Mirror movements in normal adult subjects

Armatas, Christine; Summers, Jeffery J.; Bradshaw, John L.

doi:10.1080/01688639408402651

Cited by 120 publications

(89 citation statements)

References 25 publications

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“…The finding of comparable inhibition of iM1 for movements of both hands suggests that the higher incidence of mirroring with left than right hand movements (Liepert, Dettmers, Terborg, & Weiller, 2001;Armatas, Summers, & Bradshaw, 1994;Todor & Lazarus, 1986) cannot be accounted for by a differential efficiency of IHIi. Rather, more frequent mirroring with left hand movements might relate to an increased contribution of the ipsilateral left premotor cortex when movements are performed with the nondominant hand (Verstynen et al, 2005;Haaland et al, 2004;Cramer et al, 1999;Kim, Ashe, Hendrich, et al, 1993).…”

Section: Movement-related Interhemispheric Inhibition Targeting Primamentioning

confidence: 75%

Intermanual Differences in Movement-related Interhemispheric Inhibition

Duqué

Murase

Celnik

et al. 2007

Journal of Cognitive Neuroscience

207

163

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Abstract& Interhemispheric inhibition (IHI) between motor cortical areas is thought to play a critical role in motor control and could influence manual dexterity. The purpose of this study was to investigate IHI preceding movements of the dominant and nondominant hands of healthy volunteers. Movement-related IHI was studied by means of a double-pulse transcranial magnetic stimulation protocol in right-handed individuals in a simple reaction time paradigm. IHI targeting the motor cortex contralateral (IHI c ) and ipsilateral (IHI i ) to each moving finger was determined. IHI c was comparable after the go signal, a long time preceding movement onset, in both hands. Closer to movement onset, IHI c reversed into facilitation for the right dominant hand but remained inhibitory for left nondominant hand movements.

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Section: Movement-related Interhemispheric Inhibition Targeting Primamentioning

confidence: 75%

Intermanual Differences in Movement-related Interhemispheric Inhibition

Duqué

Murase

Celnik

et al. 2007

Journal of Cognitive Neuroscience

207

163

View full text Add to dashboard Cite

show abstract

“…This relay probably includes multiple (active) levels along 107 the neuroaxis-like ipsilateral oligosynaptic pathways and corticoreticulo-or corticopropriospinal projections (Ziemann et al 1999;Leocani et al 2000). Irrespective of the exact location of the postulated inhibitory mechanisms, the proposed model indicates that an eventual loss of inhibition may result in instabilities and phase transitions or, more generally, unintended motor output (Armatas et al 1994;Leinsinger et al 1997;Daffertshofer et al 1999). 4 Against this background, modeling neural cross-talk and ipsilateral control mechanisms during manual performance requires two M1s and additional cortical mediators; here the latter were summarized as premotor areas.…”

Section: Discussionmentioning

confidence: 99%

“…On the basis of such findings, suggested that even simple voluntary movements cause exigencies prompting the motor system to 102 respond by increasing not only the regional activation but also the information flow between hemispheres. In particular, links between bilateral motor areas may play an important role in suppressing mirror movements, that is, associated movements in arms or hands not intended to move (Armatas et al 1994;Leinsinger et al 1997;Daffertshofer et al 1999), implying that those connections are effectively inhibitory. The existence of interhemispheric inhibition has indeed been demonstrated by applying transcranial magnetic (conditioning) stimuli over the motor cortex in one hemisphere, which turned out to affect responses to stimuli over the motor cortex in the other hemisphere (Ferbert et al 1992;Meyer et al 1995;Boroojerdi et al 1996;Ikeda et al 2000;Hanajima et al 2001;Meyer-Lindenberg et al 2002).…”

Section: Introductionmentioning

confidence: 99%

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

2005

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Abstract. Based on recent brain-imaging data and congruent theoretical insights, a dynamical model is derived to account for the patterns of brain activity observed during stable performance of bimanual multifrequency patterns, as well as during behavioral instabilities in the form of phase transitions between such patterns. The model incorporates four dynamical processes, defined over both motor and premotor cortices, which are coupled through inhibitory and excitatory inter-and intrahemispheric connections. In particular, the model underscores the crucial role of interhemispheric inhibition in reducing the interference between disparate frequencies during stable performance, as well as the failure of this reduction during behavioral transitions. As an aside, the model also accounts for in-and antiphase preferences during isofrequency movements. The viability of the proposed model is illustrated by magnetoencephalographic signals that were recorded from an experienced subject performing a polyrhythmic tapping task that was designed to induce transitions between multifrequency patterns. Consistent with the model's dynamics, contra-and ipsilateral cortical areas of activation were frequency-and phase-locked, while their activation strength changed markedly in the vicinity of transitions in coordination.

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“…Mirror movements typically occur in healthy adults only during sustained effortful and fatiguing voluntary contractions (Cernacek 1961;Todor and Lazarus 1986;Dimitrijevic et al 1992;Armatas et al 1994). Such effort-induced mirror movements indicate a reduced ability of the CNS to selectively control individual muscles.…”

Section: Introductionmentioning

confidence: 99%

Effort-induced mirror movements

2002

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During sustained, fatiguing maximal voluntary contraction of muscles of one hand, muscles of the other hand gradually become activated also. Such effortinduced mirror movements indicate a decreased ability of the central nervous system (CNS) to selectively control individual muscles. We studied whether altered transcallosal inhibition (TCI) contributed to this phenomenon. TCI was determined in ten healthy subjects by measuring the ipsilateral silent period (iSP) and the contralateral silent period (cSP) during a sustained contraction of the abductor digiti minimi, induced by focal unihemispheric ipsilateral transcranial magnetic stimulation. Mirror movements occurred in all subjects in response to the effort. There was a bilateral increase in cSPs and a parallel increase in the iSP in the contralateral working muscle. In contrast, the iSP in the mirroring muscle remained unchanged, explained by a balance of increased crossed pyramidal inhibition (cSP) and decreased transcallosal inhibition. In finely tuned unimanual movements, mirroring activity of the contralateral hand is suppressed by TCI originating in the working hemisphere. During sustained, effortful contractions, the outflow of the contralateral hemisphere is increased due to reduced TCI. Effort-induced mirror contractions are thus the result of disinhibition of contralateral crossed projections rather than disinhibition of ipsilateral uncrossed pathways.

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Mirror movements in normal adult subjects

Cited by 120 publications

References 25 publications

Intermanual Differences in Movement-related Interhemispheric Inhibition

Intermanual Differences in Movement-related Interhemispheric Inhibition

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

Effort-induced mirror movements

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