Figure 5.

Activity in the left hippocampal region (voxels selected from experiment 1) in experiment 2 as a function of baseline difficulty. a, Activity for all trial types relative to the easy baseline (white, first presentation; light gray, strength indices 1-5 trials; dark gray, reference trials; black, difficult baseline trials). b, Activity for all trial types relative to the difficult baseline. In both, activity was quantified for each stimulus type using the raw values from the general linear model estimate (β coefficients) of the activity summed over the ∼3-12 s after stimulus onset. c, d, Sample difficult (c) and easy (d) baseline trials. e, Hemodynamic response for the middle memory strength index (strength 3) trials from experiment 2 relative to the easy baseline (gray line), experiment 2 relative to the difficult baseline (black line), and experiment 1 relative to its easy baseline (dashed line). Individual β coefficients are plotted at each time point. Str, Strength; Ref, reference.