| 1. |
- Akgül, Özge, et al.
(författare)
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Enhanced Punishment Responses in Patients With Schizophrenia : An Event-Related Potential Study
- 2024
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Ingår i: Clinical EEG and Neuroscience. - : Sage Publications. - 1550-0594 .- 2169-5202. ; 55:2, s. 219-229
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that abnormal reward processing is a characteristic feature of various psychopathologies including schizophrenia. Reduced reward anticipation has been suggested as a core symptom of schizophrenia. The Monetary Incentive Delay Task (MID) is frequently used to detect reward anticipation. The present study aims to evaluate the amplitude and latency of event-related potential (ERP) P300 in patients with schizophrenia (SCH) compared to healthy controls during the MID task. Twenty patients with SCH and 21 demographically matched healthy controls (HC) were included in the study. ERP P300 amplitude and latency values were compared between groups using an MID task in which reward and loss cues were presented. Relations between P300 and clinical facets were investigated in the patient group. SCH group had enhanced mean P300 amplitudes and delayed peak latency in the punishment condition compared with HC. These higher responses were also associated with negative symptoms. SCH group showed altered reward processing as being more sensitive to loss of reward conditions as firstly evidenced by electrophysiological methods, possibly due to abnormality in various systems including social withdrawal, social defeat, and behavioral inhibition system.
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| 2. |
- Inagawa, Takuma, et al.
(författare)
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A Meta-Analysis of the Effect of Multisession Transcranial Direct Current Stimulation on Cognition in Dementia and Mild Cognitive Impairment
- 2019
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Ingår i: Clinical EEG and Neuroscience. - : Sage Publications. - 1550-0594 .- 2169-5202. ; 50:4, s. 273-282
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Tidskriftsartikel (refereegranskat)abstract
- There have been increasing efforts to investigate the effects of neuromodulation techniques, such as transcranial direct current stimulation (tDCS), on cognitive impairment in dementia and related conditions. In this systematic review and meta-analysis, we assessed the efficacy of multisession anodal tDCS compared with sham stimulation for improving global cognition and specific cognitive domains in both Alzheimer's disease and mild cognitive impairment. Eight articles meeting the criteria for inclusion in the meta-analysis were selected. Five studies used the Mini-Mental State Examination to examine mild cognitive impairment and dementia. In a fixed-effect model, there was a mean difference in the change score of -0.13 points. Three trials for dementia using the Alzheimer's Disease Assessment Scale-Cognition showed a mean difference of -0.53 points. At present, there is a lack of clear evidence concerning the efficacy of multisession anodal tDCS due to the small number of studies and different measures used. This underscores the need for further investigations using larger samples and common outcome measures.
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| 3. |
- Jelic, V, et al.
(författare)
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Evidence-based evaluation of diagnostic accuracy of resting EEG in dementia and mild cognitive impairment
- 2009
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Ingår i: Clinical EEG and neuroscience. - : SAGE Publications. - 1550-0594 .- 2169-5202. ; 40:2, s. 129-142
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Tidskriftsartikel (refereegranskat)abstract
- Cognitive impairment is the most frequent chronic condition in the elderly, and dementia is the most disabling form of cognitive impairment in elderly. In the absence of specific and reliable markers of etiologically different dementia syndromes and their preclinical stages, diagnosis in living patients is probabilistic and based on standardized clinical diagnostic criteria. There is still not enough information on the validity of the EEG method in dementia work-up, and an updated evidence-based consensus on appropriateness of this method in the initial evaluation of patients with suspected cognitive disorder and dementia is missing. Using an evidence-based technique we searched for articles on diagnostic accuracy of spontaneous EEG in dementia disorders published from 1980 until June 2008. Inclusion criteria were: original article published in English with 10 or more subjects per diagnostic group, diagnosed according to the established consensus clinical diagnostic criteria used as a “gold standard.” In addition, it should have been possible to calculate from the reported results indexes of diagnostic test accuracy: sensitivity, specificity, likelihood ratios and diagnostic odds ratios. Forty-six articles were retrieved that satisfied eligibility criteria. Thirty-four (74%) studies employed case-control design where study population was recruited from consecutive patients at specialist clinic settings, 12 (26%) were prospective in terms of reported clinical follow-up of study population. Four (9%) studies used population-based samples and 5 (11%) studies stated in methods the recruitment procedures for patients and healthy subjects. Number of patients included in diagnostic groups and healthy subjects varied in included studies between 10 and 180 and 10 and 171, respectively. Figures on sensitivity and specificity across the studies varied widely. Positive likelihood ratio in studies reporting classification accuracies between Alzheimer's disease and controls ranged between 2.3 and 38.5, and diagnostic odds ratios consequently showed large variations between 7 and 219. In conclusion, despite the wealth of published research and reported high indexes of diagnostic accuracy of EEG, and qEEG in particular, in individual studies, evidence of diagnostic utility of resting EEG in dementia and mild cognitive impairment (MCI) is still not sufficient to establish this method for the initial evaluation of subjects with cognitive impairment in the routine clinical practice. Joint effort of preferably multicenter studies using uniform standards should develop optimized methods, investigate added diagnostic value of EEG in clinically established dementia diagnosis and predictive utility of EEG in MCI and questionable dementia.
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| 4. |
- Johnstone, SJ, et al.
(författare)
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Development of Frontal EEG Differences Between Eyes-Closed and Eyes-Open Resting Conditions in Children: Data From a Single-Channel Dry-Sensor Portable Device
- 2021
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Ingår i: Clinical EEG and neuroscience. - : SAGE Publications. - 2169-5202 .- 1550-0594. ; 52:4, s. 235-245
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Tidskriftsartikel (refereegranskat)abstract
- Changes in EEG when moving from an eyes-closed to an eyes-open resting condition result from bottom-up sensory processing and have been referred to as activation. In children, activation is characterized by a global reduction in alpha, frontally present reductions for delta and theta, and a frontal increase for beta. The present study aimed to replicate frontal EEG activation effects using single-channel, dry-sensor EEG, and to extend current understanding by examining developmental change in children. Frontal EEG was recorded using a single-channel, dry-sensor EEG device while 182 children aged 7 to 12 years completed eyes-closed resting (EC), eyes-open resting (EO), and focus (FO) tasks. Results indicated that frontal delta, theta, and alpha power were reduced, and frontal beta power was increased, in the EO compared with the EC condition. Exploratory analysis of a form of top-down activation showed that frontal beta power was increased in the FO compared with to the EO condition, with no differences for other bands. The activation effects were robust at the individual level. The bottom-up activation effects reduced with age for frontal delta and theta, increased for frontal alpha, with no developmental change for top-down or bottom-up frontal beta activation. These findings contribute further to validation of the single-channel, dry-sensor, frontal EEG and provide support for use in a range of medical, therapeutic, and clinical domains.
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| 5. |
- Larsson, Pål G., et al.
(författare)
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Alpha Frequency Estimation in Patients With Epilepsy
- 2012
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Ingår i: Clinical EEG and Neuroscience. - : SAGE Publications. - 1550-0594 .- 2169-5202. ; 43:2, s. 97-104
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Tidskriftsartikel (refereegranskat)abstract
- We report comparison and assessment of the clinical utility of different automated methods for the estimation of the alpha frequency in electroencephalograph (EEG) and compare them with visual evaluation. A total of 56 consecutive patients, aged 17 to 78 years, who had a routine EEG recording, were included, and they were grouped as patients with epilepsy (Ep) and without epilepsy (nEp). Five different methods were used for alpha frequency estimation: visually guided manual counting and visually guided Fourier transform, and 3 methods were fully automated: time domain estimation of alpha (automatic assessment of alpha waves in time domain [ATD]) and 2 fast Fourier transform (FFT)-based methods, a segmented (automatic assessment of EEG segments by FFT) and one full FFT (automatic assessment of whole EEG by one FFT of the full recording [AWF]). The AWF discriminated significantly between Ep and nEp. Visually guided manual counting showed an almost significant difference independently in the 2 occipital electrodes. The ATD underestimated high frequencies and returned a too low mean frequency. This study shows that AWF is the best suited method for automatic assessment of the alpha frequency.
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| 6. |
- Mørch-Johnsen, Lynn, et al.
(författare)
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The neural correlates of negative symptoms in schizophrenia : examples from MRI literature
- 2018
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Ingår i: Clinical EEG and Neuroscience. - 1550-0594 .- 2169-5202. ; 49:1, s. 12-17
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Tidskriftsartikel (refereegranskat)abstract
- Negative symptoms of schizophrenia have a negative impact on psychosocial functioning and disease outcome. It is therefore important to investigate the pathophysiology underlying negative symptoms as this may aid the development of better treatment. In the current article, examples from studies investigating neural correlates of negative symptoms in schizophrenia are given. Investigations using both structural and functional magnetic resonance imaging are presented at different levels of symptomatology descriptions, from the more heterogenous construct of negative symptoms to more single discrete symptoms. Some methods to improve imaging studies of negative symptoms in schizophrenia are also suggested.
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| 7. |
- Mørch-Johnsen, Lynn, et al.
(författare)
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The neural correlates of negative symptoms in schizophrenia : examples from MRI literature
- 2018
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Ingår i: Clinical EEG and Neuroscience. - : SAGE Publications Inc.. - 1550-0594 .- 2169-5202. ; 49:1, s. 12-17
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Tidskriftsartikel (refereegranskat)abstract
- Negative symptoms of schizophrenia have a negative impact on psychosocial functioning and disease outcome. It is therefore important to investigate the pathophysiology underlying negative symptoms as this may aid the development of better treatment. In the current article, examples from studies investigating neural correlates of negative symptoms in schizophrenia are given. Investigations using both structural and functional magnetic resonance imaging are presented at different levels of symptomatology descriptions, from the more heterogenous construct of negative symptoms to more single discrete symptoms. Some methods to improve imaging studies of negative symptoms in schizophrenia are also suggested.
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| 8. |
- Ögrim, Geir, et al.
(författare)
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Predicting Clinical Gains and Side Effects of Stimulant Medication in Pediatric Attention-Deficit/Hyperactivity Disorder by Combining Measures From qEEG and ERPs in a Cued GO/NOGO Task
- 2019
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Ingår i: Clinical Eeg and Neuroscience. - : SAGE Publications. - 1550-0594 .- 2169-5202. ; 50:1, s. 34-43
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. The study aim was to develop 2 scales: predicting clinical gains and risk of acute side effects of stimulant medication in pediatric attention-deficit/hyperactivity disorder (ADHD), combining measures from EEG spectra, event-related potentials (ERPs), and a cued visual GO/NOGO task. Methods. Based on 4-week systematic medication trials, 87 ADHD patients aged 8 to 17 years were classified as responders (REs, n = 62) or non-REs (n = 25), and belonging to the side effects (SEs, n = 42) or no-SEs (n = 45) groups. Before starting the trial, a 19-channel EEG was registered twice: Test 1 (T1) without medication and T2 on a single dose of stimulant medication a few days before the trial. EEG was registered T1 and T2: 3 minutes eyes-closed, 3 minutes eyes-open, and 20 minutes cued GO/NOGO. EEG spectra, ERPs, omissions, commissions, reaction time (RT), and RT variability were computed. Groups were compared at T1 and T2 on quantitative EEG (qEEG), ERPs and behavioral parameters; effect sizes (d) were estimated. Variables with d > 0.5 were converted to quartiles, multiplied by corresponding d, and summed to obtain 2 global scales. Results. Six variables differed significantly between REs and non-REs (T1: theta/alpha ratio, P3NOGO amplitude. Differences T2-T1: Omissions, RT variability, P3NOGO, contingent negative variation [CNV]). The global scale d was 1.86. Accuracy (receiver operating characteristic) was 0.92. SEs and no-SEs differed significantly on 4 variables. (T1: RT, T2: novelty component and alpha peak frequency, and RT changes. Global scale d = 1.08 and accuracy = 0.78. Conclusion. Gains and side effects of stimulants in pediatric ADHD can be predicted with high accuracy by combining EEG spectra, ERPs, and behavior from baseline and single-dose tests. identifier: NCT02695355.
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| 9. |
- Häger, Linda Angelica, et al.
(författare)
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Is Visual Prediction Impaired in Adolescents with Autism spectrum Disorder? Event-Related Potentials in a Cued Visual GO/NOGO Task
- 2024
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Ingår i: Clinical EEG and Neuroscience. - 1550-0594. ; 55:4, s. 406-416
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Deviant visual processing has been observed in autism spectrum disorder (ASD), manifesting as decreased P1 and P2 components of visual event-related potentials (ERPs). Alterations have been attributed to a failure of Bayesian inference, characterized by hypo-activation of top-down predictive abilities. To test this hypothesis, we measured the visual negativity (vN) as an ERP index of visual preparation hypothesized to mirror predictive brain activity. Method: ERPs in a cued visual GO/NOGO task in 63 adolescents with ASD (IQ > 70, attention-deficit hyperactivity disorder excluded) were compared with ERPs in a sex- and age-matched group of 60 typically developing (TD) controls. Results: The behavioral variables (omissions, commissions, reaction time, and reaction time variability), as well as ERP components reflecting, among other processes, cognitive control (contingent negative variation, P3 GO, P3 NOGO, N2 NOGO) did not differ between the groups. There were group differences in visually based ERPs. Besides P1 and P2 differences, the vN component differentiated the 2 groups with the highest effect size (d = 0.74).Conclusion: This ERP study lends support to the hypothesis suggesting that a Bayesian hypo-prediction could underlie unique perceptual experiences in individuals with ASD. This could lead to a predisposition to perceive the world with reduced influence and modulation from contextual cues, prior experiences, and pre-existing expectations.
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