Both the left (A) and the right (B) hippocampus showed enhanced pattern similarity effects (i.e., larger “same obj.+pos.” > “same obj.”; shown on the x axis) as RT enhancement increased (i.e., larger RTRandom > RTLearned) during sequence retrieval. Similar results were obtained when hippocampal pattern similarity effects (C, left hippocampus; D, right hippocampus) were quantified by comparing “same obj.+pos.” versus “lag 2+” within learned sequences. Note that RTLearned was the average of RTs across all five constant temporal sequences (i.e., “Fixed,” “X1,” “X2,” “Y1,” and “Y2”).