Global, Regional, and Local Measures of Complexity of Multichannel Electroencephalography in Acute, Neuroleptic-Naive, First-Break Schizophrenics

Saito, Naomi; Kuginuki, T; Yagyu, Takami; Kinoshita, Toshihiko; Koenig, Thomas; Pascual-Marqui, Roberto D.; Kochi, Kieko; Wackermann, Jiřı́; Lehmann, Dietrich

doi:10.1016/s0006-3223(97)00547-7

Cited by 82 publications

(62 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nevertheless, authors were cautious when interpreting this absence of significant correlations. Higher complexity values might be still partially attributed to drug effects although similar findings of increased complexity values were obtained in non medicated samples (Saito et al, 1998).…”

Section: Significancesupporting

confidence: 65%

See 1 more Smart Citation

Lempel–Ziv complexity in schizophrenia: A MEG study

Fernández

López‐Ibor

Turrero

et al. 2011

Clinical Neurophysiology

View full text Add to dashboard Cite

SchizophreniaLempel-Ziv complexity Magnetoencephalography Neurodevelopmental Neurodegenerative• Schizophrenic patients show higher complexity values as compared to controls.• Schizophrenic patients showed a tendency to reduced complexity values as a function of age while controls showed the opposite tendency.• The tendency observed in schizophrenic patients parallels the tendency observed in Alzheimer disease patients. ABSTRACTObjective: The neurodevelopmental-neurodegenerative debate is a basic issue in the field of the neuropathological basis of schizophrenia (SCH). Neurophysiological techniques have been scarcely involved in such debate, but nonlinear analysis methods may contribute to it. Methods: Fifteen patients (age range 23-42 years) matching DSM IV-TR criteria for SCH, and 15 sex-and age-matched control subjects (age range 23-42 years) underwent a resting-state magnetoencephalographic evaluation and Lempel-Ziv complexity (LZC) scores were calculated. Results: Regression analyses indicated that LZC values were strongly dependent on age. Complexity scores increased as a function of age in controls, while SCH patients exhibited a progressive reduction of LZC values. A logistic model including LZC scores, age and the interaction of both variables allowed the classification of patients and controls with high sensitivity and specificity. Conclusions: Results demonstrated that SCH patients failed to follow the "normal" process of complexity increase as a function of age. In addition, SCH patients exhibited a significant reduction of complexity scores as a function of age, thus paralleling the pattern observed in neurodegenerative diseases. Significance: Our results support the notion of a progressive defect in SCH, which does not contradict the existence of a basic neurodevelopmental alteration.

show abstract

Section: Significancesupporting

confidence: 65%

“…However, many studies revealed a pattern of increased complexity values, especially in frontal areas, in SCH patients (Elbert et al, 1992;Saito et al, 1998;Na et al, 2002;Irisawa et al, 2006;Li et al, 2008). This may be related to the increased "irregularity" of SCH patients' behaviour (Koukkou et al, 1993).…”

Section: Introductionmentioning

confidence: 99%

Lempel–Ziv complexity in schizophrenia: A MEG study

Fernández

López‐Ibor

Turrero

et al. 2011

Clinical Neurophysiology

View full text Add to dashboard Cite

show abstract

“…The prolonged activity found in the present study might thus reflect abnormal processing at the right TPJ related to such altered top-down signals in subjects with high schizotypy scores. Alternatively, prolongation of activation at the right TPJ may also be due to an increase of independent simultaneous brain processes and/or degrading of functional connectivity (Friston and Frith, 1995;Friston, 1996;Saito et al, 1998). However, as a stable map across time indicates that the same brain generators are active and functionally connected across this time period (Lehmann, 1987), it is unlikely that other brain processes or degradation in connectivity would prolong a stable topographic map.…”

Section: Duration and Not Strength Of Right Tpj Activation Correlatesmentioning

confidence: 99%

“…Yet, due to their limited temporal resolution the abovementioned fMRI and PET studies did not allow to distinguish between strength-related versus duration-related increases in TPJ activation and can thus not assess some of the basic mechanisms of the functional aberrations in schizophrenic patients (Lehmann et al, 2005). Therefore, to further study the link between TPJ activation in positive schizotypy, we here used evoked potential (EP) mapping and electrical neuroimaging with temporal resolution in the millisecond range (Gevins et al, 1995;Dale and Halgren, 2001;Michel et al, 2001;Koenig et al, 2005; for the use of this method in patients with schizophrenia see Miyauchi et al, 1990;John et al, 1994;Omori et al, 1995;Saito et al, 1998;Koenig et al, 1999;Lehmann et al, 2005) to investigate whether not only performance but also brain activity in the OBT-task correlates with PA scores.…”

Section: Introductionmentioning

confidence: 99%

Duration and not strength of activation in temporo-parietal cortex positively correlates with schizotypy

et al. 2007

View full text Add to dashboard Cite

Impaired self-and own body processing in patients with schizophrenia and individuals along the schizophrenia spectrum have been associated with dysfunctional cortical activation at the temporo-parietal junction. Here we investigated whether strength or duration of temporo-parietal junction activation during an own body processing task correlates with level of abnormal self-processing in healthy subjects as measured by the frequency of spontaneously experienced schizotypal body schema alterations (perceptual aberrations) and dissociative experiences. Participants carried out a mental imagery task with respect to their own body. Behavioral data and high density EEG were measured. EEG data were analyzed using evoked potential mapping and electrical neuroimaging. Participants completed two validated self-report questionnaires, one asking about perceptual aberration and one about dissociative experiences. The own body transformation task activated the right temporo-parietal junction at 310-390 ms. Participants' reaction times and duration of activation at the right temporo-parietal junction, but not its strength, were found to correlate positively with perceptual aberration scores. No relationship was found with dissociative experiences scores. Brain activations proceeding and following activation of the right temporo-parietal junction did not correlate with scores on either scale. The positive correlation between performance and right temporo-parietal activation in an own body transformation task with perceptual aberrations scores in our healthy population suggests that disturbances in self-and body processing in individuals along the schizophrenia spectrum might be due to prolonged, rather than stronger activation of the right temporo-parietal junction. We argue that this might reflect local pathology, pathologies in cortico-cortical connections and/or re-entry of top-down processing.

show abstract

“…Early studies of signal synchronization in patients diagnosed with schizophrenia used a linear measure of complexity based on global correlation of all channels (Wackermann et al, 1993) and synchronization based on linear correlation between amplitudes (Saito et al, 1998). Although these methods will necessarily miss nonlinear signal characteristics, they found significant differences between patients and normal controls that were interpreted to reflect decreased coordination between different brain regions, a characteristic of schizophrenia (Uhlhaas et al, 2008;Whittington, 2008).…”

Section: Schizophreniamentioning

confidence: 99%

Neurotechnology and Psychiatric Biomarkers

Bosl¹

2012

Biomedical Science, Engineering and Technology

View full text Add to dashboard Cite

Global, Regional, and Local Measures of Complexity of Multichannel Electroencephalography in Acute, Neuroleptic-Naive, First-Break Schizophrenics

Cited by 82 publications

References 52 publications

Lempel–Ziv complexity in schizophrenia: A MEG study

Lempel–Ziv complexity in schizophrenia: A MEG study

Duration and not strength of activation in temporo-parietal cortex positively correlates with schizotypy

Neurotechnology and Psychiatric Biomarkers

Contact Info

Product

Resources

About