EEG Parameters Research Articles

Use of electroencephalogram, gait, and their combined signals for classifying cognitive impairment and normal cognition.

BackgroundEarly identification of people at risk for cognitive decline is an important step in delaying the occurrence of cognitive impairment. This study investigated whether multimodal signals assessed using electroencephalogram (EEG) and gait kinematic parameters could be used to identify individuals at risk of cognitive impairment.MethodsThe survey was conducted at the Veterans Medical Research Institute in the Veterans Health Service Medical Center. A total of 220 individuals volunteered for this study and provided informed consent at enrollment. A cap-type wireless EEG device was used for EEG recording, with a linked-ear references based on a standard international 10/20 system. Three-dimensional motion capture equipment was used to collect kinematic gait parameters. Mild cognitive impairment (MCI) was evaluated by Seoul Neuropsychological Screening Battery-Core (SNSB-C).ResultsThe mean age of the study participants was 73.5 years, and 54.7% were male. We found that specific EEG and gait parameters were significantly associated with cognitive status. Individuals with decreases in high-frequency EEG activity in high beta (25–30 Hz) and gamma (30–40 Hz) bands increased the odds ratio of MCI. There was an association between the pelvic obliquity angle and cognitive status, assessed by MCI or SNSB-C scores. Results from the ROC analysis revealed that multimodal signals combining high beta or gamma and pelvic obliquity improved the ability to discriminate MCI individuals from normal controls.ConclusionThese findings support prior work on the association between cognitive status and EEG or gait, and offer new insights into the applicability of multimodal signals to distinguish cognitive impairment.

Relationship of Neuropeptide S (NPS) with Neurocognitive, Clinical, and Electrophysiological Parameters of Patients during Structured Rehabilitation Therapy for Schizophrenia.

Introduction: Neuropeptide S is a biomarker related to various neuropsychiatric and neurocognitive functions. Since the need to improve cognitive functions in schizophrenia is unquestionable, it was valuable to investigate the possible relationships of plasma levels of NPS with neurocognitive, psychopathological and EEG parameters in patients with schizophrenia. Aim: Relationships between the serum NPS level and neurocognitive, clinical, and electrophysiological parameters were investigated in patients diagnosed with schizophrenia who underwent structured rehabilitation therapy. Methods: Thirty-three men diagnosed with schizophrenia were randomized into two groups. The REH group (N16) consisted of patients who underwent structured rehabilitation therapy, the CON group (N17) continued its previous treatment. Additionally, the reference NPS serum results were checked in a group of healthy people (N15). In the study several tests assessing various neurocognitive functions were used: d2 Sustained-Attention Test (d2), Color Trails Test (CTT), Beck Cognitive Insight Scale (BCIS), Acceptance of Illness Scale (AIS), and General Self-Efficacy Scale (GSES). The clinical parameters were measured with Positive and Negative Syndrome Scale (PANSS) and electrophysiological parameters were analyzed with auditory evoked potentials (AEPs) and quantitative electroencephalography (QEEG). The NPS, neurocognitive, clinical, and electrophysiological results of REH and CON groups were recorded at the beginning (T1) and after a period of 3 months (T2). Results: A decreased level of NPS was associated with the improvement in specific complex indices of d2 and BCIS neurocognitive tests, as well as the improvement in the clinical state (PANSS). No correlation was observed between the level of NPS and the results of AEPs and QEEG measurements. Conclusions: A decreased level of NPS is possibly related to the improvement in metacognition and social cognition domains, as well as to clinical improvement during the rehabilitation therapy of patients with schizophrenia.

Electroencephalographic Patterns in taVNS: A Systematic Review.

Transcutaneous auricular vagus nerve stimulation (taVNS) is a newer delivery system using a non-invasive stimulation device placed at the ear. taVNS research is focused on clinical trials showing potential therapeutic benefits, however the neurophysiological effects of this stimulation on brain activity are still unclear. We propose a systematic review that aims to describe the effects of taVNS on EEG measures and identify taVNS parameters that can potentially lead to consistent EEG-mediated biomarkers for this therapy. A systematic literature review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) and the Cochrane handbook for systematic reviews. Clinical trials examining EEG parameters were considered, including absolute and relative power, coherence, degree of symmetry, evoked potentials, and peak frequency of all bands. According to our criteria, 18 studies (from 122 articles) were included. Our findings show a general trend towards increased EEG power spectrum activity in lower frequencies, and changes on early components of the ERP related to inhibitory tasks. This review suggests that quantitative electroencephalography can be used to assess the effects of taVNS on brain activity, however more studies are needed to systematically establish the specific effects and metrics that would reflect the non-invasive stimulation through the auricular branch of the vagus nerve.

Efficacy of pulse intravenous methylprednisolone in epileptic encephalopathy: a randomised controlled trial

BackgroundHigh-level evidence for using steroids in epileptic encephalopathy (EE), other than West syndrome (WS), is lacking. This study investigated the efficacy and safety of pulse intravenous methylprednisolone (IVMP) in EE...

Evaluation of quantitative-qualitative levels of blood pressure by Tensioregulom

Background. Earlier we showed that the qualitative-quantitative clusters of blood pressure (BP) are very clearly different from each other by age, sex and the constellation of neuro-endocrine, immune and metabolic variables, which we called the Tensioregulome by analogy with the metabolome and the microbiome. The purpose of this study is detailing this concept. Materials and methods. Under an observations were 44 patients with chronic pyelonephritis and cholecystitis in the phase of remission. Testing was performed twice - on admission and after 7-10 days of standard balneotherapy. The main object of the study was BP. We determined parameters of EEG and HRV, plasma levels of adaptation hormones, electrolytes, lipids, and nitrogenous metabolites, components of humoral, cellular, and phagocytic links of immunity and microbiota as well as markers of pyelonephritis. Results. The forward stepwise program identified 42 Tensioregulome parameters as characteristic of quantitative-qualitative blood pressure clusters: 25 EEGs, sympathetic tone, cortisol, calcitonin, Bifidobacteria faeces, 5 metabolic and 5 immune parameters as well as sex and age. The accuracy of patient classification is 97,7%. Another 15 parameters were found to be characteristic, but were outside the discriminant model. Non-linear correlations between the BP and Tensioregulome parameters were revealed. Conclusion. The Tensioregulome allows us to reliably evaluate quantitative-qualitative levels of blood pressure without measuring it with a tonometer.

Quantitative electroencephalography parameters as neurophysiological biomarkers of schizophrenia-related deficits: A Phase II substudy of patients treated with iclepertin (BI 425809)

Patients with schizophrenia experience cognitive impairment related to neural network dysfunction and deficits in sensory processing. These deficits are thought to be caused by N-methyl-D-aspartate receptor hypofunction and can be assessed in patient populations using electroencephalography (EEG). This substudy from a Phase II, randomized, double-blind, placebo-controlled, parallel-group study investigating the safety and efficacy of the novel glycine transporter-1 inhibitor, iclepertin (BI 425809), assessed the potential of EEG parameters as clinically relevant biomarkers of schizophrenia and response to iclepertin treatment. Eligible patients were randomized to once-daily add-on iclepertin (2, 5, 10, or 25 mg), or placebo (1:1:1:1:2 ratio) for 12 weeks. EEG data were recorded from a subgroup of patients (n = 79) at baseline and end of treatment (EoT). EEG parameters of interest were mismatch negativity (MMN), auditory steady-state response (ASSR), and resting state gamma power, and their correlations with clinical assessments. At baseline, MMN and ASSR exhibited consistent correlations with clinical assessments, indicating their potential value as neurophysiological biomarkers of schizophrenia-related deficits. ASSR measures were positively correlated to the MATRICS Consensus Cognitive Battery overall and neurocognitive composite scores; MMN amplitude was positively correlated with Positive and Negative Syndrome Scale scores. However, correlations between change from baseline (CfB) at EoT in clinical assessments, and baseline or CfB at EoT for EEG parameters were modest and inconsistent between dose groups, which might indicate low potential of these EEG parameters as predictive and treatment response biomarkers. Further methodological refinement is needed to establish EEG parameters as useful drug development tools for schizophrenia.

Assessing stroke rehabilitation degree based on quantitative EEG index and nonlinear parameters.

The assessment of motor function is critical to the rehabilitation of stroke patients. However, commonly used evaluation methods are based on behavior scoring, which lacks neurological indicators that directly reflect the motor function of the brain. The objective of this study was to investigate whether resting-state EEG indicators could improve stroke rehabilitation evaluation. We recruited 68 participants and recorded their resting-state EEG data. According to Brunnstrom stage, the participants were divided into three groups: severe, moderate, and mild. Ten quantitative electroencephalographic (QEEG) and five non-linear parameters of resting-state EEG were calculated for further analysis. Statistical tests were performed, and the genetic algorithm-support vector machine was used to select the best feature combination for classification. We found the QEEG parameters show significant differences in Delta, Alpha1, Alpha2, DAR, and DTABR (P < 0.05) among the three groups. Regarding nonlinear parameters, ApEn, SampEn, Lz, and C0 showed significant differences (P < 0.05). The optimal feature classification combination accuracy rate reached 85.3%. Our research shows that resting-state EEG indicators could be used for stroke rehabilitation evaluation.

TO ASSESS SUBCLINICAL UREMIC ENCEPHALOPATHY IN NEWLY DIAGNOSED CHRONIC KIDNEY DISEASE PATIENTS BY USING ELECTROENCEPHALOGRAPHY IN TERTIARY CARE CENTRE

Background: Chronic kidney disease(CKD) is one of the leading cause of death in the world because of its late or end stage presentation. In our study we assessed patients of CKD for cognitive dysfunction with EEG (electroencephalography) and other biochemical parameters. This cross-sectionalstudy was conducted on 60Methods: newly diagnosed CKDpatients at MGM Medical College and MY Hospital Indore, MP, India, from 2019 to 2021. Baseline parameters like serum urea, creatinine, bilirubin and sodium were done and patients were subjected to electroencephalography to assess subclinical uremic encephalopathy and data were analysed using SPSS statistics version 22.0 and p value &lt;0.05 and condence interval more than 95% were considered signicant. In this study, beta wavesResults: were found to be maximum in stage1 (83.3%) whereas delta waves were found to be more in stage 5 (68%). In CKD stage 1, 16.7% patients had alpha waves and delta waves were absent. In CKD stage 5, 12% &amp; 20% patients were having beta and alpha waves respectively. Epileptiform discharges were absent in patients of CKD stage 1 with stage 5 CKD having 80% patients with epileptiform discharges (P value =0.001). All patients in CKD stage1 have symmetrical EEG waves, with 80% asymmetrical waves were present in CKD stage 5 (P value=0.021). This study supports the fact that as CKDConclusions: stages progresses, there is propensity of delta waves, asymmetrical waves and epileptiform discharges which helps in early detection of subclinical uremic encephalopathy and therefore the risk of uremic seizures.

Neural Correlates of Motor Imagery during Action Observation in Affordance-based Actions: Preliminary Results.

Object affordance, a characterization of the different functionalities of an object, refers to an object's numerous possibilities of interaction. It has a significant part to play in priming motoric actions which depends on the actor's spontaneous neurological behaviour. Action Observation (AO) and Motor Imagery (MI) also lead to the stimulation of motor system. In fact, AO and MI result in activation of overlapping brain areas as the actual motor task. AO combined with MI (referred to as AO+MI) initiates higher cortical activity in comparison with either MI or AO alone. In this paper, we investigate the influence of affordance driven motor priming during AO, MI and AO + MI. Source current density as an EEG parameter is estimated by Low Resolution Electromagnetic Tomography (LORETA). Our results demonstrate that affordance driven motor priming during AO+MI indicates stronger electrophysiological and behavioural changes. This is evident from the N2 ERP component. Further, the current source density (in brain regions associated with motor planning) during affordance driven AO+MI is found to be maximum.

Electrophysiological biomarkers of brain function in CDKL5 deficiency disorder.

CDKL5 deficiency disorder is a debilitating developmental and epileptic encephalopathy for which no targeted treatment exists. A number of promising therapeutics are under development for CDKL5 deficiency disorder but a lack of validated biomarkers of brain function and clinical severity may limit the ability to objectively assess the efficacy of new treatments as they become available. To address this need, the current study quantified electrophysiological measures in individuals with CDKL5 deficiency disorder and the association between these parameters and clinical severity. Visual and auditory evoked potentials, as well as resting EEG, were acquired across 5 clinical sites from 26 individuals with CDKL5 deficiency disorder. Evoked potential and quantitative EEG features were calculated and compared with typically developing individuals in an age- and sex-matched cohort. Baseline and Year 1 data, when available, were analysed and the repeatability of the results was tested. Two clinician-completed severity scales were used for evaluating the clinical relevance of the electrophysiological parameters. Group-level comparisons revealed reduced visual evoked potential amplitude in CDKL5 deficiency disorder individuals versus typically developing individuals. There were no group differences in the latency of the visual evoked potentials or in the latency or amplitude of the auditory evoked potentials. Within the CDKL5 deficiency disorder group, auditory evoked potential amplitude correlated with disease severity at baseline as well as Year 1. Multiple quantitative EEG features differed between CDKL5 deficiency disorder and typically developing participants, including amplitude standard deviation, 1/f slope and global delta, theta, alpha and beta power. Several quantitative EEG features correlated with clinical severity, including amplitude skewness, theta/delta ratio and alpha/delta ratio. The theta/delta ratio was the overall strongest predictor of severity and also among the most repeatable qEEG measures from baseline to Year 1.Together, the present findings point to the utility of evoked potentials and quantitative EEG parameters as objective measures of brain function and disease severity in future clinical trials for CDKL5 deficiency disorder. The results also underscore the utility of the current methods, which could be similarly applied to the identification and validation of electrophysiological biomarkers of brain function for other developmental encephalopathies.

Tensioregulome as an accompaniment of quantitative-qualitative blood pressure clusters

Background. Earlier we studied the neural, endocrine, immune, microbiome and metabolome accompaniments of quantitative-qualitative blood pressure (BP) clusters of profile patients of Truskavets’ spa. The obtained results give us grounds to put forward the concept of tensioregulome by analogy with the metabolome and the microbiome. The purpose of this study is detailing this concept. Materials and methods. Under an observations were 44 patients with chronic pyelonephritis and cholecystitis in the phase of remission. Testing was performed twice - on admission and after 7-10 days of standard balneotherapy. The main object of the study was BP. We determined parameters of EEG and HRV, plasma levels of adaptation hormones, electrolytes, lipids, and nitrogenous metabolites, components of humoral, cellular, and phagocytic links of immunity and markers of pyelonephritis. Results. The forward stepwise program identified 26 tensioregulome parameters as characteristic of quantitative-qualitative blood pressure clusters: 10 EEG, 6 metabolic, 6 immune, testosterone, cotrisol, sympathetic tone as well as sex. The accuracy of patient classification is 98,9%. Another 25 parameters were found to be characteristic, but were outside the discriminant model, including 11 EEG, 2 HRV, 5 metabolic, 4 immune, bacteriuria, body mass index, and age. Both linear and non-linear correlations between the BP and tensioregulome parameters were revealed. Conclusion. The quantitative-qualitative blood pressure clusters have a characteristic accompaniment named tensioregulome.

Effects of the Glycine Transporter-1 Inhibitor Iclepertin (BI 425809) on Sensory Processing, Neural Network Function, and Cognition in Animal Models Related to Schizophrenia.

N-methyl-D-aspartate (NMDA) receptor hypofunction leading to neural network dysfunction is thought to play an important role in the pathophysiology of cognitive impairment associated with schizophrenia (CIAS). Increasing extracellular concentrations of the NMDA receptor co-agonist glycine through inhibition of glycine transporter-1 (GlyT1) has the potential to treat CIAS by improving cortical network function through enhanced glutamatergic signaling. Indeed, the novel GlyT1 inhibitor iclepertin (BI 425809) improved cognition in a recent clinical study in patients with schizophrenia. The present study tested the ability of iclepertin to reverse deficits in auditory sensory processing and cortical network function induced by the uncompetetive NMDA receptor antagonist, MK-801, using electroencephalography (EEG) to measure auditory event-related potentials (AERPs) and 40 Hz auditory steady-state response (ASSR). In addition, improvements in memory performance with iclepertin were evaluated using the T-maze spontaneous alternation test in MK-801-treated mice and the social recognition test in naïve rats. Iclepertin reversed MK-801-induced deficits in the AERP readouts N1 amplitude and N1 gating, as well as reversing deficits in 40 Hz ASSR power and intertrial coherence. Additionally, iclepertin significantly attenuated an MK-801-induced increase in basal gamma power. Furthermore, iclepertin reversed MK-801-induced working memory deficits in mice and improved social recognition memory performance in rats. Overall, this study demonstrates that inhibition of GlyT1 is sufficient to attenuate MK-801-induced deficits in translatable EEG parameters relevant to schizophrenia. Moreover, iclepertin showed memory-enhancing effects in rodent cognition tasks, further demonstrating the potential for GlyT1 inhibition to treat CIAS. SIGNIFICANCE STATEMENT: Despite the significant patient burden caused by cognitive impairment associated with schizophrenia, there are currently no approved pharmacotherapies. In this preclinical study, the novel glycine transporter inhibitor iclepertin (BI 425809) reversed sensory processing deficits and neural network dysfunction evoked by inhibition of N-methyl-D-aspartate receptors and enhanced working memory performance and social recognition in rodents. These findings support previous clinical evidence for the procognitive effects of iclepertin.

Neuroinflammation Markers in Depressive Female Adolescents with Suicidal Attempts

IntroductionSuicide is the second leading cause of death (8.5% of all deaths) in adolescents. The search for neurobiological markers of suicidal behavior seems to be highly actual. Such markers may include quantitative EEG parameters and signs of neuroinflammation that plays an important role in the pathogenesis of various mental disorders.ObjectivesThe aim of the study was to reveal the relationships between pre-treatment clinical, EEG, and neuroimmunological parameters in depressive adolescents with suicidal attempts in their history.Methods35 female depressive patients (all right-handed, age 16–25, mean 18,7±2.9 years old) were enrolled in the study. Total HDRS-17 scores varied from 13 to 43 (mean 27,7±8.1). Multichannel resting EEG was recorded with spectral power (SP) measurements in narrow frequency sub-bands. Functional activities of leukocyte elastase (LE) and of its antagonist α1-proteinase inhibitor (α1-PI), as neuroinflammation markers, were measured in the blood plasma. Leukocyte/inhibitory index (LII=LE/α1-PI) was calculated. Spearman’s correlations between clinical, EEG, and neuroimmunological parameters were analyzed.ResultsSum of anxiety cluster of HDRS-17 scale (items 9, 10, 11) correlated positively (p&lt;0.02) with LE and α1-PI values, as well as with theta1 (4-6 Hz) and theta2 (6-8 Hz) SP in EEG leads of the right hemisphere. In turn, α1-PI values correlated negatively and LII values correlated positively with alpha3 (11-13 Hz) SP in majority of EEG leads.ConclusionsThe data obtained confirm the contribution of neuroinflammation to clinical conditions, especially to anxiety level, and to EEG pattern in depressive female adolescents with suicidal attempts. The study supported by RBRF grant No.20-013-00129a.DisclosureNo significant relationships.

Clinical–EEG-Neuroimmunological Correlations in Depressive Female Adolescents with Non-Suicidal Self-Injuries

IntroductionNon-suicidal self-injurious behavior (NSSI) is rather widespread in adolescents, especially in females, and is an important risk factor for future suicide. The search for neurobiological markers of NSSI is therefore an actual medical and social problem.ObjectivesThe aim of the study was to determine the relationships between pre-treatment quantitative clinical, EEG, and neuroimmunological parameters in female depressive adolescents with NSSI.Methods40 female depressive patients (all right-handed, 16–25 years old, mean 17.6±2.2 years old) were included in the study. Total HDRS-17 scores varied from 14 to 38 (mean 26.0±6.9). Multichannel eyes closed resting EEG was recorded with subsequent spectral power (SP) measurements in narrow frequency sub-bands. Enzymatic activities of leukocyte elastase (LE) and its antagonist α-1 proteinase inhibitor (α1-PI), as neuroinflammation markers, and the levels of autoantibodies to S100b protein (AAB-S100b) and to basic myelin protein (AAB-BMP), as neuroplasticity markers, were measured in the blood plasma. Spearman’s rank correlations were calculated between clinical, EEG, and neuroimmunological parameters.ResultsHDRS-17 scores correlated positively (p&lt;0.05) with beta2 (20-30 Hz) SP in the right anterior and mid-temporal leads. AAB-S100b values correlated positively with alpha2 (9-11 Hz) and alpha3 (11-13 Hz) SP in central-temporal-parietal-occipital leads, and correlated negatively with beta1 (13-20 Hz) and beta2 SP in the right anterior temporal lead.ConclusionsThe structure of clinical–neurobiological correlations obtained indicates that processes of neuroinflammation in depressive adolescents with NSSI are relatively mild and/or compensated by anti-inflammatory mechanisms. The study supported by RBRF grant No.20-013-00129a.DisclosureNo significant relationships.

EEG Features in Adolescent Patients with Borderline and Narcissistic Personality Disorder

IntroductionPersonality disorders (PD) in adolescence are widespread. It creates problems of social adaptation of patients and represents significant risk factors for auto-aggressive behavior, including suicidal one. The neurobiological basis and EEG markers of PD in adolescence have not been adequately studied.ObjectivesThe aim of the study was to reveal the EEG features and their correlations with clinical parameters in male adolescents with borderline personality disorder (BPD) and narcissistic personality disorder (NPD), possibly mediating some aspects of their clinical traits.Methods28 BPD patients (301.83, by DSM-5) and 24 NPD patients (301.81, by DSM-5), as well as 24 healthy controls (HC) aged 16-25 years were enrolled in the study. HDRS-21 and HAM-A scales were used for quantitative assessment of patient’s conditions. Pre-treatment resting EEG was recorded, and EEG spectral analysis was carried out in 8 narrow frequency sub-bands. Descriptive statistics and correlation analysis of EEG and clinical data were performed.ResultsEEG spectral parameters in BPD group did not differ significantly from those of HC. NPD group shows the EEG signs of more activated brain cortex than in both BPD and norm groups caused by decreased functional state of the anterior cortical regions. The structure of correlations between EEG parameters and clinical scores also differed between BPD and NPD groups.ConclusionsThe data obtained suggests that these features of the brain activity may contribute to the disturbance of emotion regulation and of behavior control in adolescent patients with BPD and NPD, more pronounced in NPD group.DisclosureNo significant relationships.

Increased spectral power of theta rhythm is not associated with decreased supragranular thickness in first-episode schizophrenia

IntroductionSchizophrenia is associated with disturbances in neurophysiological processes. However, the relation of EEG and ERP parameters to structural supragranular cortical abnormalities, observed in schizophrenia, remains unclear.ObjectivesThe purpose was to characterize EEG and ERP disturbances and their relationship to changes occurring in supragranular cortical layers in subjects with schizophrenia.Methods43 first-episode schizophrenia (FES) male patients and 43 matched healthy controls (HC) underwent background EEG and standard two-tones oddball ERP recording and structural MRI at 3T Philips scanner. MRI images were processed via FreeSurfer and MATLAB to derive two markers specific to supragranular thickness change: gyral-sulcal thickness differences (GSTD) and gyral-sulcal intrinsic curvature differences on pial surface (GSCD) (github.com/kwagstyl/schizophrenia_gyral_sulcal).ResultsTheta rhythm spectral power was increased in FES while P300 amplitudes and latencies, N100 (to non-targets) amplitudes, alpha rhythm spectral power were not altered compared to HC. GSCD measures were increased in temporal, parietal and occipital cortices, whereas both GSTD and GSCD were increased in the right frontal cortex in FES. No correlations between altered EEG and supragranular thickness markers survived correction for multiple comparisons.ConclusionsPresumably, theta rhythm has a widespread circuit of generators, including the cortical ones. However, we have not found correlations between EEG and supragranular markers in FES. Considering an absence of correlations between theta and hippocampal volumes (Lebedeva et al., 2020), a speculative interpretation is that the neurophysiological disturbances may be associated with a more complex patterns of more localized structural and functional impairments.DisclosureThe work was supported by RFBR grant 20-013-00748.

Virtual reality-based and eye tracking-assisted attention refocusing training for adult Attention-Deficit/Hyperactivity Disorder

IntroductionNeurofeedback regimes in the treatment of adult ADHD are commonly EEG-based and have several shortcomings, including a weak signal-to-noise ratio, low transfer rates from laboratory to everyday environments and ambiguous evidence in respect to adequate brain signals of interest.ObjectivesTo investigate, if an eyetracking-based real-time feedback in a virtual environment can enhance attentional performance, as measured by behavioral, EEG and eyetracking parameters.MethodsOverall, n=18 adult patients with ADHD and n=18 healthy controls (HC) performed a continuous performance task (CPT) in a virtual seminar room, while distracting virtual events occurred. In case the participant’s gaze drifted away from the task an automated audiovisual feedback indicated the participant to refocus on the task. Three 20-minutes blocks were presented in counter-balanced order, that differed in respect to whether real feedback, sham feedback or no feedback was additionally provided.ResultsMixed ANOVAs with within-subject factors ‘Condition’ (real feedback, sham feedback, no feedback) and ‘Phase’ (distractor phases vs. non-distractor phases) and a between-factor ‘Group’ (ADHD patients vs. HC) revealed better task performances in HC than ADHD patients in respect to omission errors (p = .023), mean reaction times (p = .042) and reaction time variabilities (p = .007; cf. Figure 1). Moreover, omission errors turned to be higher during distractor-present than distractor-absent trials (p = .007), especially in ADHD.Figure 1.CPT results. DP=distractor-phases, NDP=non-distractor-phasesConclusionsWhile the virtual CPT turns out to discriminate well between patients with ADHD and HC, the behavioral results do not indicate an attentional performance enhancement based on the gaze-dependent feedback.DisclosureNo significant relationships.

EEG Markers of Suicidal Ideation in Depressive Female Adolescents

IntroductionTimely detection of suicidal thoughts is one of the ways to prevent suicide. Use the psychiatric interview only for this purpose in adolescents is often insufficient due to poor compliance. Thus, the search for objective neurophysiological markers of suicidal ideation in adolescents seems to be actual.ObjectivesThe aim of the study was to reveal the relationships between pre-treatment EEG parameters and intensity of suicidal ideation in depressive female adolescents.Methods72 female depressive patients (all right-handed, age 16–25, mean 18,2±2.6 years old) were enrolled in the study. Pre-treatment total HDRS-17 scores varied from 13 to 43 (mean 26,9±7.5). Multichannel eyes closed EEG was recorded, and absolute spectral power was calculated in 8 narrow frequency sub-bands. All patients answered the inventory on intensity of suicidal thoughts. Spearman’s correlations between pre-treatment EEG parameters and suicidal ideation scores were analyzed.ResultsScores of intensity of suicidal ideation correlated positively (p&lt;0.05÷0.01) with values of EEG alpha2 (9-11 Hz) spectral power in F7, F8, F4, C3, C4, T4, P4 and O2 EEG leads, as well as with values of EEG delta (2-4 Hz) spectral power in F7, F3 and C3 EEG leads (p&lt;0.05).ConclusionsThe intensity of suicidal ideation in depressive female adolescents associates with wide propagation of EEG alpha2, especially over the right hemisphere, and with EEG signs of decreased functional state of anterior regions of the left hemisphere. The study supported by RBRF grant No.20-013-00129a.DisclosureNo significant relationships.

Synthesis of EEG signals modeled using non-linear oscillator based on speech data with EKF

In the existing literature, one of the major issue in regression technique is the noisy training data. In this research work, the mathematical model for parameter estimation of neurological signals is developed for investigation of Brain dynamics. This proposed model is developed by using non-linear dynamics of oscillator models. It is assumed that state of the brain of a given person is characterized by an unknown parameter vector ‘θ’ that parameterizes a coupled nonlinear oscillator differential equation model which generates a harmonic process serving as a model for the EEG data collected on the brain surface. It is assumed that the EEG data and speech data of the same person are correlated, so that the speech data obeys another differential equation with a parameter ‘ϕ’ that is a fixed function of the EEG a parameter ‘θ’. ‘θ’ and ‘ϕ’ are estimated by an EKF based on training process based on joint the EEG and speech data. This enables us to get accurate estimates of ‘θ’ and ‘ϕ’ for each person. This training process is repeated for ‘N’ persons and accordingly a parameter vector is obtained for each person. This completes the training process. The validation of this model involves choosing a fresh person not belonging to the training set and estimating the EEG parameter vector for this person based only on his speech data. For this, a function ‘ψ’ which correlates the speech parameter ‘ϕ’ with the EEG parameter ‘θ’ as ‘ϕ=ψ(θ̂)’ is estimated by an affine linear relationship which is substituted into the speech model. The EEG model is then used to generate this person’s EEG data and we compare this with the true EEG data of his brain. This validation scheme can also be used to classify the fresh person’s brain by comparing his parameters with those obtained from the training set.

Cognitive performance and electroencephalographic variations in air traffic controllers under various mental workload and time of day

The aim of this study was to investigate the effects of mental workload (MWL) and time of day on cognitive performance and electroencephalographic (EEG) parameters of air traffic controllers. EEG signals recorded while 20 professional air traffic controllers performed cognitive tasks [A-X Continuous Performance Test (AX-CPT) and 3-back working memory task] after they were exposed to two levels of task difficulty (high and low MWL) in the morning and afternoon. Significant decreases in cognitive performance were found when the levels of task difficulty increased in both tasks. The results confirmed the sensitivity of the theta and beta activities to levels of task difficulty in the 3-back task, while they were not affected in the AX-CPT. Theta and beta activities were influenced by time of day in the AX-CPT. The findings provide guidance for application of changes in EEG parameters when MWL level is manipulated during the day that could be implemented in future for the development of real-time monitoring systems to improve aviation safety.