Parameters Of P300 Research Articles

Longitudinal Exploration of Cortical Brain Activity in Cognitive Fog: An EEG Study in Patients with and without Anosmia.

Long-Covid, characterized by persistent symptoms following acute Covid-19 infection, represents a complex challenge for the scientific community. Among the most common and debilitating manifestations, cognitive fog is a neurological disorder characterized by mental confusion and cognitive difficulties. In this study, we investigated the long-term effects of previous Covid-19 infection on cortical brain activity in patients experiencing cognitive fog symptoms in the medium and long term. A total of 40 subjects (20 females and 20 males) aged between 45 and 70 years (mean age (M) = 59.78, standard deviation (SD) = 12.93) participated in this study. This sample included individuals with symptoms of cognitive fog, both with and without anosmia, and a control group comprised of healthy subjects. All electroencephalography (EEG) data were collected in two sessions, 1 month and 8 months after recovery from Covid-19, to measure the neurophysiological parameters of P300 and beta band rhythms. The results revealed significant differences in the neurophysiological parameters of P300 and beta band rhythms in subjects affected by cognitive fog, and these alterations persist even 8 months after recovery from Covid-19. Interestingly, no significant differences were observed between the participants with anosmia and without anosmia associated with cognitive fog. These findings provide a significant contribution to understanding the long-term effects of Covid-19 on the brain and have important implications for future interventions aimed at managing and treating brain fog symptoms. The longitudinal assessment of cortical brain activity helps highlight the persistent impact of the virus on the neurological health of Long-Covid patients.

Event-related modulation of alpha rhythm explains the auditory P300-evoked response in EEG

Evoked responses and oscillations represent two major electrophysiological phenomena in the human brain yet the link between them remains rather obscure. Here we show how most frequently studied EEG signals: the P300-evoked response and alpha oscillations (8–12 Hz) can be linked with the baseline-shift mechanism. This mechanism states that oscillations generate evoked responses if oscillations have a non-zero mean and their amplitude is modulated by the stimulus. Therefore, the following predictions should hold: (1) the temporal evolution of P300 and alpha amplitude is similar, (2) spatial localisations of the P300 and alpha amplitude modulation overlap, (3) oscillations are non-zero mean, (4) P300 and alpha amplitude correlate with cognitive scores in a similar fashion. To validate these predictions, we analysed the data set of elderly participants (N=2230, 60–82 years old), using (a) resting-state EEG recordings to quantify the mean of oscillations, (b) the event-related data, to extract parameters of P300 and alpha rhythm amplitude envelope. We showed that P300 is indeed linked to alpha rhythm, according to all four predictions. Our results provide an unifying view on the interdependency of evoked responses and neuronal oscillations and suggest that P300, at least partly, is generated by the modulation of alpha oscillations.

Event-related modulation of alpha rhythm explains the auditory P300-evoked response in EEG.

Evoked responses and oscillations represent two major electrophysiological phenomena in the human brain yet the link between them remains rather obscure. Here we show how most frequently studied EEG signals: the P300-evoked response and alpha oscillations (8-12 Hz) can be linked with the baseline-shift mechanism. This mechanism states that oscillations generate evoked responses if oscillations have a non-zero mean and their amplitude is modulated by the stimulus. Therefore, the following predictions should hold: (1) the temporal evolution of P300 and alpha amplitude is similar, (2) spatial localisations of the P300 and alpha amplitude modulation overlap, (3) oscillations are non-zero mean, (4) P300 and alpha amplitude correlate with cognitive scores in a similar fashion. To validate these predictions, we analysed the data set of elderly participants (N=2230, 60-82 years old), using (a) resting-state EEG recordings to quantify the mean of oscillations, (b) the event-related data, to extract parameters of P300 and alpha rhythm amplitude envelope. We showed that P300 is indeed linked to alpha rhythm, according to all four predictions. Our results provide an unifying view on the interdependency of evoked responses and neuronal oscillations and suggest that P300, at least partly, is generated by the modulation of alpha oscillations.

Assessing Neurocognition (P300) and Correlating Them to Depression Rating Scales in Patients With Major Depressive Disorder.

Major depression is a chronic condition that may affect cognition. Cognitive disturbances may affect clinical scales used to assess the severity of depression. To find an association between cognitive disturbance as objectively recorded using event-related potentials (P300) with the Hamilton rating scale for depression (HAM-D) and Montgomery-Asberg depression rating scale (MADRS) in newly diagnosed cases of major depression. A cross-sectional study with a sample size of 46 diagnosed cases of major depression. The assessment was done using the HAM-Dand MADRS. The P300 assessment was done with the auditory oddball paradigm using the Nihon Kohden NCV-SMG-EP system (Tokyo, Japan). Pearson correlation analysis was used to study the association between various parameters of P300 and the HAM-D and MADRS depression rating scales. A significant correlation was found between A21- P300 amplitude Cz and the MADRS score. No significant correlation was seen between other P300 parameters and HAM-D and MADRS scales. As the results were objectively recorded using various parameters of event-related potentials (P300), cognitive impairment was not significantly associated with depression rating scales i.e., the HAM-D and MADRS scores.

Comparative change in P300 indices following antidepressant treatment in patients with major depressive disorder.

Cognitive disturbance is seen in patients with major depressive disorder (MDD). Event-related potential can assist in measuring the neurocognition, and P300 is the most commonly used noninvasive electrophysiological parameter for measuring cognition. The aim of this study is to assess the baseline P300 parameters, Hamilton Rating Scale for Depression (HAM-D), and Montgomery-Asberg Depression Rating Scale (MADRS) scores and compare them with their levels after 3 months of antidepressant therapy. a longitudinal study was done on total 24 diagnosed cases of major depression who underwent P300, HAM-D, and MADRS assessment in the gap of 3 months before and after starting antidepressant therapy. Newly diagnosed cases of MDD patients were assessed using HAM-D and MADRS for severity rating. P300 assessment was also carried out with auditory oddball paradigm using Nihon Kohden NCV-SMG-EP system. The assessments were repeated after 3 months of antidepressant treatment. The Wilcoxon test was used to compare mean values of P300 parameters, HAM-D, and MADRS score. Spearman correlation analysis was done to study the association between various parameters of P300 and HAM-D and MADRS score before and after treatment of 3 months of antidepressant therapy. Significant difference is shown in various parameters P300 except for A11-P300 amplitude and A31-P300 amplitude. A significant difference was shown in HAM-D and MADRS scores. No significant correlation was seen between other P300 parameters and HAM-D and MADRS scale before as well as after antidepressant therapy. P300 may be used as an index to evaluate the response to antidepressant treatment in patients with MDD.

Когнитивный вызванный потенциал Р300 у школьников 16–17 лет, проживающих в регионах Арктической зоны РФ

Living in adverse climatic and geographical conditions of the Arctic zone of the Russian Federation requires mobilization of the adaptive mechanisms of the central nervous system in humans. The parameters of the event-related potential P300 serve as indicators of brain bioelectric processes associated with the mechanisms of information perception and processing. This study aimed to establish the parameters of the event-related potential P300 in 16–17-year-old schoolchildren living in different regions of the Arctic zone of the Russian Federation based on a comparative analysis. The auditory event-related potential P300 was evaluated in subjects living in the Nenets Autonomus Okrug (NAO), Yamalo-Nenets Autonomous Okrug (YNAO) and the Arkhangelsk Region (AR). P300 latency and amplitude were recorded by the Encephalan-131-03 electroencephalograph (Medicom MTD, Russia) in the frontal (F3, F4), central (C4, C3), parietal (P3, P4), mid-temporal (T3, T4), and anterior temporal (F7, F8) areas of the brain using the oddball method. In schoolchildren living in AR and YNAO, the amplitude-latency parameters of P300 did not differ significantly. Subjects living in NAO, the majority of whom are representatives of the indigenous peoples of the North (the Nenets), had a longer P300 latency than their peers from other regions. Р300 amplitudes in schoolchildren from all the regions under study were statistically identical. The author comes to the conclusion that longer information processing time, according to the P300 data, reflects the adaptive psychophysiological characteristics of the population with a long historical experience of living in the North.

Gender effects on auditory P300: A systematic review.

The evidence suggests that gender-related effects could influence the electrophysiological P300 parameters and stand as an additional source of variation for both clinical and non-clinical subjects. The aim of this paper is to characterize gender-related differences in P300 potential as elicited with simple auditory paradigms. This knowledge (1) is important for the practical assessment of P300 potential in normal and clinical populations, and (2) can provide an insight into the understanding of gender differences in pathophysiology, particularly those with differential risk or prevalence in males and females. With this review it is shown that a limited number of studies encounter possible gender effects on parameters of auditory P300, and the findings need to be read with caution due to methodological limitations of the studies. Nevertheless, evidence supports that the P300 amplitude could be significantly modulated by gender, with greater amplitude in females relative to males. Noteworthy, gender has a minimal effect on the P300 latency, and it is often comparable between males and females. Furthermore, the effect of gender on P300 could be modulated by hormonal background, anatomy and some methodological aspects.

Effect of nasal continuous positive airway pressure (CPAP) on auditory P300 in obstructive sleep apnea syndrome (OSAS)

Obstructive sleep apnea syndrome (OSAS) is a common sleeprelated breathing disorder OSAS is associated with diurnal symptoms such as excessive daytime sleepiness and cognitive deficits. Several cognitive functions may be altered in OSAS such as attention, memory, executive cognitive control and motor coordination. P300 is a neurophysiological correlate of selective attention, novelty detection and working memory. Deterioration of mental fatigue in patients with OSAS, directly correlated to the severity of nocturnal disorder breathing; however, supports the hypothesis that long-term Nasal continuous positive airway pressure (CPAP) therapy significantly improves sleepiness and mental fatigue. ObjectivesWe seek to explore the effect of using CPAP on OSAS patient’s attention and short term memory by measuring auditory P300 after three months of its regular use. Materials and methodsP300 and AHI before and after the regular use of CPAP were done. Results and conclusionsThe severity of OSAS decreased and the parameters of P300 improved toward better results, but, not reaching the normal average. Finally, we concluded that the CPAP regular use in OSAS improves not only sleepiness but also it improves their cognitive ability.

Различия мозгового обеспечения индивидуального, кооперативного и конкурентного поведения у субъектов с аналитическим и холистическим когнитивными стилями

To investigate specific features of systemic organization of behavior in individuals with analytic and holistic cognitive styles we presented a simple decision-making task to pairs of subjects who performed the same task in several modes of social interaction (independent, competition, and cooperation). We assumed that the modes of social interaction would reveal differences in the behavioral and EEG characteristics, related to the cognitive styles. The behavior timing and brain potentials were recorded in 78 participants. The response latencies and parameters of P300 in this task were found to be more variable in the group of participants with holistic thinking compared to analytic. The interaction mode-related differences were also more evident in the group of holistic thinkers. These results are discussed within the system-evolutionary view of brain bases of behavior. The study was supported by RFHR №14-26-18002; Academy of Finland, grant 273469. The study is performed within the research programme of one of the Leading Scientific Schools of Russian Federation “System Psychophysiology” (НШ-9808.2016.6).

The relationship between the parameters of cognitive potential P300 and emotional/affective state of patients with chronic pain

To study emotional state and parameters of cognitive evoked potentials (P300) to target emotional stimuli in patients with chronic back pain. A study included 62 patients. Trait and state anxiety was measured using the Spilberger-Khanin questionnaire. Cognitive evoked potentials were investigated. The changes in parameters and topographic distribution of cognitive evoked potentials to target emotional stimuli in patients with chronic back pain with different emotional/affective states were identified. Recording of P300 elicited by emotional stimuli allows to evaluate the characteristics of chronification of pain syndromes.

Differences in Specificity and Selectivity Between CBP and p300 Acetylation of Histone H3 and H3/H4

Although p300 and CBP lysine acetyltransferases are often treated interchangeably, the inability of one enzyme to compensate for the loss of the other suggests unique roles for each. As these deficiencies coincide with aberrant levels of histone acetylation, we hypothesized that the key difference between p300 and CBP activity is differences in their specificity/selectivity for lysines within the histones. Utilizing a label-free, quantitative mass spectrometry based technique, we determined the kinetic parameters of both CBP and p300 at each lysine of H3 and H4, under conditions we would expect to encounter in the cell (either limiting acetyl-CoA or histone). Our results show that while p300 and CBP acetylate many common residues on H3 and H4, they do in fact possess very different specificities, and these specificities are dependent on whether histone or acetyl-CoA is limiting. Steady-state experiments with limiting H3 demonstrate that both CBP and p300 acetylate H3K14, H3K18, H3K23, with p300 having specificities up to 1010-fold higher than CBP. Utilizing tetramer as a substrate, both enzymes also acetylate H4K5, H4K8, H4K12, and H4K16. With limiting tetramer, CBP displays higher specificities, especially at H3K18, where CBP specificity is 1032-fold higher than p300. With limiting acetyl-CoA, p300 has the highest specificity at H4K16, where specificity is 1018-fold higher than CBP. This discovery of unique specificity for targets of CBP- vs p300-mediated acetylation of histone lysine residues presents a new model for understanding their respective biological roles and possibly an opportunity for selective therapeutic intervention.

A change in the parameters of P300 evoked potentials in relation to the degree of exacerbation of pain syndrome

In chronic pain, the state of suprasegmental brain structures (the cortex, limbic system, truncodiencephalic structures, which form the motivational-affective and cognitive components of pain behavior), actively affects pain afferentation as well. The purpose of the study was to comparatively analyze the parameters and topographic distribution of P300 cognitive evoked potential in patients with lower back pain. Sixty patients aged 22 to 60 years were examined. The authors made their clinical and neurological examinations, collected medical history data, and assessed back pain intensity by a visual analog scale. The findings were compared with the parameters of cognitive evoked potentials (the separating of P300 to count; keystroke in the recognition of significant stimuli; elaboration of a verbal and nonverbal visual stimulation protocol, by using emotionally significant stimuli). The processes of recognition and differentiation, those of directed attention, and the rate of information processing slowed down in patients with different stages of pain syndrome. The P300 separating procedure using the emotionally significant stimuli allows one to assess the specific features of chronization of pain syndromes and the presence of pain memory in the central nervous system of such patients. The estimation of P300 parameters over time or during treatment are of particular value for the optimization and evaluation of its efficiency.

Estabilidade dos potenciais evocados auditivos em indivíduos adultos com audição normal

OBJETIVO: Avaliar a estabilidade dos parâmetros dos potenciais evocados auditivos em adultos normais. MÉTODOS: Foram submetidos à avaliação audiológica e eletrofisiológica (potencial evocado auditivo de tronco encefálico - PEATE, potencial evocado auditivo de média latência - PEAML e potencial cognitivo - P300) 49 indivíduos normais, de 18 a 40 anos (25 do gênero feminino e 24 do gênero masculino). Realizou-se reavaliação três meses após a avaliação. RESULTADOS: Foram observadas diferenças entre os gêneros na avaliação para as latências das ondas III e V e interpicos I-III e I-V do PEATE e amplitude N2-P3 do P300. Não foram verificadas diferenças significativas para os parâmetros do PEATE, PEAML (latência das ondas Na, Pa e amplitude Na - Pa) e P300 (latência da onda P300) entre os resultados obtidos na avaliação e reavaliação. CONCLUSÃO: Exceção feita à amplitude N2-P3, observou-se estabilidade dos parâmetros de PEATE, PEAML e P300 em adultos normais após período de três meses.

Amplitude-time characteristics of the long-latency components (N1, N2, and P300) of acoustic evoked potential in healthy subjects

The aim of the study was to trace the cumulative changes in the amplitude-time parameters of the AEP (acoustic evoked potential) components N1, N2, and P300 in the experimental situations of different complexities (counting and listening to sounds) and to compare the differences between young and mature subjects. The AEP was recorded in 12 healthy subjects aged 18 to 22 years and in 12 subjects aged 32 to 59 years. It was revealed that the components N1, N2, and P300 recorded in the situation of listening without any preliminary instruction did not differ in young and mature individuals. In the younger subjects, a higher N1 amplitude was revealed when they counted sounds, compared to listening, whereas the latency values of this component did not differ, irrespective of the complexity of the task. The component N2 was shown to demonstrate latency stability in relation to the age and the experimental situation. The N2 amplitude was higher in the situation of counting sounds in both age groups. The amplitude-time parameters of P300 did not differ in subjects of different ages in the listening task. The features of the components N1, N2, and P300 revealed in young and mature subjects in the experimental situations differing in complexity lead us to suggest that, with age, humans develop adaptive mechanisms contributing to successful task performance.

217. Variations of the parameters of the wave P300 and the neurodynamic esthesiometry in healthy subjects of different ages

217. Variations of the parameters of the wave P300 and the neurodynamic esthesiometry in healthy subjects of different ages

Correlations between indices of P300 EEG potential, cognitive tests, and variational pulsometry in Parkinsonian patients

The parameters of an event-related EEG potential (ERP), P300 wave, are now extensively used as objective neurophysiological indices of the state of cognitive functions. At the same time, information on the effects of the autonomic nervous system on the parameters of P300 is limited. In Parkinson’s disease clinics, in addition to the leading motor disorders, more or less clear psychoemotional, cognitive, and autonomic (in particular cardiovascular) impairments are usually observed. This allows one to study the dependence between the cardiovascular dysfunction and intensity of cognitive disorders in Parkinsonian patients. In our study on this contingent, we analyzed correlations between the parameters of P300 potential, indices of the state of the cognitive sphere (determined using a questionnaire, Mini Mental State Examination, MMSE, and a Luriya’s test), and indices of variational pulsometry. Thirty-five Parkinsonian patients (49 to 74 years, severity of disease 1.5 to 3.0 by the international classification) were examined. We found a negative influence of excessive sympathetic tonus in cardiovascular control on the state of cognitive functions. The latency of P300 potential was longer in patients with greater intensities of sympathetic influences on the cardiovascular system. The coefficients of correlation of the latency of P300 with the amplitude of mode of R-R intervals (AMo), index of tension in the regulatory systems by Baevskii (IT), and index of autonomic balance by Baevskii (IAB) were 0.52 (P < 0.01), 0.36 (P < 0.05), and 0.37 (P < 0.05), respectively. The above autonomic indices demonstrated significant negative correlations with the volume of short-term memory measured by Luriya’s test. The P300 latency, in turn, showed negative correlations with the memory volume estimated by the MMSE scale and Luriya’s test. With increase in the age of patients, the degree of the above-mentioned correlations between the P300 latency, memory volume (by Luriya’s test), and parameters of variational pulsometry increased. Our data emphasize the expedience of “routine” studies of the balance of sympathetic and parasympathetic control in pathological states accompanied by clear or subclinical cognitive disorders. Early recognition of cardiovascular dysfunction and its corresponding therapeutic correction should improve the state of brain functions and quality of life in patients suffering from neurodegenerative diseases, in particular from Parkinson’s disease.

P30.13 Mental processing in epilepsy in children and adolescents

Long latency auditory evoked potentials, especially P300, are an objective and non-invasive procedure and a recommended standard for clinical evaluation of mental processing. Aim of the study: In order to evaluate the results of epilepsy treatment in children and adolescents the influence of two antiepileptic drugs (AED) carbamazepine (CBZ) and valproates (VPA) on cognitive functions was analyzed. Materials and methods: The examination was performed in 30 newly diagnosed patients with epilepsy 8–18 years old before AED therapy and in 62 patients to whom both formulations of CBZ or VPA was administered in monotherapy. Neuropediatric status as well as the neuroimaging in the groups were unremarkable. All showed normal mentality measured by psychological tests. Control group consisted of 66 healthy children and adolescents of the same age. According to the IFCN standards, we applied the oddball paradigm to elicit P300. Results: Significant prolongation of P300 and N2 latency was observed and the increase of N1–P2, P2–N2 and N2–P3 amplitude values in all epileptic patients in comparison to healthy controls was detected. There were also significant changes of N1 and P2 latency recorded in children receiving CBZ. P300 latency was longer in patients with newly diagnosed epilepsy than in control group. It was also shown that patients with partial seizures demonstrated longer P300 and N2 latency than recorded in case history as well as N2–P3 amplitude was higher than in patients with generalized seizures. There was not any statistically significant relation between parameters of P300 and the age of the child at the moment of epilepsy being diagnosed, the duration of the disease and the level of AED in blood serum. Conclusions: There were significant differences indicated in parameters of P300 in epileptic children and adolescents in comparison to control group. The type of epileptic seizures and the choice of AED influence their values significantly.

Individual personality-related characteristics of event-related EEG potentials recorded in an experimental situation requiring production of time intervals

Event-related EEG potentials (ERP) were recorded from 75 tested adult men and women; recording was performed from C3 and C4 points. The experimental situation required internal counting of time intervals limited by two pushes of a button. The experimental paradigm provided a substantial level of uncertainty, and a high level of attention needed to be maintained. The tested subjects were not informed by the experimenter about the precise value of the preset time interval; they knew only its limits, 17–23 sec. The subject obtained information about the agreement or disagreement between the produced interval and its value preset by the experimenter by visual feedback signals obtained 2 sec after termination of counting; in the case of agreement the subject had to perform a confirming (third) push of the button. Pushes were preceded by readiness potentials (RP); contingent negative variation (CNV) developed before the feedback signals, and the latter were accompanied by P300 potentials. Significant positive correlations were found between the parameters of RP and P300 in both hemispheres. In general, ERP were characterized by very high interindividual variability, which in a few respects correlated with the personality-related characteristics of tested subjects evaluated by psychological testing with the use of corresponding questionnaires. In particular, under the experimental conditions used, negative correlations were observed between the RP amplitude and psychotism indices, CNV amplitude and emotional stability; CNV amplitude and extroversive features, and P300 amplitude and domination properties of a person. Positive correlations were observed between the CNV amplitude and autia factor (according to Eysenck’s PEN and Cattell’s 16 PF questionnaires). We suppose that correlations between the personal psychical features and ERP parameters are grounded in both inherited constitutional specificities of the nervous system and neurochemical/structural modifications in the brain determined by the acquired vital experience.

Amplitudes of auditory P300 in remitted and residual schizophrenics: correlations with clinical features.

The parameters of auditory P300 were studied with reference-independent methods in a group of 18 remitted and residual schizophrenics, and in 18 age- and sex-matched controls. In the schizophrenic group, significant inverse correlations were found between P300 amplitudes and level of psychopathology assessed with the Scale for Assessment of Negative Symptoms and with the Brief Psychiatric Rating Scale. Clinical variables regarding social functioning and adaptation, assessed with the Schedule for Affective Disorders and Schizophrenia, and with axis V of DSM-III-R, correlated significantly with low amplitudes. The scalp locations of the maxima and minima of the P300 potentials had the tendency to be dislocated to the right in schizophrenics compared with controls. The results indicate low P300 amplitudes to be associated with pervasive cognitive impairment. Future studies will determine whether low P300 amplitudes have prognostic validity for course and outcome of schizophrenic disorders.