Flexible recruitment of memory-based choice representations by human medial-frontal cortex

Flexibly switching between different tasks is a fundamental human cognitive ability that allows us to make selective use of only the information needed for a given decision. Minxha et al. used single-neuron recordings from patients to understand how the human brain retrieves memories on demand when needed for making a decision and how retrieved memories are dynamically routed in the brain from the temporal to the frontal lobe. When memory was not needed, only medial frontal cortex neural activity was correlated with the task. However, when outcome choices required memory retrieval, frontal cortex neurons were phase-locked to field potentials recorded in the medial temporal lobe. Therefore, depending on demands of the task, neurons in different regions can flexibly engage and disengage their activity patterns