A rat study has revealed that as the rats slowly learned a new rule, groups of neurons in the medial frontal cortex switched quite abruptly to a new pattern corresponding directly to the shift in behavior, rather than showing signs of gradual transition. Such sudden neural and behavioral transitions may correspond to so- called "a-ha" moments, and support the idea that rule learning is an evidence-based decision process, perhaps accompanied by moments of sudden insight.
(2010). Abrupt Transitions between Prefrontal Neural Ensemble States Accompany Behavioral Transitions during Rule Learning.
Neuron. 66(3), 438 - 448.