Neural underpinnings of the evidence accumulator.

•Gradual accumulation of evidence, core to decision-making, can be studied in rodents.•Pulse-based sensory evidence stimuli facilitate behavioral and neural analysis.•High-time-resolution inactivation helps identify role of different brain regions.•Differential role of the five brain regions studied so far is being distinguished.•Causal circuit for accumulation involves only some of the regions studied so far.