Matthew M. Botvinick, Yael Niv & Andrew G. Barto (2009), Cognition 113(3):262–280 — DOI-10.1016/j.cognition.2008.08.011

Key takeaways

  • Temporal abstraction addresses RL’s scaling problem. An option is a “mini-policy” with an initiation set, a termination condition and its own policy, which may call other options. Selecting options reduces the number of independent choices needed to find a rewarded path: two choices instead of seven in the paper’s illustration. It also reduces the decision points at which learning must happen.
  • An actor-critic HRL maps onto known anatomy. Four extensions to the actor-critic, each with a proposed substrate:
    • option identifiers held in DLPFC (and pre-SMA, SMA, premotor cortex), which selects among stimulus–response pathways as in guided activation theory;
    • option-specific policies in dorsolateral striatum;
    • option-specific value functions in OFC;
    • prediction errors computed over a whole option, a semi-Markov process, which predicts phasic dopamine at subtask boundaries.
  • Options can hurt. With options aimed at the wrong subgoals, learning is slowed. With the original doorway options and a new shortcut, the agent ignores the shortcut that a primitive-only learner finds. This mirrors negative transfer in human problem solving.
  • Option discovery is the key question. Candidate answers include:
    • evolution;
    • bottleneck states found in rewarded trajectories or by graph partitioning;
    • intrinsic reward for unexpected salient events;
    • impasses, as in Soar;
    • and, which HRL had not yet explored, social learning of subgoals from others.

Standing in the record

Filed on 2026-10-03 at the owner’s request, for the record’s coverage of how an organism’s behaviour is organized into a hierarchy and comes to act as one. It is the record’s reading of hierarchical control from the reinforcement-learning side.

The boundary. The paper presents an HRL implementation, but its purpose is to interpret behaviour and brain function, and it recommends nothing for machine-learning practice. Its subject, the neural and psychological foundations of hierarchical behaviour, is not one any anthology topic holds, so it belongs here. A reader looking for HRL as an ML method should look in the anthology. The anthology held no copy of this paper when it was filed.

It connects to three readings filed with it:

  • Daw, Niv and Dayan (LIT-580). The paper places HRL in the cache-based (model-free) system, and adds that options can be given models (“option models”) that let model-based search “skip over” sequences of primitive actions.
  • Shenhav, Botvinick and Cohen (LIT-585). The later EVC account says it “does not speak directly” to hierarchy, and points to HRL-motivated accounts of dACC as neighbours.
  • Norman and Shallice (LIT-600). The paper’s account of slips and overlapping routines in everyday tasks sits in the tradition of action schemas. The chapter was not read, so no closer relation is claimed.

Among older holdings, Brooks’s layered architecture (LIT-436) and Minsky’s Society of Mind (LIT-432) are hierarchical control by design. This paper adds learning: how the hierarchy’s units come to exist.

No instruction for machine-learning practice; nothing here belongs in the anthology.