One way to facilitate research collaboration between research groups at an institute is to view each new PI hire as an opportunity to bring the existing complement of scientists together.
As an example: one might hope that by hiring a new cognitive neuroscientist who uses fused data from say fMRI, dtMRI, MEG and Near Infrared Imaging one might succeed in bringing together existing groups where one group operates pretty much exclusively in the domain of brain nuclei or cortical regions and another group that operates pretty much in the domain of neurophysiology and perhaps aspects of cytoarchitecture.
This is of course strategic hiring and is often thought to be at odds with the traditional search committee approach of academia, but I don’t think it has to be. You just need search committees with a strategic focus on the future of your institute.
Jim
Discoverers and Discoveries 