Figure 4.

fMRI activity patterns across encoding and trial periods. A, We used a condition × time interaction analysis to identify the brain regions with statistical differences in response shape across conditions. Red regions have statistically significant time points larger for novel tasks, while blue regions have time points larger for practiced tasks. Previous research has found that PCC, lateral temporal lobe (including aTL), and aPFC are involved in LTM retrieval. Their greater involvement in practiced task encoding suggests they are involved in LTM retrieval of practiced task sets. B, Several regions outside PFC reversed between encoding and trial periods. Most of these regions (such as CMA/SMA) matched the DLPFC activity pattern, suggesting they are involved in rule activation. For instance, in the case of CMA/SMA, this activation was likely for the motor rule.