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The feature extraction of resting-state EEG signal from amnestic mild cognitive impairment with type 2 diabetes mellitus based on feature-fusion multispectral image method. Neural Netw 2020; 124:373-382. [PMID: 32058892 DOI: 10.1016/j.neunet.2020.01.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 10/06/2019] [Accepted: 01/21/2020] [Indexed: 11/23/2022]
Abstract
Recently, combining feature extraction and classification method of electroencephalogram (EEG) signals has been widely used in identifying mild cognitive impairment. However, it remains unclear which feature of EEG signals is best effective in assessing amnestic mild cognitive impairment (aMCI) with type 2 diabetes mellitus (T2DM) when combining one classifier. This study proposed a novel feature extraction method of EEG signals named feature-fusion multispectral image method (FMIM) for diagnosis of aMCI with T2DM. The FMIM was integrated with convolutional neural network (CNN) to classify the processed multispectral image data. The results showed that FMIM could effectively identify aMCI with T2DM from the control group compared to existing multispectral image method (MIM), with improvements including the type and quantity of feature extraction. Meanwhile, part of the invalid calculation could be avoided during the classification process. In addition, the classification evaluation indexes were best under the combination of Alpha2-Beta1-Beta2 frequency bands in data set based on FMIM-1, and were also best under the combination of the Theta-Alpha1-Alpha2-Beta1-Beta2 frequency bands in data set based on FMIM-2. Therefore, FMIM can be used as an effective feature extraction method of aMCI with T2DM, and as a valuable biomarker in clinical applications.
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Kumral D, Şansal F, Cesnaite E, Mahjoory K, Al E, Gaebler M, Nikulin VV, Villringer A. BOLD and EEG signal variability at rest differently relate to aging in the human brain. Neuroimage 2019; 207:116373. [PMID: 31759114 DOI: 10.1016/j.neuroimage.2019.116373] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 10/17/2019] [Accepted: 11/17/2019] [Indexed: 01/22/2023] Open
Abstract
Variability of neural activity is regarded as a crucial feature of healthy brain function, and several neuroimaging approaches have been employed to assess it noninvasively. Studies on the variability of both evoked brain response and spontaneous brain signals have shown remarkable changes with aging but it is unclear if the different measures of brain signal variability - identified with either hemodynamic or electrophysiological methods - reflect the same underlying physiology. In this study, we aimed to explore age differences of spontaneous brain signal variability with two different imaging modalities (EEG, fMRI) in healthy younger (25 ± 3 years, N = 135) and older (67 ± 4 years, N = 54) adults. Consistent with the previous studies, we found lower blood oxygenation level dependent (BOLD) variability in the older subjects as well as less signal variability in the amplitude of low-frequency oscillations (1-12 Hz), measured in source space. These age-related reductions were mostly observed in the areas that overlap with the default mode network. Moreover, age-related increases of variability in the amplitude of beta-band frequency EEG oscillations (15-25 Hz) were seen predominantly in temporal brain regions. There were significant sex differences in EEG signal variability in various brain regions while no significant sex differences were observed in BOLD signal variability. Bivariate and multivariate correlation analyses revealed no significant associations between EEG- and fMRI-based variability measures. In summary, we show that both BOLD and EEG signal variability reflect aging-related processes but are likely to be dominated by different physiological origins, which relate differentially to age and sex.
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Affiliation(s)
- D Kumral
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; MindBrainBody Institute at the Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany.
| | - F Şansal
- International Graduate Program Medical Neurosciences, Charité-Universitätsmedizin, Berlin, Germany; Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - E Cesnaite
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - K Mahjoory
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Muenster, Germany
| | - E Al
- MindBrainBody Institute at the Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany; Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - M Gaebler
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; MindBrainBody Institute at the Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany
| | - V V Nikulin
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Neurophysics Group, Department of Neurology, Campus Benjamin Franklin, Charité Universitätsmedizin Berlin, Berlin, Germany; Centre for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of Economics, Moscow, Russia
| | - A Villringer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; MindBrainBody Institute at the Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany; Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany; Department of Cognitive Neurology, University Hospital Leipzig, Leipzig, Germany
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McDonough IM, Letang SK, Erwin HB, Kana RK. Evidence for Maintained Post-Encoding Memory Consolidation Across the Adult Lifespan Revealed by Network Complexity. ENTROPY 2019. [PMCID: PMC7514376 DOI: 10.3390/e21111072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Memory consolidation is well known to occur during sleep, but might start immediately after encoding new information while awake. While consolidation processes are important across the lifespan, they may be even more important to maintain memory functioning in old age. We tested whether a novel measure of information processing known as network complexity might be sensitive to post-encoding consolidation mechanisms in a sample of young, middle-aged, and older adults. Network complexity was calculated by assessing the irregularity of brain signals within a network over time using multiscale entropy. To capture post-encoding mechanisms, network complexity was estimated using functional magnetic resonance imaging (fMRI) during rest before and after encoding of picture pairs, and subtracted between the two rest periods. Participants received a five-alternative-choice memory test to assess associative memory performance. Results indicated that aging was associated with an increase in network complexity from pre- to post-encoding in the default mode network (DMN). Increases in network complexity in the DMN also were associated with better subsequent memory across all age groups. These findings suggest that network complexity is sensitive to post-encoding consolidation mechanisms that enhance memory performance. These post-encoding mechanisms may represent a pathway to support memory performance in the face of overall memory declines.
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Supervised dictionary learning of EEG signals for mild cognitive impairment diagnosis. Biomed Signal Process Control 2019. [DOI: 10.1016/j.bspc.2019.101559] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Nimmy John T, Subha Dharmapalan P, Ramshekhar Menon N. Exploration of time-frequency reassignment and homologous inter-hemispheric asymmetry analysis of MCI-AD brain activity. BMC Neurosci 2019; 20:38. [PMID: 31366317 PMCID: PMC6670117 DOI: 10.1186/s12868-019-0519-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 07/20/2019] [Indexed: 11/10/2022] Open
Abstract
Background In this study, nonlinear based time–frequency (TF) and time domain investigations are employed for the analysis of electroencephalogram (EEG) signals of mild cognitive impairment–Alzheimer’s disease (MCI–AD) patients and healthy controls. This study attempts to comprehend the cognitive decline of MCI–AD under both resting and cognitive task conditions. Results Wavelet-based synchrosqueezing transform (SST) alleviates the smearing of energy observed in the spectrogram around the central frequencies in short-time Fourier transform (STFT), and continuous wavelet transform (CWT). A precise TF representation is assured due to the reassignment of scale variable to the frequency variable. It is discerned from the studies of time domain measures encompassing fractal dimension (FD) and approximate entropy (ApEn), that the parietal lobe is the most affected in MCI–AD under both resting and cognitive states. Alterations in asymmetry in the brain hemispheres are analysed using the homologous areas inter-hemispheric symmetry (HArS). Conclusion Time and time–frequency domain analysis of EEG signals have been used for distinguishing various brain states. Therefore, EEG analysis is highly useful for the screening of AD in its prodromal phase.
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Affiliation(s)
- T Nimmy John
- Department of Electrical Engineering, National Institute of Technology Calicut, Calicut, Kerala, India.
| | | | - N Ramshekhar Menon
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
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Williams P, White A, Merino RB, Hardin S, Mizelle JC, Kim S. Facial Recognition Task for the Classification of Mild Cognitive Impairment with Ensemble Sparse Classifier. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2019; 2019:2242-2245. [PMID: 31946347 DOI: 10.1109/embc.2019.8857203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Conventional methods for detecting mild cognitive impairment (MCI) require cognitive exams and follow-up neuroimaging, which can be time-consuming and expensive. A great need exists for objective and cost-effective biomarkers for the early detection of MCI. This study uses a sequential imaging oddball paradigm to determine if familiar, unfamiliar, or inverted faces are effective visual stimuli for the early detection of MCI. Unlike the traditional approach where the amplitude and latency of certain deflection points of event-related potentials (ERPs) are selected as electrophysiological biomarkers (or features) of MCI, we used the entire ERPs as potential biomarkers and relied on an advanced machine-learning technique, i.e. an ensemble of sparse classifier (ESC), to choose the set of features to best discriminate MCI from healthy controls. Five MCI subjects and eight age-matched controls were given the MoCA exam before EEG recordings in a sensory-deprived room. Traditional time-domain comparisons of averaged ERPs between the two groups did not yield any statistical significance. However, ESC was able to discriminate MCI from controls with 95% classification accuracy based on the averaged ERPs elicited by familiar faces. By adopting advanced machine-learning techniques such as ESC, it may be possible to accurately diagnose MCI based on the ERPs that are specifically elicited by familiar faces.
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Li X, Zhang J, Shi C. [Study on the improvement of brain cognitive function status by mind-control game training]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2019; 36:364-370. [PMID: 31232537 PMCID: PMC9929962 DOI: 10.7507/1001-5515.201810030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Indexed: 06/09/2023]
Abstract
This study uses mind-control game training to intervene in patients with mild cognitive impairment to improve their cognitive function. In this study, electroencephalogram (EEG) data of 40 participants were collected before and after two training sessions. The continuous complexity of EEG signals was analyzed to assess the status of cognitive function and explore the effect of mind-control game training on the improvement of cognitive function. The results showed that after two training sessions, the continuous complexity of EEG signal of the subject increased (0.012 44 ± 0.000 29, P < 0.05) and amplitude of curve fluctuation decreased gradually, indicating that with increase of training times, the continuous complexity increased significantly, the cognitive function of brain improved significantly and state was stable. The results of this paper may show that mind-control game training can improve the status of the brain cognitive function, which may provide support and help for the future intervention of cognitive dysfunction.
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Affiliation(s)
- Xin Li
- Institute of Biomedical Engineering, Yanshan University, Qinhuangdao, Hebei 066004, P.R.China;Measurement Technology and Instrumentation Key Lab of Hebei Province, Qinhuangdao, Hebei 066004,
| | - Jie Zhang
- Institute of Biomedical Engineering, Yanshan University, Qinhuangdao, Hebei 066004, P.R.China;Measurement Technology and Instrumentation Key Lab of Hebei Province, Qinhuangdao, Hebei 066004, P.R.China
| | - Chunyan Shi
- Institute of Biomedical Engineering, Yanshan University, Qinhuangdao, Hebei 066004, P.R.China;Measurement Technology and Instrumentation Key Lab of Hebei Province, Qinhuangdao, Hebei 066004, P.R.China
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Abstract
Mild cognitive impairment (MCI) represents a transitional stage between healthy aging and dementia, and affects 10-15% of the population over the age of 65. The failure of drug trials in Alzheimer's disease (AD) treatment has shifted researchers' focus toward delaying progression from MCI to dementia, which would reduce the prevalence and costs of dementia profoundly. Diagnostic criteria for MCI increasingly emphasize the need for positive biomarkers to detect preclinical AD. The phenomenology of MCI comprises lower quality-of-life, greater symptoms of depression, and avoidant coping strategies including withdrawal from social engagement. Neurobiological features of MCI are hypoperfusion and hypometabolism in temporoparietal cortices, medial temporal lobe atrophy particularly in rhinal cortices, elevated tau and phosphorylated tau and decreased Aβ42 in cerebrospinal fluid, and brain Aβ42 deposition. Elevated tau can be identified in MCI, particularly in the entorhinal cortex, using positron emission tomography, and analysis of signal complexity using electroencephalography or magnetoencephalography holds promise as a biomarker. Assessment of MCI also relies on cognitive screening and neuropsychological assessment, but there is an urgent need for standardized cognitive tests to capitalize on recent discoveries in cognitive neuroscience that may lead to more sensitive measures of MCI. Cholinesterase inhibitors are frequently prescribed for MCI, despite the lack of evidence for their efficacy. Exercise and diet interventions hold promise for increasing reserve in MCI, and group psychoeducational programs teaching practical memory strategies appear effective. More work is needed to better understand the phenomenology and neurobiology of MCI, and how best to assess it and delay progression to dementia.
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59
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Ieracitano C, Mammone N, Bramanti A, Hussain A, Morabito FC. A Convolutional Neural Network approach for classification of dementia stages based on 2D-spectral representation of EEG recordings. Neurocomputing 2019. [DOI: 10.1016/j.neucom.2018.09.071] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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60
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Ruiz-Gómez SJ, Gómez C, Poza J, Martínez-Zarzuela M, Tola-Arribas MA, Cano M, Hornero R. Measuring Alterations of Spontaneous EEG Neural Coupling in Alzheimer's Disease and Mild Cognitive Impairment by Means of Cross-Entropy Metrics. Front Neuroinform 2018; 12:76. [PMID: 30459586 PMCID: PMC6232874 DOI: 10.3389/fninf.2018.00076] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 10/11/2018] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's Disease (AD) represents the most prevalent form of dementia and is considered a major health problem due to its high prevalence and its economic costs. An accurate characterization of the underlying neural dynamics in AD is crucial in order to adopt effective treatments. In this regard, mild cognitive impairment (MCI) is an important clinical entity, since it is a risk-state for developing dementia. In the present study, coupling patterns of 111 resting-state electroencephalography (EEG) recordings were analyzed. Specifically, we computed Cross-Approximate Entropy (Cross-ApEn) and Cross-Sample Entropy (Cross-SampEn) of 37 patients with dementia due to AD, 37 subjects with MCI, and 37 healthy control (HC) subjects. Our results showed that Cross-SampEn outperformed Cross-ApEn, revealing higher number of significant connections among the three groups (Kruskal-Wallis test, FDR-corrected p-values < 0.05). AD patients exhibited statistically significant lower similarity values at θ and β1 frequency bands compared to HC. MCI is also characterized by a global decrease of similarity in all bands, being only significant at β1. These differences shows that β band might play a significant role in the identification of early stages of AD. Our results suggest that Cross-SampEn could increase the insight into brain dynamics at different AD stages. Consequently, it may contribute to develop early AD biomarkers, potentially useful as diagnostic information.
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Affiliation(s)
- Saúl J. Ruiz-Gómez
- Biomedical Engineering Group, University of Valladolid, Valladolid, Spain
| | - Carlos Gómez
- Biomedical Engineering Group, University of Valladolid, Valladolid, Spain
| | - Jesús Poza
- Biomedical Engineering Group, University of Valladolid, Valladolid, Spain
- IMUVA, Mathematics Research Institute, University of Valladolid, Valladolid, Spain
- INCYL, Neuroscience Institute of Castilla y León, University of Salamanca, Salamanca, Spain
| | | | | | - Mónica Cano
- Department of Clinical Neurophysiology, Río Hortega University Hospital, Valladolid, Spain
| | - Roberto Hornero
- Biomedical Engineering Group, University of Valladolid, Valladolid, Spain
- IMUVA, Mathematics Research Institute, University of Valladolid, Valladolid, Spain
- INCYL, Neuroscience Institute of Castilla y León, University of Salamanca, Salamanca, Spain
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Cassani R, Estarellas M, San-Martin R, Fraga FJ, Falk TH. Systematic Review on Resting-State EEG for Alzheimer's Disease Diagnosis and Progression Assessment. DISEASE MARKERS 2018; 2018:5174815. [PMID: 30405860 PMCID: PMC6200063 DOI: 10.1155/2018/5174815] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 07/12/2018] [Accepted: 07/29/2018] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder that accounts for nearly 70% of the more than 46 million dementia cases estimated worldwide. Although there is no cure for AD, early diagnosis and an accurate characterization of the disease progression can improve the quality of life of AD patients and their caregivers. Currently, AD diagnosis is carried out using standardized mental status examinations, which are commonly assisted by expensive neuroimaging scans and invasive laboratory tests, thus rendering the diagnosis time consuming and costly. Notwithstanding, over the last decade, electroencephalography (EEG) has emerged as a noninvasive alternative technique for the study of AD, competing with more expensive neuroimaging tools, such as MRI and PET. This paper reports on the results of a systematic review on the utilization of resting-state EEG signals for AD diagnosis and progression assessment. Recent journal articles obtained from four major bibliographic databases were analyzed. A total of 112 journal articles published from January 2010 to February 2018 were meticulously reviewed, and relevant aspects of these papers were compared across articles to provide a general overview of the research on this noninvasive AD diagnosis technique. Finally, recommendations for future studies with resting-state EEG were presented to improve and facilitate the knowledge transfer among research groups.
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Affiliation(s)
- Raymundo Cassani
- Institut national de la recherche scientifique (INRS-EMT), University of Québec, Montreal, Canada
| | - Mar Estarellas
- Institut national de la recherche scientifique (INRS-EMT), University of Québec, Montreal, Canada
- Department of Bioengineering, Imperial College London, London, UK
| | - Rodrigo San-Martin
- Center for Mathematics, Computation and Cognition, Universidade Federal do ABC, São Bernardo do Campo, Brazil
| | - Francisco J. Fraga
- Engineering, Modeling and Applied Social Sciences Center, Universidade Federal do ABC, São Bernardo do Campo, Brazil
| | - Tiago H. Falk
- Institut national de la recherche scientifique (INRS-EMT), University of Québec, Montreal, Canada
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62
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Wan L, Huang H, Schwab N, Tanner J, Rajan A, Lam NB, Zaborszky L, Li CSR, Price CC, Ding M. From eyes-closed to eyes-open: Role of cholinergic projections in EC-to-EO alpha reactivity revealed by combining EEG and MRI. Hum Brain Mapp 2018; 40:566-577. [PMID: 30251753 DOI: 10.1002/hbm.24395] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 08/11/2018] [Accepted: 08/31/2018] [Indexed: 12/13/2022] Open
Abstract
Alpha rhythm (8 to 12 Hz) observed in EEG over human posterior cortex is prominent during eyes-closed (EC) resting and attenuates during eyes-open (EO) resting. Research shows that the degree of EC-to-EO alpha blocking or alpha desynchronization, termed alpha reactivity here, is a neural marker of cognitive health. We tested the role of acetylcholine in EC-to-EO alpha reactivity by applying a multimodal neuroimaging approach to a cohort of young adults and a cohort of older adults. In the young cohort, simultaneous EEG-fMRI was recorded from twenty-one young adults during both EO and EC resting. In the older cohort, functional MRI was recorded from forty older adults during EO and EC resting, along with FLAIR and diffusion MRI. For a subset of twenty older adults, EEG was recorded during EO and EC resting in a separate session. In both young and older adults, functional connectivity between the basal nucleus of Meynert (BNM), the major source of cortical acetylcholine, and the visual cortex increased from EC to EO, and this connectivity increase was positively associated with alpha reactivity; namely, the stronger the BNM-visual cortex functional connectivity increase from EC to EO, the larger the EC-to-EO alpha desynchronization. In older adults, lesions of the fiber tracts linking BNM and visual cortex quantified by leukoaraiosis volume, associated with reduced alpha reactivity. These findings support a role of acetylcholine and particularly cholinergic pathways in mediating EC-to-EO alpha reactivity and suggest that impaired alpha reactivity could serve as a marker of the integrity of the cholinergic system.
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Affiliation(s)
- Lu Wan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Haiqing Huang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida.,Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Nadine Schwab
- Department of Clinical & Health Psychology, University of Florida, Gainesville, Florida
| | - Jared Tanner
- Department of Clinical & Health Psychology, University of Florida, Gainesville, Florida
| | - Abhijit Rajan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Ngoc B Lam
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Laszlo Zaborszky
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, New Jersey
| | - Chiang-Shan R Li
- Departments of Psychiatry and Neuroscience, Yale University School of Medicine, New Haven, Connecticut
| | - Catherine C Price
- Department of Clinical & Health Psychology, University of Florida, Gainesville, Florida
| | - Mingzhou Ding
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
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63
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Can Chaotic Analysis of Electroencephalogram Aid the Diagnosis of Encephalopathy? Neurol Res Int 2018; 2018:8192820. [PMID: 30002930 PMCID: PMC5996471 DOI: 10.1155/2018/8192820] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 04/05/2018] [Accepted: 04/23/2018] [Indexed: 11/18/2022] Open
Abstract
Chaotic analysis is a relatively novel area in the study of physiological signals. Chaotic features of electroencephalogram have been analyzed in various disease states like epilepsy, Alzheimer's disease, sleep disorders, and depression. All these diseases have primary involvement of the brain. Our study examines the chaotic parameters in metabolic encephalopathy, where the brain functions are involved secondary to a metabolic disturbance. Our analysis clearly showed significant lower values for chaotic parameters, correlation dimension, and largest Lyapunov exponent for EEG in patients with metabolic encephalopathy compared to normal EEG. The chaotic features of EEG have been shown in previous studies to be an indicator of the complexity of brain dynamics. The smaller values of chaotic features for encephalopathy suggest that normal complexity of brain function is reduced in encephalopathy. To the best knowledge of the authors, no similar work has been reported on metabolic encephalopathy. This finding may be useful to understand the neurobiological phenomena in encephalopathy. These chaotic features are then utilized as feature sets for Support Vector Machine classifier to identify cases of encephalopathy from normal healthy subjects yielding high values of accuracy. Thus, we infer that chaotic measures are EEG parameters sensitive to functional alterations of the brain, caused by encephalopathy.
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64
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Kim D, Kim K. Detection of Early Stage Alzheimer's Disease using EEG Relative Power with Deep Neural Network. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:352-355. [PMID: 30440409 DOI: 10.1109/embc.2018.8512231] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Electroencephalogram (EEG) signal based early diagnosis of Alzheimer's Disease (AD), especially a discrimination between healthy control (HC) and mild cognitive impairment (MCI) has received remarkable attentions to complement conventional diagnosing methods in clinical fields. A relative power (RP) metric which quantifies the abnormal EEG pattern 'slowing' has widely been used as a major feature to distinguish HC and MCI, however, the optimal spectral ranges of the RP are influenced by the given dataset. In this study, we proposed the deep neural network based classifier using the RP to fully exploit and recombine the features through its own learning structure. The DNN enhanced the diagnosis results compared to shallow neural network, and enabled to interpret the results as we used the wellknown RP features as the domain knowledge. We investigated and explored the potentials of DNN based detection of the earlystage AD.
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65
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Simjanoska M, Gjoreski M, Gams M, Madevska Bogdanova A. Non-Invasive Blood Pressure Estimation from ECG Using Machine Learning Techniques. SENSORS (BASEL, SWITZERLAND) 2018; 18:E1160. [PMID: 29641430 PMCID: PMC5949031 DOI: 10.3390/s18041160] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/13/2018] [Accepted: 03/26/2018] [Indexed: 12/14/2022]
Abstract
BACKGROUND Blood pressure (BP) measurements have been used widely in clinical and private environments. Recently, the use of ECG monitors has proliferated; however, they are not enabled with BP estimation. We have developed a method for BP estimation using only electrocardiogram (ECG) signals. METHODS Raw ECG data are filtered and segmented, and, following this, a complexity analysis is performed for feature extraction. Then, a machine-learning method is applied, combining a stacking-based classification module and a regression module for building systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP) predictive models. In addition, the method allows a probability distribution-based calibration to adapt the models to a particular user. RESULTS Using ECG recordings from 51 different subjects, 3129 30-s ECG segments are constructed, and seven features are extracted. Using a train-validation-test evaluation, the method achieves a mean absolute error (MAE) of 8.64 mmHg for SBP, 18.20 mmHg for DBP, and 13.52 mmHg for the MAP prediction. When models are calibrated, the MAE decreases to 7.72 mmHg for SBP, 9.45 mmHg for DBP and 8.13 mmHg for MAP. CONCLUSION The experimental results indicate that, when a probability distribution-based calibration is used, the proposed method can achieve results close to those of a certified medical device for BP estimation.
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Affiliation(s)
- Monika Simjanoska
- Faculty of Computer Science and Engineering, Ss. Cyril and Methodius University, Rugjer Boshkovikj 16, 1000 Skopje, Macedonia.
| | - Martin Gjoreski
- Department of Intelligent Systems, Jožef Stefan Institute, Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia.
| | - Matjaž Gams
- Department of Intelligent Systems, Jožef Stefan Institute, Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia.
| | - Ana Madevska Bogdanova
- Faculty of Computer Science and Engineering, Ss. Cyril and Methodius University, Rugjer Boshkovikj 16, 1000 Skopje, Macedonia.
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Automated Multiclass Classification of Spontaneous EEG Activity in Alzheimer's Disease and Mild Cognitive Impairment. ENTROPY 2018; 20:e20010035. [PMID: 33265122 PMCID: PMC7512207 DOI: 10.3390/e20010035] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 01/04/2018] [Accepted: 01/05/2018] [Indexed: 12/24/2022]
Abstract
The discrimination of early Alzheimer’s disease (AD) and its prodromal form (i.e., mild cognitive impairment, MCI) from cognitively healthy control (HC) subjects is crucial since the treatment is more effective in the first stages of the dementia. The aim of our study is to evaluate the usefulness of a methodology based on electroencephalography (EEG) to detect AD and MCI. EEG rhythms were recorded from 37 AD patients, 37 MCI subjects and 37 HC subjects. Artifact-free trials were analyzed by means of several spectral and nonlinear features: relative power in the conventional frequency bands, median frequency, individual alpha frequency, spectral entropy, Lempel–Ziv complexity, central tendency measure, sample entropy, fuzzy entropy, and auto-mutual information. Relevance and redundancy analyses were also conducted through the fast correlation-based filter (FCBF) to derive an optimal set of them. The selected features were used to train three different models aimed at classifying the trials: linear discriminant analysis (LDA), quadratic discriminant analysis (QDA) and multi-layer perceptron artificial neural network (MLP). Afterwards, each subject was automatically allocated in a particular group by applying a trial-based majority vote procedure. After feature extraction, the FCBF method selected the optimal set of features: individual alpha frequency, relative power at delta frequency band, and sample entropy. Using the aforementioned set of features, MLP showed the highest diagnostic performance in determining whether a subject is not healthy (sensitivity of 82.35% and positive predictive value of 84.85% for HC vs. all classification task) and whether a subject does not suffer from AD (specificity of 79.41% and negative predictive value of 84.38% for AD vs. all comparison). Our findings suggest that our methodology can help physicians to discriminate AD, MCI and HC.
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67
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Wang B, Niu Y, Miao L, Cao R, Yan P, Guo H, Li D, Guo Y, Yan T, Wu J, Xiang J, Zhang H. Decreased Complexity in Alzheimer's Disease: Resting-State fMRI Evidence of Brain Entropy Mapping. Front Aging Neurosci 2017; 9:378. [PMID: 29209199 PMCID: PMC5701971 DOI: 10.3389/fnagi.2017.00378] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 11/03/2017] [Indexed: 01/05/2023] Open
Abstract
Alzheimer's disease (AD) is a frequently observed, irreversible brain function disorder among elderly individuals. Resting-state functional magnetic resonance imaging (rs-fMRI) has been introduced as an alternative approach to assessing brain functional abnormalities in AD patients. However, alterations in the brain rs-fMRI signal complexities in mild cognitive impairment (MCI) and AD patients remain unclear. Here, we described the novel application of permutation entropy (PE) to investigate the abnormal complexity of rs-fMRI signals in MCI and AD patients. The rs-fMRI signals of 30 normal controls (NCs), 33 early MCI (EMCI), 32 late MCI (LMCI), and 29 AD patients were obtained from the Alzheimer's disease Neuroimaging Initiative (ADNI) database. After preprocessing, whole-brain entropy maps of the four groups were extracted and subjected to Gaussian smoothing. We performed a one-way analysis of variance (ANOVA) on the brain entropy maps of the four groups. The results after adjusting for age and sex differences together revealed that the patients with AD exhibited lower complexity than did the MCI and NC controls. We found five clusters that exhibited significant differences and were distributed primarily in the occipital, frontal, and temporal lobes. The average PE of the five clusters exhibited a decreasing trend from MCI to AD. The AD group exhibited the least complexity. Additionally, the average PE of the five clusters was significantly positively correlated with the Mini-Mental State Examination (MMSE) scores and significantly negatively correlated with Functional Assessment Questionnaire (FAQ) scores and global Clinical Dementia Rating (CDR) scores in the patient groups. Significant correlations were also found between the PE and regional homogeneity (ReHo) in the patient groups. These results indicated that declines in PE might be related to changes in regional functional homogeneity in AD. These findings suggested that complexity analyses using PE in rs-fMRI signals can provide important information about the fMRI characteristics of cognitive impairments in MCI and AD.
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Affiliation(s)
- Bin Wang
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China.,Department of Radiology, First Hospital of Shanxi Medical University, Taiyuan, China
| | - Yan Niu
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China
| | - Liwen Miao
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China
| | - Rui Cao
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China
| | - Pengfei Yan
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China
| | - Hao Guo
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China
| | - Dandan Li
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China
| | - Yuxiang Guo
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China
| | - Tianyi Yan
- School of Life Science, Beijing Institute of Technology, Beijing, China.,Key Laboratory of Convergence Medical Engineering System and Healthcare Technology, Ministry of Industry and Information Technology, Beijing Institute of Technology, Beijing, China
| | - Jinglong Wu
- Key Laboratory of Biomimetic Robots and Systems, Ministry of Education, Beijing Institute of Technology, Beijing, China.,Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Jie Xiang
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China
| | - Hui Zhang
- Department of Radiology, First Hospital of Shanxi Medical University, Taiyuan, China
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68
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Classification of mild cognitive impairment EEG using combined recurrence and cross recurrence quantification analysis. Int J Psychophysiol 2017; 120:86-95. [DOI: 10.1016/j.ijpsycho.2017.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 06/10/2017] [Accepted: 07/11/2017] [Indexed: 11/21/2022]
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69
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Abstract
BACKGROUND Memory deficits are dominant in dementia and are positively correlated with electroencephalographic (EEG) beta power. EEG beta power can predict the progression of Alzheimer´s (AD) as early as at the stage of mild cognitive impairment (MCI) and could possibly be used as surrogate marker for memory impairment. The objective of this study is to analyze the relationship between frontal and parietal EEG beta power and memory-test outcome. Frontal and parietal beta power is analyzed for a resting state and an eyes-closed backward counting condition and related to memory impairment parameters. METHODS A total of 28 right-handed female geriatric patients (mean age = 80.6) participated voluntarily in this study. Beta 1 (12.9-19.2 Hz) and beta 2 (19.2-32.4 Hz) EEG power at F3, F4, Fz, P3, P4, and Pz are correlated with immediate wordlist recall, delayed wordlist recall, recognition of learned words, and delayed figure recall. For classification between impaired and intact memory, we calculated a binary logistic regression model with memory impairment as a dependent variable and beta 2 power as an independent variable. RESULTS We found significant positive correlations between frontal and parietal beta power and delayed memory recall. A significant correlation (Bonferroni correction, p < 0.05) was found at F4 beta 2 during backward counting. The binary logistic regression model with F4 beta 2 power during the counting condition as a predictor yielded a sensitivity of 76.9% (95% CI) and a specificity of 73.3% (95% CI) for classifying patients into "verbal-memory impaired" and "intact." CONCLUSIONS EEG beta 2 power recorded during a backward counting condition with eyes closed can be used as surrogate marker for verbal memory impairment in geriatric patients. Antidepressant treatment was correlated with EEG data in resting state but not in counting condition. Further studies are necessary to verify the results of this pilot study.
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70
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Quantitative EEG Markers of Entropy and Auto Mutual Information in Relation to MMSE Scores of Probable Alzheimer’s Disease Patients. ENTROPY 2017. [DOI: 10.3390/e19030130] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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71
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Jiang Y, Abiri R, Zhao X. Tuning Up the Old Brain with New Tricks: Attention Training via Neurofeedback. Front Aging Neurosci 2017; 9:52. [PMID: 28348527 PMCID: PMC5346575 DOI: 10.3389/fnagi.2017.00052] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 02/22/2017] [Indexed: 12/03/2022] Open
Abstract
Neurofeedback (NF) is a form of biofeedback that uses real-time (RT) modulation of brain activity to enhance brain function and behavioral performance. Recent advances in Brain-Computer Interfaces (BCI) and cognitive training (CT) have provided new tools and evidence that NF improves cognitive functions, such as attention and working memory (WM), beyond what is provided by traditional CT. More published studies have demonstrated the efficacy of NF, particularly for treating attention deficit hyperactivity disorder (ADHD) in children. In contrast, there have been fewer studies done in older adults with or without cognitive impairment, with some notable exceptions. The focus of this review is to summarize current success in RT NF training of older brains aiming to match those of younger brains during attention/WM tasks. We also outline potential future advances in RT brainwave-based NF for improving attention training in older populations. The rapid growth in wireless recording of brain activity, machine learning classification and brain network analysis provides new tools for combating cognitive decline and brain aging in older adults. We optimistically conclude that NF, combined with new neuro-markers (event-related potentials and connectivity) and traditional features, promises to provide new hope for brain and CT in the growing older population.
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Affiliation(s)
- Yang Jiang
- Aging Brain and Cognition Laboratory, Department of Behavioral Science, College of Medicine, University of KentuckyLexington, KY, USA; Sanders-Brown Center on Aging, College of Medicine, University of KentuckyLexington, KY, USA
| | - Reza Abiri
- Department of Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee Knoxville, TN, USA
| | - Xiaopeng Zhao
- Department of Mechanical, Aerospace, and Biomedical Engineering, University of TennesseeKnoxville, TN, USA; Institute for Medical Engineering and Science, Massachusetts Institute of TechnologyCambridge, MA, USA
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72
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Li J, Broster LS, Jicha GA, Munro NB, Schmitt FA, Abner E, Kryscio R, Smith CD, Jiang Y. A cognitive electrophysiological signature differentiates amnestic mild cognitive impairment from normal aging. ALZHEIMERS RESEARCH & THERAPY 2017; 9:3. [PMID: 28100252 PMCID: PMC5244569 DOI: 10.1186/s13195-016-0229-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 12/08/2016] [Indexed: 12/19/2022]
Abstract
Background Noninvasive and effective biomarkers for early detection of amnestic mild cognitive impairment (aMCI) before measurable changes in behavioral performance remain scarce. Cognitive event-related potentials (ERPs) measure synchronized synaptic neural activity associated with a cognitive event. Loss of synapses is a hallmark of the neuropathology of early Alzheimer’s disease (AD). In the present study, we tested the hypothesis that ERP responses during working memory retrieval discriminate aMCI from cognitively normal controls (NC) matched in age and education. Methods Eighteen NC, 17 subjects with aMCI, and 13 subjects with AD performed a delayed match-to-sample task specially designed not only to be easy enough for impaired participants to complete but also to generate comparable performance between subjects with NC and those with aMCI. Scalp electroencephalography, memory accuracy, and reaction times were measured. Results Whereas memory performance separated the AD group from the others, the performance of NC and subjects with aMCI was similar. In contrast, left frontal cognitive ERP patterns differentiated subjects with aMCI from NC. Enhanced P3 responses at left frontal sites were associated with nonmatching relative to matching stimuli during working memory tasks in patients with aMCI and AD, but not in NC. The accuracy of discriminating aMCI from NC was 85% by using left frontal match/nonmatch effect combined with nonmatch reaction time. Conclusions The left frontal cognitive ERP indicator holds promise as a sensitive, simple, affordable, and noninvasive biomarker for detection of early cognitive impairment.
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Affiliation(s)
- Juan Li
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, 100101, Beijing, China. .,Department of Behavioral Science, University of Kentucky College of Medicine, Lexington, KY, 40536, USA.
| | - Lucas S Broster
- Department of Behavioral Science, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Gregory A Jicha
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, 40536, USA.,Department of Neurology, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | | | - Frederick A Schmitt
- Department of Behavioral Science, University of Kentucky College of Medicine, Lexington, KY, 40536, USA.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, 40536, USA.,Department of Neurology, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Erin Abner
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, 40536, USA.,Department of Epidemiology, University of Kentucky College of Public Health, Lexington, KY, 40536, USA
| | - Richard Kryscio
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, 40536, USA.,Department of Statistics, University of Kentucky, Lexington, KY, 40536, USA.,Department of Biostatistics, University of Kentucky College of Public Health, Lexington, KY, 40536, USA
| | - Charles D Smith
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, 40536, USA.,Department of Neurology, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Yang Jiang
- Department of Behavioral Science, University of Kentucky College of Medicine, Lexington, KY, 40536, USA. .,Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, 40536, USA.
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73
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Zhang Y, Wei S, Liu H, Zhao L, Liu C. A novel encoding Lempel-Ziv complexity algorithm for quantifying the irregularity of physiological time series. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2016; 133:7-15. [PMID: 27393795 DOI: 10.1016/j.cmpb.2016.05.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 04/21/2016] [Accepted: 05/19/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND AND OBJECTIVE The Lempel-Ziv (LZ) complexity and its variants have been extensively used to analyze the irregularity of physiological time series. To date, these measures cannot explicitly discern between the irregularity and the chaotic characteristics of physiological time series. Our study compared the performance of an encoding LZ (ELZ) complexity algorithm, a novel variant of the LZ complexity algorithm, with those of the classic LZ (CLZ) and multistate LZ (MLZ) complexity algorithms. METHODS AND RESULTS Simulation experiments on Gaussian noise, logistic chaotic, and periodic time series showed that only the ELZ algorithm monotonically declined with the reduction in irregularity in time series, whereas the CLZ and MLZ approaches yielded overlapped values for chaotic time series and time series mixed with Gaussian noise, demonstrating the accuracy of the proposed ELZ algorithm in capturing the irregularity, rather than the complexity, of physiological time series. In addition, the effect of sequence length on the ELZ algorithm was more stable compared with those on CLZ and MLZ, especially when the sequence length was longer than 300. A sensitivity analysis for all three LZ algorithms revealed that both the MLZ and the ELZ algorithms could respond to the change in time sequences, whereas the CLZ approach could not. Cardiac interbeat (RR) interval time series from the MIT-BIH database were also evaluated, and the results showed that the ELZ algorithm could accurately measure the inherent irregularity of the RR interval time series, as indicated by lower LZ values yielded from a congestive heart failure group versus those yielded from a normal sinus rhythm group (p < 0.01).
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Affiliation(s)
- Yatao Zhang
- School of Control Science and Engineering, Shandong University, Jinan 250061, China; School of Mechanical, Electrical & Information Engineering, Shandong University, Weihai 264209, China
| | - Shoushui Wei
- School of Control Science and Engineering, Shandong University, Jinan 250061, China.
| | - Hai Liu
- School of Mechanical, Electrical & Information Engineering, Shandong University, Weihai 264209, China
| | - Lina Zhao
- School of Control Science and Engineering, Shandong University, Jinan 250061, China
| | - Chengyu Liu
- School of Control Science and Engineering, Shandong University, Jinan 250061, China.
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74
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Weighted-Permutation Entropy Analysis of Resting State EEG from Diabetics with Amnestic Mild Cognitive Impairment. ENTROPY 2016. [DOI: 10.3390/e18080307] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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75
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Alberdi A, Aztiria A, Basarab A. On the early diagnosis of Alzheimer's Disease from multimodal signals: A survey. Artif Intell Med 2016; 71:1-29. [PMID: 27506128 DOI: 10.1016/j.artmed.2016.06.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/23/2016] [Accepted: 06/07/2016] [Indexed: 11/15/2022]
Abstract
INTRODUCTION The number of Alzheimer's Disease (AD) patients is increasing with increased life expectancy and 115.4 million people are expected to be affected in 2050. Unfortunately, AD is commonly diagnosed too late, when irreversible damages have been caused in the patient. OBJECTIVE An automatic, continuous and unobtrusive early AD detection method would be required to improve patients' life quality and avoid big healthcare costs. Thus, the objective of this survey is to review the multimodal signals that could be used in the development of such a system, emphasizing on the accuracy that they have shown up to date for AD detection. Some useful tools and specific issues towards this goal will also have to be reviewed. METHODS An extensive literature review was performed following a specific search strategy, inclusion criteria, data extraction and quality assessment in the Inspec, Compendex and PubMed databases. RESULTS This work reviews the extensive list of psychological, physiological, behavioural and cognitive measurements that could be used for AD detection. The most promising measurements seem to be magnetic resonance imaging (MRI) for AD vs control (CTL) discrimination with an 98.95% accuracy, while electroencephalogram (EEG) shows the best results for mild cognitive impairment (MCI) vs CTL (97.88%) and MCI vs AD distinction (94.05%). Available physiological and behavioural AD datasets are listed, as well as medical imaging analysis steps and neuroimaging processing toolboxes. Some issues such as "label noise" and multi-site data are discussed. CONCLUSIONS The development of an unobtrusive and transparent AD detection system should be based on a multimodal system in order to take full advantage of all kinds of symptoms, detect even the smallest changes and combine them, so as to detect AD as early as possible. Such a multimodal system might probably be based on physiological monitoring of MRI or EEG, as well as behavioural measurements like the ones proposed along the article. The mentioned AD datasets and image processing toolboxes are available for their use towards this goal. Issues like "label noise" and multi-site neuroimaging incompatibilities may also have to be overcome, but methods for this purpose are already available.
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Affiliation(s)
- Ane Alberdi
- Mondragon University, Electronics and Computing Department, Goiru Kalea, 2, Arrasate 20500, Spain.
| | - Asier Aztiria
- Mondragon University, Electronics and Computing Department, Goiru Kalea, 2, Arrasate 20500, Spain.
| | - Adrian Basarab
- Université de Toulouse, Institut de Recherche en Informatique de Toulouse, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5505, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse, France.
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76
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Li T, Wen P. Depth of anaesthesia assessment based on adult electroencephalograph beta frequency band. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2016; 39:773-81. [DOI: 10.1007/s13246-016-0459-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 06/12/2016] [Indexed: 11/29/2022]
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77
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Chiang HS, Pao SC. An EEG-Based Fuzzy Probability Model for Early Diagnosis of Alzheimer's Disease. J Med Syst 2016; 40:125. [PMID: 27059738 DOI: 10.1007/s10916-016-0476-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 03/14/2016] [Indexed: 01/19/2023]
Abstract
Alzheimer's disease is a degenerative brain disease that results in cardinal memory deterioration and significant cognitive impairments. The early treatment of Alzheimer's disease can significantly reduce deterioration. Early diagnosis is difficult, and early symptoms are frequently overlooked. While much of the literature focuses on disease detection, the use of electroencephalography (EEG) in Alzheimer's diagnosis has received relatively little attention. This study combines the fuzzy and associative Petri net methodologies to develop a model for the effective and objective detection of Alzheimer's disease. Differences in EEG patterns between normal subjects and Alzheimer patients are used to establish prediction criteria for Alzheimer's disease, potentially providing physicians with a reference for early diagnosis, allowing for early action to delay the disease progression.
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Affiliation(s)
- Hsiu-Sen Chiang
- Department of Information Management, National Taichung University of Science and Technology, No. 129, Section 3, Sanmin Road, Taichung City 404, Taiwan, Republic of China.
| | - Shun-Chi Pao
- Department of Information Management, National Taichung University of Science and Technology, No. 129, Section 3, Sanmin Road, Taichung City 404, Taiwan, Republic of China
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78
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Akbar Y, Khotimah SN, Haryanto F. Spectral and brain mapping analysis of EEG based on Pwelch in schizophrenic patients. ACTA ACUST UNITED AC 2016. [DOI: 10.1088/1742-6596/694/1/012070] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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79
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Smits FM, Porcaro C, Cottone C, Cancelli A, Rossini PM, Tecchio F. Electroencephalographic Fractal Dimension in Healthy Ageing and Alzheimer's Disease. PLoS One 2016; 11:e0149587. [PMID: 26872349 PMCID: PMC4752290 DOI: 10.1371/journal.pone.0149587] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 02/01/2016] [Indexed: 11/18/2022] Open
Abstract
Brain activity is complex; a reflection of its structural and functional organization. Among other measures of complexity, the fractal dimension is emerging as being sensitive to neuronal damage secondary to neurological and psychiatric diseases. Here, we calculated Higuchi’s fractal dimension (HFD) in resting-state eyes-closed electroencephalography (EEG) recordings from 41 healthy controls (age: 20–89 years) and 67 Alzheimer’s Disease (AD) patients (age: 50–88 years), to investigate whether HFD is sensitive to brain activity changes typical in healthy aging and in AD. Additionally, we considered whether AD-accelerating effects of the copper fraction not bound to ceruloplasmin (also called “free” copper) are reflected in HFD fluctuations. The HFD measure showed an inverted U-shaped relationship with age in healthy people (R2 = .575, p < .001). Onset of HFD decline appeared around the age of 60, and was most evident in central-parietal regions. In this region, HFD decreased with aging stronger in the right than in the left hemisphere (p = .006). AD patients demonstrated reduced HFD compared to age- and education-matched healthy controls, especially in temporal-occipital regions. This was associated with decreasing cognitive status as assessed by mini-mental state examination, and with higher levels of non-ceruloplasmin copper. Taken together, our findings show that resting-state EEG complexity increases from youth to maturity and declines in healthy, aging individuals. In AD, brain activity complexity is further reduced in correlation with cognitive impairment. In addition, elevated levels of non-ceruloplasmin copper appear to accelerate the reduction of neural activity complexity. Overall, HDF appears to be a proper indicator for monitoring EEG-derived brain activity complexity in healthy and pathological aging.
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Affiliation(s)
- Fenne Margreeth Smits
- LET’S—ISTC—CNR, Ospedale Fatebenefratelli, Isola Tiberina, Rome, Italy
- University of Amsterdam, Amsterdam, The Netherlands
| | - Camillo Porcaro
- LET’S—ISTC—CNR, Ospedale Fatebenefratelli, Isola Tiberina, Rome, Italy
- Institute of Neuroscience, Newcastle University, Medical School, Newcastle upon Tyne, United Kingdom
- Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy
| | - Carlo Cottone
- LET’S—ISTC—CNR, Ospedale Fatebenefratelli, Isola Tiberina, Rome, Italy
| | - Andrea Cancelli
- LET’S—ISTC—CNR, Ospedale Fatebenefratelli, Isola Tiberina, Rome, Italy
- Institute of Neurology, Cattolica del Sacro Cuore University, Rome, Italy
| | - Paolo Maria Rossini
- Institute of Neurology, Cattolica del Sacro Cuore University, Rome, Italy
- Unit of Neuroimaging, IRCCS San Raffaele Pisana, Rome, Italy
| | - Franca Tecchio
- LET’S—ISTC—CNR, Ospedale Fatebenefratelli, Isola Tiberina, Rome, Italy
- Unit of Neuroimaging, IRCCS San Raffaele Pisana, Rome, Italy
- * E-mail:
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80
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Kashefpoor M, Rabbani H, Barekatain M. Automatic Diagnosis of Mild Cognitive Impairment Using Electroencephalogram Spectral Features. JOURNAL OF MEDICAL SIGNALS AND SENSORS 2016; 6:25-32. [PMID: 27014609 PMCID: PMC4786960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Alzheimer's disease (AD) is one of the most expensive and fatal diseases in the elderly population. Up to now, no cure have been found for AD, so early stage diagnosis is the only way to control it. Mild cognitive impairment (MCI) usually is the early stage of AD which is defined as decreasing in mental abilities such a cognition, memory, and speech not too severe to interfere daily activities. MCI diagnosis is rather hard and usually assumed as normal consequences of aging. This study proposes an accurate, mobile, and nonexpensive diagnostic approach based on electroencephalogram (EEG) signal. EEG signals were recorded using 19 electrodes positioned according to the 10-20 International system at resting eyes closed state from 16 normal and 11 MCI participants. Nineteen Spectral features are computed for each channel and examined using a correlation based algorithm to select the best discriminative features. Selected features are classified using a combination of neurofuzzy system and k-nearest neighbor classifier. Final results reach 88.89%, 100%, and 83.33% for accuracy, sensitivity, and specificity, respectively, which shows the potential of proposed method to be used as an MCI diagnostic tool, especially for screening a large population.
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Affiliation(s)
- Masoud Kashefpoor
- Department of Biomedical Engineering, Faculty of Advanced Medical Technologies, Isfahan University of Medical Sciences, Isfahan, Iran,Student Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Hossein Rabbani
- Department of Biomedical Engineering, Faculty of Advanced Medical Technologies, Isfahan University of Medical Sciences, Isfahan, Iran,Medical Image and Signal Processing Research Center, Isfahan University of Medical Sciences, Isfahan, Iran,Address for correspondence: Department of Advanced Medical Technologies, Medical Image and Signal Processing Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. E-mail:
| | - Majid Barekatain
- Psychosomatic Research Center, Department of Psychiatry, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran
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81
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Ghorbanian P, Ramakrishnan S, Ashrafiuon H. Stochastic non-linear oscillator models of EEG: the Alzheimer's disease case. Front Comput Neurosci 2015; 9:48. [PMID: 25964756 PMCID: PMC4408857 DOI: 10.3389/fncom.2015.00048] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 04/07/2015] [Indexed: 11/29/2022] Open
Abstract
In this article, the Electroencephalography (EEG) signal of the human brain is modeled as the output of stochastic non-linear coupled oscillator networks. It is shown that EEG signals recorded under different brain states in healthy as well as Alzheimer's disease (AD) patients may be understood as distinct, statistically significant realizations of the model. EEG signals recorded during resting eyes-open (EO) and eyes-closed (EC) resting conditions in a pilot study with AD patients and age-matched healthy control subjects (CTL) are employed. An optimization scheme is then utilized to match the output of the stochastic Duffing—van der Pol double oscillator network with EEG signals recorded during each condition for AD and CTL subjects by selecting the model physical parameters and noise intensity. The selected signal characteristics are power spectral densities in major brain frequency bands Shannon and sample entropies. These measures allow matching of linear time varying frequency content as well as non-linear signal information content and complexity. The main finding of the work is that statistically significant unique models represent the EC and EO conditions for both CTL and AD subjects. However, it is also shown that the inclusion of sample entropy in the optimization process, to match the complexity of the EEG signal, enhances the stochastic non-linear oscillator model performance.
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Affiliation(s)
- Parham Ghorbanian
- Department of Mechanical Engineering, Center for Nonlinear Dynamics and Control, Villanova University Villanova, PA, USA
| | - Subramanian Ramakrishnan
- Department of Mechanical and Industrial Engineering, University of Minnesota Duluth Duluth, MN, USA
| | - Hashem Ashrafiuon
- Department of Mechanical Engineering, Center for Nonlinear Dynamics and Control, Villanova University Villanova, PA, USA
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McBride J, Zhao X, Munro N, Jicha G, Smith C, Jiang Y. Discrimination of mild cognitive impairment and Alzheimer's disease using transfer entropy measures of scalp EEG. JOURNAL OF HEALTHCARE ENGINEERING 2015; 6:55-70. [PMID: 25708377 DOI: 10.1260/2040-2295.6.1.55] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Mild cognitive impairment (MCI) is a neurological condition related to early stages of dementia including Alzheimer's disease (AD). This study investigates the potential of measures of transfer entropy in scalp EEG for effectively discriminating between normal aging, MCI, and AD participants. Resting EEG records from 48 age-matched participants (mean age 75.7 years)-15 normal controls, 16 MCI, and 17 early AD-are examined. The mean temporal delays corresponding to peaks in inter-regional transfer entropy are computed and used as features to discriminate between the three groups of participants. Three-way classification schemes based on binary support vector machine models demonstrate overall discrimination accuracies of 91.7- 93.8%, depending on the protocol condition. These results demonstrate the potential for EEG transfer entropy measures as biomarkers in identifying early MCI and AD. Moreover, the analyses based on short data segments (two minutes) render the method practical for a primary care setting.
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Affiliation(s)
- Joseph McBride
- Department of Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee, Knoxville, TN, USA
| | - Xiaopeng Zhao
- Department of Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee, Knoxville, TN, USA
| | - Nancy Munro
- Oak Ridge Nation Laboratory, Oak Ridge, TN, USA
| | - Gregory Jicha
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA Department of Neurology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Charles Smith
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA Department of Neurology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Yang Jiang
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA Department of Behavioral Science, University of Kentucky College of Medicine, Lexington, KY, USA
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83
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Ghorbanian P, Devilbiss DM, Hess T, Bernstein A, Simon AJ, Ashrafiuon H. Exploration of EEG features of Alzheimer's disease using continuous wavelet transform. Med Biol Eng Comput 2015; 53:843-55. [PMID: 25863694 DOI: 10.1007/s11517-015-1298-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 04/03/2015] [Indexed: 10/23/2022]
Abstract
We have developed a novel approach to elucidate several discriminating EEG features of Alzheimer's disease. The approach is based on the use of a variety of continuous wavelet transforms, pairwise statistical tests with multiple comparison correction, and several decision tree algorithms, in order to choose the most prominent EEG features from a single sensor. A pilot study was conducted to record EEG signals from Alzheimer's disease (AD) patients and healthy age-matched control (CTL) subjects using a single dry electrode device during several eyes-closed (EC) and eyes-open (EO) resting conditions. We computed the power spectrum distribution properties and wavelet and sample entropy of the wavelet coefficients time series at scale ranges approximately corresponding to the major brain frequency bands. A predictive index was developed using the results from statistical tests and decision tree algorithms to identify the most reliable significant features of the AD patients when compared to healthy controls. The three most dominant features were identified as larger absolute mean power and larger standard deviation of the wavelet scales corresponding to 4-8 Hz (θ) during EO and lower wavelet entropy of the wavelet scales corresponding to 8-12 Hz (α) during EC, respectively. The fourth reliable set of distinguishing features of AD patients was lower relative power of the wavelet scales corresponding to 12-30 Hz (β) followed by lower skewness of the wavelet scales corresponding to 2-4 Hz (upper δ), both during EO. In general, the results indicate slowing and lower complexity of EEG signal in AD patients using a very easy-to-use and convenient single dry electrode device.
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Affiliation(s)
- Parham Ghorbanian
- Center for Nonlinear Dynamics and Control, Villanova University, Villanova, PA, 19085, USA
| | | | - Terry Hess
- Palm Drive Hospital, Sebastopol, CA, 95472, USA
| | | | | | - Hashem Ashrafiuon
- Center for Nonlinear Dynamics and Control, Villanova University, Villanova, PA, 19085, USA.
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84
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Ghorbanian P, Ramakrishnan S, Whitman A, Ashrafiuon H. A phenomenological model of EEG based on the dynamics of a stochastic Duffing-van der Pol oscillator network. Biomed Signal Process Control 2015. [DOI: 10.1016/j.bspc.2014.08.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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85
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Wang R, Wang J, Li S, Yu H, Deng B, Wei X. Multiple feature extraction and classification of electroencephalograph signal for Alzheimers' with spectrum and bispectrum. CHAOS (WOODBURY, N.Y.) 2015; 25:013110. [PMID: 25637921 DOI: 10.1063/1.4906038] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this paper, we have combined experimental neurophysiologic recording and statistical analysis to investigate the nonlinear characteristic and the cognitive function of the brain. Spectrum and bispectrum analyses are proposed to extract multiple effective features of electroencephalograph (EEG) signals from Alzheimer's disease (AD) patients and further applied to distinguish AD patients from the normal controls. Spectral analysis based on autoregressive Burg method is first used to quantify the power distribution of EEG series in the frequency domain. Compared to the control group, the relative power spectral density of AD group is significantly higher in the theta frequency band, while lower in the alpha frequency bands. In addition, median frequency of spectrum is decreased, and spectral entropy ratio of these two frequency bands undergoes drastic changes at the P3 electrode in the central-parietal brain region, implying that the electrophysiological behavior in AD brain is much slower and less irregular. In order to explore the nonlinear high order information, bispectral analysis which measures the complexity of phase-coupling is further applied to P3 electrode in the whole frequency band. It is demonstrated that less bispectral peaks appear and the amplitudes of peaks fall, suggesting a decrease of non-Gaussianity and nonlinearity of EEG in ADs. Notably, the application of this method to five brain regions shows higher concentration of the weighted center of bispectrum and lower complexity reflecting phase-coupling by bispectral entropy. Based on spectrum and bispectrum analyses, six efficient features are extracted and then applied to discriminate AD from the normal in the five brain regions. The classification results indicate that all these features could differentiate AD patients from the normal controls with a maximum accuracy of 90.2%. Particularly, different brain regions are sensitive to different features. Moreover, the optimal combination of features obtained by discriminant analysis may improve the classification accuracy. These results demonstrate the great promise for scape EEG spectral and bispectral features as a potential effective method for detection of AD, which may facilitate our understanding of the pathological mechanism of the disease.
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Affiliation(s)
- Ruofan Wang
- School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072, China
| | - Jiang Wang
- School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072, China
| | - Shunan Li
- School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072, China
| | - Haitao Yu
- School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072, China
| | - Bin Deng
- School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072, China
| | - Xile Wei
- School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072, China
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86
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McBride JC, Zhao X, Munro NB, Jicha GA, Schmitt FA, Kryscio RJ, Smith CD, Jiang Y. Sugihara causality analysis of scalp EEG for detection of early Alzheimer's disease. NEUROIMAGE-CLINICAL 2014; 7:258-65. [PMID: 25610788 PMCID: PMC4300018 DOI: 10.1016/j.nicl.2014.12.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 10/10/2014] [Accepted: 12/01/2014] [Indexed: 12/30/2022]
Abstract
Recently, Sugihara proposed an innovative causality concept, which, in contrast to statistical predictability in Granger sense, characterizes underlying deterministic causation of the system. This work exploits Sugihara causality analysis to develop novel EEG biomarkers for discriminating normal aging from mild cognitive impairment (MCI) and early Alzheimer's disease (AD). The hypothesis of this work is that scalp EEG based causality measurements have different distributions for different cognitive groups and hence the causality measurements can be used to distinguish between NC, MCI, and AD participants. The current results are based on 30-channel resting EEG records from 48 age-matched participants (mean age 75.7 years) - 15 normal controls (NCs), 16 MCI, and 17 early-stage AD. First, a reconstruction model is developed for each EEG channel, which predicts the signal in the current channel using data of the other 29 channels. The reconstruction model of the target channel is trained using NC, MCI, or AD records to generate an NC-, MCI-, or AD-specific model, respectively. To avoid over fitting, the training is based on the leave-one-out principle. Sugihara causality between the channels is described by a quality score based on comparison between the reconstructed signal and the original signal. The quality scores are studied for their potential as biomarkers to distinguish between the different cognitive groups. First, the dimension of the quality scores is reduced to two principal components. Then, a three-way classification based on the principal components is conducted. Accuracies of 95.8%, 95.8%, and 97.9% are achieved for resting eyes open, counting eyes closed, and resting eyes closed protocols, respectively. This work presents a novel application of Sugihara causality analysis to capture characteristic changes in EEG activity due to cognitive deficits. The developed method has excellent potential as individualized biomarkers in the detection of pathophysiological changes in early-stage AD.
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Affiliation(s)
- Joseph C McBride
- Department of Mechanical, Aerospace and Biomedical Engineering, Knoxville, TN 37996, USA
| | - Xiaopeng Zhao
- Department of Mechanical, Aerospace and Biomedical Engineering, Knoxville, TN 37996, USA ; National Institute of Mathematical and Biological Synthesis, University of Tennessee, Knoxville, TN 37996, USA
| | - Nancy B Munro
- Oak Ridge National Laboratory, Oak Ridge, TN 37831-6418, USA
| | - Gregory A Jicha
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA ; Department of Neurology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Frederick A Schmitt
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA ; Department of Neurology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Richard J Kryscio
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA ; Department of Statistics, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Charles D Smith
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA ; Department of Neurology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Yang Jiang
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA ; Department of Behavioral Science, University of Kentucky College of Medicine, Lexington, KY 40356, USA
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87
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Bai W, Yi H, Liu T, Wei J, Tian X. Incoordination between spikes and LFPs in Aβ1-42-mediated memory deficits in rats. Front Behav Neurosci 2014; 8:411. [PMID: 25505877 PMCID: PMC4245911 DOI: 10.3389/fnbeh.2014.00411] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 11/12/2014] [Indexed: 01/23/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease that gradually induces cognitive deficits. Impairments of working memory have been typically observed in AD. It is well known that spikes and local field potentials (LFPs) as well as the coordination between them encode information in normal brain function. However, the abnormal coordination between spikes and LFPs in the cognitive deficits of AD has remained largely unexplored. As amyloid-β peptide (Aβ) is a causative factor for the cognitive impairments of AD, developing a mechanistic understanding of the contribution of Aβ to cognitive impairments may yield important insights into the pathophysiology of AD. In the present study, we simultaneously recorded spikes and LFPs from multiple electrodes implanted in the prefrontal cortex of rats (control and intra-hippocampal Aβ injection group) that performed a Y-maze working memory task. The information changes in spikes and LFPs during the task were assessed by calculation of entropy. Then the coordination between spikes and LFPs was estimated by the correlation of LFP entropy and spike entropy. Compared with the control group, the Aβ group showed significantly weaker coordination between spikes and LFPs. Our results indicate that the incoordination between spikes and LFPs may provide a potential mechanism for the cognitive deficits in working memory of AD.
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Affiliation(s)
- Wenwen Bai
- Department of Biomedical Engineering, School of Biomedical Engineering and Technology, Tianjin Medical University Tianjin, China
| | - Hu Yi
- Department of Biomedical Engineering, School of Biomedical Engineering and Technology, Tianjin Medical University Tianjin, China
| | - Tiaotiao Liu
- Department of Biomedical Engineering, School of Biomedical Engineering and Technology, Tianjin Medical University Tianjin, China
| | - Jing Wei
- Department of Biomedical Engineering, School of Biomedical Engineering and Technology, Tianjin Medical University Tianjin, China
| | - Xin Tian
- Department of Biomedical Engineering, School of Biomedical Engineering and Technology, Tianjin Medical University Tianjin, China
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Ben Ali J, Abid S, William Jervis B, Fnaiech F, Bigan C, Besleaga M. Identification of early-stage Alzheimer׳s disease using SFAM neural network. Neurocomputing 2014. [DOI: 10.1016/j.neucom.2014.06.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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89
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Karthick PA, Makaram N, Ramakrishnan S. Analysis of progression of fatigue conditions in biceps brachii muscles using surface electromyography signals and complexity based features. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2014; 2014:3276-3279. [PMID: 25570690 DOI: 10.1109/embc.2014.6944322] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Muscle fatigue is a neuromuscular condition where muscle performance decreases due to sustained or intense contraction. It is experienced by both normal and abnormal subjects. In this work, an attempt has been made to analyze the progression of muscle fatigue in biceps brachii muscles using surface electromyography (sEMG) signals. The sEMG signals are recorded from fifty healthy volunteers during dynamic contractions under well defined protocol. The acquired signals are preprocessed and segmented in to six equal parts for further analysis. The features, such as activity, mobility, complexity, sample entropy and spectral entropy are extracted from all six zones. The results are found showing that the extracted features except complexity feature have significant variations in differentiating non-fatigue and fatigue zone respectively. Thus, it appears that, these features are useful in automated analysis of various neuromuscular activities in normal and pathological conditions.
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