Figure 1.

A, Left, Participants viewed a sequence of fractal images. Middle, During the exposure phase, transitions between fractal images were defined by an undirected graph that organized the images into communities. Right, During the parsing phase, the boundary nodes from two communities were switched with inner nodes for a block of trials, creating novel boundary transitions (green borders). Other boundary transitions remained unchanged (learned boundary, blue borders). B, During the exposure phase, participants performed similarly on the rotation task (p = 0.53) but responded more slowly to learned boundary trials (p = 0.03). C, During the parsing phase, nonboundary transitions were less likely to be parsed compared with novel (p = 0.03) and learned (p = 0.01) boundary transitions. Response times for novel boundary transitions were slower than for learned (p = 0.02) and nonboundary (p = 0.001) transitions. D, On the posttest for explicit memory for the associations, accuracy was above chance (65.6%; p = 8.3 × 10⁻⁶).