Nakayama Depth Manipulation
This page is a brief guide to the stereoscopic depth manipulation used in:
- A Harris, GK Aguirre. (2008) The Effects of Parts, Wholes, and Familiarity on Face-Selective Responses in MEG. Journal of Vision, 8(10), 1-12.
- A Harris, GK Aguirre. (2008) The Representation of Parts and Wholes in Face-Selective Cortex. Journal of Cognitive Neuroscience, 20(5), 863-78.
The manipulation of stereoscopic depth cues to alter amodal completion was initially described by:
- K Nakayama, S Shimojo, GH Silverman (1989) Stereoscopic depth: its relation to image segmentation, grouping, and the recognition of occluded objects. Perception, 18(1), 55-68.
The approach
Stereoscopic stimuli were created by hand in Adobe Photoshop. The stimuli consist of 5 layers: a white background, a patterned noise background (50% opacity to appear gray), a layer of white stripes, and green and red noise pattern overlays to be placed over the white stripes. The percept of depth was achieved by shifting the distance between the red and green layers (9 min of ocular disparity for the StripsBack and 6 min of ocular disparity for StripsFront).
Stimulus faces were copied into a separate layer positioned below the white stripe layer and adjusted manually to ensure adequate visibility.
The stimuli are viewed with Anaglyphic Red & Green 3D Glasses.
