estimation of latent left-handedness, and of subjective complexity of real and imagery movements. The success of brain states recognition during imagination of left hand (LH) movement compared to the rest is higher in reserved, practical, skeptical, and not very sociable individuals. Extraversion, liveliness, and dominance are significant for the imagination of right hand (RH) movements in "pure" right-handers, and sensitivity in latent left-handers. Subjective complexity of real LH and of imagery RH movements correlates with the success of brain states recognition in the imagination of movement of LH compared to RH and depends on the level of handedness. Thus, the level of handedness is the factor influencing the success of BCI control. The data are supposed to be connected with hemispheric differences in motor control, lateralization of dopamine, and may be important for rehabilitation of patients after a stroke.

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.

Brain structure links trait conscientiousness to academic performance

In the long history of identifying factors to predict academic performance, conscientiousness, a so-called ‘big five’ personality trait describing self-regulation and goal-directed behavior, has emerged as a stable predictor for this purpose. However, the neuroanatomical substrates of trait conscientiousness and the underlying brain mechanism linking trait conscientiousness and academic performance are still largely unknown. Here, we examined these issues in 148 high school students within the same grade by estimating cortical gray matter volume (GMV) utilizing a voxel-based morphometry method based on structural magnetic resonance imaging. A whole-brain regression analysis showed that trait conscientiousness was positively associated with the GMV in the bilateral superior parietal lobe (SPL) and was negatively associated with the GMV in the right middle frontal gyrus (MFG). Furthermore, mediation analysis revealed that trait conscientiousness mediated the influences of the SPL and MFG volume on academic performance. Importantly, our results persisted even when we adjusted for general intelligence, family socioeconomic status and ‘big five’ personality traits other than conscientiousness. Altogether, our study suggests that the GMV in the frontoparietal network is a neurostructural marker of adolescents’ conscientiousness and reveals a potential brain-personality-achievement pathway for predicting academic performance in which gray matter structures affect academic performance through trait conscientiousness.

Connecting Openness and the Resting-State Brain Network: A Discover-Validate Approach

In personality neuroscience, the openness-brain association has been a topic of interest. Previous studies usually started from difference in openness trait and used it to infer brain functional activity characteristics, but no study has used a "brain-first" research strategy to explore that association based on more objective brain imaging data. In this study, we used a fully data-driven approach to discover and validate the association between openness and the resting-state brain network. We collected data of 120 subjects as a discovery sample and 56 subjects as a validation sample. The Neuroticism Extraversion Openness Five-Factor Inventory (NEO-FFI) was used to measure the personality characteristics of all the subjects. Using an exploratory approach based on independent component analysis of resting-state functional magnetic resonance imaging (fMRI) data, we identified a parietal network that consisted of the precuneus and inferior parietal lobe. The inter-subject similarity of the parietal memory network exhibited significant associations with openness trait, and this association was validated using the 56-subject independent sample. This finding connects the openness trait to the characteristics of a neural network and helps to understand the underlying biology of the openness trait.

Rod Driven Frequency Entrainment and Resonance Phenomena

A controversy exists on photic driving in the human visual cortex evoked by intermittent photic stimulation. Frequency entrainment and resonance phenomena are reported for frequencies higher than 12 Hz in some studies while missing in others. We hypothesized that this might be due to different experimental conditions, since both high and low intensity light stimulation were used. However, most studies do not report radiometric measurements, which makes it impossible to categorize the stimulation according to photopic, mesopic, and scotopic vision. Low intensity light stimulation might lead to scotopic vision, where rod perception dominates. In this study, we investigated photic driving for rod-dominated visual input under scotopic conditions. Twelve healthy volunteers were stimulated with low intensity light flashes at 20 stimulation frequencies, leading to rod activation only. The frequencies were multiples of the individual alpha frequency (α) of each volunteer in the range from 0.40 to 2.30(∗)α. Three hundred and six-channel whole head magnetoencephalography recordings were analyzed in time, frequency, and spatiotemporal domains with the Topographic Matching Pursuit algorithm. We found resonance phenomena and frequency entrainment for stimulations at or close to the individual alpha frequency (0.90-1.10(∗)α) and half of the alpha frequency (0.40-0.55(∗)α). No signs of resonance and frequency entrainment phenomena were revealed around 2.00(∗)α. Instead, on-responses at the beginning and off-responses at the end of each stimulation train were observed for the first time in a photic driving experiment at frequencies of 1.30-2.30(∗)α, indicating that the flicker fusion threshold was reached. All results, the resonance and entrainment as well as the fusion effects, provide evidence for rod-dominated photic driving in the visual cortex.

Resting-state EEG, impulsiveness, and personality in daily and nondaily smokers

OBJECTIVES

Resting EEG is sensitive to transient, acute effects of nicotine administration and abstinence, but the chronic effects of smoking on EEG are poorly characterized. This study measures the resting EEG profile of chronic smokers in a non-deprived, non-peak state to test whether differences in smoking behavior and personality traits affect pharmaco-EEG response.

METHODS

Resting EEG, impulsiveness, and personality measures were collected from daily smokers (n=22), nondaily smokers (n=31), and non-smokers (n=30).

RESULTS

Daily smokers had reduced resting delta and alpha EEG power and higher impulsiveness (Barratt Impulsiveness Scale) compared to nondaily smokers and non-smokers. Both daily and nondaily smokers discounted delayed rewards more steeply, reported lower conscientiousness (NEO-FFI), and reported greater disinhibition and experience seeking (Sensation Seeking Scale) than non-smokers. Nondaily smokers reported greater sensory hedonia than nonsmokers.

CONCLUSIONS

Altered resting EEG power in daily smokers demonstrates differences in neural signaling that correlated with greater smoking behavior and dependence. Although nondaily smokers share some characteristics with daily smokers that may predict smoking initiation and maintenance, they differ on measures of impulsiveness and resting EEG power.

SIGNIFICANCE

Resting EEG in non-deprived chronic smokers provides a standard for comparison to peak and trough nicotine states and may serve as a biomarker for nicotine dependence, relapse risk, and recovery.

Phase-locking index and power of 40-Hz auditory steady-state response are not related to major personality trait dimensions

Although a number of studies have demonstrated state-related dependence of auditory steady-state responses (ASSRs), the investigations assessing trait-related ASSR changes are limited. Five consistently identified major trait dimensions, also referred to as "big five" (Neuroticism, Extraversion, Openness, Agreeableness and Conscientiousness), are considered to account for virtually all personality variances in both healthy people and those with psychiatric disorders. The purpose of the present study was, for the first time, to establish the link between 40-Hz ASSR and "big five" major personality trait dimensions in young healthy adults. Ninety-four young healthy volunteers participated (38 males and 56 females; mean age ± SD 22.180 ± 2.75). The 40-Hz click trains were presented for each subject 30 times with an inter-train interval of 1-1.5 s. The EEG responses were recorded from F3, Fz, F4, C3, Cz, C4, P3, Pz and P4 locations according to 10/20 electrode placement system. Phase-locking index (PLI) and event-related power perturbation (ERSP) were calculated, each providing the following characteristics: peak time, entrainment frequency, peak value and mean value. For assessing "big five" personality traits, NEO Personality Inventory Revised (NEO-PI-R) was used. No significant correlation between 40-Hz ASSR PLI or ERSP and "big five" personality traits was observed. Our results indicate that there is no dependence between 40-Hz ASSR entrainment and personality traits, demonstrating low individual 40-Hz variability in this domain. Our results support further development of 40-Hz ASSR as a neurophysiological marker allowing distinguishing between healthy population and patients with psychiatric disorders.

Auditory beat stimulation and its effects on cognition and mood States

Auditory beat stimulation may be a promising new tool for the manipulation of cognitive processes and the modulation of mood states. Here, we aim to review the literature examining the most current applications of auditory beat stimulation and its targets. We give a brief overview of research on auditory steady-state responses and its relationship to auditory beat stimulation (ABS). We have summarized relevant studies investigating the neurophysiological changes related to ABS and how they impact upon the design of appropriate stimulation protocols. Focusing on binaural-beat stimulation, we then discuss the role of monaural- and binaural-beat frequencies in cognition and mood states, in addition to their efficacy in targeting disease symptoms. We aim to highlight important points concerning stimulation parameters and try to address why there are often contradictory findings with regard to the outcomes of ABS.

Psychophysiological responses to competition and the big five personality traits

This study examines the relationship between psychophysiological arousal, cognitive anxiety, and personality traits in young taekwondo athletes. A total of 20 male and 10 female taekwondo athletes (mean age = 18.6 years; ± 1.8) volunteered for the study. The Five Factor Personality Inventory and the state scale of the Spielberger State-Trait Anxiety Inventory (STAI) were used to measure personality and cognitive state anxiety. Electrodermal activity (EDA) was measured twice, one day and approximately one hour prior to the competition, to determine psychophysiological arousal. Descriptive statistics, Pearson product-moment correlations, and stepwise regression were used to analyze the data. Several “Big Five” facets were related to the EDA delta scores that were measured both one day and one hour before the competition. Two stepwise regressions were conducted to examine whether personality traits could significantly predict both EDA delta scores. The final model, containing only neuroticism from the Big Five factors, can significantly explain the variations in the EDA delta scores measured one day before the competition. Agreeableness can significantly explain variations in the EDA delta scores measured one hour before the competition. No relationship was found between cognitive anxiety and the EDA delta scores measured one hour before the competition. In conclusion, personality traits, especially agreeableness and neuroticism, might be useful in understanding arousal responses to competition.

Differential relationships between personality and brain function in monetary and goal-oriented subjective motivation: multichannel near-infrared spectroscopy of healthy subjects

AIM

To examine relationships between personality traits and cerebral cortex reactivity under different motivating conditions.

METHODS

Relationships between personality traits assessed using the NEO Personality Inventory-Revised (NEO-PI-R) and cerebral cortex reactivity during a verbal fluency task monitored using multichannel near-infrared spectroscopy (NIRS) were examined under three different motivational conditions: control, monetary reward, and goal-oriented, in healthy young male volunteers.

RESULTS

Significant correlations between cerebral cortex reactivity and personality traits were found in the frontopolar region: a positive correlation with agreeableness and a negative correlation with the neuroticism and conscientiousness scores of the NEO-PI-R under the three motivational conditions. Higher scores for agreeableness were more strongly associated with a greater increase in total hemoglobin concentration ([total-Hb]) under the goal-oriented and control conditions than under the monetary reward condition. In addition, higher scores for neuroticism were more strongly associated with a greater increase in deoxygenated hemoglobin concentration ([deoxy-Hb]) under the monetary reward condition than the goal-oriented condition, and higher scores for conscientiousness were more strongly associated with a greater increase in [deoxy-Hb] under control conditions than under the goal-oriented condition.

CONCLUSION

Using multichannel NIRS, certain personality traits of the big-five model are related to frontopolar reactivity. These relationships vary depending on the motivational condition when brain functions are monitored: agreeableness, neuroticism, and conscientiousness are all related to frontopolar reactivity depending on the motivational condition.

A high-density EEG investigation into steady state binaural beat stimulation

Binaural beats are an auditory phenomenon that has been suggested to alter physiological and cognitive processes including vigilance and brainwave entrainment. Some personality traits measured by the NEO Five Factor Model have been found to alter entrainment using pulsing light stimuli, but as yet no studies have examined if this occurs using steady state presentation of binaural beats for a relatively short presentation of two minutes. This study aimed to examine if binaural beat stimulation altered vigilance or cortical frequencies and if personality traits were involved. Thirty-one participants were played binaural beat stimuli designed to elicit a response at either the Theta (7 Hz) or Beta (16 Hz) frequency bands while undertaking a zero-back vigilance task. EEG was recorded from a high-density electrode cap. No significant differences were found in vigilance or cortical frequency power during binaural beat stimulation compared to a white noise control period. Furthermore, no significant relationships were detected between the above and the Big Five personality traits. This suggests a short presentation of steady state binaural beats are not sufficient to alter vigilance or entrain cortical frequencies at the two bands examined and that certain personality traits were not more susceptible than others.

Psychophysiological responses to pain stimulation and cognitive tasks in female temporomandibular disorder patients

Background and purpose Psychophysiological factors may contribute to the development of temporomandibular disorders (TMD). Both local orofacial and systemic responses have been investigated. However, most studies have concentrated on physiological responding during cognitive challenges, while responses during painful tasks may be highly relevant for the development of chronic pain conditions. Moreover, the relationship between experimental challenges and physiological responding may be influenced by affective responses during the experimental tasks, an issue not often considered in the literature. Methods This study compared electromyography (EMG) of the left masseter and left trapezius muscles, orofacial and digital skin blood-flow (SBF), mean arterial pressure (MAP), and heart rate (HR) at rest, during orofacial isometric contraction, electrocutaneous pain stimulation of the left hand, pressure pain stimulation of the masseter muscle and the sternum, and three cognitive tasks (reading aloud, a simulated job interview, and visuomotoric tracking). The participants were 25 TMD patients and 25 matched pain-free controls, all females. Affective responses were assessed with the State part of the State-Trait Personality Inventory and with Visual Analogue Scales. Results Masseter EMG levels were significantly lower in the TMD group relative to the control group during jaw contraction, pressure pain stimulation, the relaxation periods, and cognitive tasks. SBF, MAP, and HR responses were largely similar in the two groups, with SBF responses to pain stimulation evident at lower levels of stimulation than previously found. The TMD patients reported significantly higher levels of negative affect during the experiment. Conclusions and implications The low EMG responses in the TMD group may be taken in support of the Pain Adaptation Model of musculoskeletal pain, in which reduced muscular activity serves to protect a painful area. However, it may also be supportive of the Integrated Pain Adaptation Model, where higher central nervous structures influence local muscular output. The group similarities in systemic physiological responding in combination with the elevated levels of negative state affect in the TMD patients confirm previous reports of psychosocial differences being more reliable indicators of TMD than generalized physiological responding.

ELECTROENCEPHALOGRAPHIC, PERSONALITY, AND EXECUTIVE FUNCTION MEASURES ASSOCIATED WITH FREQUENT MOBILE PHONE USE

The present study employs standardized data acquired from the Brain Resource International Database to study the relationship between mobile phone usage, personality, and brain function (n = 300). Based on the frequency and duration of mobile phone usage, three groups were formed. The findings suggest a subtle slowing of brain activity related to mobile phone use that is not explained by differences in personality. These changes are still within normal physiological ranges. Better executive function in mobile phone users may reflect more focused attention, possibly associated with a cognitive training effect (i.e., frequently making phone calls in distracting places), rather than a direct effect of mobile phone use on cognition.

“Dark Nights of the Soul”: Phenomenology and Neurocognition of Spiritual Suffering in Mysticism and Psychosis

Phenomenological, clinical, and neurocognitive levels of analysis are combined to understand the cognitive bases of spirituality and spiritual suffering. In particular, the “dark night of the soul” in classical mysticism, with its painful “metapathological” loss of felt meaning is compared with the anhedonias central to the negative symptoms of schizophrenia and schizotypicality. Paul Schilder's early understanding of instabilities in the body image, as our core sense of self, offers a key to both the disorganized hallucinatory syndromes of psychosis and to the relative enhancements of body image/ecological self in spirituality. Expanded versus deleted felt presence/embodiment, as outwardly indexed in measures of physical balance and spatial abilities, becomes the general dimension underlying integrative versus disintegrative transformations of consciousness. “Dark night” suffering can be seen as a semantic satiation leading to a relative deletion of experienced presence in the context of its previous enhancement, a focalized version of the more general anhedonic despair shared by clinical schizotypy and aspects of a larger secularized culture.

Lack of efficacy of music to improve sleep: A polysomnographic and quantitative EEG analysis

An increasing number of studies have been examining non-pharmacological methods to improve the quality of sleep, including the use of music and other types of auditory stimulation. While many of these studies have found significant results, they suffer from a combination of subjective self-report measures as the primary outcome, a lack of proper controls, often combine music with some type of relaxation therapy, or do not randomise subjects to control and treatment conditions. It is therefore difficult to assess the efficacy of music to induce or improve sleep. The present study therefore examined the effects of music using standard polysomnographic measures and quantitative analysis of the electroencephalogram, along with subjective ratings of sleep quality. In addition, a tones condition was used to compare any effects of music with the effects of general auditory stimulation. Using a counter-balanced within-subjects design, the music was not significantly better than the tones or control conditions in improving sleep onset latency, sleep efficiency, wake time after sleep onset, or percent slow wave sleep, as determined by objective physiological criteria.

Personality and subjective well-being in orangutans (Pongo pygmaeus and Pongo abelii)

Orangutans (Pongo pygmaeus and Pongo abelii) are semisolitary apes and, among the great apes, the most distantly related to humans. Raters assessed 152 orangutans on 48 personality descriptors; 140 of these orangutans were also rated on a subjective well-being questionnaire. Principal-components analysis yielded 5 reliable personality factors: Extraversion, Dominance, Neuroticism, Agreeableness, and Intellect. The authors found no factor analogous to human Conscientiousness. Among the orangutans rated on all 48 personality descriptors and the subjective well-being questionnaire, Extraversion, Agreeableness, and low Neuroticism were related to subjective well-being. These findings suggest that analogues of human, chimpanzee, and orangutan personality domains existed in a common ape ancestor.

Personality traits and its association with resting regional brain activity

The association between personality and resting brain activity was investigated. Personality was assessed using the NEO-Five-factor Inventory (NEO-FFI) and resting brain activity was indexed by eyes closed EEG spectral magnitude from four frequency bands over the entire cortex. Results suggest that there are differences between males and females in the NEO-FFI personality traits. The NEO FFI traits were associated with lower frequency brain activity in both males and females. Mild significant and consistent associations were found between delta and theta activity across all cortical regions with Extraversion and Conscientiousness. There were few associations between personality traits and alpha and beta activity, this was shown in males only. Fewer associations between personality and faster frequency bands such as alpha may be due to the methodological problem of using fixed alpha bands. Multiple regression analyses showed that individual alpha frequencies had a greater contribution to personality traits than fixed band alpha waves.

Frontal EEG asymmetry as a moderator and mediator of emotion

Frontal EEG asymmetry appears to serve as (1) an individual difference variable related to emotional responding and emotional disorders, and (2) a state-dependent concomitant of emotional responding. Such findings, highlighted in this review, suggest that frontal EEG asymmetry may serve as both a moderator and a mediator of emotion- and motivation-related constructs. Unequivocal evidence supporting frontal EEG asymmetry as a moderator and/or mediator of emotion is lacking, as insufficient attention has been given to analyzing the frontal EEG asymmetries in terms of moderators and mediators. The present report reviews the frontal EEG asymmetry literature from the framework of moderators and mediators, and overviews data analytic strategies that would support claims of moderation and mediation.

Heritability and "environmentability" of electroencephalogram in infants: the twin study

We estimated relative contribution of genetic and environmental factors to electroencephalogram (EEG) frequency and amplitude parameters in infants. EEG was registered in 49 pairs of monozygotic and 45 pairs of dizygotic twins aged 7-12 months during (1) visual attention and (2) darkness. The variability of occipital alpha frequency depended mainly on genetic, probably nonadditive factors. The mean heritability for the spectral amplitudes in the delta, theta, and alpha bands were 0.37, 0.13, and 0.22 during visual attention, and 0.22, 0.40, and 0.10 during darkness. The influence of shared environment was probable for many of the EEG parameters. It was greatest for the amplitude of the theta rhythm during visual attention. The theta amplitude depended on such a parameter of early social environmental enrichment as the number of caregivers in the family. The possible relationship between infant theta rhythm and developmental outcome is discussed. For many of the EEG parameters, heritability increased during the second half of the first year of life, thus supporting the hypothesis about amplification of genetic effects and decrease of common environmental influences with age.