The two types of blocks repeated 12 times for a total of 384 s (192 fMRI acquisitions). The images used are described in Stanley and Rubin (2003). They were shown in isolation on a homogeneous background, BI-6727 and had a mean height of 7.6° and a mean width of 8.9°. Successive images were jittered ±0.6°. Participants were required to maintain fixation, observe the images, and press a button whenever the same

image repeated twice consecutively. MRI scanning during the Study session of Experiment 3 was conducted on a 3T Trio Magnetom Siemens scanner at the Weizmann Institute of Science. Eleven healthy participants took part in the imaging experiment. They were all paid for their participation. Informed consent was obtained from all participants, and the experimental protocol was approved by the Institutional Review Board of the Sourasky Medical Center, Tel-Aviv. Two participants were discarded from the analysis since they had almost no REM trials (one participant had one REM trial and the other had two trials), and hence their data could not be used for subsequent memory prediction. All images selleck chemical were acquired using a 12 channel head matrix coil. Three-dimensional T1-weighted anatomical scans were acquired with high-resolution 1 mm slice thickness (3D MPRAGE sequence, TR 2300 ms, TE 2.98 ms, 1 mm3 voxels). Functional high-resolution scans were acquired, resulting in 2 × 2 × 2 mm

voxels (22 slices without gap, TR = 2000 ms, TE = 36 ms, flip angle = 75°). The slices were obtained at 30° toward the coronal plane from AC/PC, with the amygdala at the center of the FOV, covering also most of the hippocampus, most of the temporal lobes, and the inferior half of the frontal lobes (see Figure S3). To obtain a precise alignment between the functional data and the MPRAGE images,

a T1-weighted spin echo sequence resulting in 2 × 1 × 1 mm voxels was taken with the same slice prescription as that used for the functional scans. In Experiment 3, participants were continually scanned during presentation nearly of the 40 camouflage images of the Study session. Each trial lasted 22–38 s, separated by an ITI of 4–8 s. The scans lasted a total of 1358–1416 s. Unless otherwise indicated, fMRI data were processed using the BrainVoyager QX 1.3 software package (Brain Innovation, Maastricht, Netherlands). Data were first corrected for head motion (scans with head movement larger than 2 mm were rejected) and for slice-timing acquisition. The runs were high-pass filtered according to the period of stimulation (at 0.016 Hz for the camouflage runs and at 0.005 for the localizer runs). The complete data set was converted into Talairach space. For the multisubject voxel-by-voxel GLM analyses (see below), data from the camouflage runs were spatially smoothed with a 6 mm (full-width at half-height) Gaussian kernel. In all other analyses, which were subject-specific, data were not spatially smoothed.