Performance differs according to task rule. (A) Diagram of task rules. Place blocks (top) reward continual visits to a particular (E or W) arm, and alternation blocks (bottom) reward alternation between E and W arms on successive trials. Sessions consist of three block switches. Switches occurred when 12 of the previous 15 choices were consistent with the target rule. (B) Multiple measures of performance are better for alternation blocks compared to place blocks. Unpaired cumulative distributions for choice accuracy within a block are leftward shifted for place blocks (top left, green line), whereas alternation block durations are leftward shifted (top right, gold line). P-values are calculated using unpaired, two-sample, two-sided T-tests. Within the session, paired comparisons suggest the same conclusion (bottom). Differences between choice accuracy in adjacent place and alternation blocks (bottom left, solid blue line, place minus alternation) are shifted to the left of zero, whereas differences in block duration are shifted to the right of zero (bottom right, solid blue line, place minus alternation). P-values are calculated using signed-rank tests. Red dashed lines are zero-mean (left) or median (right) standard deviation-matched, normal cumulative distributions for comparison.
