Abstract
Neural activity underlying decision making has been reported in many brain regions in the form of choice-specific neuronal sequences that span entire task periods. In contrast to this behavioral-timescale activity, recent work has raised the possibility of fast-timescale decision-making activity in hippocampal and prefrontal regions. Whether these are distinct or complementary mechanisms is unknown. Here, we examined simultaneous hippocampal and prefrontal ensemble activity during learning of a spatial working-memory decision task. We found that both regions formed choice-specific sequences at the behavioral timescale (~seconds), as well as two fast timescales (~100-200 ms), theta cycles during navigation and sharp-wave ripples in inter-trial periods. Behavioral-timescale sequences maintained representations of current goals during navigation. In contrast, at the fast timescales, hippocampal sequences supported deliberation, whereas prefrontal ensembles predicted actual choices. Error trials resulted from impaired interaction between behavioral- and fast-timescale mechanisms. These results establish cooperative interaction at multiple timescales for memory-guided decision making.
Competing Interest Statement
The authors have declared no competing interest.