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Objective Studies of the effect of valproate (VPA) on the background EEG have shown varying results. Therefore, we compared the effect of VPA and levetiracetam (LEV) on the EEG alpha peak frequency (APF). Methods We retrospectively examined the APF in resting-state EEG of patients undergoing inpatient video-EEG monitoring (VEM) during withdrawal of VPA or LEV. We assessed APF trends by computing linear fits across individual patients’ APF as a function of consecutive days, and correlated the APF and daily antiseizure medication (ASM) doses on a single-patient and group level. Results The APF in the VPA-group significantly increased over days with falling VPA doses (p = 0.005, n = 13), but did not change significantly in the LEV-group (p = 0.47, n = 18). APF correlated negatively with daily ASM doses in the VPA-group (average of r = −0.74 ± 0.12 across patients, p = 0.0039), but not in the LEV-group (average of r = −0.17 ± 0.18 across patients, p = 0.4072). Conclusions Our results suggest that VPA treatment slows the APF. This APF reduction correlates with the daily dose of VPA and is not present in LEV treatment. Significance Our study identifies a VPA-related slowing of the APF even in patients without electroencephalographic or overt clinical signs of encephalopathy.

Objective Chronic pain studies investigating the ability to detect sensory processing differences related to thalamic gating using electroencephalographic (EEG) alpha have yielded conflicting results. Alpha’s basic psychometric properties in pain populations requires further study. The present study reports on the test–retest reliability and internal consistency of EEG alpha power in older adults with chronic knee pain. Methods Repeated EEG alpha power measurements were taken of older adults (N = 31) with chronic knee pain across two sessions separated by a ten-day period associated with a pilot clinical trial study. Recordings included resting periods (eyes open and eyes closed) as well as periods involving a pain management activity. Results Most single alpha-power measures and all within-participant averages of alpha obtained within a session showed high internal consistency (Cronbach’s α > 0.7) and satisfactory-to-excellent re-test reliability (Pearson’s rs > 0.6) of both alpha power and alpha blocking (eyes closed minus eyes open) across repeated conditions. Conclusions EEG alpha power seems mostly reliable and consistent, particularly when participants’ eyes are closed, after a period of habituation, and when alpha measures are averaged as within-participant estimates. Significance This analysis suggests that within-subject averages of EEG alpha are the most reliable for developing indices of chronic knee pain.

Objective Global EEG alpha activity is negatively correlated with skin conductance level (SCL), supporting alpha as an inverse marker of arousal. Frequency Principal Components Analysis (f-PCA) of resting EEG amplitude spectra has demonstrated natural components in the alpha band of healthy persons. This is a preliminary exploration of whether such components differ with arousal, possibly underpinning the anomalous ADHD hypoarousal link to reduced alpha. Method Twenty-seven right-handed undergraduate students participated in three 2 minute blocks of resting eyes-open/closed EEG and SCL: EO1, EC, EO2. For each condition, mean EEG spectra were submitted to separate f-PCAs. Results The inverse alpha/SCL relationship was confirmed for band amplitudes. EO had two alpha components; both correlated negatively with SCL. EC alpha contained four components, but only one had a substantial negative correlation with SCL; two had no relationship, suggesting natural alpha components with different non-arousal functionality in EC. Conclusion Some alpha components in both EC and EO reflect arousal, with other non-arousal components in EC. Our f-PCA approach offers insight into previously-noted alpha anomalies in disorders such as ADHD. Significance This proof of concept demonstration in typical participants may provide the basis for a new research effort in clinical disorders involving atypical arousal patterns.

In this study, neural-signal electroencephalogram (EEG) methods to improve human-building interaction under different indoor air quality conditions were investigated. Experiment was conducted to study correlations between EEG frequency bands and subjective perception as well as task performance. Machine learning-based EEG pattern recognition methods as feedback mechanisms were also investigated. Results showed that EEG theta band (4–8 Hz) correlated with subjective perceptions, and EEG alpha band (8–13 Hz) correlated with task performance. These EEG indices could be utilized as more objective metrics in addition to questionnaire and task-based metrics. For the machine learning-based EEG pattern recognition methods, the linear discriminant analysis (LDA) and support vector machine (SVM) classifiers can classify mental states under different indoor air quality conditions with high accuracy. In general, the EEG theta and alpha bands as more objective indices and the machine learning-based EEG pattern recognition methods as real-time feedback mechanisms have good potential to improve the human-building interaction.

It is aimed at finding the correlation between golfer’s performance and EEG signals from the successful and unsuccessful putts. To address this issue, the inertial motion capture(mocap) system and wireless Emotiv equipment have been introduced to collect simultaneously the golfer’s performance data and EEG signals in 6 right-handed expert golfers and 6 right-handed amateur golfers. Inertial mocap modules were placed on right arm, right leg of subjects and the club-head. Subjects stood upright on a golf green simulator while playing 80 golf putts with Emotiv recording simultaneously. Then, wavelet packet decomposition(WPD) was used for extracting the alpha wave: low-frequency(8–10 Hz) and high-frequency(10–12 Hz). The correlation of alpha rhythm power spectral in two electrodes should be estimated to analyze the relationship between successful and unsuccessful putts and EEG signals. The results of the statistical variance indicated that AF3-AF4(left ahead frontal-right ahead frontal areas) and O1-O2(left occipital-right occipital areas) had a higher spectral correlation of alpha rhythm in successful putts than that in unsuccessful putts. Alpha rhythm (8–12 Hz) in the successful putts was higher than that in the unsuccessful condition and fluctuated obviously. F3-AF3(frontal-ahead frontal areas), F3-O2(left frontal-occipital areas), F4-F8, F4-O2(right frontal-occipital areas) and F4-AF3 had a higher negative correlation of successful putts from -2 s to zero time than that from the -5 s to -2 s of the putting time. P7-AF3(parietal-ahead frontal areas) had a higher negative correlation of both successful putts and unsuccessful putts from -2 s to zero time than that from the -5 s to -2 s of the putting time. P7-O2(parietal-occipital areas) had a higher negative correlation of successful putts from -2 s to zero time than that from the -5 s to -2 s of the putting time. P8-AF3 and P8-O2 had a higher negative correlation of the successful putts from -2 s to zero time than that from the -5 s to -2 s of the putting time. Experimental results of the club-head putting acceleration showed that the putting acceleration of overall high-skilled golfer was more stable than that of amateur golfers’, that had a higher successful rate of putts. Statistical results of putting acceleration of the professional players and amateur players indicated that professional players had a higher successful and stable putts than others. Experimental results demonstrated that alpha rhythm plays a major role in cognition, judgment, sensory and motor.

Working memory contents can be prioritized by retroactively deploying attention within memory. This is broadly interpreted as evidence of a concentration of memory resources to the attended, to-be-remembered stimulus. However, online attentional selection is known to additionally depend on distractor inhibition, raising the viable alternative that attentional deployment in working memory involves inhibitory control processes. Here, we demonstrate that active inhibition plays a central role in the deployment of attention in working memory. We do so using a retroactive cueing paradigm, where a briefly presented memory array is followed by a cue indicating a to-be-remembered target (Experiment 1) or a to-be-forgotten distractor (Experiment 2). We identify discrete indices of target selection and distractor inhibition in lateralized oscillatory activity over visual areas. When a retroactive cue identifies the location of a target, results show rapid decrease of lateral, target-elicited alpha band activity, representing attentional orienting toward the target. This is followed only later by emergence of an increase in distractor-elicited alpha activity, reflecting distractor inhibition. In contrast, when the retroactive cue identifies a distractor, evidence of distractor inhibition emerges first, only later followed by target selection. These results thus demonstrate that separate excitatory and inhibitory processes underlie the deployment of attention on the level of working memory representations.

The allocation of mental workload is critical to maintain cognitive-motor performance under various demands. While mental workload has been investigated during performance, limited efforts have examined it during cognitive-motor learning, while none have concurrently manipulated task difficulty. It is reasonable to surmise that the difficulty level at which a skill is practiced would impact the rate of skill acquisition and also the rate at which mental workload is reduced during learning (relatively slowed for challenging compared to easier tasks). This study aimed to monitor mental workload by assessing cortical dynamics during a task practiced under two difficulty levels over four days while perceived task demand, performance, and electroencephalography (EEG) were collected. As expected, self-reported mental workload was reduced, greater working memory engagement via EEG theta synchrony was observed, and reduced cortical activation, as indexed by progressive EEG alpha synchrony was detected during practice. Task difficulty was positively related to the magnitude of alpha desynchrony and accompanied by elevations in the theta-alpha ratio. Counter to expectation, the absence of an interaction between task difficulty and practice days for both theta and alpha power indicates that the refinement of mental processes throughout learning occurred at a comparable rate for both levels of difficulty. Thus, the assessment of brain dynamics was sensitive to the rate of change of cognitive workload with practice, but not to the degree of difficulty. Future work should consider a broader range of task demands and additional measures of brain processes to further assess this phenomenon.

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.

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 this study was to compare the development of sleepiness during manual driving versus level 2 partially automated driving, when driving on a motorway in Sweden. The hypothesis was that partially auto-mated driving will lead to higher levels of fatigue due to underload. Eighty-nine drivers were included in the study using a 2 ? 2 design with the conditions manual versus partially automated driving and daytime (full sleep) versus night-time (sleep deprived). The results showed that night-time driving led to markedly increased levels of sleepiness in terms of subjective sleepiness ratings, blink durations, PERCLOS, pupil diameter and heart rate. Partially automated driving led to slightly higher subjective sleepiness ratings, longer blink durations, decreased pupil diameter, slower heart rate, and higher EEG alpha and theta activity. However, elevated levels of sleepiness mainly arose from the night-time drives when the sleep pressure was high. During daytime, when the drivers were alert, partially automated driving had little or no detrimental effects on driver fatigue. Whether the negative effects of increased sleepiness during partially automated driving can be compensated by the positive effects of lateral and longitudinal driving support needs to be investigated in further studies. Funding Agencies|ADASME [688900]; Mediator projects - European Unions Horizon 2020 research and innovation programme [814735]; Autoliv Development; SmartEye AB

In two separate recent studies, researchers have reported an association between increases in children's shyness (i.e., social avoidance and inhibition) and decreases on frontal baseline electroencephalogram (EEG) alpha-to-delta ratio (ADR) scores (i.e., Schmidt & Poole, 2018, 2020). Here we attempted to extend these findings by examining whether different types of children's shyness were distinguishable on this same frontal ADR score, which is thought to be one electrocortical proxy of brain maturation. We coded expressions of positive shyness (i.e., co-occurrence of smiling and avoidance behaviors) versus non-positive shyness (i.e., avoidance behaviors) from direct observations during a social presentation speech in children (N = 63; Mage = 10.41 years) and examined these expressions of shyness in relation to the children's frontal baseline EEG ADR scores. We found preliminary evidence that children expressing positive shyness exhibited the lowest frontal baseline EEG ADR score (i.e., ostensibly less brain maturation) relative to children expressing non-positive shyness and low levels of shyness. We speculate that relatively less frontal brain maturation may be linked to some adaptive features of shyness.

Background EEG mu rhythm suppression is assessed in experiments on the execution, observation and imagination of movements. It is utilised for studying of actions, language, empathy in healthy individuals and preservation of sensorimotor system functions in patients with schizophrenia and autism spectrum disorders. While EEG alpha and mu rhythms are recorded in the same frequency range (8−13 Hz), their specification becomes a serious issue. The new method is based on the spatial and functional characteristics of the mu wave, which are: (1) the mu rhythm is located over the sensorimotor cortex; (2) it desynchronises during movement processing and does not respond on the eyes opening. In EEG recordings, we analysed the mu rhythm under conditions with eyes opened and eyes closed (baseline), and during a motor imagery task with eyes closed. EEG recordings were processed by principal component analysis (PCA). Results The analysis of EEG data with the proposed approach revealed the maximum spectral power of mu rhythm localised in the sensorimotor areas. During motor imagery, mu rhythm was suppressed more in frontal and central sites than in occipital sites, whereas alpha rhythm was suppressed more in parietal and occipital sites. Mu rhythm desynchronization in sensorimotor sites during motor imagery was greater than alpha rhythm desynchronization. The proposed method enabled EEG mu rhythm separation from its mix with alpha rhythm. Conclusions EEG mu rhythm separation with the proposed method satisfies its classical definition.

Objective The present study examined whether neural indices of working memory maintenance differ between young adults with ADHD and their healthy peers (Study 1), and whether this neural index would change after working memory training (Study 2). Methods Study 1 involved 136 college students with ADHD and 41 healthy peers (aged 18–35 years) and measured their posterior alpha activity during a visual delayed-match-to-sample task using electroencephalography (EEG). Study 2 involved 99 of the participants with ADHD who were randomized into a standard-length or shortened-length Cogmed working memory training program or a waitlist control group. Results The ADHD group tended to be less accurate than the peers. Similarly, the ADHD group exhibited lower posterior alpha power at a trend level compared to their healthy peers. There were no training effects on participants’ performance and only marginal increases in posterior alpha power in training groups compared to the waitlist group. Conclusions Considering that the training effects were small and there was no load and dose effect, we conclude that the current study provides no convincing evidence for specific effects of Cogmed. Significance These findings provide unique insights into neuroplasticity, or lack thereof, with near-transfer tasks in individuals with ADHD.

Previous research has indicated that in several domains, women and men may use different cognitive processes along with different neurophysiological activation to achieve similar behavioral performance. The present study extended this line of research to the novel field of soccer playing. In female and male active soccer players, we investigated patterns of brain activation and functional connectivity of brain networks during imagination of creative soccer moves, using EEG methods that are well established in creativity research. Participants were presented with scenarios taken from real soccer games. Female and male soccer players showed comparable creative performance in their imagined moves to score a goal, which was rated by top qualified experts (UEFA A licensed soccer coaches). Notwithstanding, they differed with respect to their brain activation and functional connectivity of brain networks. While men exhibited relatively higher parietal/occipital task-related EEG alpha power, women showed significantly higher within-hemisphere functional coupling in the upper alpha band. The findings add important new evidence to the field of cognitive gender research in an applied, sports-related domain of creative cognition.

In a community-based sample of 104 infants and their mothers, we hypothesized a pathway from postnatal maternal symptoms of depression to child emotion dysregulation, and tested at 6 months of age the mediation role of alpha asymmetry at frontal and parietal sites. We recorded infant resting-state EEG at 6 months of age. Child emotion dysregulation was measured at 24 months by the Child Behavior Checklist Dysregulation Profile derived from the CBCL 1½-5. Maternal depression symptoms were scored 6 months after the delivery by the Anxious/Depressed scale of the Adult Self-Report. We used structural equation modeling to test the mediation model from maternal depression symptoms to child emotion dysregulation mediated by frontal and parietal alpha asymmetry. The mediation model provided an excellent fit to the data [χ2(3) = 3.088, p = .378; RMSEA = .017, CFI = .1.00; SRMR = 0.040] and explained 23.3% of the variance in child emotion dysregulation. The indirect path via parietal alpha asymmetry was significant (β = .065; SE = .033; 95% CI = .001–.139; p = .048), i.e. greater levels of maternal depression symptoms predicted left parietal alpha asymmetry, which predicted higher levels of child emotion dysregulation. The direct effect, i.e. the pathway linking maternal depression symptoms and child emotion dysregulation above and beyond the indirect effects, was also significant. We found evidence for a partial mediation role of left parietal alpha asymmetry in a longitudinal pathway from postnatal maternal symptoms of depression to child emotion dysregulation, providing support for left parietal asymmetry as an index of biological vulnerability to emotion dysregulation in the first years of life.

Affective dispositions may shape students' typical ways of coping when faced with demanding performance situations in their educational lives. We recorded frontal EEG alpha asymmetry responses in psychology students (n = 62) during the course of a scenario designed to simulate a real examination, which required oral explanation of statistical concepts. While students with lower levels of trait positive affect (PANAS) showed relative right hemispheric activation, sustained relative left hemispheric activation was observed in students with higher levels of trait positive affect. In line with relevant models of frontal brain asymmetry, the findings suggest that students' coping behaviors in the context of academic performance situations are in part instantaneously initiated, which is reflected in spontaneous activation of relative approach versus avoidance motivation. Independently of negative affect and momentary affective states, trait positive affectivity seems to be linked to recruitment of brain processes supporting a more adaptive response in that matter.

Resting and task-related EEG alpha are used in studies of cognition and psychopathology. Although Laplacian methods have been applied, apprehensions about loss of global activity dissuade researchers from greater use except as a supplement to reference-dependent measures. The unfortunate result has been continued reliance on reference strategies that differ across labs, and a systemic preference for a montage-dependent average reference over true reference-free measures. We addressed these concerns by comparing resting- and task-related EEG alpha using three EEG transformations: nose- (NR) and average-referenced (AR) EEG, and the corresponding CSD. Amplitude spectra of resting and prestimulus task-related EEG (novelty oddball) and event-related spectral perturbations were scaled to equate each transformation. Alpha measures quantified for 8–12 Hz bands were: 1) net amplitude (eyes-closed minus eyes-open) and 2) overall amplitude (eyes-closed plus eyes-open); 3) task amplitude (prestimulus baseline) and 4) task event-related desynchronization (ERD). Mean topographies unambiguously represented posterior alpha for overall, net and task, as well as poststimulus alpha ERD. Topographies were similar for the three transformations, but differed in dispersion, CSD being sharpest and NR most broadly distributed. Transformations also differed in scale, AR showing less attenuation or spurious secondary maxima at anterior sites, consistent with simulations of distributed posterior generators. Posterior task alpha and alpha ERD were positively correlated with overall alpha, but not with net alpha. CSD topographies consistently and appropriately represented posterior EEG alpha for all measures.

Several studies reveal that unpleasant pictures elicit higher beta and gamma responses than pleasant and/or neutral pictures; however, the effect of stimulation design (block or random) has not been studied before. The aim of the study is to analyze the common and distinct parameters of affective picture perception in block and random designs by means of analysis of high frequency oscillatory dynamics (beta and gamma). EEG of 22 healthy subjects was recorded at 32 locations. The participants passively viewed 120 emotional pictures (10 x 4 unpleasant, 10 x 4 pleasant, 10 x 4 neutral) in block and random designs. The phase-locking and power of event related beta (14-28 Hz) and gamma (29-48 Hz) oscillations were analyzed for two different time windows (0-200 ms/200-400 ms). Statistical analysis showed that in the 0-200 ms time window, during the block design, unpleasant stimulation elicited higher beta phase-locking and beta power than the pleasant and neutral stimulation (p

Exploring EEG alpha oscillations has generated considerable interest, in particular with regards to the role they play in cognitive, psychomotor, psycho-emotional and physiological aspects of human life. However, there is no clearly agreed upon definition of what constitutes ‘alpha activity’ or which of the many indices should be used to characterize it. To address these issues this review attempts to delineate EEG alpha-activity, its physical, molecular and morphological nature, and examine the following indices: (1) the individual alpha peak frequency; (2) activation magnitude, as measured by alpha amplitude suppression across the individual alpha bandwidth in response to eyes opening, and (3) alpha “auto-rhythmicity” indices: which include intra-spindle amplitude variability, spindle length and steepness. Throughout, the article offers a number of suggestions regarding the mechanism(s) of alpha activity related to inter and intra-individual variability. In addition, it provides some insights into the various psychophysiological indices of alpha activity and highlights their role in optimal functioning and behavior.

Research has shown that chewing gum improves attention, although the mechanism for this effect remains unclear. This study investigated the effects and after-effects of chewing gum on vigilance, mood, heart rate and EEG. Participants completed a vigilance task four times; at baseline, with or without chewing gum, and twice post-chewing. EEG alpha and beta power at left frontal and temporal lobes, subjective mood and heart rate were assessed. Chewing gum quickened reaction time and increased the rate of correct target detections, although correct detections fell during the second post-chewing task. Chewing gum heightened heart rate, but only during chewing. Gum also increased beta power at F7 and T3 immediately post-chewing, but not following the post-chewing tasks. The findings show that chewing gum affects several different indicators of alertness.

The influence of the illumination condition on our cognitive-performance seems to be more critical in the modern life, wherein, most people work in an office under a specific illumination condition. However, neurophysiological changes in a specific illumination state and their cognitive interpretation still remain unclear. Thereby, in the present study, the effect of different illumination conditions on the same cognitive performance was evaluated particularly by EEG wavelet analyses. During a sustained attention task, we observed that the higher illumination condition yielded significantly lower parietal tonic electroencephalogram (EEG) alpha activity before the presentation of the probe digit and longer reaction times, than that of the other illumination conditions. Although previous studies suggest that lower prestimulus EEG alpha activity is related to higher performance in an upcoming task, the reduced prestimulus alpha activity under higher illumination was associated with delayed reaction times in the present study. Presumably, the higher background illumination condition seems to be too bright for normal attentional processing and distracted participants' attention during a sustained attention task. Such a bottom–up effect by stimulus salience seemed to overwhelm a prestimulus top-down effect reflected in prestimulus alpha power during the bright background condition. This finding might imply a dynamic competition between prestimulus top-down and poststimulus bottom–up processes. Our findings provide compelling evidence that the illumination condition substantially modulates our attentional processing. Further refinement of the illumination parameters and subsequent exploration of cognitive-modulation are necessary to facilitate our cognitive performance.

article i nfo The stimulus-evoked response is the principle measure used to elucidate the timing and spatial location of human brain activity. Brain and behavioural responses to pain are influenced by multiple intrinsic and extrin- sic factors and display considerable, natural trial-by-trial variability. However, because the neuronal sources of this variability are poorly understood the functional information it contains is under-exploited for under- standing the relationship between brain function and behaviour. We recorded simultaneous EEG-fMRI dur- ing rest and noxious thermal stimulation to characterise the relationship between natural fluctuations in behavioural pain-ratings, the spatiotemporal dynamics of brain network responses and intrinsic connectivity. We demonstrate that fMRI response variability in the pain network is: dependent upon its resting-state func- tional connectivity; modulated by behaviour; and correlated with EEG evoked-potential amplitude. The pre-stimulus default-mode network (DMN) fMRI signal predicts the subsequent magnitude of pain ratings, evoked-potentials and pain network BOLD responses. Additionally, the power of the ongoing EEG alpha os- cillation, an index of cortical excitability, modulates the DMN fMRI response to pain. The complex interaction between alpha-power, DMN activity and both the behavioural report of pain and the brain's response to pain demonstrates the neurobiological significance of trial-by-trial variability. Furthermore, we show that multi- ple, interconnected factors contribute to both the brain's response to stimulation and the psychophysiological emergence of the subjective experience of pain.

Objective Studies indicate that the change from closed to open eyes in a resting condition results in an increase in skin conductance level (SCL) and a global decrease in EEG alpha activity, both indicative of increased arousal. Other studies show that ingestion of caffeine also produces SCL increase and alpha reduction. This study investigated the additivity of the effects of these two independent arousing variables. Method EEG activity and SCL were recorded from 22 university students during both eyes-closed and eyes-open resting conditions, under the action of both caffeine and placebo, in a counterbalanced randomised double-blind study. Results SCL increased significantly from eyes-closed to eyes-open conditions, and from placebo to caffeine, with no interaction. Global reductions in EEG alpha amplitude were apparent with opening of the eyes and caffeine ingestion; again, there was no interaction. Caffeine had a larger effect than opening the eyes on SCL, but their relative effect sizes were reversed in alpha. The two dependent measures showed the predicted negative correlation in both eyes-closed placebo and eyes-open caffeine conditions, with the latter substantially reduced relative to the former. Conclusions Caffeine and opening the eyes have additive effects on two measures of arousal, increasing SCL and reducing global EEG alpha. However, the independent variable effects are not equivalent, suggesting that one or both measures reflect additional non-arousal processes. Significance As caffeine is widely used by both children and adults, knowledge of the additivity of arousal effects of caffeine and opening the eyes is important in controlling participant state in EEG studies. The current results confirm the use of mean global alpha amplitude as a measure of resting-state arousal, but also point to non-arousal effects of visual input.

The importance to recognize a learner's Learning Style (LS) is ever-essential as to substantiate success in a teaching and learning process. At the same time, the learner's IQ and personality traits such as Stress also being actively investigated in educational research as educationists consistently attempted to understand learners in a more adept way. Nevertheless, the effort was usually confined to psychoanalysis test. With the emergence of Electroencephalography (EEG) technology, learner's brain characteristics could be accessed directly and the outcome may well hand-in-hand supported the conventional test. In this study, the participants (n= 80) are grouped to the LS of Diverger, Assimilator, Converger or Accommodator using the Kolb's Learning Style Inventory (KLSI). Subsequently, their brain signals were then recorded using EEG at resting baseline state of Open Eyes and Closed Eyes. A statistical tool of SPSS 16 was used for data analysis purposes. Using the Two Step Cluster analysis, the participants’ EEG datasets were 100% classified to the corresponding LS. Then, EEG Alpha band was selected to link between LS, IQ and Stress. The study concluded that Diverger is the LS with highest IQ while Converger and Diverger are the LS that prone to Stress.

The authors examined the long-term stability of resting regional EEG alpha asymmetry and power (i.e., markers of affective style) in a sample of 15 stable community outpatients with schizophrenia. We found that resting frontal EEG alpha asymmetry and power both remained stable over a 36-month interval before and after controlling for patients' positive and negative symptoms. This same pattern was not evidenced in the posterior EEG sites. These findings provide preliminary evidence of a putative psychophysiological trait marker of affective style in stable community outpatients with schizophrenia.

A moving base driving simulator experiment was carried out in order to investigate the effects of milled rumble strips on driver fatigue. There were rumble strips both at the edge line and centre line. Four different physical designs of milled rumble strips (yielding noise values from 1.5 to 16 dBA) and two placements on shoulder were used in the experiment. Sound and vibrations from real milled rumble strips were reproduced in the simulator. In total 35 regular shift workers drove during the morning hours after a full night shift. The main results showed an increase in sleepiness indicators (EEG alpha/theta activity, eye closure duration, standard deviation of lateral position, subjective sleepiness) from start to before hitting the rumble strip, an alerting effect in most parameters (not subjective sleepiness) after hitting the strip. The alertness enhancing effect was, however, short and the sleepiness signs returned 5 min after the rumble strip hit. Essentially no effects were seen due to type of strip. It was concluded that various aspects of sleepiness are increased before hitting a rumble strip and that the effect is very short-lived. Type of strip, as used in the present study did not have any effect.

In order to test the hypothesis that prestimulus alpha activity reflects top-down inhibitory processing, EEG was recorded from 16 subjects performing a color and a shape discrimination task. Both tasks required the inhibition of the task-irrelevant feature. Longer reaction times and P3 latencies showed that the shape task was more difficult than the color task. We suppose that these different task-difficulties are due to a higher salience of the color feature as compared to the shape feature. Interestingly, we observed significantly higher prestimulus total alpha activity in the shape task than the color task. We concluded that the inhibition of the more salient color feature in the shape task resulted in enhanced prestimulus alpha activity. Such a relationship between prestimulus alpha and poststimulus performance implies that prestimulus alpha reflects prestimulus top-down processing for preparing subsequent task-performance. Since we observed the 'task' effect of prestimulus alpha activity also in reaction times and in P3 latencies, prestimulus alpha seems to predict such poststimulus responses. Consequently, prestimulus ongoing alpha activity probably reflects top-down information and modulates subsequent poststimulus responses.

Objective : We aimed to examine the relation between the phase of electroencephalogram (EEG) alpha activity at stimulus onset and event-related potentials (ERPs) in a fixed-inter-stimulus interval auditory ‘oddball’ task, using a novel conceptualisation of orthogonal phase effects (cortical negativity versus positivity, negative driving versus positive driving, waxing versus waning). Methods : EEG responses to button-press targets, from 14 subjects presented with 4 blocks of 150 stimuli (50% target probability), were examined. Pre-stimulus alpha activity (8–13 Hz) at Pz was assessed for each trial by digital filtering of the EEG. The alpha cycle at Pz, starting from a negative-going zero crossing, was used to sort trials into 4 phases, for which ERPs were derived from both the filtered and unfiltered EEG activity at Fz, Cz, and Pz. Results : Preferred brain states in this paradigm were indicated by an 8% greater occurrence of negative driving than positive driving, and a 33% greater occurrence of waxing than waning phases. Negative driving phases were associated with increased N1 latencies and decreased N2 amplitudes. Latencies of N1 and P2 were reduced in waxing phases. These reflected systematic changes in alpha frequency and amplitude at stimulus onset. Conclusions : In a fixed-inter-stimulus interval paradigm, component frequencies of the EEG are dynamically adjusted in order to provide brain states at the moment of stimulus presentation which differentially affect the EEG correlates of stimulus processing. Significance : The results add to our understanding of the genesis of the ERP, indicating the importance of the dynamic interplay between instantaneous EEG activity and stimulus processing reflected in the ERP.

Neurophysiological measures, such as decreased P300 amplitude and altered EEG alpha activity, have been associated with increased alcoholism risk. The purpose of the present study was to extend the assessment of the neurophysiological indices associated with alcohol consumption to a recently developed mouse model of high ethanol consumption, the first replicate line of high alcohol preferring (HAP-1) and low alcohol preferring (LAP-1) mice. Male HAP-1, LAP-1, and HS mice from the Institute for Behavioral Genetics at the University of Colorado Health Science Center (i.e., HS/Ibg mice) were implanted with cortical electrodes. EEG activity, and event related potentials (ERPs) were then examined. Following electrophysiological assessment, ethanol preference was assessed to examine the relationship between neurophysiological indices and ethanol consumption. EEG analyses revealed that HAPs and HS/Ibgs had greater peak frequency in the 2-4-Hz band and lower peak frequency in the 6-8- and 1-50-Hz bands of the cortical EEG compared to LAPs. Compared to HAPs, LAPs and HS/Ibgs had decreased peak EEG frequency in the 8-16-Hz band. Decreased parietal cortical power from 8 to 50 Hz was associated with high initial ethanol preference in HAP mice. In regards to ERPs, P1 amplitude was greater in HAPs compared to both LAPs and HS/Ibgs and the P3 latency in LAPs was decreased compared to both HAPs and HS/Ibgs. As expected, HAPs consumed more ethanol and had higher ethanol preference than LAPs and HS/Ibgs. There were no significant differences in ethanol intake or preference between HS/Ibgs and LAPs. These data indicate that selective breeding of the HAP and LAP lines has resulted in the divergence of EEG and ERP phenotypes. The differences observed suggest that increased cortical P1 amplitude and altered cortical EEG activity in the 8-50-Hz frequency range may be neurophysiological 'risk factors' associated with high ethanol consumption in mice. Decreased P3 latency in LAPs compared to HAPs and HS/Ibgs mice may be a 'protective factor'.

The hypothesis was tested whether alpha power in different subbands (lower-1, lower-2, and upper alpha) is selectively related to intelligence. For 74 subjects, the EEG was recorded during a resting session. Two different intelligence tests (LGT-3 and IST-70) were performed. We found a strong positive correlation between intelligence and alpha power. Large differences between the two intelligence tests and alpha power subbands were obtained. Whereas the upper alpha band shows the strongest correlation with the IST-70, power in the two lower alpha bands tend to show a more consistent relationship with the LGT-3. Considering the fact that the IST-70 has a strong emphasis on semantic memory demands, whereas the LGT-3 focuses more on the ability to learn new material, we conclude that upper alpha is related to the ability to process semantic information, whereas the two lower alpha bands are associated with attentional demands that dominate during the encoding of new information.

Objectives It is known that sex hormones affect the brain in women. However, there are not enough studies that explain the relationship between sex hormone fluctuations during menstrual cycle and brain waves. Our aim in this study is to show the effects of sex hormone fluctuations on the EEG alpha response in menstrual phase and follicular phase. Methods EEG recordings on resting state was performed in 11 healthy volunteer women in two different phases (menstrual and follicular). The alpha power values were analyzed by artifact-free 45 epochs lasting 2 s. Blood samples of volunteers were drawn simultaneously and estradiol, progesterone, FSH and LH were analyzed with electrochemiluminesence immunoassay method. The assessment of alpha power values and its relationship with hormone levels were performed in two phases of menstrual cycle. Results The highest difference between the mean power value in the menstrual phase (46.06) and the follicular phase (36.08) was obtained from the parietal region of the brain. At the same time, the lowest difference between the mean power value (41.06) in the menstrual phase and the follicular phase (39.37) was obtained from the occipital region of the brain. Estrodiol, progesterone, FSH, LH mean levels were 30.2 pg/ml; 0.17 ng/ml; 6.7 mIU/ml; 5.43 mIU/ml in the menstrual cycle and 123.9 pg/ml; 0.23 ng/ml; 7.3 mIU/ml; 17.12 mIU/ml in the follicular phase, respectively. Conclusion We found that increased estradiol levels in response to the elevation of LH levels in blood during follicular phase resulted in a decrease in the power of the alpha waves from the parietal region. Sex hormone fluctuations in menstrual cycle has minimal effect on the EEG alpha response in occipital region.

This study compared EEG and autonomic patterns during transcending to ‘other’ experiences during Transcendental Meditation (TM) practice. To correlate specific meditation experiences with physiological measures, the experimenter rang a bell three times during the TM session. Subjects categorized their experiences around each bell ring. Transcending, in comparison to ‘other’ experiences during TM practice, was marked by: (1) significantly lower breath rates; (2) higher respiratory sinus arrhythmia amplitudes; (3) higher EEG alpha amplitude; and (4) higher alpha coherence. In addition, skin conductance responses to the experimenter-initiated bell rings were larger during transcending. These findings suggest that monitoring patterns of physiological variables may index dynamically changing inner experiences during meditation practice. This could allow a more precise investigation into the nature of meditation experiences and a more accurate comparison of meditation states with other eyes-closed conditions.

Brain processes elicited by speech were studied in 10 right-handed subjects by means of examining the desynchronization and synchronization of the 8–10 Hz and 10–12 Hz EEG alpha frequency bands. The subjects listened to an auditorily presented 5 min text passage. The text was presented both forward and backward. Listening to the text forward elicited alpha desynhronization in both of the frequency bands studied, whereas listening to the same text presented backward elicited synchronization in the 10–12 Hz frequency band only. Listening to the text forward elicited greater desynchronization than listening to the text backward. In the 10–12 Hz frequency band, listening to the text forward elicited desynchronization whereas listening to the same text backward elicited synchronization. This dissociation was not observed in the 8–10 Hz frequency band. The results suggest that the lower and upper alpha bands differ such that the 10–12 Hz frequency band exhibits reactivity to the presence of linguistic content while the 8–10 Hz band shows an unspecific response.

EEG alpha power covaries with changes in visual input and with changes in other aspects of cortical processing. We present an synopsis of three experiments that demonstrate these effects. A concurrent analysis of the EEG dimension indicates that the dynamics of EEG alpha may result from at least two different mechanisms. © 1997 Elsevier Science B.V.

In three experiments, differences in EEG alpha activity between gifted (mean IQ = 137) and average (mean IQ = 105) individuals were investigated. EEG activity was monitored over 16 scalp locations. A fast Fourier transform was performed on 15 artifact-free 2-second chunks of data to derive a spectral power average in the alpha band (7.5–13 Hz). In the first experiment, EEG of gifted and average individuals during two relaxation phases—eyes closed and eyes open—was recorded. Gifted individuals showed higher EEG alpha power only while resting with eyes open. In the second experiment, gifted and average individuals solved two problems that were divided into phases of problem solving and preparing for problem solving (reading, making a plan of how to solve the problem). Significant differences were obtained only for the problem-solving stages. Gifted individuals in comparison with average ones showed higher alpha power (less mental effort) while solving the two problems. The third experiment investigated whether the lower mental activity displayed by gifted individuals was related to their ability to form more abstract schemata. For that purpose EEG was recorded while gifted and average individuals memorized lists of words and pictures that either allowed, or did not allow, for classification into more abstract categories. For both types of lists, gifted individuals displayed higher alpha power than average ones. The results obtained confirm the hypothesis that the higher EEG alpha power during information processing displayed by gifted individuals may derive from the nonuse of many brain areas not required for the problem at hand.

The electroencephalogram (EEG) reflects stable individual differences in brain function and therefore can be a powerful instrument for exploring the biological basis of intelligence. However, the question of whether the EEG, and, in particular, the alpha rhythm frequency (AF) is related to intelligence in normal adults remained unclear. We analyzed EEG spectra and performance on different intelligence tests in 101 healthy males aged 20 to 45 (M IQ = 119.2; SD = 9.4) with a special regard to brain region and specific mental abilities. Scores on Raven's Standard Progressive Matrices (SPM) correlated positively with AF in prefrontal and frontal regions. Verbal abilities factors derived from the verbal subtests of Amthauer's Intelligence Structure Test (IST) and Horn's LPS test of mental performance correlated positively with both mean and peak AF factors (r = .34 and .35, correspondingly; p < .001). However, AF did not show any significant relationship with the factors of general (g factor), spatial, and arithmetic abilities.

Quantitative electroencephalographic (QEEG) analyses are presented for a group of 90 subjects recovering from polysubstance abuse (median = 90 days abstinent) who preferentially used cocaine. QEEGs showed significant decreases from normal in both absolute and relative delta power and decreased theta power in both absolute and relative power. Significantly increased relative but not absolute alpha and beta power was found. Asymmetry of frontal delta, theta, and alpha power differed from normal with right power greater than left. Globally, reduced interhemispheric coherence was found in delta and theta bands and frontally in the beta band. An atypical EEG pattern was observed in about half of the subjects. This was a paroxysmal-like EEG alpha pattern reminiscent of vertex waves typically associated with drowsiness but lacking the waxing and waning of alpha and the slow lateral eye drift associated with drowsiness.

The present study was conducted to determine if there is a neurophysiological correlate of marihuana-induced good effects or euphoria. Three groups of 6 male occasional marihuana smokers were prepared for electroencephalographic (EEG) recording and smoked either placebo or marihuana cigarettes containing 1.26% or 2.53% Δ 9 -tetrahydrocannabinol ( Δ 9 -THC) in a controlled laboratory setting. Using a continuously available non-verbal joystick device and a questionnaire, subjects reported changes in their subjective mood state while EEG activity was continuously recorded. Subjects reported multiple episodes of intense good effects or euphoria during the first 15 min after marihuana. These episodes of euphoria occurred while plasma Δ 9 -THC levels were rapidly rising. EEG alpha power during these discrete episodes of euphoria was significantly higher suggesting that these transient EEG changes may reflect a neurophysiological correlate of the reinforcing effects of marihuana.

The EEG alpha asymmetry technique was used to gather data during the perception, formulation and production phases of a quasi-conversational speech task which controlled imagery value of verbal stimuli presented during the perceptual phase. Data were gathered from both anterior and posterior speech/language areas in adult male stutterers and male and female nonstutterers. Control subjects showed significantly more posterior left hemispheric alpha suppression for all conditions of the quasi-conversational speech task. Female subjects were found to have greater anterior right hemispheric alpha suppression, a finding not found for either of the two male groups. Stutterers demonstrated no significant hemispheric activation differences between the right and left hemispheres. These findings are discussed with respect to prior findings about the distinctive nature of hemispheric processing of meaningful information for the three subject groups and the need to consider stimulus, task and subject variables in the interpretation of hemispheric processing research.

s / Brain Stimulation 8 (2015) 326e342 337 Introduction: The inter-individual variability is one of topics in the human neuro-plasticity induced by NIBS. The aim of this paper was to study the inter-individual variability of the humanmotor cortical plasticity induced by quadripulse stimulation (QPS). Methods: We performed QPS 5 for LTP induction and QPS 50 for LTD induction in 33 healthy volunteers (age 38+ 7 years old). To obtain the normal range of the size ratio in the control condition, we recorded MEPs for 30 minutes in 15 of the above subjects without any interventions. We obtained the average size ratio (5-30 minutes) by averaging the size ratios at the all times after QPS from 5 minutes to 30 minutes after QPS, and used that ratio for the following evaluations. Results