Figure 1.
The future event simulation paradigm.
(A) Pre-scan session: Participants recalled memories and identified a unique person, location and object in each. (B) Scan session: Participants imagined future events containing the three recombined memory details, and subsequently rated these simulations for detail. Participants also completed control trials, during which three common nouns are incorporated in the sentence “X is bigger than Y is bigger than Z”, followed by a difficulty rating. Runs also contained fixation trials. The sequence of trials from a portion of an example run is also provided in the bottom panel of (B): Repetitions of any one future event were separated by a variable number of intervening trials (other future event trials, control trials and fixation trials).
Table 1.
Mean reaction times, detail ratings, and post-scan ratings of future events.
Table 2.
Regions evident in Future>Control contrast analysis.
Figure 2.
Results from contrast analyses.
(A) Regions from the interaction analysis in which fMRI signal decreased across repetitions for the future condition only: right hippocampus (xyz 22 −10 −14, top panel) and left inferior frontal gyrus (−36 28 −16, bottom panel), and associated percent signal change data for future and control conditions (First = FirstFuture and time1Control conditions; Second = SecondFuture; Third = ThirdFuture and time2Control conditions). These regions were also evident in the contrast of First>Second>Third (see Table 3). (B) Regions from the interaction analysis in which fMRI signal increased across repetitions for the future condition only: right precuneus (14 −64 38, top panel) and left anterior prefrontal cortex (−30 52 20, bottom panel) with associated percent signal change data. These regions were also evident in the contrast of Third>Second>First (see Table 3). Activity is shown at puncorrected <.0001 overlaid on a standard anatomical template; all peak activations survived a corrected threshold of pFWE <.05; see Table 3. Note that error bars are not included as these plots are for descriptive purposes only [54].
Table 3.
Regions evident in repetition contrast analyses.
Figure 3.
Results from functional connectivity analyses.
(A) Location of the RHC seed (xyz 32 −16 −18). (B) Average brain scores indicating the strength of correlation between activity in the seed region and the associated whole brain network, with 95% confidence intervals for the First, Second and Third presentations (p = .05). (C) Regions which were significantly connected with the RHC seed during First, but not during Second and Third during TR 5, including: right frontopolar cortex (leftmost image), putamen, cerebellum and lingual gyrus (middle images), posterior cingulate cortex, thalamus and right medial frontal gyrus (rightmost image). These data are thresholded using a BSR of 5, which corresponds to p<.0001.
Table 4.
Regions showing significant functional connectivity with the right hippocampal seed region.