Electroencephalographic Power Research Articles

EMCI: A Novel EEG-Based Mental Workload Assessment Index of Mild Cognitive Impairment.

As aging deepens, early detection of mild cognitive impairment (MCI) is increasingly important to prevent Alzheimer Dementia (AD) and improve the quality of life of older adults. In recent years, a large number of studies focus on the abnormal brain cognitive function of MCI, while ignoring the quantitative evaluation of MCI's mental workload. In this study, we propose a workload index for MCI screening, named EMCI, which is a linear discriminant cumulative estimate of subjects' electroencephalography (EEG) power spectra in α and β rhythms. Then, we design a matched prototype system to verify the effectiveness of EMCI. The results show that the EMCI is sensitive to changes of subjects' mental workload, and is significantly lower in MCI than in HC (Health control), which may be precisely caused by cognitive dysfunction. The proposed EMCI index can be used for online assessment of mental workload in older adults, which can help achieve quick screening of MCI and provide a critical window for clinical treatment interventions.

Enlarged Interior Built Environment Scale Modulates High-Frequency EEG Oscillations.

There is currently no robust method to evaluate how built environment design affects our emotion. Understanding emotion is significant, as it influences cognitive processes, behavior, and wellbeing, and is linked to the functioning of physiological systems. As mental health problems are becoming more prevalent, and exposure to indoor environments is increasing, it is important we develop rigorous methods to understand whether design elements in our environment affect emotion. This study examines whether the scale of interior built environments modulate neural networks involved in emotion regulation. Using a Cave Automatic Virtual Environment (CAVE) and controlling for indoor environmental quality (IEQ), 66 adults (31 female, aged 18-55) were exposed to context-neutral enclosed indoor room scenes to understand whether built environment scale affected self-report, autonomic nervous system, and central nervous system correlates of emotion. Our results revealed enlarged scale increased electroencephalography (EEG) power in the β bandwidth. Frontal midline low-γ and high-γ power were also found to increase with enlarged scale, but contrary to our hypothesis, scale did not modulate frontal midline power or lateralization in the θ or α bandwidths. We did not detect an effect of scale on autonomic indicators or self-reported emotion. However, we did find increased range in skin conductance response (SCR) and heart rate variability (HRV) to the built environment conditions. This study provides a rigorous empirical framework for assessing the environmental impact of a design characteristic on human emotion and suggests that measures of high-frequency oscillations may provide a useful marker of the response to built environment.

Resting-state electroencephalography of neural oscillation and functional connectivity patterns in late-life depression

BackgroundThe clinical manifestations of late-life depression (LLD) are highly heterogeneous. Currently, abnormal characteristics of resting-state electroencephalography (EEG) power and functional connectivity are considered trait markers of depressive symptoms in major depression. However, the relationship between EEG spectral features and functional connectivity in LLD remains unknown. MethodsForty-one patients with LLD and 44 participants without depression underwent an eyes-closed resting-state EEG. EEG power spectra, alpha asymmetry, and functional connectivity were calculated and analyzed. ResultsAlthough alpha frontal asymmetry and cortical functional connectivity between the two groups showed no significant differences, the LLD group exhibited abnormal neural oscillation patterns of higher beta frequency activity in the parietal, central, and occipital lobes while alpha activity was increased in the parietal central electrodes. LimitationsThe number of EEG electrodes used in this study was low, and the sample size was limited. ConclusionsIncreased alpha and beta frequency band powers were observed in patients with LLD. These abnormal patterns may be associated with a disturbed balance of cortical excitation, inhibition, and hyperactivity. In the future, a neurofeedback protocol based on the findings of neural oscillation patterns in certain types of LLD should be explored.

Picture-word interference in language production studies: Exploring the roles of attention and processing times.

The picture-word interference paradigm (participants name target pictures while ignoring distractor words) is often used to model the planning processes involved in word production. The participants' naming times are delayed in the presence of a distractor (general interference). The size of this effect depends on the relationship between the target and distractor words. Distractors of the same semantic category create more interference (semantic interference), and distractors overlapping in phonology create less interference (phonological facilitation). The present study examined the relationships between these experimental effects, processing times, and attention in order to better understand the cognitive processes underlying participants' behavior in this paradigm. Participants named pictures with a superimposed line of Xs, semantically related distractors, phonologically related distractors, or unrelated distractors. General interference, semantic interference, and phonological facilitation effects were replicated. Distributional analyses revealed that general and semantic interference effects increase with naming times, while phonological facilitation decreases. The phonological facilitation and semantic interference effects were found to depend on the synchronicity in processing times between the planning of the picture's name and the processing of the distractor word. Finally, electroencephalographic power in the alpha band before stimulus onset varied with the position of the trial in the experiment and with repetition but did not predict the size of interference/facilitation effects. Taken together, these results suggest that experimental effects in the picture-word interference paradigm depend on processing times to both the target word and distractor word and that distributional patterns could partly reflect this dependency. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Study on the Effect of Mentha × piperita L. Essential Oil on Electroencephalography upon Stimulation with Different Visual Effects.

Essential oils have long been used to fight infections and treat various diseases. Peppermint (Mentha × piperita L.) is an herbal medicine that has been widely used in daily life since ancient times, and it has a wide range of applications in food, cosmetics, and medicine. Mint oil is refreshing because of its cool and comfortable smell; therefore, it is often used in ethnopharmacological studies. The present study investigated the effects of peppermint essential oil in electroencephalographic activity response to various visual stimuli. The electroencephalographic changes of participants during peppermint essential oil inhalation under white, red, and blue colour stimulations were recorded. A rapid Fourier transform analysis was used to examine the electroencephalograph power spectra of the various microstates induced by inhaling the oils. Peppermint essential oil had various effects on the brain when subjected to different visual stimuli. Alpha waves increased in the prefrontal area in the white-sniffing group, which facilitated learning and thinking. In the blue-sniffing group, the changes were less pronounced than those in the red group, and the increased alpha wave activity in the occipital area was more controlled, indicating that the participants’ visual function increased in this state. Based on EEG investigations, this is the first study to indicate that vision influences the effects of peppermint essential oils. Hence, the results of this study support the use of essential oils in a broader context to serve as a resource for future studies on the effects of different types of essential oils.

Exploring resting frontal EEG and reflective functioning in maternal substance use.

Maternal substance use is associated with altered neural activity and poor offspring outcomes, which may be facilitated by suboptimal caregiving in the form of impaired parental reflective functioning (PRF). To investigate these associations, the resting-state frontal electroencephalography (EEG) power of 48 substance-using mothers and 37 non-substance-using mothers were examined, specifying seven frequency bands: delta, theta, alpha, alpha1, alpha2, beta, and gamma. Substance-using mothers exhibited enhanced beta and gamma spectral power compared to non-substance-using mothers, potentially reflecting higher arousal states in substance-using mothers. There were no between-group differences in any component of PRF (i.e., levels of pre-mentalizing, certainty, and interest and curiosity). Whole-sample analyses revealed significant positive correlations between pre-mentalizing and delta spectral power. Taken together, these findings suggest potential neural correlates of maternal substance use and PRF, providing an important next step into examining associations between maternal substance use and poor child outcomes.

0092 The Effects of Slow-Oscillatory Galvanic Vestibular Stimulation on Sleep Physiology in Healthy Humans

Abstract Introduction Recent studies have demonstrated that rocking promotes sleep in animals and humans. The application of an alternating current galvanic vestibular stimulation (GVS) can elicit body sway like rocking sensation. Here, we examined the effects of slow-oscillatory GVS, which can evoke the virtual rocking sensation in the brain, on objective and subjective sleep quality in healthy young adults. Methods We studied 14 healthy subjects (age: 22.7 p/m 1.4 years) who underwent 3 nap conditions (adaptation, sham [SHAM], and stimulation [STIM]), where SHAM and STIM were randomly allocated with a 1-week interval in general. The polysomnographic recordings were started at 2 pm and time in bed was restricted to 90 min for all subjects. In both conditions, electrodes were placed on both mastoids for GVS; in STIM condition, the slow-oscillatory (0.25 Hz sinusoidal) GVS was applied throughout the nap period with a current intensity of approximately 80% of sensory thresholds of each subject. The pattern of center of pressure during quiet standing was also measured using a force plate, with or without the same slow-oscillatory GVS. We analyzed sleep variables and electroencephalographic (EEG) spectral power and compared them between STIM and SHAM. Subjective sleep quality was also measured and compared between STIM and SHAM. Results We confirmed that subsensory slow-oscillatory GVS induced body sway corresponding to the stimulation frequency for all subjects. We found that sleep latency was significantly shorter and total sleep time as well as N2 duration were significantly longer in STIM than in SHAM. N3 duration did not differ significantly between the conditions. EEG power spectrum densities in delta, theta, and sigma bands were significantly greater in STIM than in SHAM. Subjective sleep quality was significantly better in STIM than in SHAM. Conclusion We demonstrated that subsensory slow-oscillatory GVS facilitated wake-sleep transition and improved objective and subjective sleep quality. The results suggest that weak periodic inputs into vestibular systems promote sleep by modulating the thalamocortical mechanisms in humans. This finding may open a new avenue toward a development of novel techniques for human sleep augmentation. Support (If Any) JST PRESTO (JPMJPR19J3) and JSPS KAKENHI (18K17891) to AK.

Neurophysiological effects of human-derived pathological tau conformers in the APPKM670/671NL.PS1/L166P amyloid mouse model of Alzheimer’s disease

Alzheimer’s Disease (AD) is a neurodegenerative disease characterized by two main pathological hallmarks: amyloid plaques and intracellular tau neurofibrillary tangles. However, a majority of studies focus on the individual pathologies and seldom on the interaction between the two pathologies. Herein, we present the longitudinal neuropathological and neurophysiological effects of a combined amyloid-tau model by hippocampal seeding of human-derived tau pathology in the APP.PS1/L166P amyloid animal model. We statistically assessed both neurophysiological and pathological changes using linear mixed modelling to determine if factors such as the age at which animals were seeded, genotype, seeding or buffer, brain region where pathology was quantified, and time-post injection differentially affect these outcomes. We report that AT8-positive tau pathology progressively develops and is facilitated by the amount of amyloid pathology present at the time of injection. The amount of AT8-positive tau pathology was influenced by the interaction of age at which the animal was injected, genotype, and time after injection. Baseline pathology-related power spectra and Higuchi Fractal Dimension (HFD) score alterations were noted in APP.PS1/L166P before any manipulations were performed, indicating a baseline difference associated with genotype. We also report immediate localized hippocampal dysfunction in the electroencephalography (EEG) power spectra associated with tau seeding which returned to comparable levels at 1 month-post-injection. Longitudinal effects of seeding indicated that tau-seeded wild-type mice showed an increase in gamma power earlier than buffer control comparisons which was influenced by the age at which the animal was injected. A reduction of hippocampal broadband power spectra was noted in tau-seeded wild-type mice, but absent in APP.PS1 animals. HFD scores appeared to detect subtle effects associated with tau seeding in APP.PS1 animals, which was differentially influenced by genotype. Notably, while tau histopathological changes were present, a lack of overt longitudinal electrophysiological alterations was noted, particularly in APP.PS1 animals that feature both pathologies after seeding, reiterating and underscoring the difficulty and complexity associated with elucidating physiologically relevant and translatable biomarkers of Alzheimer’s Disease at the early stages of the disease.

Effectiveness of Transcranial Direct Current Stimulation and Monoclonal Antibodies Acting on the CGRP as a Combined Treatment for Migraine (TACTIC): Protocol for a Randomized, Double-Blind, Sham-Controlled Trial

BackgroundMigraine is a recurrent headache disorder that has a still unclear pathophysiology, involving several circuits of both the central and peripheral nervous system. Monoclonal antibodies acting on the calcitonin gene-related (CGRP) pathway (CGRP-MAbs) are the first drugs specifically designed for migraine; those drugs act peripherally on the trigeminal ganglion without entering the blood-brain barrier. Conversely, neuromodulation techniques such as transcranial direct current stimulation (tDCS) act centrally by increasing or decreasing the neuronal firing rate of brain cortical areas. The aim of the study will be to evaluate whether tDCS, in addition to CGRP-MAbs, is an effective add-on treatment in reducing headache frequency, intensity and acute medication use in patients with migraine. To demonstrate the biological effects of tDCS, the electroencephalographic (EEG) power changes after tDCS will be assessed.MethodsWe will include patients with migraine on treatment with CGRP-MAbs and reporting ≥8 monthly migraine days. During a prospective 28-day baseline period, patients will fill in a headache diary and questionnaires to evaluate migraine-related disability, anxiety and depressive symptoms, sleep quality, and health-related quality of life. Subjects will be randomly assigned in a 1:1 ratio to active or sham tDCS. The stimulation protocol will consist in five daily sessions, the cathodes will be applied bilaterally above the occipital areas, with the reference anode electrodes positioned above the primary motor areas. Before the first, and immediately after the last stimulation session, patients will perform a 10-min resting EEG recording. During a 28-day follow-up period following tDCS, patients will have to fill in a headache diary and questionnaires identical to those of the baseline period.DiscussionThis trial will evaluate the efficacy of an add-on treatment acting on the brain in patients with migraine, who are already treated with peripherally acting drugs, showing how tDCS acts in restoring the dysfunctional brain networks typical of the migraine patient.Clinical Trial RegistrationNCT05161871.

Detection of Schizophrenia Cases From Healthy Controls With Combination of Neurocognitive and Electrophysiological Features.

BackgroundThe search for a method that utilizes biomarkers to identify patients with schizophrenia from healthy individuals has occupied researchers for decades. However, no single indicator can be employed to achieve the good in clinical practice. We aim to develop a comprehensive machine learning pipeline based on neurocognitive and electrophysiological combined features for distinguishing schizophrenia patients from healthy people.MethodsIn the present study, 69 patients with schizophrenia and 50 healthy controls participated. Neurocognitive (contains seven specific domains of cognition) and electrophysiological [prepulse inhibition, electroencephalography (EEG) power spectrum, detrended fluctuation analysis, and fractal dimension (FD)] features were collected, all these features were taken together to generate the identification models of schizophrenia by applying logistics, random forest, and extreme gradient boosting algorithm. The classification capabilities of these models were also evaluated.ResultsBoth the neurocognitive and electrophysiological feature sets showed a good classification effect with the highest accuracy greater than 85% and AUC greater than 90%. Specifically, the performances of the combined neurocognitive and electrophysiological feature sets achieved the highest accuracy of 93.28% and AUC of 97.91%. The extreme gradient boosting algorithm as a whole presented more stably and precisely in classification efficiency.ConclusionThe highest classification accuracy of 93.28% by combination of neurocognitive and electrophysiological features shows that both measurements are appropriate indicators to be used in discriminating schizophrenia patients and healthy individuals. Also, among three algorithms, extreme gradient boosting had better classified performances than logistics and random forest algorithms.

Mathematical Model Insights into EEG Origin under Transcranial Direct Current Stimulation (tDCS) in the Context of Psychosis.

Schizophrenia is a psychotic disease that develops progressively over years with a transition from prodromal to psychotic state associated with a disruption in brain activity. Transcranial Direct Current Stimulation (tDCS), known to alleviate pharmaco-resistant symptoms in patients suffering from schizophrenia, promises to prevent such a psychotic transition. To understand better how tDCS affects brain activity, we propose a neural cortico-thalamo-cortical (CTC) circuit model involving the Ascending Reticular Arousal System (ARAS) that permits to describe major impact features of tDCS, such as excitability for short-duration stimulation and electroencephalography (EEG) power modulation for long-duration stimulation. To this end, the mathematical model relates stimulus duration and Long-Term Plasticity (LTP) effect, in addition to describing the temporal LTP decay after stimulus offset. This new relation promises to optimize future stimulation protocols. Moreover, we reproduce successfully EEG-power modulation under tDCS in a ketamine-induced psychosis model and confirm the N-methyl-d-aspartate (NMDA) receptor hypofunction hypothesis in the etiopathophysiology of schizophrenia. The model description points to an important role of the ARAS and the -rhythm synchronicity in CTC circuit in early-stage psychosis.

EEG Power Band Asymmetries in Children with and without Classical Ensemble Music Training

Much evidence shows that music training influences the development of functional brain organization and cerebral asymmetry in an auditory-motor integrative neural system also associated with language and speech. Such overlap suggests that music training could be used for interventions in disadvantaged populations. Accordingly, we investigated neurofunctional changes associated with the influence of socially based classical ensemble music (CEM) training on executive auditory functions of children from low socioeconomic status (LSES), as compared to untrained counterparts. We conducted a novel ROI-focused reanalysis of stimulus-locked event-related electroencephalographic (EEG) band power data previously recorded from fifteen LSES children (9–10 years), with and without CEM, while performing a series of auditory Go/No-Go trials (involving 1100 Hz or 2000 Hz tones). An analysis of collapsed Alpha2, Beta1, Beta2, Delta, and Theta EEG bands showed significant differences in increased and decreased left asymmetry between the CEM and the Comparison group in key frontal and central electrodes typically associated with learning music. Overall, in Go trials, the CEM group responded more quickly and accurately. Linear regression analyses revealed both positive and negative correlations between left hemispheric asymmetry and behavioral measures of PPVT score, auditory sensitivity, Go accuracy, and reaction times. The pattern of results suggests that tone frequency and EEG asymmetries may be attributable to a shift to left lateralization as a byproduct of CEM. Our findings suggest that left hemispheric laterality associated with ensemble music training may improve the efficiency of productive language processing and, accordingly, may be considered as a supportive intervention for LSES children and youth.

Sleep Power Topography in Children with Attention Deficit Hyperactivity Disorder (ADHD).

Objective: Recent years saw an increasing interest towards sleep microstructure abnormalities in attention-deficit/hyperactivity disorder (ADHD). However, the existing literature on sleep electroencephalographic (EEG) power in ADHD is still controversial, often based on single electrode recordings, and mainly focused on slow wave activity (SWA) during NREM sleep. This study aimed to systematically investigate sleep power topography in all traditional frequency bands, in all sleep stages and across sleep cycles using high-density EEG (HD-EEG). Method: Thirty drug-naïve children with ADHD (10.5 ± 2.1 years, 21 male) and 23 typically developing (TD) control participants (mean age: 10.2 ± 1.6 years, 13 male) were included in the current analysis. Signal power topography was computed in classical frequency bands during sleep, contrasted between groups and sleep cycles, and correlated with measures of ADHD severity, cognitive functioning and estimated total sleep time. Results: Compared to TD subjects, patients with ADHD consistently displayed a widespread increase in low-frequency activity (between 3 and 10 Hz) during NREM sleep, but not during REM sleep and wake before sleep onset. Such a difference involved a wide centro-posterior cluster of channels in the upper SWA range, in Theta, and low-Alpha. Between-group difference was maximal in sleep stage N3 in the first sleep cycle, and positively correlated with average total sleep time. Conclusions: These results support the concept that children with ADHD, compared to TD peers, have a higher sleep pressure and altered sleep homeostasis, which possibly interfere with (and delay) cortical maturation.

Temporal changes in electroencephalographic power spectrum on passive listening to three selected melodic scales of Indian music on healthy young individuals - a randomized controlled trial

Music is said to affect the brain in different ways. To the best of our knowledge, research works on the effect of passive listening to different melodic scales of Indian music on Electroencephalogram (EEG) power spectrum is rare to find. In this randomized control trial, 137 healthy subjects were randomly divided into 4 groups (A to D, n~32 in each group), of which A (raga Ahir Bhairav), B (raga Kaunsi Kanada), C (raga Bhimpalas) received music intervention while group D was the control arm. Nineteen channel scalp EEG was recorded for 30 minutes [10 min for each condition, before (BI), during (DI) and after intervention (AI)] and conducted power spectral analysis of waveforms in standard frequency bands. Two-way ANOVA was performed across conditions and groups, to determine the scalp regions showing significant changes, for each frequency band separately. Across conditions, significant change in BI alpha and AI theta, beta1, beta2 bands, while between groups, group B had significant change in alpha and group C in beta1 power, mostly involving frontal regions was seen. Mid Frontal PSA exhibited an increased theta power in group C and D (AI), while alpha and beta1 power increased in group B and C (in group C, beta2 increased significantly). Temporal trend analysis (2-minute segments), showed that there was a significant fall in frontal alpha DI in group B; while in A, C and D groups, the drop seen BI reduced DI and AI. Similarly, the beta1 drop reduced DI and AI in group C and D, while it increased in group B (DI) and group A (AI). Music caused relaxation effect with scales B and C causing maximal effect. In line with existing literature, it may be concluded that listening to these melodic scales was associated with mind wandering effect and probable visual imagery/recall.

EEG power spectral analysis and saccadic eye movement for true and false information

The purpose of this study was to examine the differences between the electroencephalography (EEG) power spectral analysis and saccadic eye movements (SEM)’s the response toward true and false information. The research method was conducted using an experimental design with true and false autobiographical information as stimuli. There were23 female participants aged between 19-24 years old (M=21,45; SD=1,5). The results showed a significant difference in the number of SEM between false information and true information. The EEG power is greater in the frontal, temporal and central areas for false information. Interestingly, we found a correlation between EEG power and SEM in detecting true and false information. Our result findings indicated evidence of multimodality by combining electroencephalography (EEG) and saccadic eye movement (SEM) to dissociate false and true information responses. The distinct dissociative process between true and false information can be used for memory studies and developing lie detectors.

Negative Allosteric Modulation of Gamma-Aminobutyric Acid A Receptors at α5 Subunit–Containing Benzodiazepine Sites Reverses Stress-Induced Anhedonia and Weakened Synaptic Function in Mice

BackgroundAbnormal reward processing, typically anhedonia, is a hallmark of human depression and is accompanied by altered functional connectivity in reward circuits. Negative allosteric modulators of GABAA (gamma-aminobutyric acid A) receptors (GABA-NAMs) have rapid antidepressant-like properties in rodents and exert few adverse effects, but molecular targets underlying their behavioral and synaptic effects remain undetermined. We hypothesized that GABA-NAMs act at the benzodiazepine site of GABAA receptors containing α5 subunits to increase gamma oscillatory activity, strengthen synapses in reward circuits, and reverse anhedonia. MethodsAnhedonia was induced by chronic stress in male mice and assayed by preferences for sucrose and female urine (n = 5–7 mice/group). Hippocampal slices were then prepared for electrophysiological recording (n = 1–6 slices/mouse, 4–6 mice/group). Electroencephalography power was quantified in response to GABA-NAM and ketamine administration (n = 7–9 mice/group). ResultsChronic stress reduced sucrose and female urine preferences and hippocampal temporoammonic-CA1 synaptic strength. A peripheral injection of the GABA-NAM MRK-016 restored hedonic behavior and AMPA-to-NMDA ratios in wild-type mice. These actions were prevented by pretreatment with the benzodiazepine site antagonist flumazenil. MRK-016 administration increased gamma power over the prefrontal cortex in wild-type mice but not α5 knockout mice, whereas ketamine promoted gamma power in both genotypes. Hedonic behavior and AMPA-to-NMDA ratios were only restored by MRK-016 in stressed wild-type mice but not α5 knockout mice. Conclusionsα5-Selective GABA-NAMs exert rapid anti-anhedonic actions and restore the strength of synapses in reward regions by acting at the benzodiazepine site of α5-containing GABAA receptors. These results encourage human studies using GABA-NAMs to treat depression by providing readily translatable measures of target engagement.

Alteration of Resting Electroencephalography by Acute Caffeine Consumption in Early Phase Psychosis.

Individuals with schizophrenia use twice as much caffeine on average when compared to healthy controls. Knowing the high rates of consumption, and the potential negative effects of such, it is important we understand the cortical mechanisms that underlie caffeine use, and the consequences of caffeine use on neural circuits in this population. Using a randomized, placebo controlled, double-blind, repeated measures design, the current study examines caffeine's effects on resting electroencephalography (EEG) power in those who have been recently diagnosed with schizophrenia (SZ) compared to regular-using healthy controls (HC). Correlations between average caffeine consumption, withdrawal symptoms, drug related symptoms and clinical psychosis symptoms were measured and significant correlations with neurophysiological data were examined. Results showed caffeine had no effect on alpha asymmetry in the SZ group, although caffeine produced a more global effect on the reduction of alpha2 power in the SZ group. Further, those with more positive symptoms were found to have a greater reduction in alpha2 power following caffeine administration. Caffeine also reduced beta power during eyes closed and eyes open resting in HC, but only during eyes closed resting conditions in the SZ group. These findings provide a descriptive profile of the resting EEG state following caffeine administration in individuals with schizophrenia. The findings ultimately suggest caffeine does not affect alpha or beta power as readily in this population and a higher dose may be needed to achieve the desired effects, which may elucidate motivational factors for high caffeine use.

Power spectral densities of electroencephalographic theta and alpha frequency waves during information processing of language comprehension

A cross sectional study was conducted to assess electroencephalograph (EEG) Power Spectral Densities (PSD) of alpha and theta frequency bands for an integrative functional role of working memory (WM) in the architectonics of a synthesized and coordinated communication system as exemplified by the observable phenomenon of the evolved structured Language of Human Mind by using Visuo-Spatial Delayed Match to Sample (DMTS) task. The analysis exhibited significant Event Related Synchronization (ERS) along theta wave-form at temporal region along with Lateral Asymmetry Index (LAI) of Alpha Event Related Desynchronization (ERD) at parietal region suggestive of the phenomenal singularity of ERS of theta along temporal regions that seems to be intricately interwoven onto the spectacle of LAI of alpha ERD, presumably evolving a synthesized enveloped working memory, along the virtual phase-space of Human Mind and eventually translating into the comprehensible means of communication of Humans, i.e., Language.

A Novel Electroencephalogram-derived Measure of Disrupted Delta Wave Activity during Sleep Predicts All-Cause Mortality Risk.

Rationale: Conventional markers of sleep disturbance, based on manual electroencephalography scoring, may not adequately capture important features of more fundamental electroencephalography-related sleep disturbance. Objectives: This study aimed to determine if more comprehensive power-spectral measures of delta wave activity during sleep are stronger independent predictors of mortality than conventional sleep quality and disturbance metrics. Methods: Power spectral analysis of the delta frequency band and spectral entropy-based markers to quantify disruption of electroencephalography delta power during sleep were performed to examine potential associations with mortality risk in the Sleep Heart Health Study cohort (N = 5,804). Adjusted Cox proportional hazard models were used to determine the association between disrupted delta wave activity at baseline and all-cause mortality over an approximately 11-year follow-up period. Results: Disrupted delta electroencephalography power during sleep was associated with a 32% increased risk of all-cause mortality compared with no fragmentation (hazard ratio, 1.32 [95% confidence interval, 1.14-1.50]), after adjusting for total sleep time and other clinical and lifestyle-related covariates, including sleep apnea. The association was of similar magnitude to a reduction in total sleep time from 6.5 hours to 4.25 hours. Conventional measures of sleep quality, including wake after sleep onset and arousal index, were not predictive of all-cause mortality. Conclusions: Delta wave activity disruption during sleep is strongly associated with all-cause mortality risk, independent of traditional potential confounders. Future investigation into the potential role of delta sleep disruption on other specific adverse health consequences such as cardiometabolic, mental health, and safety outcomes has considerable potential to provide unique neurophysiological insight.

Changes of electroencephalography power spectrum during joint position perception test after anterior cruciate ligament rupture

OBJECTIVE To measure the electroencephalography (EEG) of the patients with anterior cruciate ligament (ACL) rupture when performing joint position perception movement task, to compare the differences between the ACL rupture side and the unaffected side, to identify the EEG change in the power spectrum caused by the ACL rupture, and to provide evidence for the diagnosis, treatment and rehabi-litation for ACL injury as well as knee instability. METHODS Sixteen male patients, selected from the Department of Sports Medicine, Peking University Third Hospital from November 2014 to April 2015, with only ACL rupture on one side used isokinetic muscle strength testing equipment were enrolled in the study to perform unilateral active knee joint positional movement and passive knee joint positional movement tasks. EEG was recorded to compare between the affected and unaffected limb of ACL rupture patients when doing single leg movement tasks, including passive knee joint position test and active knee joint position sensation test. The target position of the active knee joint position movement task and the passive knee joint position movement task was 30 degrees of knee flexion. RESULTS During the passive knee joint position test, there was no significant difference in EEG power spectrum of Delta[F (1, 15)=0.003, P=0.957, ηP2 =0.001], Theta[F (1, 15)=0.002, P=0.962, ηP2 < 0.001], Alpha[F (1, 15)=0.002, P=0.966, ηP2 =0.001], Beta[F (1, 15)=0.008, P=0.929, ηP2 =0.001] at Fz, Cz, and Pz between the affected and unaffected limbs in the ACL patients. During the active knee joint position movement task, the EEG power spectrum of Delta, Theta, Alpha, Beta at Fz and Cz location, on the affected side was significant higher than on the unaffected side. CONCLUSION This study compared the differences between the ACL rupture side and the unaffected side during active knee position movement task and passive knee position movement task, and identifyied the EEG changes in the power spectrum caused by the ACL rupture, It was found that the central changes caused by unilateral ACL rupture still existed during contralateral (unaffected) side movement. The EEG power spectrum of the affected side during active exercise was significantly higher than that of the unaffected side This study provides new electrophysiological evidence for the study of ACL injury.