Abstract
Transcallosal connections between motor cortices are pivotal for bimanual
coordination and previous work demonstrated that inter-hemispheric
inhibition is modulated by symmetry of bimanual movements [1]. The
amount of modulation during movement preparation and the role of
‘dynamic force context’ (increase vs decease) remain unknown.
The ipsilateral silent period (iSP) (ISP area /pre-stimulus EMG) quantified
inter-hemispheric inhibition during dynamic bimanual grip force control.
The iSP was elicited by a TMS pulse to the left primary motor hand area
while participants (N¼17) performed a visually cued bimanual pinch-grip
task, requiring to match two changing semi-circles by increasing or
decreasing pinch force in the left and right hand. The influence of force was
tested in three conditions: (1) steady symmetric pinch (baseline), (2) leftled asymmetric pinch (left hand increases force, right simultaneously releases) (3) right-led asymmetric pinch (right hand increases force, left
hand releases). Three time points during movement preparation were
assessed (100ms, 150ms, 200ms post visual-cue change).
An ANOVA showed a significant main effect for Time (p¼ 0.03) and Condition (p¼ 0.04) but no Time x Condition interaction. Post-hoc testing
revealed that iSP was stronger during baseline compared to left-led (p
¼0.02) and right-led (p ¼ 0.07) movement types with no significant difference between the two asymmetric conditions (p¼0.4). Generally, iSP
was strongest when assessed at 100ms post-cue change across conditions.
A Pearson’s product-moment correlation indicated negative correlation
between iSP modulation during asymmetric movements and the reaction
time of the left hand, reaching significance in the left-led condition (r¼-0.5
p¼0.02).
Asymmetric isometric grip force generation decreases inter-hemispheric
inhibition during movement preparation. The magnitude of down-regulating transcallosal inhibition is tied to faster reaction times. For the time
window studied, our data provide no evidence in support of the dynamic
force context on inter-hemispheric interactions as expressed by the iSP.
coordination and previous work demonstrated that inter-hemispheric
inhibition is modulated by symmetry of bimanual movements [1]. The
amount of modulation during movement preparation and the role of
‘dynamic force context’ (increase vs decease) remain unknown.
The ipsilateral silent period (iSP) (ISP area /pre-stimulus EMG) quantified
inter-hemispheric inhibition during dynamic bimanual grip force control.
The iSP was elicited by a TMS pulse to the left primary motor hand area
while participants (N¼17) performed a visually cued bimanual pinch-grip
task, requiring to match two changing semi-circles by increasing or
decreasing pinch force in the left and right hand. The influence of force was
tested in three conditions: (1) steady symmetric pinch (baseline), (2) leftled asymmetric pinch (left hand increases force, right simultaneously releases) (3) right-led asymmetric pinch (right hand increases force, left
hand releases). Three time points during movement preparation were
assessed (100ms, 150ms, 200ms post visual-cue change).
An ANOVA showed a significant main effect for Time (p¼ 0.03) and Condition (p¼ 0.04) but no Time x Condition interaction. Post-hoc testing
revealed that iSP was stronger during baseline compared to left-led (p
¼0.02) and right-led (p ¼ 0.07) movement types with no significant difference between the two asymmetric conditions (p¼0.4). Generally, iSP
was strongest when assessed at 100ms post-cue change across conditions.
A Pearson’s product-moment correlation indicated negative correlation
between iSP modulation during asymmetric movements and the reaction
time of the left hand, reaching significance in the left-led condition (r¼-0.5
p¼0.02).
Asymmetric isometric grip force generation decreases inter-hemispheric
inhibition during movement preparation. The magnitude of down-regulating transcallosal inhibition is tied to faster reaction times. For the time
window studied, our data provide no evidence in support of the dynamic
force context on inter-hemispheric interactions as expressed by the iSP.
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation |
| Vol/bind | 12 |
| Udgave nummer | 2 |
| Sider (fra-til) | 561-561 |
| Antal sider | 1 |
| DOI | |
| Status | Udgivet - 2019 |
| Begivenhed | Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation: 3rd International Brain Stimulation Conference - Vancouver, Canada Varighed: 24 feb. 2019 → 27 feb. 2019 https://www.brainstimjrnl.com/article/S1935-861X(19)30032-4/fulltext |
Konference
| Konference | Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation |
|---|---|
| Land/Område | Canada |
| By | Vancouver |
| Periode | 24/02/2019 → 27/02/2019 |
| Internetadresse |