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Biased attention towards emotional stimuli is adaptive, as it facilitates responses to important threats and rewards. An unfortunate consequence is that emotional stimuli can become potent distractors when they are irrelevant to current goals. How can this distraction be overcome despite the bias to attend to emotional stimuli? Recent studies show that distraction by irrelevant flankers is reduced when distractor frequency is high, even if they are emotional. A parsimonious explanation is that the expectation of frequent distractors promotes the use of proactive control, whereby attentional control settings can be altered to minimize distraction before it occurs. It is difficult, however, to infer proactive control on the basis of behavioral data alone. We therefore measured neural indices of proactive control while participants performed a target-detection task in which irrelevant peripheral distractors (either emotional or neutral) could appear either frequently (on 75% of trials) or rarely (on 25% of trials). We measured alpha power during the pre-stimulus period to assess proactive control and during the post-stimulus period to determine the consequences of control for subsequent processing. Pre-stimulus alpha power was tonically suppressed in the high, compared to low, distractor frequency condition, regardless of expected distractor valence, indicating sustained use of proactive control. In contrast, post-stimulus alpha suppression was reduced in the high-frequency condition, suggesting that proactive control reduced the need for post-stimulus adjustments. Our findings indicate that a sustained proactive control strategy accounts for the reduction in both emotional and non-emotional distraction when distractors are expected to appear frequently.

Objective The aim of this study is to evaluate the effectiveness of a seat-integrated mobilization system for maintaining vigilance under monotonous driving situations. Method For this purpose, vigilance indicators were compared intra-individually in a test condition with mobilization (seat-integrated stimulation) and a placebo condition under standardized conditions in a real driving study (N = 31). During a monotonous two-hour ride, physiological (brain activity by the EEG alpha spindle rate), performance-based (reaction times) and subjective indicators were recorded. Results The necessary precondition for the paradigm of inducing fatigue through monotony was confirmed by a significant increase in the EEG alpha spindle rate and the subjective vigilance indices. The mobilization system had a significant impact on the most fatigue-sensitive parameter of the alpha spindle rate, whereas the other parameters of vigilance did not reflect a significant effect of mobilization. Conclusion The Mobilization Seat is an effective measure to prevent drivers’ fatigue during monotonous situations.

Summary To behave adaptively with sufficient flexibility, biological organisms must cognize beyond immediate reaction to a physically present stimulus. For this, humans use visual mental imagery [1, 2], the ability to conjure up a vivid internal experience from memory that stands in for the percept of the stimulus. Visually imagined contents subjectively mimic perceived contents, suggesting that imagery and perception share common neural mechanisms. Using multivariate pattern analysis on human electroencephalography (EEG) data, we compared the oscillatory time courses of mental imagery and perception of objects. We found that representations shared between imagery and perception emerged specifically in the alpha frequency band. These representations were present in posterior, but not anterior, electrodes, suggesting an origin in parieto-occipital cortex. Comparison of the shared representations to computational models using representational similarity analysis revealed a relationship to later layers of deep neural networks trained on object representations, but not auditory or semantic models, suggesting representations of complex visual features as the basis of commonality. Together, our results identify and characterize alpha oscillations as a cortical signature of representations shared between visual mental imagery and perception., Highlights • Perception and imagery share neural representations in the alpha frequency band • Shared representations stem from parieto-occipital sources • Modeling suggests contents of shared representations are complex visual features, Visual imagination is a key cognitive function with the feel of weak visual perception. Xie et al. show that this phenomenal likeness is mirrored by neural likeness in shared representations of complex visual features in the alpha frequency band activity arising from parieto-occipital cortex.

To validate the use of functional near-infrared spectroscopy (fNIRS) in auditory perception experiments, combined fNIRS and electroencephalography (EEG) data were obtained from normal-hearing subjects passively listening to speech-like stimuli without linguistic content. The fNIRS oxy-haemoglobin (HbO) results were found to be inconsistent with the deoxy-haemoglobin (HbR) and EEG data, as they were dominated by pronounced cerebral blood stealing in anterior- to-posterior direction. This large-scale bilateral gradient in the HbO data masked the right-lateralised neural activity in the auditory cortex that was clearly evident in the HbR data and EEG source reconstructions. When the subjects were subsequently split into subgroups with more positive or more negative HbO responses in the right auditory cortex, the former group surprisingly showed smaller event-related potentials, less activity in frontal cortex, and increased EEG alpha power, all indicating reduced attention and vigilance. These findings thus suggest that positive HbO responses in the auditory cortex may not necessarily be a favourable result when investigating auditory perception using fNIRS. More generally, the results show that the interpretation of fNIRS HbO signals can be misleading and demonstrate the benefits of combined fNIRS-EEG analyses in resolving this issue.

The ability to quickly identify fearful faces is important for the activation of defense mechanisms that allow an individual to deal with potential emergencies. This study examined the relationship between frontal electroencephalography (EEG) alpha asymmetry and the processing of congruent and incongruent fearful faces among female participants using event-related potentials (ERPs). Behavioral results showed that individuals with more left frontal EEG alpha asymmetry had shorter response times than individuals with more right frontal EEG alpha asymmetry during the cue-target task. ERP results indicated that, for individuals with more left frontal EEG alpha asymmetry, enhanced N1 reflected more rapid processing of emotional faces in the early stage, and enhanced P3 indicated that these individuals directed more attentional and motivational resources to the evaluation of emotional faces in the late stage. For individuals with more right frontal EEG alpha asymmetry, enhanced N2 indicated that these individuals experienced more conflict for incongruent fearful faces in the late stage. The present findings suggest that frontal EEG alpha asymmetry during resting conditions can reflect individual differences in the processing of congruent and incongruent fearful faces.

Many traditions have utilized silent environments to induce altered states of consciousness and spiritual experiences. Neurocognitive explorations of spiritual experience can aid in understanding the underlying mechanism, but these are surprisingly rare. We present the verbal report and the electroencephalographic (EEG) alpha profile of a female participant scoring a maximal 34 on the Absorption Scale, recorded before and while she was immersed in a whole-body perceptual deprivation (WBPD) tank. We analyze her trancelike experience in terms of the imagery reported: a spaceship, corridors, doors, a man dressed in white, speaking to God, the sun, supernova, concentric images, and an out-of-body experience. Her report is indicative of a spiritual experience, given that she felt that she was “meeting God” in the laboratory. She exhibited both frontal and parietal left > right alpha power asymmetry at baseline, whereas in the WBPD condition, there was a global increase in alpha power and especially a sharp increase in right-frontal alpha power. Her verbal report and EEG alpha profile were compared to those of another female participant, also scoring high on absorption, whose verbal report was also indicative of a trancelike experience. For further comparison, we present the data for two participants scoring low on absorption. Spiritual experience that can be verbalized might be associated with a marked increase in right-frontal alpha power, as reported here. In contrast, a mystical experience characterized by ineffability would be indicated by a marked increase in left-frontal alpha power.

The evolution of virtual reality (VR) technologies requires setting boundaries of its use. In this study, 3 female participants were experiencing VR scenarios with stressful content and their activity of the autonomic nervous system and EEG were recorded. It has been discovered that virtual reality can evoke acute stress reactions accompanied by activation of the sympathetic nervous system and a decrease in the activity of the parasympathetic nervous system. The high-stress response is accompanied by a decrease in the power of the EEG, and, on the contrary, the activation of the avoidance reaction is accompanied by an increase in the power of the EEG alpha waves. Therefore, the use of stressful VR content can cause high emotional stress to a user and restrictions should be considered.

In recent years, the influence of alpha (7–13 Hz) phase on visual processing has received a lot of attention. Magneto‐/encephalography (M/EEG) studies showed that alpha phase indexes visual excitability and task performance. Studies with transcranial alternating current stimulation (tACS) aim to modulate oscillations and causally impact task performance. Here, we applied right occipital tACS (O2 location) to assess the functional role of alpha phase in a series of experiments. We presented visual stimuli at different pre‐determined, experimentally controlled, phases of the entraining tACS signal, hypothesizing that this should result in an oscillatory pattern of visual performance in specifically left hemifield detection tasks. In experiment 1, we applied 10 Hz tACS and used separate psychophysical staircases for six equidistant tACS‐phase conditions, obtaining contrast thresholds for detection of visual gratings in left or right hemifield. In experiments 2 and 3, tACS was at EEG‐based individual peak alpha frequency. In experiment 2, we measured detection rates for gratings with (pseudo‐)fixed contrast. In experiment 3, participants detected brief luminance changes in a custom‐built LED device, at eight equidistant alpha phases. In none of the experiments did the primary outcome measure over phase conditions consistently reflect a one‐cycle sinusoid. However, post hoc analyses of reaction times (RT) suggested that tACS alpha phase did modulate RT for specifically left hemifield targets in both experiments 1 and 2 (not measured in experiment 3). This observation requires future confirmation, but is in line with the idea that alpha phase causally gates visual inputs through cortical excitability modulation., In a series of experiments, visual stimuli were presented at pre‐determined phases of an alpha‐frequency tACS signal applied to right occipital cortex. Curve‐fitting analyses revealed no effects on visual detection or thresholds, but possible post hoc effects on reaction times in left visual field.

Background In China, Jin's three-needle acupuncture therapy has been widely used for stroke treatment. However, its mechanism remains unclear. The aim of this study was to investigate the effects of Jin's three-needle acupuncture therapy on stroke patients using multi-channel EEGs. Materials and methods Fifty stroke patients participated and their EEG signals were recorded before, during, and after acupuncture. Results Comparing with baseline before acupuncture, the alpha rhythm was significantly increased during the acupuncture needle retention stage and became stronger after removing the needles. The increase of alpha rhythm occurred when inserting and removing the needles, with its high amplitude remaining during retention and after removal of the needles. As the alpha rhythm was significantly correlated with patients' movement and daily-living abilities, the alteration of alpha rhythm during and after acupuncture suggests a possible electrophysiological mechanism of the curative effect of acupuncture for stroke rehabilitation. Conclusion From the electrophysiological study, Jin's three-needle acupuncture therapy is efficient in stroke patients.

Visual working memory (VWM) distinguishes between representations relevant for imminent versus future perceptual goals. We investigated how the brain sequentially prioritizes visual working memory representations that serve consecutive tasks. Observers remembered two targets for a sequence of two visual search tasks, thus making one target currently relevant, and the other prospectively relevant. We show that during the retention interval prior to the first search, lateralized parieto-occipital EEG alpha (8–14 Hz) suppression is stronger for current compared with prospective search targets. Crucially, between the first and second search task, this difference in posterior alpha lateralization reverses, reflecting the change in priority states of the two target representations. Connectivity analyses indicate that this switch in posterior alpha lateralization is driven by frontal delta/low-theta (2–6 Hz) activity. Moreover, this frontal low-frequency signal also predicts task performance after the switch. We thus obtained evidence for large-scale network interactions underlying the flexible shifting between the priority states of multiple memory representations in VWM.

The present study tested the validity of inferring verbal-analytic motor processing from EEG left-temporal alpha activity. Participants (n = 20) reached for and transport a jar under three conditions: one control condition and two self-talk conditions aimed at eliciting either task-unrelated verbal processing or task-related conscious control, while 32-channel EEG and kinematics were recorded. Compared to the control condition, both self-talk conditions elicited greater self-reported levels of verbal processing, but only the task-related self-talk condition was accompanied by greater left temporal activity (i.e., EEG alpha power decreased) during movement production. However, this increase was not localised to the left temporal region but was rather evident over all scalp regions examined, suggesting an interpretation more consistent with diminished neural efficiency. No effects for left temporal-frontal (T7-Fz) connectivity were detected across conditions. Our results failed to endorse left-temporal EEG alpha activity as valid index of verbal-analytic processing during motor tasks.

An increasing population suffers from visual stress like eye strain, even myopia, which may be related with the high blue component of artificial light sources. The aim of this study is to investigate the influence of blue component on visual discomfort using EEG and EOG measurements. The results revealed that complex visual discomfort yielded under blue-enriched white light with EEG alpha activity enhanced near the central area and around parietal and occipital regions, as well as frequent blink. It suggests that the long-term exposure to commonly used light source with enriched blue component might relate with the produce of myopia.

Acute physical exercise (APE) induces an increase in the individual alpha peak frequency (iAPF), a cortical parameter associated with neural information processing speed. The aim of this study was to further scrutinize the influence of different APE intensities on post-exercise iAPF as well as its time course after exercise cessation. 95 healthy young (18-35 years) subjects participated in two randomized controlled experiments (EX1 and EX2). In EX1, all participants completed a graded exercise test (GXT) until exhaustion and were randomly allocated into different delay groups (immediately 0, 30, 60 and 90 min after GXT). The iAPF was determined before, immediately after as well as after the group-specific delay following the GXT. In EX2, participants exercised for 35 min at either 45-50%, 65-70% or 85-90% of their maximum heart rate (HRmax). The iAPF was determined before, immediately after as well as 20 min after exercise cessation. In EX1, the iAPF was significantly increased immediately after the GXT in all groups. This effect was not any more detectable after 30 min following exercise cessation. In EX2, a significant increase of the iAPF was found only after high-intensity (85-90% HRmax) exercise. The results indicate intense or exhaustive physical exercise is required to induce a transient increase in the iAPF that persists about 30 min following exercise cessation. Based on these findings, further research will have to scrutinize the behavioral implications associated with iAPF modulations following exercise.

In the majority of studies investigating cortical alpha oscillations the alpha frequency is defined as a fixed band thus, neglecting recommendations in the EEG literature to adjust the alpha band according to the individual alpha peak frequency (iAPF). Based on our previous findings indicating exhaustive exercise induces an increase of the post-exercise iAPF, we scrutinized the influence of exercise on post-exercise alpha power by comparing fixed and iAPF-adjusted alpha frequency bands. Resting EEG was recorded from 13 scalp locations in nine subjects before, immediately after as well as ten minutes following an exhaustive exercise protocol on a cycle ergometer. Lower and upper band alpha power was calculated for fixed and iAPF-adjusted frequency bands. Post-exercise lower alpha power increased in both fixed and individually defined bands while a higher upper alpha power was only observed in the fixed frequency band condition. Further, the increase in iAPF was positively related to the changes in fixed-band upper alpha power. It is concluded that lower alpha power is significantly increased following exhaustive exercise whereas the results for upper alpha power are substantially influenced by the method of frequency band definition. Therefore, caution is indicated when analyzing and interpreting exercise-induced changes in alpha power.

Heterogeneity of the posterior alpha rhythm (AR) is a widely assumed but rarely tested phenomenon. We decomposed the posterior AR in the cortical source space with a 3-way PARAFAC technique, taking into account the spatial, frequency, and temporal aspects of mid-density EEG. We found a multicomponent AR structure in 90% of a group of 29 healthy adults. The typical resting-state structure consisted of a high-frequency occipito-parietal component of the AR (ARC1) and a low-frequency occipito-temporal component (ARC2), characterized by individual dynamics in time. In a few cases, we found a 3-component structure, with two ARC1s and one ARC2. The AR structures were stable in their frequency and spatial features over weeks to months, thus representing individual EEG alpha phenotypes. Cortical topography, individual stability, and similarity to the primate AR organization link ARC1 to the dorsal visual stream and ARC2 to the ventral one. Understanding how many and what kind of posterior AR components contribute to the EEG is essential for clinical neuroscience as an objective basis for AR segmentation and for interpreting AR dynamics under various conditions, both normal and pathological, which can selectively affect individual components.

Do physiological and behavioral performance indicators of effortful cognitive self-regulation converge additively or interactively in their statistical prediction of individual differences in harsh parenting? To answer this question, we examined heart rate (HR) and electroencephalography alpha (α) reactivity during executive function (EF) tasks, along with observed and self-reported indicators of harsh parenting. A socioeconomically diverse sample of 115 mothers with 3- to 7-year-old children completed questionnaires and a laboratory visit. Three quarters of the mothers showed typical patterns of task reactivity that were interpretable (i.e., increases in HR and decreases in α). Among them, we found no evidence to suggest that variance in harsh parenting was associated with magnitude of HR or α reactivity independently. Instead, the physiological variables interacted to enhance the EF statistical effect. EF explained one third of the variance in harsh parenting among mothers showing the largest α decreases when accompanied by modest to moderate (rather than substantial) HR increases. Physiological indicators can clarify the role and estimation of the strength of the effect of direct behavioral measures of cognitive regulation in the etiology of harsh parenting behaviors. (PsycINFO Database Record

Frontal electroencephalographic (EEG) alpha asymmetry is widely researched in studies of emotion, motivation, and psychopathology, yet it is a metric that has been quantified and analyzed using diverse procedures, and diversity in procedures muddles cross-study interpretation. The aim of this article is to provide an updated tutorial for EEG alpha asymmetry recording, processing, analysis, and interpretation, with an eye towards improving consistency of results across studies. First, a brief background in alpha asymmetry findings is provided. Then, some guidelines for recording, processing, and analyzing alpha asymmetry are presented with an emphasis on the creation of asymmetry scores, referencing choices, and artifact removal. Processing steps are explained in detail, and references to MATLAB-based toolboxes that are helpful for creating and investigating alpha asymmetry are noted. Then, conceptual challenges and interpretative issues are reviewed, including a discussion of alpha asymmetry as a mediator/moderator of emotion and psychopathology. Finally, the effects of two automated component-based artifact correction algorithms—MARA and ADJUST—on frontal alpha asymmetry are evaluated.

The objective of the study is to analyze electroencephalograms (EEGs) of patients with schizophrenia using power spectral density. The proposed method measures various absolute powers that are related to the amount of information contained in the frequency components. 57 schizophrenia subjects and 24 normal subjects were included the study. EEG recordings were obtained under resting, hyperventilation and post-hyperventilation with eyes closed conditions. The absolute total power for 10 s epochs of EEGs was calculated using Welch’s method. The delta, theta, alpha, and beta bands were extracted from EEGs using a finite impulse response band pass filter and the power was determined. The differences in the absolute powers of the beta band and alpha bands were significant between the two groups (p

Introduction: Diabetes is a major health problem in India, Type 2 is also the most common type seen. Diabetes is associated with cognitive decline in elderly patients. Hyperglycemia, age, sex and duration of diabetes mellitus all seems to affect cognitive function. Objectives: Aim of the study is to assess the EEG changes and cognitive function in elderly type 2 diabetes mellitus patients. Materials and methods: Two groups of people, 20 in each group who are age sex matched were selected and case group of elderly diabetic patients and control group of healthy subjects were selected. EEG recordings were done using MP36 – BIOPAC 4 channel instrument and cognitive function was assessed using MMSE. Results: The elderly diabetic group was having declined cognitive function – MCI (Mild Cognitive Impairment) and reduced EEG wave activity. Conclusion: Reduced EEG alpha wave activity is seen in elderly diabetic patients. Reduced functional connections in cortex and hyperglycemia induced pathologic changes could be the causative factors.

Adolescent idiopathic scoliosis (AIS) is a multifactorial disorder characterized by a tridimensional deformation of the spine. AIS pathophysiology is still unclear and its aetiology is unknown. Results from several studies revealed balance control alterations in adolescents with AIS suggesting cortical sensorimotor processing impairments. Studies assessing cortical activity involved in balance control revealed an increase in alpha peak frequency (APF), which is a neurophysiological marker of thalamo-cortical transmission, related to a more challenging balance task. The objective of this study is to assess APF of adolescents with AIS during balance control in upright standing posture using electroencephalography (EEG). EEG was recorded in 16 girls with AIS and 15 control girls in normal standing posture on a force platform. The participants stood upright for 2 min with eyes open and 2 min with eyes closed. Fast Fourier transformations of EEG data were calculated to obtain APF. Balance performances were assessed through the area of an ellipse covering the center of pressure (COP) displacement and the root mean square value of the COP velocity. Compared to the control group, APF was higher in the AIS group at central, frontal, parietal and occipital regions. Further, COP analyses did not reveal any difference between AIS and control groups. A higher APF may indicate the need for increased cortical processing to maintain balance control in normal upright standing in adolescents with AIS compared to healthy controls. We suggest that this may be a compensatory strategy to overcome balance control challenges.

Made available in DSpace on 2019-10-04T12:39:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-07-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Portable EEG devices have a great potential to become efficient computer interfaces. However, a necessary step is to accurately describe the EEG signal in order to quantify brain rhythms. This study explored two signal analysis techniques, Matching Pursuit (MP) and Fast Fourier Transform (FFT), for differentiation between two states, eyes open (EO) and eyes closed (EC), through the detection of EEG alpha activity obtained from seven scalp regions, using a portable EEG device. Subjects were ten healthy male volunteers. MP results generally reproduced the results from FFT analysis, and all methods performed well on the occipital region. However, there was better state discrimination with MP atom number, and MP atom number was the only variable that reached statistical significance on all locations under study. When employing EEG alpha rhythm for EO vs. EC state discrimination, it may be useful to compute MP atom number, especially when extra-occipital acquisition is warranted. (C) 2019 Elsevier Ltd. All rights reserved. Univ Estadual Paulista, Inst Biosci, Dept Phys & Biophys, Dist Rubido Jr S-N, BR-18618970 Botucatu, SP, Brazil Univ Caxias Do Sul, Ctr Ciencias Exatas & Tecnol, Rua Francisco Getulio Vargas 1130, BR-95001970 Caxias Do Sul, RS, Brazil Hosp Clin Porto Alegre, Neurol Div, Rua Ramiro Barcelos 2350,Sala 2040, BR-90035003 Porto Alegre, RS, Brazil Univ Estadual Paulista, Inst Biosci, Dept Phys & Biophys, Dist Rubido Jr S-N, BR-18618970 Botucatu, SP, Brazil CNPq: 458810/2013-4 CNPq: 181242/2014-1 CNPq: 182472/2015-9 CNPq: 181963/2014-0 CNPq: 185855/2014-8 CNPq: 314178/2014-7 CNPq: 310001/2015-3

Oscillatory neural activity is a fundamental characteristic of the mammalian brain spanning multiple levels of spatial and temporal scale. Current theories of neural oscillations and analysis techniques employed to investigate their functional significance are based on an often implicit assumption: In the absence of experimental manipulation, the spectral content of any given EEG- or MEG-recorded neural oscillator remains approximately stationary over the course of a typical experimental session (~1 hour), spontaneously fluctuating only around its dominant frequency. Here, we examined this assumption for ongoing neural oscillations in the alpha-band (8:13 Hz). We found that alpha peak frequency systematically decreased over time, while alpha-power increased. Intriguingly, these systematic changes showed partial independence of each other: Statistical source separation (independent component analysis) revealed that while some alpha components displayed concomitant power increases and peak frequency decreases, other components showed either unique power increases or frequency decreases. Interestingly, we also found these components to differ in frequency. Components that showed mixed frequency/power changes oscillated primarily in the lower alpha-band (~8-10Hz), while components with unique changes oscillated primarily in the higher alpha-band (~9-13Hz). Our findings provide novel clues on the time-varying intrinsic properties of large-scale neural networks as measured by M/EEG, with implications for the analysis and interpretation of studies that aim at identifying functionally relevant oscillatory networks or at driving them through external stimulation.

Apathy is a common non-motor symptom of Parkinson's disease (PD) that is difficult to quantify and poorly understood. Some studies have used incentivized motor tasks to assess apathy, as the condition is often associated with a reduction in motivated behavior. Normally event-related desynchronization, a reduction of power in specific frequency bands, is observed in the motor cortex during the peri-movement period. Also, alpha (8–12 Hz) and theta (4–7 Hz) oscillations are sensitive to rewards that are closely related to motivational states however these oscillations have not been widely investigated in relation to apathy in PD. Using EEG recordings, we investigated the neural oscillatory characteristics of apathy in PD during an incentivized motor task with interleaved rest periods. Apathetic and non-apathetic PD subjects on dopaminergic medication and healthy control subjects were instructed to squeeze a hand grip device for a monetary reward proportional to the subject's grip force and the monetary value attributed to that trial. Apathetic PD subjects exhibited higher alpha and theta powers in the pre-trial baseline rest period compared to non-apathetic PD subjects and healthy subjects. Further, we found that both resting power and relative power in alpha and theta bands during incentivized movement predicted PD subjects' apathy scores. Our results suggest that apathetic PD patients may need to overcome greater baseline alpha and theta oscillatory activity in order to facilitate incentivized movement. Clinically, resting alpha and theta power as well as alpha and theta event-related desynchronization during movement may serve as potential neural markers for apathy severity in PD., Highlights • Apathetic patients with Parkinson's disease on dopaminergic medication have distinct neural oscillatory characteristics. • Apathetic patients exhibit a higher resting EEG theta and alpha power compared to non-apathetic patients. • Both resting power and relative event-related theta and alpha desynchronization during squeezing are able to predict patient apathy scores.

The paper surveys the behavior and psychophysiological responses (electroencephalographic power modulations of the alpha and beta rhythms) in 16 boys and 33 girls aged from 1.5 to 3.5 years when they were distributing reward tokens (carton cookies) among the toy characters who previously demonstrated proand antisocial behavior (rendering help and causing harm, respectively). The individual way of distributing the reward was translated into a moral evaluation index (MEI) for each child. When children were distributing the reward tokens, an increase in power, relative to the baseline, was registered for theta rhythm in the prefrontal, frontal and occipital cortex regions, and for beta rhythm in the temporal and occipital regions. Besides, those children who tended to give a bigger reward to the good-acting toy character (i.e., having higher MEI) showed a significantly greater increase in beta rhythm power compared to the children with lower MEI. The reason for that might be that children with higher MEI engage their cognitive resources into making socially significant decisions more effectively and adequately process emotionally significant information.

A recently developed tripolar concentric ring electrode enables accurate estimation of the local Laplacian of the electroencephalogram (EEG). Here, we tested the ability of this tripolar EEG (tEEG) system to detect the extent to which the alpha rhythm—an 8-13 Hz oscillation found in the EEG when the subject is at rest with the eyes closed—is modulated by opening the eyes, and compared it with simultaneous conventional EEG measurements. In a preliminary study comprising ten independent sessions on seven subjects, opening the eyes reduced alpha power by an average of 66.5 ± 9% and 59.1 ± 10% in tEEG and conventional EEG recordings, respectively. These findings suggest that the dynamical changes in brain rhythms may be more easily detected by tEEG than by conventional EEG with implications for clinical diagnosis and neurofeedback applications.

There are ample inter-individual differences in the frequency with which people perceive meaningful coincidences. Previous research has identified increased proactive interference, that is a reduced working memory capacity, as one possible mechanism associated with this phenomenon. The present study aimed at extending this finding into the domain of neuroscience, (1) by assessing EEG alpha oscillations during the retention of information, (2) by replicating the behavioral link between meaningful coincidences and proactive interference. In a sample of 52 participants, the behavioral replication was successful. Furthermore, participants who perceived more meaningful coincidences showed higher alpha power increases at parietal-occipital sites, and at the same time, displayed lower alpha power increases at frontal areas, during retention of information. This neurophysiological activation pattern further underlines the assumption that participants who perceive more meaningful coincidences show lower working memory capacities, since increased alpha power at parietal areas reflects a higher load on working memory demands.

Studies on the use of alpha spectrum of an Electroencephalogram (EEG) and its relationship towards emotion, have been carried out extensively. Asymmetric Relationship Ratio (ARR) is usually used, extracted as features. To calculate the ARR, the EEG spectrum between 8 and 13 Hz needs to be averaged. Investigating the EEG alpha spectrum individually, by representing the ARR in terms of its emotional state, shows that, some EEG components produce negative relationships over others. By averaging these conflicting EEG components, it reduces the accuracy of an EEG-based emotion recognition system. This paper studies the relationship of the EEG within the alpha spectrum. Pearson, Spearman Rank and Kendall Rank correlation coefficient methods have been used to measure the dependency of the EEG components. From this study, it can be concluded that, EEG spectrums between 10 to 12 Hz are highly dependents between each other. Thus, it is proposed that only EEG within these frequency bands to be used in calculating the ARR.