ihybrid
Figure1
Procedure used to create iHybrid faces. The spatial frequencies (SFs) of two original face images (illustrated here with Brad Pitt and William H. Macy) were decomposed separately into four nonoverlapping SF bands of one octave each ( 12 cycles per degree of visual angle). A Gaussian window (SD = 25 pixels, ~1° of visual angle) was then centered on every potential fixation location on each face; this procedure formed a lattice of 5- × 5-pixel cells covering the original 260 × 260 image. When an observer fixated on the stimulus, the local information across the four SF bands for one identity was extracted through the Gaussian window at that location, and the complementary global SF information was extracted from the other identity. The sum of the complementary, fixation dependent identities formed the iHybrid stimulus. In the example illustrated here, the dashed red line indicates a fixation location at the left eye; local SF information was extracted from this location in the image of Brad Pitt, and the complementary SF information was taken from the image of William H. Macy. Observers who identified the resulting face as Brad Pitt used local information, and observers who identified this face as William H. Macy used global information.
Figure1
Procedure used to create iHybrid faces. The spatial frequencies (SFs) of two original face images (illustrated here with Brad Pitt and William H. Macy) were decomposed separately into four nonoverlapping SF bands of one octave each ( 12 cycles per degree of visual angle). A Gaussian window (SD = 25 pixels, ~1° of visual angle) was then centered on every potential fixation location on each face; this procedure formed a lattice of 5- × 5-pixel cells covering the original 260 × 260 image. When an observer fixated on the stimulus, the local information across the four SF bands for one identity was extracted through the Gaussian window at that location, and the complementary global SF information was extracted from the other identity. The sum of the complementary, fixation dependent identities formed the iHybrid stimulus. In the example illustrated here, the dashed red line indicates a fixation location at the left eye; local SF information was extracted from this location in the image of Brad Pitt, and the complementary SF information was taken from the image of William H. Macy. Observers who identified the resulting face as Brad Pitt used local information, and observers who identified this face as William H. Macy used global information.