Unraveling Interlimb Interactions Underlying Bimanual Coordination

Abstract

. Three sources of interlimb interactions have been postulated to underlie the stability characteristics of bimanual coordination but have never been evaluated in conjunction: integrated timing of feedforward control signals, phase entrainment by contralateral afference, and timing corrections based on the perceived error of relative phase. In this study, the relative contributions of these interactions were discerned through systematic comparisons of five tasks involving rhythmic flexion-extension movements about the wrist, performed bimanually (in-phase and antiphase coordination) or unimanually with or without comparable passive movements of the contralateral hand. The main findings were the following. 1) Contralateral passive movements during unimanual active movements induced phase entrainment to interlimb phasing of either 0°(in-phase) or 180°(antiphase). 2) Entrainment strength increased with the passive movements' amplitude, but was similar for in-phase and antiphase movements. 3) Coordination of unimanual active movements with passive movements of the contralateral hand (kinesthetic tracking) was characterized by similar bilateral EMG activity as observed in active bimanual coordination. 4) During kinesthetic tracking the timing of the movements of the active hand was modulated by afference-based error corrections, which were more pronounced during in-phase coordination. 5) Indications of in-phase coordination being more stable than antiphase coordination were most prominent during active bimanual coordination and marginal during kinesthetic tracking. Together the results indicated that phase entrainment by contralateral afference contributed equally to the stability of in-phase and antiphase coordination, and that differential stability of these patterns depended predominantly on integrated timing of feedforward signals, with only a minor role for afference-based error corrections.

Bilateral motor unit synchronization is functionally organized

“…For instance, aVerent Wbers have no direct, crossed eVect on MUs of homologous muscle but only modulate the excitability of interneurons (Harrison and Zytnicki 1984;Arya et al 1991;McCrea 2001). Furthermore, behavioral data showed that aVerent information plays only an ancillary role in bilateral coupling (RidderikhoV et al 2005a;Spencer et al 2005). It was shown for both maximal and submaximal contractions that there is a common drive to homologous muscles that might be instigated by interneuronal connectivity between both motor areas (Oda 1997).…”

“…Interlimb coordination is governed by interactions between limbs arising from various constraints residing at diVerent levels of the motor system (Carson and Kelso 2004) and several studies have been carried out to pinpoint the neural structures involved (see Carson 2005, for a review). Recently, evidence has been presented that bilateral coupling primarily stems from shared eVerent information (RidderikhoV et al 2005a;Spencer et al 2005) and that aVerent processes only play an ancillary role. For instance, muscles that are normally coactivated may share a common drive arising from branched presynaptic Wbers or from presynaptic synchronization of last-order inputs (Carr et al 1994).…”

Perception and action influences on discrete and reciprocal bimanual coordination

“…Research has revealed a pivotal role for proprioception (Baldissera, Cavaliari, Marini, & Tassone, 1991;Ridderikhoff, Peper & Beek, 2005) and tactile input (Aschersleben & Prinz, 1995;Buchanan & Ryu, 2005;Kelso, Fink, DeLaplain, & Carson, 2001) in stabilizing in-phase and anti-phase coordination. Clues as to the importance of visual perceptual information to bimanual coordination have also been found in interpersonal coordination tasks , where two people coordinate their movements, and unimanual tracking tasks (Wilson, Collins, & Bingham, 2005a,b), whereby performers coordinate their movements to an external signal, which also exhibit stable coordination patterns at 0 o and 180 o relative phase.…”

“…Some research has shown that with the loss of somatosensory feedback there is a decrease in the stability of anti-phase coordination, however, this loss does not keep the system from establishing and maintaining symmetric and asymmetric bimanual circle tracing patterns (Spencer, Ivry, Cattaert, & Semjen, 2005). Thus, one contribution to the coupling and stability characteristics of bimanual coordination clearly resides in forward commands and the interactions that arise from those commands as the result of shared neural pathways (Ridderikhoff et al, 2005). It should be noted that constraints related to crossed and uncrossed neural pathways should affect to varying extents all iso-and poly-rhythmic bimanual coordination patterns except the in-phase 1:1 coordination pattern.…”

Behavior generation for interpersonal coordination with virtual humans : on specifying, scheduling and realizing multimodal virtual human behavior

“…Periodic bimanual movements are often the focus of studies on basic organization of human actions [102,133,134,191,237]. A common finding in all these studies is that only two patterns of rhythmic bimanual coordination can be achieved without training: a stable 'in-phase' pattern and a less stable 'anti-phase' pattern.…”