Eichenbaum and crew show that neurons in different parts of the CA3 area of the rat hippocampus acquire different memories at different levels. More specific memories are rapidly acquired by dorsal CA3 whereas the ventral CA3 neurons more gradually accumulate information across training episodes to form broader, more generalized context representations.
The interplay between brain systems that rapidly acquire specific information and systems that more slowly build generalizations may be a common theme of brain function (Seger and Miller, 2010). We have suggested a similar relationship between the basal ganglia and frontal cortex for goal directed learning. Think of it as the basal ganglia learning the pieces of a puzzle and the prefrontal cortex gradually putting the puzzle together (Miller and Buschman, 2007).
The idea is that rapid plasticity in the basal ganglia learns simple, specific things very quickly. The output of the basal ganglia repeatedly “trains” slower plasticity in the frontal cortex (Pasupathy and Miller, 2005). In this way, the frontal cortex gradually forms abstractions from the common structure in the information fed to it by the basal ganglia. We have seen direct evidence for this during category learning (Antzoulatos and Miller, 2011). Early in learning, when animals try to solve the task by learning about each specific exemplar, basal ganglia neurons lead the charge. Then, when the number of exemplars becomes overwhelming and the animals finally start abstracting the categories, the prefrontal cortex takes over.
For further reading see:
Antzoulatos,E.G. and Miller, E.K. (2011) Differences between neural activity in prefrontal cortex and striatum during learning of novel, abstract categories. Neuron. 71(2): 243-249. View PDF »
Seger, C.A. and Miller, E.K. (2010) Category learning in the brain. Annual Review of Neuroscience, Vol. 33: 203-219. View PDF »
Miller, E.K. and Buschman, T.J. (2007) Rules through recursion: How interactions between the frontal cortex and basal ganglia may build abstract, complex, rules from concrete, simple, ones. In: The Neuroscience of Rule-Guided Behavior, S. Bunge & J. Wallis (eds.), Oxford University Press. View PDF »
Pasupathy, A. and Miller, E.K. (2005) Different time courses for learning-related activity in the prefrontal cortex and striatum. Nature, 433:873-876. View PDF »
About the Author
The Miller Lab uses experimental and theoretical approaches to study the neural basis of the high-level cognitive functions that underlie complex goal-directed behavior. ekmillerlab.mit.edu