OP could describe these intensive, concentrated studies as, focused research.
focused adjective: giving a lot of attention to one particular thing: the need for more focused research research (Cambridge Dictionaries online)
1. careful or diligent search
2. studious inquiry or examination; especially: investigation or experimentation aimed at the discovery and interpretation of facts, revision of accepted theories or laws in the light of new facts, or practical application of such new or revised theories or laws
3. the collecting of information about a particular subject; (Merriam-Webster online)