  To address complex problems, scholars are increasingly faced with challenges
of integrating diverse knowledge domains. We analyzed the evolution of this
convergence paradigm in the broad ecosystem of brain science, which provides a
real-time testbed for evaluating two modes of cross-domain integration -
subject area exploration via expansive learning and cross-disciplinary
collaboration among domain experts. We show that research involving both modes
features a 16% citation premium relative to a mono-disciplinary baseline.
Further comparison of research integrating neighboring versus distant research
domains shows that the cross-disciplinary mode is essential for integrating
across relatively large disciplinary distances. Yet we find research utilizing
cross-domain subject area exploration alone - a convergence shortcut - to be
growing in prevalence at roughly 3% per year, significantly faster than the
alternative cross-disciplinary mode, despite being less effective at
integrating domains and markedly less impactful. By measuring shifts in the
prevalence and impact of different convergence modes in the 5-year intervals
before and after 2013, our results indicate that these counterproductive
patterns may relate to competitive pressures associated with global Human Brain
flagship funding initiatives. Without additional policy guidance, such Grand
Challenge flagships may unintentionally incentivize such convergence shortcuts,
thereby undercutting the advantages of cross-disciplinary teams in tackling
challenges calling on convergence.
