  We study the collective behaviour of an ensemble of coupled motile elements
whose interactions depend on time and are alternatively attractive or
repulsive. The evolution of interactions is driven by individual internal
variables with autonomous dynamics. The system exhibits different dynamical
regimes, with various forms of collective organization, controlled by the range
of interactions and the dispersion of time scales in the evolution of the
internal variables. In the limit of large interaction ranges, it reduces to an
ensemble of coupled identical phase oscillators and, to some extent, admits to
be treated analytically. We find and characterize a transition between ordered
and disordered states, mediated by a regime of dynamical clustering.
