Effects of attention on phase transitions between bimanual coordination patterns: a behavioral and cost analysis in humans

The present study aimed to obtain a behavioral analysis of the effects of a ttentional focus on the dynamics of phase transitions in bimanual coordinat ion and to evaluate the central cost expended by the central nervous system to maintain and stabilize such coordination patterns before and after the transition. Eight subjects were asked to execute an antiphase coordination pattern (180 degrees of relative phase), while gradually increasing the fre quency of oscillation. The central cost was assessed using a dual-task para digm associating the bimanual coordination task with a reaction time task. Results showed that: (1) the transition process was significantly altered b y focusing attention on the bimanual coordination task; and (2) the cost in volved in sustaining the bimanual patterns was determined by their coordina tion dynamics. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.