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Setting up the speech production network: how oscillations contribute to lateralized information routing.

Gehrig J, Wibral M, Arnold C, Kell CA - Front Psychol (2012)

Bottom Line: This MEG study focuses on the spectro-temporal dynamics that contribute to the setup of this network.While a broadband low frequency effect was found for any task preparation in bilateral prefrontal cortices, preparation for overt speech production was specifically associated with left-lateralized alpha and beta suppression in temporal cortices and beta suppression in motor-related brain regions.Beta phase coupling in the entire speech production network was modulated by anticipation of overt reading.

View Article: PubMed Central - PubMed

Affiliation: Cognitive Neuroscience Group, Department of Neurology, Brain Imaging Center, Goethe University Frankfurt, Germany.

ABSTRACT
Speech production involves widely distributed brain regions. This MEG study focuses on the spectro-temporal dynamics that contribute to the setup of this network. In 21 participants performing a cue-target reading paradigm, we analyzed local oscillations during preparation for overt and covert reading in the time-frequency domain and localized sources using beamforming. Network dynamics were studied by comparing different dynamic causal models of beta phase coupling in and between hemispheres. While a broadband low frequency effect was found for any task preparation in bilateral prefrontal cortices, preparation for overt speech production was specifically associated with left-lateralized alpha and beta suppression in temporal cortices and beta suppression in motor-related brain regions. Beta phase coupling in the entire speech production network was modulated by anticipation of overt reading. We propose that the processes underlying the setup of the speech production network connect relevant brain regions by means of beta synchronization and prepare the network for left-lateralized information routing by suppression of inhibitory alpha and beta oscillations.

No MeSH data available.


Related in: MedlinePlus

Summary of tested DCMs. (A) Models with unidirectional (top-down, bottom-up) and bidirectional coupling. (B) Models with different interhemispheric coupling and (C) models with different coupling modulated by preparation for overt vs. preparation for covert reading (in green). The model that explains the data best is marked by an asterisk.
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Figure 2: Summary of tested DCMs. (A) Models with unidirectional (top-down, bottom-up) and bidirectional coupling. (B) Models with different interhemispheric coupling and (C) models with different coupling modulated by preparation for overt vs. preparation for covert reading (in green). The model that explains the data best is marked by an asterisk.

Mentions: For model selection, various models that differ in their coupling constants between network nodes are compared in terms of their Bayesian model evidence. The model evidence here serves as a way to assess the fit of the model to the data, penalized for the number of parameters. We performed model selection as follows: first, we tested the anatomical models for unidirectional (top-down or bottom-up coupling) and bidirectional phase coupling in the beta band within hemispheres (data from both conditions combined). Second, models with different phase coupling between hemispheres were compared. Third, we tested the model that explained the data best in step two for modulation of phase coupling in the beta band by overt speech production and allowed connections to be modulated (top-down, bottom-up, both) or un-modulated. In total, we estimated 13 biologically plausible models (Figure 2) in each single subject and compared model probabilities on the group level using a random effects Bayesian model selection procedure (Boly et al., 2011).


Setting up the speech production network: how oscillations contribute to lateralized information routing.

Gehrig J, Wibral M, Arnold C, Kell CA - Front Psychol (2012)

Summary of tested DCMs. (A) Models with unidirectional (top-down, bottom-up) and bidirectional coupling. (B) Models with different interhemispheric coupling and (C) models with different coupling modulated by preparation for overt vs. preparation for covert reading (in green). The model that explains the data best is marked by an asterisk.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3368321&req=5

Figure 2: Summary of tested DCMs. (A) Models with unidirectional (top-down, bottom-up) and bidirectional coupling. (B) Models with different interhemispheric coupling and (C) models with different coupling modulated by preparation for overt vs. preparation for covert reading (in green). The model that explains the data best is marked by an asterisk.
Mentions: For model selection, various models that differ in their coupling constants between network nodes are compared in terms of their Bayesian model evidence. The model evidence here serves as a way to assess the fit of the model to the data, penalized for the number of parameters. We performed model selection as follows: first, we tested the anatomical models for unidirectional (top-down or bottom-up coupling) and bidirectional phase coupling in the beta band within hemispheres (data from both conditions combined). Second, models with different phase coupling between hemispheres were compared. Third, we tested the model that explained the data best in step two for modulation of phase coupling in the beta band by overt speech production and allowed connections to be modulated (top-down, bottom-up, both) or un-modulated. In total, we estimated 13 biologically plausible models (Figure 2) in each single subject and compared model probabilities on the group level using a random effects Bayesian model selection procedure (Boly et al., 2011).

Bottom Line: This MEG study focuses on the spectro-temporal dynamics that contribute to the setup of this network.While a broadband low frequency effect was found for any task preparation in bilateral prefrontal cortices, preparation for overt speech production was specifically associated with left-lateralized alpha and beta suppression in temporal cortices and beta suppression in motor-related brain regions.Beta phase coupling in the entire speech production network was modulated by anticipation of overt reading.

View Article: PubMed Central - PubMed

Affiliation: Cognitive Neuroscience Group, Department of Neurology, Brain Imaging Center, Goethe University Frankfurt, Germany.

ABSTRACT
Speech production involves widely distributed brain regions. This MEG study focuses on the spectro-temporal dynamics that contribute to the setup of this network. In 21 participants performing a cue-target reading paradigm, we analyzed local oscillations during preparation for overt and covert reading in the time-frequency domain and localized sources using beamforming. Network dynamics were studied by comparing different dynamic causal models of beta phase coupling in and between hemispheres. While a broadband low frequency effect was found for any task preparation in bilateral prefrontal cortices, preparation for overt speech production was specifically associated with left-lateralized alpha and beta suppression in temporal cortices and beta suppression in motor-related brain regions. Beta phase coupling in the entire speech production network was modulated by anticipation of overt reading. We propose that the processes underlying the setup of the speech production network connect relevant brain regions by means of beta synchronization and prepare the network for left-lateralized information routing by suppression of inhibitory alpha and beta oscillations.

No MeSH data available.


Related in: MedlinePlus