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Granger causality analysis reveals distinct spatio-temporal connectivity patterns in motor and perceptual visuo-spatial working memory.

Protopapa F, Siettos CI, Evdokimidis I, Smyrnis N - Front Comput Neurosci (2014)

Bottom Line: We employed spectral Granger causality analysis on a full set of 56 electroencephalographic recordings acquired during the execution of either a 2D movement pointing or a perceptual (yes/no) change detection task with memory and non-memory conditions.On the basis of network characteristics across frequency bands, we provide evidence for the full dissociation of the corresponding cognitive processes.Our results favor the hypothesis which considers spatial working memory as a by-product of specific mental processes that engages common brain areas under different network organizations.

View Article: PubMed Central - PubMed

Affiliation: School of Applied Mathematics and Physical Sciences, National Technical University of Athens Athens, Greece.

ABSTRACT
We employed spectral Granger causality analysis on a full set of 56 electroencephalographic recordings acquired during the execution of either a 2D movement pointing or a perceptual (yes/no) change detection task with memory and non-memory conditions. On the basis of network characteristics across frequency bands, we provide evidence for the full dissociation of the corresponding cognitive processes. Movement-memory trial types exhibited higher degree nodes during the first 2 s of the delay period, mainly at central, left frontal and right-parietal areas. Change detection-memory trial types resulted in a three-peak temporal pattern of the total degree with higher degree nodes emerging mainly at central, right frontal, and occipital areas. Functional connectivity networks resulting from non-memory trial types were characterized by more sparse structures for both tasks. The movement-memory trial types encompassed an apparent coarse flow from frontal to parietal areas while the opposite flow from occipital, parietal to central and frontal areas was evident for the change detection-memory trial types. The differences among tasks and conditions were more profound in α (8-12 Hz) and β (12-30 Hz) and less in γ (30-45 Hz) band. Our results favor the hypothesis which considers spatial working memory as a by-product of specific mental processes that engages common brain areas under different network organizations.

No MeSH data available.


Related in: MedlinePlus

Characteristic snapshots of the directed functional causal connectivity networks for the movement-memory (M-M) and change detection-memory (CD-M) trial types for: (A) α band at ~1 s for the M-M and at ~1.3 s for the CD-M, (B) β band at ~0.9 s for the M-M and at ~1.3 s for the CD-M. Left column corresponds to M-M and right column to CD-M. The directed connections are colored with red, black and blue depending from which area are originated (frontal, central and parietal, respectively).
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Figure 8: Characteristic snapshots of the directed functional causal connectivity networks for the movement-memory (M-M) and change detection-memory (CD-M) trial types for: (A) α band at ~1 s for the M-M and at ~1.3 s for the CD-M, (B) β band at ~0.9 s for the M-M and at ~1.3 s for the CD-M. Left column corresponds to M-M and right column to CD-M. The directed connections are colored with red, black and blue depending from which area are originated (frontal, central and parietal, respectively).

Mentions: Figure 8 illustrates characteristic snapshots of the resulting directed functional networks for the M-M and CD-M trial types taken at the maxima of the corresponding total degrees of α band (Figure 8A) and β band (Figure 8B). As it is shown, the connectivity of the M-M differs vastly from that of CD-M (actually they are mostly non-overlapping). In the case of M-M there is an apparent coarse flow from the frontal to the parietal nodes. On the other hand, the functional connectivity of the CD-M is characterized by a coarse flow from occipital and parietal to central and frontal areas.


Granger causality analysis reveals distinct spatio-temporal connectivity patterns in motor and perceptual visuo-spatial working memory.

Protopapa F, Siettos CI, Evdokimidis I, Smyrnis N - Front Comput Neurosci (2014)

Characteristic snapshots of the directed functional causal connectivity networks for the movement-memory (M-M) and change detection-memory (CD-M) trial types for: (A) α band at ~1 s for the M-M and at ~1.3 s for the CD-M, (B) β band at ~0.9 s for the M-M and at ~1.3 s for the CD-M. Left column corresponds to M-M and right column to CD-M. The directed connections are colored with red, black and blue depending from which area are originated (frontal, central and parietal, respectively).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4230052&req=5

Figure 8: Characteristic snapshots of the directed functional causal connectivity networks for the movement-memory (M-M) and change detection-memory (CD-M) trial types for: (A) α band at ~1 s for the M-M and at ~1.3 s for the CD-M, (B) β band at ~0.9 s for the M-M and at ~1.3 s for the CD-M. Left column corresponds to M-M and right column to CD-M. The directed connections are colored with red, black and blue depending from which area are originated (frontal, central and parietal, respectively).
Mentions: Figure 8 illustrates characteristic snapshots of the resulting directed functional networks for the M-M and CD-M trial types taken at the maxima of the corresponding total degrees of α band (Figure 8A) and β band (Figure 8B). As it is shown, the connectivity of the M-M differs vastly from that of CD-M (actually they are mostly non-overlapping). In the case of M-M there is an apparent coarse flow from the frontal to the parietal nodes. On the other hand, the functional connectivity of the CD-M is characterized by a coarse flow from occipital and parietal to central and frontal areas.

Bottom Line: We employed spectral Granger causality analysis on a full set of 56 electroencephalographic recordings acquired during the execution of either a 2D movement pointing or a perceptual (yes/no) change detection task with memory and non-memory conditions.On the basis of network characteristics across frequency bands, we provide evidence for the full dissociation of the corresponding cognitive processes.Our results favor the hypothesis which considers spatial working memory as a by-product of specific mental processes that engages common brain areas under different network organizations.

View Article: PubMed Central - PubMed

Affiliation: School of Applied Mathematics and Physical Sciences, National Technical University of Athens Athens, Greece.

ABSTRACT
We employed spectral Granger causality analysis on a full set of 56 electroencephalographic recordings acquired during the execution of either a 2D movement pointing or a perceptual (yes/no) change detection task with memory and non-memory conditions. On the basis of network characteristics across frequency bands, we provide evidence for the full dissociation of the corresponding cognitive processes. Movement-memory trial types exhibited higher degree nodes during the first 2 s of the delay period, mainly at central, left frontal and right-parietal areas. Change detection-memory trial types resulted in a three-peak temporal pattern of the total degree with higher degree nodes emerging mainly at central, right frontal, and occipital areas. Functional connectivity networks resulting from non-memory trial types were characterized by more sparse structures for both tasks. The movement-memory trial types encompassed an apparent coarse flow from frontal to parietal areas while the opposite flow from occipital, parietal to central and frontal areas was evident for the change detection-memory trial types. The differences among tasks and conditions were more profound in α (8-12 Hz) and β (12-30 Hz) and less in γ (30-45 Hz) band. Our results favor the hypothesis which considers spatial working memory as a by-product of specific mental processes that engages common brain areas under different network organizations.

No MeSH data available.


Related in: MedlinePlus