Decreased spectral entropy modulation in patients with schizophrenia during a P300 task

Bachiller, Alejandro; Díez, Álvaro; Suazo, Vanessa; Domínguez, César; Ayuso, Marta; Hornero, Roberto; Poza, Jesús; Molina, Vicente

doi:10.1007/s00406-014-0488-6

Cited by 45 publications

(78 citation statements)

References 42 publications

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“…In contrast, P3b seems to be related to conscious top-down target processing, likely contributing to processing the stimulus information and performing cognitive response (Polich, 2007;Strobel et al, 2008). In previous reports, we found a blunted ERP modulation in Sz as response to both target (Bachiller et al, 2014) and distractor (Bachiller et al, 2015b) tones during an oddball paradigm. Thus, the analysis of the differences in neural pattern generators between Sz patients and healthy controls becomes an interesting research topic to clarify the neural substrate of reduced P300 amplitude in Sz.…”

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confidence: 46%

Auditory P3a and P3b neural generators in schizophrenia: An adaptive sLORETA P300 localization approach

Bachiller

Romero

Molina

et al. 2015

Schizophrenia Research

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The present study investigates the neural substrates underlying cognitive processing in schizophrenia (Sz) patients. To this end, an auditory 3-stimulus oddball paradigm was used to identify P3a and P3b components, elicited by rare-distractor and rare-target tones, respectively. Event-related potentials (ERP) were recorded from 31 Sz patients and 38 healthy controls. The P3a and P3b brain-source generators were identified by time-averaging of low-resolution brain electromagnetic tomography (LORETA) current density images. In contrast with the commonly used fixed window of interest (WOI), we proposed to apply an adaptive WOI, which takes into account subjects' P300 latency variability. Our results showed different P3a and P3b source activation patterns in both groups. P3b sources included frontal, parietal and limbic lobes, whereas P3a response generators were localized over bilateral frontal and superior temporal regions. These areas have been related to the discrimination of auditory stimulus and to the inhibition (P3a) or the initiation (P3b) of motor response in a cognitive task. In addition, differences in source localization between Sz and control groups were observed. Sz patients showed lower P3b source activity in bilateral frontal structures and the cingulate. P3a generators were less widespread for Sz patients than for controls in right superior, medial and middle frontal gyrus. Our findings suggest that target and distractor processing involves distinct attentional subsystems, both being altered in Sz. Hence, the study of neuroelectric brain information can provide further insights to understand cognitive processes and underlying mechanisms in Sz.

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confidence: 46%

Auditory P3a and P3b neural generators in schizophrenia: An adaptive sLORETA P300 localization approach

Bachiller

Romero

Molina

et al. 2015

Schizophrenia Research

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“…There are few studies that conducted discriminant analyses for differentiating SCH and control subjects. For instance, Bachiller et al [21] used linear discriminant analysis (LDA) applied to Shannon spectral entropy to achieve an accuracy of 0.77. In other study, Sabeti et al [22] used LDA and adaptive boosting with five spectral and nonlinear features to classify SCH group, achieving a maximum accuracy of 0.91.…”

Section: Resultsmentioning

confidence: 99%

Novel measure of the weigh distribution balance on the brain network: Graph complexity applied to schizophrenia

Gómez‐Pilar

Poza

Bachiller

et al. 2016

2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)

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Abstract-The aim of this study was to assess brain complexity dynamics in schizophrenia (SCH) patients during an auditory oddball task. For that task, we applied a novel graph measure based on the balance of the node weighs distribution. Previous studies applied complexity parameters that were strongly dependent on network topology. This fact could bias the results besides being necessary correction techniques as surrogating process. In the present study, we applied a novel graph complexity measure from the information theory: Shannon Graph Complexity (SGC). Complexity patterns form electroencephalographic recordings of 20 healthy controls and 20 SCH patients during an auditory oddball task were analyzed. Results showed a significantly more pronounced decrease of SGC for controls than for SCH patients during the cognitive task. These findings suggest an important change in the brain configuration towards more balanced networks, mainly in the connections related to longrange interactions. Since these changes are significantly more pronounced in controls, it implies a deficit in the neural network reorganization in SCH patients. In addition, SGC showed a suitable discrimination ability using a leave-one-out cross-validation: 0.725 accuracy and 0.752 area under receiver operating characteristics curve. The novel complexity measure proposed in this study demonstrated to be independent of network topology and, therefore, it complements traditional graph measures to characterize brain networks.

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“…In this study, we computed RP in order to study the spectral features of the EEG recordings, assess the validity of the database by comparing the results with those of a different one [15], and check its relationship with KLD. It is worth pointing out that the TFR needs to be normalized to the sum of the absolute values in all bands in order for RP to be a relative measure.…”

Section: Relative Powermentioning

confidence: 99%

“…Several methods have been used to analyze transient dynamics in neural activity during an auditory oddball task or during resting-state. Such measures, of a time-dependent nature, include wavelet entropy [6,13], multiscale entropy [14], median frequency [12,15] and relative power (RP) [15], among others. Many of these studies have found widespread lower neural reorganization (i.e., transient dynamical reorganization of brain activity during an attentional process) for SCH subjects compared to controls during the active task response [6,12,15].…”

Section: Introductionmentioning

confidence: 99%

Exploring non-stationarity patterns in schizophrenia: neural reorganization abnormalities in the alpha band

et al. 2017

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Objective. The aim of this paper was to characterize brain non-stationarity during an auditory oddball task in schizophrenia (SCH). The level of non-stationarity was measured in the baseline and response windows of relevant tones in SCH patients and healthy controls. Approach. Eventrelated potentials were recorded from 28 SCH patients and 51 controls. Non-stationarity was estimated in the conventional electroencephalography frequency bands by means of KullbackLeibler divergence (KLD). Relative power (RP) was also computed to assess a possible complementarity with KLD. Main results. Results showed a widespread statistically significant increase in the level of non-stationarity from baseline to response in all frequency bands for both groups. Statistically significant differences in non-stationarity were found between SCH patients and controls in beta-2 and especially in the alpha band. SCH patients showed more nonstationarity in the left parieto-occipital region during the baseline window in the beta-2 band. A leave-one-out cross validation classification study with feature selection based on binary stepwise logistic regression to discriminate between SCH patients and controls provided an accuracy of 89.87% and area under ROC of 0.9510. Significance. KLD can characterize transient neural reorganization during an attentional task in response to novelty and relevance. Our findings suggest anomalous reorganization of neural dynamics in SCH during an oddball task. The abnormal frequency-dependent modulation found in SCH patients during relevant tones is in agreement with the hypothesis of aberrant salience detection in SCH. The increase in nonstationarity in the alpha band during the active task supports the notion that this band is involved in top-down processing. The baseline differences in the beta-2 band suggest that hyperactivation of the default mode network during attention tasks may be related to SCH symptoms. Furthermore, the binary stepwise logistic regression procedure selected features from both KLD and RP, supporting the idea that these measures can be complementary.

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Decreased spectral entropy modulation in patients with schizophrenia during a P300 task

Cited by 45 publications

References 42 publications

Auditory P3a and P3b neural generators in schizophrenia: An adaptive sLORETA P300 localization approach

Auditory P3a and P3b neural generators in schizophrenia: An adaptive sLORETA P300 localization approach

Novel measure of the weigh distribution balance on the brain network: Graph complexity applied to schizophrenia

Exploring non-stationarity patterns in schizophrenia: neural reorganization abnormalities in the alpha band

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