Handedness and performance variability as factors influencing mirror movement occurrence

Abstract

A finger flexion task was used to investigate the effect of hand preference and performance variability on intensity of mirror movement. Right- and left-handed subjects were asked to maintain target forces, with either their index or small finger, that represented 25, 50, or 75% of their maximum strength capacity for the active finger. Greater mirror movement occurred when the small finger was active, and where there was greater variability in task performance, while mirror movement intensity was less when the dominant hand and the index finger were active. These findings were consistent with the cortical activation explanation of motor overflow (Todor & Lazarus, 1986a), and suggest that task variability is an important factor influencing motor overflow production. It was concluded that, if performance variability reflects the efficiency of cortical activation underlying control of a voluntary task, then refined cortical control decreases the potential for motor overflow to occur. However, it is necessary to clarify the relationship between hand preference, performance variability, and motor overflow, perhaps by examining the neural pathways involved in motor overflow production.

High Gamma Oscillations of Sensorimotor Cortex During Unilateral Movement in the Developing Brain: a MEG Study

“…Most previous studies that explored asymmetry of the physiological mirroring have reported that there was a stronger mirror activity during a voluntary movement of the nondominant hand. (Armatas et al 1994(Armatas et al , 1996Uttner et al 2007;Liederman and Foley 1987) Although the reverse pattern (Cernacek 1961) or no difference between the hands (Armatas and Summers 2001) has also been found. In our results, 17 out of the 20 participants who showed the ipsilateral activation just during left finger movement were right-handed.…”

Clinical Characteristics and Brain Activation Patterns of Mirror Movements in Patients with Corona Radiata Infarct

“…Many studies reported that MMs or unaffected motor cortex activation can be changed or manipulated by exercise [30,37,38,39,40,41,42,43,44]. This suggests that MMs can be manipulated by rehabilitative management.…”

Electromyographic analysis of joint-dependent global synkinesis in the upper limb of healthy adults: Laterality of intensity and symmetry of spatial representation

“…As intercortical effect could be crucial, debate as to whether laterality of the human hemisphere contributes to asymmetrical synkinesis invites researchersÕ attention. Many studies among healthy subjects have presented a greater amount or higher occurrence frequency of motor overflow when the non-dominant limb is active [5,12,38]. The invariant standpoint of GS asymmetry, however, was challenged by Parlow [30] who reported that synkinesis laterality depends primarily upon task characteristics.…”

“…Moreover, the extent of GS asymmetry may depend on how GS is characterized. It is noteworthy that earlier studies of GS symmetry was based merely upon occurrence frequency of the homologous muscle [5,30], overlooking non-homologous irradiation coupled with synergistic movement of the whole nonexercised limb [17,43]. Besides, several factors that may influence GS characteristics have not been systematically investigated.…”