a, In monkey behavior b, In human behavior. X-axis indicates quantiles used for the split in high- and low-decoding trials (Fig. 5), from a total of n=1362 trials in a, and a range of 792-908 trials per subject in b. Error bars are ±s.e.m. (over n=1362 trials in a, and over n=15 subjects in b) and colored bars mark where corresponding difference in serial biases is different than zero (p<0.05, two-sided bootstrap test).