Figure 3. Encoding the “when” of odor sequences.

(A-B) Cross-trial consistency of theta phase preference for each sequence position. (A) For each sequence position, we show single-subject trial-averaged theta phase distributions of cue odor-induced gamma power (PCx and AH data from different subjects). In both regions of interest, cue odors in each position induced gamma within specific phase ranges of theta during successful sequence encoding (solid circles; cluster-corrected p < 0.025). In contrast, in sequence-incorrect trials, odor-induced gamma did not demonstrate a consistent cross-trial theta phase preference (in PCx example subject, only Cue 1 was associated with a significant phase cluster). (B) At the group level, the number of sequence positions with significant phase clusters for each subject was greater during successful vs. unsuccessful sequence memory formation (paired-sample t-test, *p < 0.05).

(C) Separability of theta phase preference between sequence positions. The preferred theta phases of single trial responses to cue odors were compared between each unique pair of sequence positions (position 1 vs. 2, 2 vs. 3, 1 vs. 3). The number of significant pairwise phase comparisons per subject was greater during sequence-correct vs. incorrect trials (**p < 0.01, ***p < 0.001).

In (B, C), colors indicate individual subjects.