Figure 7. Example of similar dimensional-reduction and task-variable encoding across individuals.

In all cats, 5 synergies accounted for >96% of the variability in response to translation at the preferred stance. A) Muscle synergies for each individual. Colored bars indicate muscles that were measured across all individuals. Gray bars indicate the remaining muscles collected for each individual. While there are general similarities in the most highly activated muscles in each synergy, substantial variation in muscles contributing to the synergies exist across individuals. B) Activation coefficients across animals are similar, indicating that they are activated in similar perturbation directions. C) Force vectors produced by each synergy are also quite similar. Taken together, this data demonstrates that neural commands encoding force-vector directions are quite similar across individuals, but the specific muscle synergy mapping used can vary. (Adapted from Torres-Oviedo et al. 2006.)