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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

Relationship between MEG resting-state functional connectivity (imaginary coherence) data and performance on the Hopkins Verbal Learning Task (HVLT; delay component) in 15 healthy controls (in pink) and 30 patients with schizophrenia (in green). Global connectivity of a region in right dorsolateral pre-frontal cortex (DLPFC; over the middle frontal gyrus) was positively correlated with HVLT performance (overlay, in red). However, this correlation was only significant for the patient group, indicating that this association between reduced connectivity of right DLPFC and verbal working memory is specific to the disorder. No significant relationship between functional connectivity of any region and performance during immediate recall in the HVLT was identified in either group.
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Figure 7: Relationship between MEG resting-state functional connectivity (imaginary coherence) data and performance on the Hopkins Verbal Learning Task (HVLT; delay component) in 15 healthy controls (in pink) and 30 patients with schizophrenia (in green). Global connectivity of a region in right dorsolateral pre-frontal cortex (DLPFC; over the middle frontal gyrus) was positively correlated with HVLT performance (overlay, in red). However, this correlation was only significant for the patient group, indicating that this association between reduced connectivity of right DLPFC and verbal working memory is specific to the disorder. No significant relationship between functional connectivity of any region and performance during immediate recall in the HVLT was identified in either group.

Mentions: Although performance on HVLT-delayed recall was poorer in the patient group, this difference was not statistically significantly when compared against education-matched controls (p = 0.07). However, HVLT-delayed performance was positively and significantly correlated with IC measures of right dorsolateral pre-frontal cortex (DLPFC; Figure 7) only for patients with schizophrenia (r = 0.51, p < 0.05, false-discovery rate (FDR) corrected for multiple comparisons) and not healthy comparison subjects (r = 0.34, p = 0.21). Such an effect found only in the patient group even when HVLT-delayed scores were not significantly different between the two groups suggests that this relationship between DLPFC connectivity and verbal memory is specific to schizophrenia. Active-state fMRI studies have shown that the functional connections of this region in the right hemisphere, in Brodmann's Area 9 of the middle frontal gyrus, are reduced in schizophrenia during various cognitive tasks such as movement sequencing and continuous performance (Salgado-Pineda et al., 2007; Woodward et al., 2009).


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)

Relationship between MEG resting-state functional connectivity (imaginary coherence) data and performance on the Hopkins Verbal Learning Task (HVLT; delay component) in 15 healthy controls (in pink) and 30 patients with schizophrenia (in green). Global connectivity of a region in right dorsolateral pre-frontal cortex (DLPFC; over the middle frontal gyrus) was positively correlated with HVLT performance (overlay, in red). However, this correlation was only significant for the patient group, indicating that this association between reduced connectivity of right DLPFC and verbal working memory is specific to the disorder. No significant relationship between functional connectivity of any region and performance during immediate recall in the HVLT was identified in either group.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 7: Relationship between MEG resting-state functional connectivity (imaginary coherence) data and performance on the Hopkins Verbal Learning Task (HVLT; delay component) in 15 healthy controls (in pink) and 30 patients with schizophrenia (in green). Global connectivity of a region in right dorsolateral pre-frontal cortex (DLPFC; over the middle frontal gyrus) was positively correlated with HVLT performance (overlay, in red). However, this correlation was only significant for the patient group, indicating that this association between reduced connectivity of right DLPFC and verbal working memory is specific to the disorder. No significant relationship between functional connectivity of any region and performance during immediate recall in the HVLT was identified in either group.
Mentions: Although performance on HVLT-delayed recall was poorer in the patient group, this difference was not statistically significantly when compared against education-matched controls (p = 0.07). However, HVLT-delayed performance was positively and significantly correlated with IC measures of right dorsolateral pre-frontal cortex (DLPFC; Figure 7) only for patients with schizophrenia (r = 0.51, p < 0.05, false-discovery rate (FDR) corrected for multiple comparisons) and not healthy comparison subjects (r = 0.34, p = 0.21). Such an effect found only in the patient group even when HVLT-delayed scores were not significantly different between the two groups suggests that this relationship between DLPFC connectivity and verbal memory is specific to schizophrenia. Active-state fMRI studies have shown that the functional connections of this region in the right hemisphere, in Brodmann's Area 9 of the middle frontal gyrus, are reduced in schizophrenia during various cognitive tasks such as movement sequencing and continuous performance (Salgado-Pineda et al., 2007; Woodward et al., 2009).

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