Figure 1. Experimental procedures and univariate responses.

(A) In the encoding phase, subjects watched 10 short movies approximately 2–8 min long. Each movie started with a 6 s title scene. In the free spoken recall phase, subjects verbally recounted each movie plot in as much detail as possible regardless of the order of presentation. After recalling one movie, subjects spontaneously proceeded to the next movie, and the transitions between movies were considered as internally driven boundaries. Red arrows indicate the boundaries (onsets and offsets) between watched or recalled movies. Black arrows indicate the non-boundary moments (middle) of each watched or recalled movie. (B) Whole-brain maps of unthresholded mean activation (blood oxygen level-dependent [BOLD] signals z-scored across all volumes within a scanning run) following between-movie boundaries during recall (4.5–19.5 s from the offset of each movie). Blue areas indicate regions with lower-than-average activation, where the average activation of a scanning run was z = 0. Likewise, red areas indicate regions with higher-than-average activation. White outlines indicate areas that showed significantly lower or higher activation following between-movie boundaries compared to non-boundary periods (false discovery rate-corrected q < 0.05; minimum surface area = 16 mm²). The non-boundary periods were defined as the middle 15 s of each recalled movie, shifted forward by 4.5 s. Changes in whole-brain univariate responses across time around the boundaries are shown in Figure 1—video 1 (recall phase) and Figure 1—video 2 (encoding phase).

Figure 1—figure supplement 1. Mean activation time courses around between-movie boundaries.

For each subject and region of interest (top row = posterior medial cortex [PMC]; middle row = angular gyrus [ANG]; bottom row = auditory cortex [AUD]), blood oxygen level-dependent [BOLD] signals measured during the encoding phase (left column) or recall phase (right column) were locked to the offset of each watched or recalled movie, and then averaged across movies. Thin gray lines show individual subjects’ time courses. Thick black lines show the mean time courses averaged across all subjects. Red bars on the x-axis indicate the 15 s boundary period time window (4.5–19.5 s from the offset of each movie) used for subsequent analyses comparing the boundary and non-boundary periods.

Figure 1—video 1. Changes in univariate activation at between-movie boundaries during recall (video).

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The animation shows the time series of whole-brain activation maps (blood oxygen level-dependent [BOLD] signals z-scored across all volumes within a scanning run) locked to the offset of the recall of each movie, from 30 s before to 45 s after the offset. Within each of the 7.5 s time windows shown as a red bar on the time axis, BOLD signals in each vertex were averaged across time points, movies, and subjects. Blue-cyan areas indicate regions with lower-than-average activation. Red-yellow areas indicate regions with higher-than-average activation.

Figure 1—video 2. Changes in univariate activation at between-movie boundaries during encoding (video).

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The animation shows the time series of whole-brain activation maps (blood oxygen level-dependent [BOLD] signals z-scored across all volumes within a scanning run) locked to the offset of each movie clip during the encoding phase, from 30 s before to 45 s after the offset. Within each of the 7.5 s time windows shown as a red bar on the time axis, BOLD signals in each vertex were averaged across time points, movies, and subjects. Blue-cyan areas indicate regions with lower-than-average activation. Red-yellow areas indicate regions with higher-than-average activation.