Variability in memory benefits over sleep is explained by shared semantic context. (A) We hypothesized that bonds between objects linked within the same contextually bound sets would drive changes in memory performance over sleep. If this were the case, memory trajectories (i.e., changes in memory between the first and second session) would be correlated within sets for the sleep group. Intraclass correlation coefficients (ICC) were calculated to estimate within-set correlations and converted to Z-scores for each participant in the sleep (left) and wake (right) groups. Insets show the distribution of the nonnormalized ICC values for both groups. (B) Direct comparison between the correlation coefficients for the sleep and wake groups. (C) We hypothesized that the temporal context binding together sets that were learned within the same blocks would drive changes in memory performance over sleep. If this were the case, average memory trajectories within sets would be correlated within blocks for the sleep group. Intraclass correlation analyses to consider the effect of temporal context on memory. Designations follow those introduced in B. (D) Direct comparison between the correlation coefficients for the sleep and wake groups. Error bars signify standard errors of the mean across participants in all panels. (*) P < 0.05, (n.s) P > 0.05.
