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Interactions between posterior gamma and frontal alpha/beta oscillations during imagined actions.

de Lange FP, Jensen O, Bauer M, Toni I - Front Hum Neurosci (2008)

Bottom Line: Several studies have revealed that posterior parietal and frontal regions support planning of hand movements but far less is known about how these cortical regions interact during the mental simulation of a movement.Our results provide novel information about the oscillatory brain activity of posterior and frontal regions.The persistent functional coupling between these regions during task performance emphasizes the importance of sustained interactions between frontal and occipito-parietal areas during mental simulation of action.

View Article: PubMed Central - PubMed

Affiliation: F.C. Donders Centre for Cognitive Neuroimaging, Radboud University Nijmegen The Netherlands. florisdelange@gmail.com

ABSTRACT
Several studies have revealed that posterior parietal and frontal regions support planning of hand movements but far less is known about how these cortical regions interact during the mental simulation of a movement. Here, we have used magnetoencephalography (MEG) to investigate oscillatory interactions between posterior and frontal areas during the performance of a well-established motor imagery task that evokes motor simulation: mental rotation of hands. Motor imagery induced sustained power suppression in the alpha and beta band over the precentral gyrus and a power increase in the gamma band over bilateral occipito-parietal cortex. During motor imagery of left hand movements, there was stronger alpha and beta band suppression over the right precentral gyrus. The duration of these power changes increased, on a trial-by-trial basis, as a function of the motoric complexity of the imagined actions. Crucially, during a specific period of the movement simulation, the power fluctuations of the frontal beta-band oscillations became coupled with the occipito-parietal gamma-band oscillations. Our results provide novel information about the oscillatory brain activity of posterior and frontal regions. The persistent functional coupling between these regions during task performance emphasizes the importance of sustained interactions between frontal and occipito-parietal areas during mental simulation of action.

No MeSH data available.


Related in: MedlinePlus

Beta suppression during motor imagery of left and right hands. (A) Grand average of the topography of changes in power in the beta band (16–24 Hz) between task and baseline (LH & RH, left panel) and between hands (LH-RH, right panel). Dots indicate clusters of significant differences (p < 0.05 corrected for multiple comparisons). (B) Source reconstruction of the changes in power in the beta band between task and baseline (left panel) and between hands (right panel). The power of the source representation is thresholded at half-maximum. (C) Outline of a group of sensors overlying left and right motor cortex that were selected for subsequent analysis. (D) Grand-averaged time-frequency representation of power over left motor cortex (left panel) and right motor cortex (right panel). The time-frequency plots have been aligned to the presentation of the visual stimulus (time = 0, left panel) or to the button-press (time = 0, right panel). (E) Grand-averaged power in the beta band, plotted separately for trials showing drawings of left and right hands [LH, RH, respectively; other conventions as in (D)], for the left motor cortex (left panel) and right motor cortex (right panel). (F) Relationship between trial duration and beta suppression. Beta band power for single trials (sorted by reaction time, time = 0 corresponds to visual stimulus presentation) is plotted against trial duration, for one representative subject and for the sensor selections as outlined in (C). Power values were smoothed over 10 trials windows.
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Figure 3: Beta suppression during motor imagery of left and right hands. (A) Grand average of the topography of changes in power in the beta band (16–24 Hz) between task and baseline (LH & RH, left panel) and between hands (LH-RH, right panel). Dots indicate clusters of significant differences (p < 0.05 corrected for multiple comparisons). (B) Source reconstruction of the changes in power in the beta band between task and baseline (left panel) and between hands (right panel). The power of the source representation is thresholded at half-maximum. (C) Outline of a group of sensors overlying left and right motor cortex that were selected for subsequent analysis. (D) Grand-averaged time-frequency representation of power over left motor cortex (left panel) and right motor cortex (right panel). The time-frequency plots have been aligned to the presentation of the visual stimulus (time = 0, left panel) or to the button-press (time = 0, right panel). (E) Grand-averaged power in the beta band, plotted separately for trials showing drawings of left and right hands [LH, RH, respectively; other conventions as in (D)], for the left motor cortex (left panel) and right motor cortex (right panel). (F) Relationship between trial duration and beta suppression. Beta band power for single trials (sorted by reaction time, time = 0 corresponds to visual stimulus presentation) is plotted against trial duration, for one representative subject and for the sensor selections as outlined in (C). Power values were smoothed over 10 trials windows.

Mentions: We first looked at general differences in alpha and beta oscillations during motor imagery, irrespective of the handedness of the visual stimulus. There were highly significant power suppressions during motor imagery compared to baseline, both in the alpha band (Figure 2A-left panel; 8–12 Hz, [0 1] s after stimulus onset: p < 0.001; [−1 0] s before response: p < 0.001) and in the beta band (Figure 3A-left panel; 16–24 Hz, [0 1] s after stimulus onset: p < 0.001; [−1 0] s before response: p < 0.001). Source reconstructions showed that this alpha and beta suppression was widespread, and was mainly generated in occipito-parietal and motor cortex (Figures 2B and 3B). We selected a group of sensors over the left motor cortex (Figures 2C and 3C-left panel) for subsequent analysis. The onset of the sustained power suppressions over left motor cortex was ∼0.3 s after stimulus presentation (Figures 2D,E-left panel and 3D,E-left panel). Single-trial analysis showed that the duration of the alpha and beta suppression over left motor cortex was strongly correlated with the reaction times (alpha: mean Z = −4.29, p < 0.001, Figure 2F-left panel; beta: mean Z = −6.14, p < 0.001; Figure 3F-left panel). Thus, alpha and beta oscillations in left motor cortex were suppressed during the full trial duration, independently of presented left or right hands.


Interactions between posterior gamma and frontal alpha/beta oscillations during imagined actions.

de Lange FP, Jensen O, Bauer M, Toni I - Front Hum Neurosci (2008)

Beta suppression during motor imagery of left and right hands. (A) Grand average of the topography of changes in power in the beta band (16–24 Hz) between task and baseline (LH & RH, left panel) and between hands (LH-RH, right panel). Dots indicate clusters of significant differences (p < 0.05 corrected for multiple comparisons). (B) Source reconstruction of the changes in power in the beta band between task and baseline (left panel) and between hands (right panel). The power of the source representation is thresholded at half-maximum. (C) Outline of a group of sensors overlying left and right motor cortex that were selected for subsequent analysis. (D) Grand-averaged time-frequency representation of power over left motor cortex (left panel) and right motor cortex (right panel). The time-frequency plots have been aligned to the presentation of the visual stimulus (time = 0, left panel) or to the button-press (time = 0, right panel). (E) Grand-averaged power in the beta band, plotted separately for trials showing drawings of left and right hands [LH, RH, respectively; other conventions as in (D)], for the left motor cortex (left panel) and right motor cortex (right panel). (F) Relationship between trial duration and beta suppression. Beta band power for single trials (sorted by reaction time, time = 0 corresponds to visual stimulus presentation) is plotted against trial duration, for one representative subject and for the sensor selections as outlined in (C). Power values were smoothed over 10 trials windows.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Figure 3: Beta suppression during motor imagery of left and right hands. (A) Grand average of the topography of changes in power in the beta band (16–24 Hz) between task and baseline (LH & RH, left panel) and between hands (LH-RH, right panel). Dots indicate clusters of significant differences (p < 0.05 corrected for multiple comparisons). (B) Source reconstruction of the changes in power in the beta band between task and baseline (left panel) and between hands (right panel). The power of the source representation is thresholded at half-maximum. (C) Outline of a group of sensors overlying left and right motor cortex that were selected for subsequent analysis. (D) Grand-averaged time-frequency representation of power over left motor cortex (left panel) and right motor cortex (right panel). The time-frequency plots have been aligned to the presentation of the visual stimulus (time = 0, left panel) or to the button-press (time = 0, right panel). (E) Grand-averaged power in the beta band, plotted separately for trials showing drawings of left and right hands [LH, RH, respectively; other conventions as in (D)], for the left motor cortex (left panel) and right motor cortex (right panel). (F) Relationship between trial duration and beta suppression. Beta band power for single trials (sorted by reaction time, time = 0 corresponds to visual stimulus presentation) is plotted against trial duration, for one representative subject and for the sensor selections as outlined in (C). Power values were smoothed over 10 trials windows.
Mentions: We first looked at general differences in alpha and beta oscillations during motor imagery, irrespective of the handedness of the visual stimulus. There were highly significant power suppressions during motor imagery compared to baseline, both in the alpha band (Figure 2A-left panel; 8–12 Hz, [0 1] s after stimulus onset: p < 0.001; [−1 0] s before response: p < 0.001) and in the beta band (Figure 3A-left panel; 16–24 Hz, [0 1] s after stimulus onset: p < 0.001; [−1 0] s before response: p < 0.001). Source reconstructions showed that this alpha and beta suppression was widespread, and was mainly generated in occipito-parietal and motor cortex (Figures 2B and 3B). We selected a group of sensors over the left motor cortex (Figures 2C and 3C-left panel) for subsequent analysis. The onset of the sustained power suppressions over left motor cortex was ∼0.3 s after stimulus presentation (Figures 2D,E-left panel and 3D,E-left panel). Single-trial analysis showed that the duration of the alpha and beta suppression over left motor cortex was strongly correlated with the reaction times (alpha: mean Z = −4.29, p < 0.001, Figure 2F-left panel; beta: mean Z = −6.14, p < 0.001; Figure 3F-left panel). Thus, alpha and beta oscillations in left motor cortex were suppressed during the full trial duration, independently of presented left or right hands.

Bottom Line: Several studies have revealed that posterior parietal and frontal regions support planning of hand movements but far less is known about how these cortical regions interact during the mental simulation of a movement.Our results provide novel information about the oscillatory brain activity of posterior and frontal regions.The persistent functional coupling between these regions during task performance emphasizes the importance of sustained interactions between frontal and occipito-parietal areas during mental simulation of action.

View Article: PubMed Central - PubMed

Affiliation: F.C. Donders Centre for Cognitive Neuroimaging, Radboud University Nijmegen The Netherlands. florisdelange@gmail.com

ABSTRACT
Several studies have revealed that posterior parietal and frontal regions support planning of hand movements but far less is known about how these cortical regions interact during the mental simulation of a movement. Here, we have used magnetoencephalography (MEG) to investigate oscillatory interactions between posterior and frontal areas during the performance of a well-established motor imagery task that evokes motor simulation: mental rotation of hands. Motor imagery induced sustained power suppression in the alpha and beta band over the precentral gyrus and a power increase in the gamma band over bilateral occipito-parietal cortex. During motor imagery of left hand movements, there was stronger alpha and beta band suppression over the right precentral gyrus. The duration of these power changes increased, on a trial-by-trial basis, as a function of the motoric complexity of the imagined actions. Crucially, during a specific period of the movement simulation, the power fluctuations of the frontal beta-band oscillations became coupled with the occipito-parietal gamma-band oscillations. Our results provide novel information about the oscillatory brain activity of posterior and frontal regions. The persistent functional coupling between these regions during task performance emphasizes the importance of sustained interactions between frontal and occipito-parietal areas during mental simulation of action.

No MeSH data available.


Related in: MedlinePlus