Physiological motor asymmetry in human handedness: evidence from transcranial magnetic stimulation

Triggs, William J.; Calvanio, Ronald; Macdonell, Richard; Cros, Didier; Chiappa, Keith H.

doi:10.1016/0006-8993(94)91026-x

Cited by 158 publications

(81 citation statements)

References 42 publications

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“…For upper limb movements, handedness-related asymmetries in cortical (e.g., Dassonville, Zhu, Ugurbil, Kim, & Ashe, 1997;Jancke et al, 1998;Kim et al, 1993;Viviani, Perani, Grassi, Bettinardi, & Fazio, 1998) and corticospinal activity (e.g., De Genarro et al, 2004;Triggs, Calvanio, & Levine, 1997;Triggs, Calvanio, Macdonell, Cros, & Chiappa, 1994) have been established as well as changes in brain activity in response to attentional manipulations (Johansen-Berg & Matthews, 2002). However, the relation between the neurophysiological correlates of these two factors has (to our knowledge) not been examined to date.…”

Section: Resultsmentioning

confidence: 96%

Laterally focused attention modulates asymmetric coupling in rhythmic interlimb coordination

Poel

Peper

Beek

2006

Psychological Research

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Peters (J Motor Behav 21:151-155, 1989; Interlimb coordination: neural, dynamical and cognitive constraints, Academic, Orlando, pp 595-615, 1994) suggested that expressions of handedness in bimanual coordination may be reflections of an inherent attentional bias. Indeed, previous results indicated that focusing attention on one of the limbs affected the relative phasing between the limbs in a manner comparable to the effects of hand dominance. The present study extended the comparison between the effects of attentional focus and handedness by testing their impact on the interactions between the limbs. Both lefthanded and right-handed participants performed rhythmic bimanual coordination tasks (in-phase and antiphase coordination), while directing attention to either limb. Using brief mechanical perturbations, the degree to which the limbs were influenced by each other was determined. The results revealed that the non-dominant limb was more strongly affected by the dominant limb than vice versa and that, in line with Peters' proposition, this handedness-related asymmetry in coupling strength was reduced when attention was focused on the non-dominant limb, thereby highlighting the potential relation between inherent (handednessrelated) asymmetries and voluntary attentional asymmetries. In contrast to previous findings, the (commonly observed) phase lead of the dominant limb was attenuated (rather than accrued) when attention was focused on this limb. This unexpected result was explained in terms of the observed attention-related difference in amplitude between the limbs.

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Section: Resultsmentioning

confidence: 96%

Laterally focused attention modulates asymmetric coupling in rhythmic interlimb coordination

Poel

Peper

Beek

2006

Psychological Research

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“…In both LB and CD, MEPs were obtained from the left BB with lower stimulation intensities than those needed to obtain MEPs in the right BB, with this left/right asymmetry present in LB even before the graft. These findings are intriguing because in normal subjects stimulation levels necessary to evoke MEP responses are generally lower for the dominant hand (44,45, but see ref. 46).…”

Section: Discussionmentioning

confidence: 99%

Re-emergence of hand-muscle representations in human motor cortex after hand allograft

Vargas

Aballéa

Rodrigues

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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The human primary motor cortex (M1) undergoes considerable reorganization in response to traumatic upper limb amputation. The representations of the preserved arm muscles expand, invading portions of M1 previously dedicated to the hand, suggesting that former hand neurons are reassigned to the control of remaining proximal upper limb muscles. Hand allograft offers a unique opportunity to study the reversibility of such long-term cortical changes. We used transcranial magnetic stimulation in patient LB, who underwent bilateral hand transplantation 3 years after a traumatic amputation, to longitudinally track both the emergence of intrinsic (from the donor) hand muscles in M1 as well as changes in the representation of stump (upper arm and forearm) muscles. The same muscles were also mapped in patient CD, the first bilateral hand allograft recipient. Newly transplanted intrinsic muscles acquired a cortical representation in LB's M1 at 10 months postgraft for the left hand and at 26 months for the right hand. The appearance of a cortical representation of transplanted hand muscles in M1 coincided with the shrinkage of stump muscle representations for the left but not for the right side. In patient CD, transcranial magnetic stimulation performed at 51 months postgraft revealed a complete set of intrinsic hand-muscle representations for the left but not the right hand. Our findings show that newly transplanted muscles can be recognized and integrated into the patient's motor cortex.amputation ͉ longitudinal ͉ plasticity ͉ reorganization ͉ TMS I t is now well established that the adult brain is highly influenced by changes occurring at the body's periphery. Evidence from human and animal models show that, when deprived of its afferent sensory input and/or its motor effectors, the primary sensory (S1) and motor (M1) cortical regions undergo plastic modifications (1-10).Traumatic upper limb amputation in humans produces lifelong consequences. Patients often report a global feeling that the missing body part is still present. This feeling is frequently associated with specific sensory and kinesthetic sensations and pain in the missing limb. Many patients further describe that the phantom limb can be moved voluntarily (review in refs. 11 and 12).Functional investigation of human M1 reorganization after amputation has demonstrated that instead of becoming inactive, the hand area is now activated during proximal limb movements (5,13,14), and that cortical stimulation of this region evokes contraction of proximal upper limb muscles (4, 9, 15, 16). Face and forearm motor representations that surround the representation of the missing hand have also been shown to expand into the de-efferented cortex (16,17), with the expansion of lip movements into the former hand area correlating positively with the amount of phantom limb pain (18). Studies employing TMS paired-pulse protocols have shown less intracortical inhibition in the region corresponding to the amputated limb when compared with the intact limb's region (19,20), suggest...

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“…In young adults, a mean difference of 5% (ranging between −10 and +15%) has been consistently found between the dominant (lower) and non-dominant MEP threshold (Triggs et al, 1997;Triggs et al, 1994;Triggs et al, 1999). Asymmetry appears to be present in cortical maps (larger maps on the dominant hemisphere) (Cicinelli et al, 1997); the CSP (shorter duration when the dominant motor cortex is stimulated) (Priori et al, 1999); and interhemispheric inhibition using the two-coil paired pulse paradigm (greater inhibition when the conditioning stimulus is delivered to the dominant hemisphere) (Netz et al, 1995).…”

Section: Age-related Changes In Asymmetrymentioning

confidence: 91%

Transcranial magnetic stimulation in children

Garvey

Mall

2008

Clinical Neurophysiology

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Developmental disabilities (e.g. attention deficit disorder; cerebral palsy) are frequently associated with deviations of the typical pattern of motor skill maturation. Neurophysiologic tools, such as transcranial magnetic stimulation (TMS), which probe motor cortex function, can potentially provide insights into both typical neuromotor maturation and the mechanisms underlying the motor skill deficits in children with developmental disabilities. These insights may set the stage for finding effective interventions for these disorders. We review the literature pertaining to the use of TMS in pediatrics. Most TMS-evoked parameters show age-related changes in typically developing children and some of these are abnormal in a number of childhood-onset neurological disorders. Although no TMS-evoked parameters are diagnostic for any disorder, changes in certain parameters appear to reflect disease burden or may provide a measure of treatment-related improvement. Furthermore, TMS may be especially useful when combined with other neurophysiologic modalities (e.g. fMRI). However, much work remains to be done to determine if TMS-evoked parameters can be used as valid and reliable biomarkers for disease-burden, the natural history of neurological injury and repair, and the efficacy of pharmacological and rehabilitation interventions.

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Physiological motor asymmetry in human handedness: evidence from transcranial magnetic stimulation

Cited by 158 publications

References 42 publications

Laterally focused attention modulates asymmetric coupling in rhythmic interlimb coordination

Laterally focused attention modulates asymmetric coupling in rhythmic interlimb coordination

Re-emergence of hand-muscle representations in human motor cortex after hand allograft

Transcranial magnetic stimulation in children

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