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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

Gamma activity during motor imagery. (A) Grand average of the topography of gamma power (50–80 Hz), showing the relative comparison of task and baseline. Dots indicate clusters of significant differences (p < 0.05 corrected for multiple comparisons). (B) Source reconstruction of gamma power increase. Upper panel shows a posterior view, and lower panel shows a view from the top. Power of the source representations is thresholded at half-maximum. (C) Outline of a group of sensors overlying left motor cortex and occipito-parietal cortex that were selected for subsequent analysis. (D) Grand-averaged time-frequency representation of power of sensors overlying occipito-parietal cortex (left panel), and of a group of sensors overlying the left motor cortex (right panel). Both groups of sensors showed a significant gamma power increase during the task, but with different temporal profile. Sensor selection is outlined in (C). (E) Grand-averaged gamma power, averaged over 50–80 Hz, for the same sensor selection as in (D) (occipito-parietal sensors: left panel; left motor sensors: right panel), plotted for left and right hands separately. (F) Relationship between trial duration and gamma increase. Gamma-band power, averaged over 50–80 Hz, for single trials (sorted by reaction time) is plotted against trial duration, for one representative subject and for the sensor selection as outlined in (C) (occipito-parietal sensors: left panel; left motor sensors: right panel). Power values were smoothed over 10 trial windows.
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Figure 4: Gamma activity during motor imagery. (A) Grand average of the topography of gamma power (50–80 Hz), showing the relative comparison of task and baseline. Dots indicate clusters of significant differences (p < 0.05 corrected for multiple comparisons). (B) Source reconstruction of gamma power increase. Upper panel shows a posterior view, and lower panel shows a view from the top. Power of the source representations is thresholded at half-maximum. (C) Outline of a group of sensors overlying left motor cortex and occipito-parietal cortex that were selected for subsequent analysis. (D) Grand-averaged time-frequency representation of power of sensors overlying occipito-parietal cortex (left panel), and of a group of sensors overlying the left motor cortex (right panel). Both groups of sensors showed a significant gamma power increase during the task, but with different temporal profile. Sensor selection is outlined in (C). (E) Grand-averaged gamma power, averaged over 50–80 Hz, for the same sensor selection as in (D) (occipito-parietal sensors: left panel; left motor sensors: right panel), plotted for left and right hands separately. (F) Relationship between trial duration and gamma increase. Gamma-band power, averaged over 50–80 Hz, for single trials (sorted by reaction time) is plotted against trial duration, for one representative subject and for the sensor selection as outlined in (C) (occipito-parietal sensors: left panel; left motor sensors: right panel). Power values were smoothed over 10 trial windows.

Mentions: There was a large increase in gamma-band power during imagined actions of left and right hands (Figure 4A; [0 1] s after stimulus onset: p < 0.001; [−1 0] s before response: p < 0.001; sensors in significant cluster indicated by dots). The gamma-band increase was present over occipito-parietal cortex and over the left motor cortex (Figure 4A). Source reconstructions confirmed the involvement of occipito-parietal and left motor cortex (Figure 4B). We selected a group of sensors over occipito-parietal cortex (Figure 4C, posterior sensors) and over the left motor cortex (Figure 4C, left central sensors) for subsequent analysis. The power of both the occipito-parietal and left motor cortex concentrated around 50–80 Hz (Figure 4D), but their time course differed markedly. The occipito-parietal gamma cluster showed a steep increase in gamma-band activity following stimulus onset, which was sustained until the subject provided his response (Figure 4D, E-left panel). Conversely, the left motor gamma cluster showed a transient increase in gamma-band activity that peaked around the time the subject responded with a right hand button press (Figure 4D, E-right panel). Single-trial analysis showed that the duration of the occipito-parietal gamma-band increase was correlated with the reaction time of the trial (Figure 4F-left panel; mean Z = 1.90, p = 0.046). Conversely, the duration of the left motor gamma response was independent of the duration of the trial (Figure 4F-right panel; mean Z = −0.87, p = 0.166). There were no significant differences in gamma-band power between the left and right hand (p > 0.10). In summary, there were increases in gamma power in occipito-parietal and left motor cortex. The duration of occipito-parietal gamma was sustained and proportional to the duration of the motor imagery process, while the duration of left motor cortex gamma was transient and related to the button press at the end of the trial.


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)

Gamma activity during motor imagery. (A) Grand average of the topography of gamma power (50–80 Hz), showing the relative comparison of task and baseline. Dots indicate clusters of significant differences (p < 0.05 corrected for multiple comparisons). (B) Source reconstruction of gamma power increase. Upper panel shows a posterior view, and lower panel shows a view from the top. Power of the source representations is thresholded at half-maximum. (C) Outline of a group of sensors overlying left motor cortex and occipito-parietal cortex that were selected for subsequent analysis. (D) Grand-averaged time-frequency representation of power of sensors overlying occipito-parietal cortex (left panel), and of a group of sensors overlying the left motor cortex (right panel). Both groups of sensors showed a significant gamma power increase during the task, but with different temporal profile. Sensor selection is outlined in (C). (E) Grand-averaged gamma power, averaged over 50–80 Hz, for the same sensor selection as in (D) (occipito-parietal sensors: left panel; left motor sensors: right panel), plotted for left and right hands separately. (F) Relationship between trial duration and gamma increase. Gamma-band power, averaged over 50–80 Hz, for single trials (sorted by reaction time) is plotted against trial duration, for one representative subject and for the sensor selection as outlined in (C) (occipito-parietal sensors: left panel; left motor sensors: right panel). Power values were smoothed over 10 trial windows.
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Figure 4: Gamma activity during motor imagery. (A) Grand average of the topography of gamma power (50–80 Hz), showing the relative comparison of task and baseline. Dots indicate clusters of significant differences (p < 0.05 corrected for multiple comparisons). (B) Source reconstruction of gamma power increase. Upper panel shows a posterior view, and lower panel shows a view from the top. Power of the source representations is thresholded at half-maximum. (C) Outline of a group of sensors overlying left motor cortex and occipito-parietal cortex that were selected for subsequent analysis. (D) Grand-averaged time-frequency representation of power of sensors overlying occipito-parietal cortex (left panel), and of a group of sensors overlying the left motor cortex (right panel). Both groups of sensors showed a significant gamma power increase during the task, but with different temporal profile. Sensor selection is outlined in (C). (E) Grand-averaged gamma power, averaged over 50–80 Hz, for the same sensor selection as in (D) (occipito-parietal sensors: left panel; left motor sensors: right panel), plotted for left and right hands separately. (F) Relationship between trial duration and gamma increase. Gamma-band power, averaged over 50–80 Hz, for single trials (sorted by reaction time) is plotted against trial duration, for one representative subject and for the sensor selection as outlined in (C) (occipito-parietal sensors: left panel; left motor sensors: right panel). Power values were smoothed over 10 trial windows.
Mentions: There was a large increase in gamma-band power during imagined actions of left and right hands (Figure 4A; [0 1] s after stimulus onset: p < 0.001; [−1 0] s before response: p < 0.001; sensors in significant cluster indicated by dots). The gamma-band increase was present over occipito-parietal cortex and over the left motor cortex (Figure 4A). Source reconstructions confirmed the involvement of occipito-parietal and left motor cortex (Figure 4B). We selected a group of sensors over occipito-parietal cortex (Figure 4C, posterior sensors) and over the left motor cortex (Figure 4C, left central sensors) for subsequent analysis. The power of both the occipito-parietal and left motor cortex concentrated around 50–80 Hz (Figure 4D), but their time course differed markedly. The occipito-parietal gamma cluster showed a steep increase in gamma-band activity following stimulus onset, which was sustained until the subject provided his response (Figure 4D, E-left panel). Conversely, the left motor gamma cluster showed a transient increase in gamma-band activity that peaked around the time the subject responded with a right hand button press (Figure 4D, E-right panel). Single-trial analysis showed that the duration of the occipito-parietal gamma-band increase was correlated with the reaction time of the trial (Figure 4F-left panel; mean Z = 1.90, p = 0.046). Conversely, the duration of the left motor gamma response was independent of the duration of the trial (Figure 4F-right panel; mean Z = −0.87, p = 0.166). There were no significant differences in gamma-band power between the left and right hand (p > 0.10). In summary, there were increases in gamma power in occipito-parietal and left motor cortex. The duration of occipito-parietal gamma was sustained and proportional to the duration of the motor imagery process, while the duration of left motor cortex gamma was transient and related to the button press at the end of the trial.

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