Figure 1. a, Experimental design: schematic figure of the experimental sessions. S 1, Dual-task training; S 2, prescanning behavioral training; S 3, dual task before scanning; S 4, training to automaticity during scanning; S 5, dual task after scanning and greater automaticity; orange, unrepeated training stimuli; red, low-learning condition; blue, high-learning condition (see Materials and Methods for specific details about each session). Note that the RT bar plots are schematic only; see Figure 2 for the data. b, Conditional learning trial structure. Each trial was divided into two 6 s periods (instructions occurred in the first period, and the trigger, response, and outcome (modeled as a single event) occurred in the second). Onsets of instructions and trigger-related events occurred pseudorandomly between 0.5 and 6 s within these periods, allowing us to statistically partition activity time locked to instructions from activity time locked to subsequent events (see Materials and Methods).