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When performing bimanual tasks, hands are typically not controlled individually but rather as a coupled system to achieve high spatiotemporal coordination. On a brain level, intrahemispheric and interhemispheric networks that control the left and right hand are necessary to exchange information between hemispheres and to couple movements. Behaviourally, coupling is, however, highly task‐specific requiring, for example, to maintain a specific relative phase in cyclic tasks (e.g., inphase or antiphase) or to perform a role differentiated task where one hand is modulating and the other hands is stabilizing and needs to be kept as still as possible (e.g., holding a notepad and writing on it). In this study, we used electroencephalography to investigate functional brain network characteristics (task‐related activation and connectivity) in bimanual force‐control tasks with different coordination modes: inphase, antiphase and role‐differentiated with the left‐ or right‐hand stabilizing and the other hand manipulating. We aimed to examine (1) how network characteristics differ with respect to the coordination mode and (2) how they are related to the performance. Results revealed task‐related differences in the overall activation and connectivity with role‐differentiated tasks leading to higher desynchronization as compared to inphase and antiphase tasks. In addition, we showed that the strength of bimanual coupling is modulated task specifically through left‐hemispheric networks including C3, FC3 and F3 electrodes. Results highlight the importance of the left frontocentral regions for bimanual coordination. [ABSTRACT FROM AUTHOR]

Mastery of many tasks in daily life requires role differentiated bimanual hand use with high spatiotemporal cooperation and minimal interference. The authors investigated developmental changes in the performance of a disparate bimanual movement task requiring sequenced movements. Age groups were attributed to changes in CNS structures critical for bimanual control such as the corpus callosum (CC) and the prefrontal cortex; young children (5-6 years old), older children (7-9 years old), and adolescents (10-16 years old). Results show qualitative changes in spatiotemporal sequencing between the young and older children which typically marks a phase of distinct reduction of growth and myelination of the CC. Results show qualitative changes in spatiotemporal sequencing between the young and older children, which coincides with distinct changes in the growth rate and myelination of the CC. The results further support the hypothesis that CC maturation plays an important role in the development of bimanual skills. [ABSTRACT FROM AUTHOR]

Children with unilateral Cerebral Palsy (uCP) experience problems performing tasks requiring the coordinated use of both hands (bimanual coordination; BC). Additionally, some children with uCP display involuntary symmetrical activation of the opposing hand (mirrored movements). Measures, used to investigate therapy-related improvements focus on the functionality of the affected hand during unimanual or bimanual tasks. None however specifically address spatiotemporal integration of both hands. We explored the kinematics of hand movements during a bimanual task to identify parameters of BC. Thirty-seven children (aged 10.9±2.6years, 20 male) diagnosed with uCP participated. 3D kinematic motion analysis was performed during the task requiring opening of a box with their affected- (AH) or less-affected hand (LAH), and pressing a button inside with the opposite hand. Temporal and spatial components of data were extracted and related to measures of hand function and level of impairment. Total task duration was correlated with the Jebsen-Taylor Test of Hand Function in both conditions (either hand leading with the lid-opening). Spatial accuracy of the LAH when the box was opened with their AH was correlated with outcomes on the Children's Hand Use Experience Questionnaire. Additionally, we found a subgroup of children displaying non-symmetrical movement interference associated with greater movement overlap when their affected hand opened the box. This subgroup also demonstrated decreased use of the affected hand during bimanual tasks. Further investigation of bimanual interference, which goes beyond small scaled symmetrical mirrored movements, is needed to consider its impact on bimanual task performance following early unilateral brain injury. [ABSTRACT FROM AUTHOR]