The term I was looking for is "concurrent activities". Some research in the domain of hierarchical learning has been done in this domain by [Rohanimanesh and Mahadevan][1]. According to [this literature review on hierarchical learning][2], basically what they did was determine how multiple tasks can be managed without interfering with one another and how they should be scheduled. I couldn't find any cognitive models of this concurrency, so there appears to be quite a bit of work done on the idea of [multi-tasking][3], which might be synonymous. Unfortunately, most of this seems to be quite firmly in the camp of the Classical Cognitive Science Paradigm (such as the work by [Niels Taatgen which interestingly rejects hierarchy][4]) with not a lot of thought put into neurobiological plausibility. Additional answers pointing to fMRI experimental data similar to the one found [here][5] for hierarchical learning would be greatly appreciated. [1]: http://arxiv.org/pdf/1301.2307.pdf [2]: http://people.cs.umass.edu/~mahadeva/papers/hrl.pdf [3]: https://www.cs.drexel.edu/~salvucci/publications/Salvucci-PR08.pdf [4]: http://www.ai.rug.nl/~niels/procedural.html [5]: http://www.sciencedirect.com/science/article/pii/S0896627310001960