e., trials in which the SOL served only as a confirmation of correct spontaneous perception and not as an

event of perceptual insight); REM (“remembered”), trials in which the camouflage image was not spontaneously identified during CAM1 and the solution was subsequently remembered, yielding correct performance on both the multiple choice and the Grid tasks at Test 1 week later (i.e., trials in which the SOL served as a learning event); and NotREM (“not remembered”), trials in which the camouflage was not identified during Study and its solution was not remembered during Test. Each of the three protocol stages (CAM1, SOL, and CAM2) was assigned a separate predictor. Combined with the labels of performance, this resulted in nine predictors (CAM1-REM, CAM1-NotREM, CAM1-SPONT, www.selleckchem.com/products/Romidepsin-FK228.html et cetera). BMN673 An additional

predictor, blank, was used for all the time frames in which the participants viewed a gray screen. These include 10 s prior to the start of the camouflage run, and the ISIs and ITIs during the run. For each predictor, a boxcar function valued 1 (and 0 for the blank predictor) was convolved with a canonical hemodynamic response function (Boynton et al., 1996). For each comparison of interest, contrasts were created between the appropriate predictors (the main contrast compared activation during REM and NotREM trials; see also the following ROIs subsections and Results), and p values were calculated (t test) for each voxel. For the SOL versus baseline and the object localizer objects versus scrambled-objects contrasts, the p values were adjusted for multiple comparisons using False Discovery Rate controlling procedures (Benjamini Idoxuridine and Hochberg, 1995, Genovese et al., 2002 and Stanley and Rubin, 2003) before thresholding. Finally, voxels that did not belong to

contiguous clusters of at least five significant functional voxels were eliminated. ROIs were defined in three different ways. First, and based on prior results indicating the occipito-temporal stream as crucial to shape perception and object recognition (Grill-Spector and Malach, 2004), visual cortical ROIs were created from the data obtained in the localizer scan. Data from those runs were modeled using a boxcar predictor for each experimental condition except fixation (objects and scrambled objects). A hemodynamic lag of 4 or 6 s was fitted to the model of each subject by maximizing the extent of the overall visual activations. Statistical maps were created, separately for each observer, by contrasting the objects and scrambled objects predictors, and thresholded at q < 0.005.