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Cognitive Impairments in Schizophrenia as Assessed Through Activation and Connectivity Measures of Magnetoencephalography (MEG) Data.

Hinkley LB, Owen JP, Fisher M, Findlay AM, Vinogradov S, Nagarajan SS - Front Hum Neurosci (2010)

Bottom Line: Although studies utilizing electroencephalography (EEG), PET and fMRI have contributed significantly to our understanding of these mechanisms, magnetoencephalography (MEG) possesses great potential to answer long-standing questions linking brain interactions to cognitive operations in the disorder.Finally, both bivariate and multivariate functional connectivity metrics of MEG data are useful for understanding how these interactions in the brain are impaired in schizophrenia, and how cognitive and clinical outcomes are affected as a result.We also present here data from our own laboratory that illustrates how some of these novel functional connectivity measures, specifically imaginary coherence (IC), are quite powerful in relating disconnectivity in the brain to characteristic behavioral findings in the disorder.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, CA, USA.

ABSTRACT
The cognitive dysfunction present in patients with schizophrenia is thought to be driven in part by disorganized connections between higher-order cortical fields. Although studies utilizing electroencephalography (EEG), PET and fMRI have contributed significantly to our understanding of these mechanisms, magnetoencephalography (MEG) possesses great potential to answer long-standing questions linking brain interactions to cognitive operations in the disorder. Many experimental paradigms employed in EEG and fMRI are readily extendible to MEG and have expanded our understanding of the neurophysiological architecture present in schizophrenia. Source reconstruction techniques, such as adaptive spatial filtering, take advantage of the spatial localization abilities of MEG, allowing us to evaluate which specific structures contribute to atypical cognition in schizophrenia. Finally, both bivariate and multivariate functional connectivity metrics of MEG data are useful for understanding how these interactions in the brain are impaired in schizophrenia, and how cognitive and clinical outcomes are affected as a result. We also present here data from our own laboratory that illustrates how some of these novel functional connectivity measures, specifically imaginary coherence (IC), are quite powerful in relating disconnectivity in the brain to characteristic behavioral findings in the disorder.

No MeSH data available.


Related in: MedlinePlus

Functional connections between brain regions active during an emotional processing task estimated through MEG. Robust influence amongst time courses (mutual information) can be derived between the right inferior frontal gyrus (IFG), FG, visual cortex (V1/V2) and amygdala (AMY) in healthy controls (A). Coupling between these regions become more isolated in patients with schizophrenia, with reductions in the relatedness between two sources (dashed lines) as well as deviations in activation onset and latency (B). Reproduced, with permission, from Ioannides et al. (2004).
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Figure 5: Functional connections between brain regions active during an emotional processing task estimated through MEG. Robust influence amongst time courses (mutual information) can be derived between the right inferior frontal gyrus (IFG), FG, visual cortex (V1/V2) and amygdala (AMY) in healthy controls (A). Coupling between these regions become more isolated in patients with schizophrenia, with reductions in the relatedness between two sources (dashed lines) as well as deviations in activation onset and latency (B). Reproduced, with permission, from Ioannides et al. (2004).

Mentions: Ioannides et al. (2004) used MEG to examine functional connectivity in schizophrenia during emotional valence judgments in order to explore which segments of the cortical network are dysfunctional in the disorder. Patients were instructed to make decisions regarding the emotional content of the face (happy or sad) presented to the participant during MEG recordings. Interactions between brain sources were assessed using mutual information, a functional connectivity metric that evaluates the extent to which two cortical sources share a common time-series. Robust interactions between inferior frontal cortex, the fusiform gyrus (FG), primary and secondary visual cortex (V1/V2), and the amygdala were identified through functional connectivity analysis in healthy control subjects (Figure 5A). A markedly different pattern is seen in patients with schizophrenia, with reduced interactions between functionally critical brain regions during this task (Figure 5B).


Cognitive Impairments in Schizophrenia as Assessed Through Activation and Connectivity Measures of Magnetoencephalography (MEG) Data.

Hinkley LB, Owen JP, Fisher M, Findlay AM, Vinogradov S, Nagarajan SS - Front Hum Neurosci (2010)

Functional connections between brain regions active during an emotional processing task estimated through MEG. Robust influence amongst time courses (mutual information) can be derived between the right inferior frontal gyrus (IFG), FG, visual cortex (V1/V2) and amygdala (AMY) in healthy controls (A). Coupling between these regions become more isolated in patients with schizophrenia, with reductions in the relatedness between two sources (dashed lines) as well as deviations in activation onset and latency (B). Reproduced, with permission, from Ioannides et al. (2004).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2991173&req=5

Figure 5: Functional connections between brain regions active during an emotional processing task estimated through MEG. Robust influence amongst time courses (mutual information) can be derived between the right inferior frontal gyrus (IFG), FG, visual cortex (V1/V2) and amygdala (AMY) in healthy controls (A). Coupling between these regions become more isolated in patients with schizophrenia, with reductions in the relatedness between two sources (dashed lines) as well as deviations in activation onset and latency (B). Reproduced, with permission, from Ioannides et al. (2004).
Mentions: Ioannides et al. (2004) used MEG to examine functional connectivity in schizophrenia during emotional valence judgments in order to explore which segments of the cortical network are dysfunctional in the disorder. Patients were instructed to make decisions regarding the emotional content of the face (happy or sad) presented to the participant during MEG recordings. Interactions between brain sources were assessed using mutual information, a functional connectivity metric that evaluates the extent to which two cortical sources share a common time-series. Robust interactions between inferior frontal cortex, the fusiform gyrus (FG), primary and secondary visual cortex (V1/V2), and the amygdala were identified through functional connectivity analysis in healthy control subjects (Figure 5A). A markedly different pattern is seen in patients with schizophrenia, with reduced interactions between functionally critical brain regions during this task (Figure 5B).

Bottom Line: Although studies utilizing electroencephalography (EEG), PET and fMRI have contributed significantly to our understanding of these mechanisms, magnetoencephalography (MEG) possesses great potential to answer long-standing questions linking brain interactions to cognitive operations in the disorder.Finally, both bivariate and multivariate functional connectivity metrics of MEG data are useful for understanding how these interactions in the brain are impaired in schizophrenia, and how cognitive and clinical outcomes are affected as a result.We also present here data from our own laboratory that illustrates how some of these novel functional connectivity measures, specifically imaginary coherence (IC), are quite powerful in relating disconnectivity in the brain to characteristic behavioral findings in the disorder.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, CA, USA.

ABSTRACT
The cognitive dysfunction present in patients with schizophrenia is thought to be driven in part by disorganized connections between higher-order cortical fields. Although studies utilizing electroencephalography (EEG), PET and fMRI have contributed significantly to our understanding of these mechanisms, magnetoencephalography (MEG) possesses great potential to answer long-standing questions linking brain interactions to cognitive operations in the disorder. Many experimental paradigms employed in EEG and fMRI are readily extendible to MEG and have expanded our understanding of the neurophysiological architecture present in schizophrenia. Source reconstruction techniques, such as adaptive spatial filtering, take advantage of the spatial localization abilities of MEG, allowing us to evaluate which specific structures contribute to atypical cognition in schizophrenia. Finally, both bivariate and multivariate functional connectivity metrics of MEG data are useful for understanding how these interactions in the brain are impaired in schizophrenia, and how cognitive and clinical outcomes are affected as a result. We also present here data from our own laboratory that illustrates how some of these novel functional connectivity measures, specifically imaginary coherence (IC), are quite powerful in relating disconnectivity in the brain to characteristic behavioral findings in the disorder.

No MeSH data available.


Related in: MedlinePlus