Stabilization of bimanual coordination due to active interhemispheric inhibition: a dynamical account

Daffertshofer, Andreas; Peper, C. E.; Beek, Peter J.

doi:10.1007/s00422-004-0539-6

Cited by 72 publications

(85 citation statements)

References 75 publications

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“…For the present study, this appears consistent with the view that during the initial stage of motor learning additional attention is required as the motor skill is not yet automated (e.g., Halsband and Lange, 2006). This interpretation finds more support by the stronger increase in beta modulation of the motor cortex contralateral to the slow finger which is known to be the bottleneck for proper performance of a challenging polyrhythm (Daffertshofer et al, 2005). In agreement, we observed that beta modulation of the contralateral motor cortex of the slow finger was directly correlated with the motor performance itself.…”

Section: Discussionsupporting

confidence: 90%

Multivariate time–frequency analysis of electromagnetic brain activity during bimanual motor learning

et al. 2007

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Although the relationship between brain activity and motor performance is reasonably well established, the manner in which this relationship changes with motor learning remains incompletely understood. This paper presents a study of cortical modulations of eventrelated beta activity when participants learned to perform a complex bimanual motor task: 151 channel MEG data were acquired from nine healthy adults whilst learning a bimanual 3:5 polyrhythm. Sources of MEG activity were determined by means of synthetic aperture magnetometry that yielded locations and time courses of beta activities. The relationship between changes in performance and corresponding changes in event-related power were assessed using partial least squares. Behavioral data revealed that participants successfully learned to perform the 3:5 polyrhythm and that performance improvement was mainly achieved through the proper timing of the finger producing the slow rhythm. We found event-related modulation of beta power in the contralateral motor cortex that was inversely related to force output. The degree of beta modulation increased during the experimentalthough the force level remained constant -and was positively correlated with motor performance, in particular for the motor cortex contralateral to the slow hand. These electrophysiological findings support the view that activity in motor cortex co-varies closely with behavioral changes over the course of learning.

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Section: Discussionsupporting

confidence: 90%

Multivariate time–frequency analysis of electromagnetic brain activity during bimanual motor learning

et al. 2007

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“…On the other side, the activity-dependent changes in IHI-SICI identified here may provide insights to better understand unwanted mirror EMG activity in the opposite limb, which is frequently reported during unimanual movements in patients with motor disorders (Hashimoto et al, 2001;Georgiou-Karistianis et al, 2004;Cincotta and Ziemann, 2008). Although it has been widely considered that mirroring may relate to IHI (Carson, 2005;Daffertshofer et al, 2005;Duque et al, 2005Duque et al, , 2007Li et al, 2007), our results suggest a more complex relationship in which mirroring might relate to interactions between circuits, such as IHI and SICI in the M1 ipsilateral rather than only to IHI. These results raise the importance of considering interactions between multiple circuits and not only the state of individual pathways when we search for the neural underpinnings of a behavioral phenomenon-like mirroring.…”

Section: Ihi From M1 Contralateral To M1 Ipsilateralmentioning

confidence: 70%

Mechanisms Underlying Functional Changes in the Primary Motor Cortex Ipsilateral to an Active Hand

Pérez¹,

Cohen²

2008

J. Neurosci.

241

254

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Performance of a unimanual hand motor task results in functional changes in both primary motor cortices (M1 ipsilateral and M1 contralateral ). The neuronal mechanisms controlling the corticospinal output originated in M1 ipsilateral and the resting hand during a unimanual task remain unclear. Here, we assessed functional changes within M1 ipsilateral and in interhemispheric inhibition (IHI) associated with parametric increases in unimanual force. We measured motor-evoked potential (MEP) recruitment curves (RCs) and shortinterval intracortical inhibition (SICI) in M1 ipsilateral , IHI from M1 contralateral to M1 ipsilateral , and the influence of IHI over SICI using transcranial magnetic stimulation at rest and during 10, 30, and 70% of maximal right wrist flexion force. EMG from the left resting flexor carpi radialis (FCR) muscle was comparable across conditions. Left FCR MEP RCs increased, and SICI decreased with increasing right wrist force. Activity-dependent (rest and 10, 30, and 70%) left FCR maximal MEP size correlated with absolute changes in SICI. IHI decreased with increasing force at matched conditioned MEP amplitudes. IHI and SICI were inversely correlated at increasing forces. In the presence of IHI, SICI decreased at rest and 70% force. In summary, we found activity-dependent changes in (1) SICI in M1 ipsilateral , (2) IHI from M1 contralateral to M1 ipsilateral , and (3) the influence of IHI over SICI in the left resting hand during force generation by the right hand. Our findings indicate that interactions between GABAergic intracortical circuits mediating SICI and interhemispheric glutamatergic projections between M1s contribute to control activity-dependent changes in corticospinal output to a resting hand during force generation by the opposite hand.

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“…This phenomenon of inhibition has been recently examined in bimanual rhythmic movements using Magnetoencephalography (MEG) (Daffertshofer et al 2005). They suggested that inter-hemispheric inhibition may be also necessary in performance of polyrhythms, to maintain independent performance of each hand, in polyrhythms with a non-integer ratio (3:8 or 5:8).…”

Section: Discussionmentioning

confidence: 99%

Interval timing and trajectory in unequal amplitude movements

2008

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The Wing-Kristofferson (WK) model of movement timing emphasises the separation of central timer and motor processes. Several studies of repetitive timing have shown that increase in variability at longer intervals is attributable to timer processes; however, relatively little is known about the way motor aspects of timing are affected by task movement constraints. In the present study, we examined timing variability in finger tapping with differences in interval to assess central timer effects, and with differences in movement amplitude to assess motor implementation effects. Then, we investigated whether effects of motor timing observed at the point of response (flexion offset/tap) are also evident in extension, which would suggest that both phases are subject to timing control. Eleven participants performed bimanual simultaneous tapping, at two target intervals (400, 600 ms) with the index finger of each hand performing movements of equal (3 or 6 cm) or unequal amplitude (left hand 3, right hand 6 cm and vice versa). As expected, timer variability increased with the mean interval but showed only small, non-systematic effects with changes in movement amplitude. Motor implementation variability was greater in unequal amplitude conditions. The same pattern of motor variability was observed both at flexion and extension phases of movement. These results suggest that intervals are generated by a central timer, triggering a series of events at the motor output level including flexion and the following extension, which are explicitly represented in the timing system.

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Stabilization of bimanual coordination due to active interhemispheric inhibition: a dynamical account

Cited by 72 publications

References 75 publications

Multivariate time–frequency analysis of electromagnetic brain activity during bimanual motor learning

Multivariate time–frequency analysis of electromagnetic brain activity during bimanual motor learning

Mechanisms Underlying Functional Changes in the Primary Motor Cortex Ipsilateral to an Active Hand

Interval timing and trajectory in unequal amplitude movements

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