On the Contribution of Binocular Disparity to the Long-Term Memory for Natural Scenes

Abstract

Binocular disparity is a fundamental dimension defining the input we receive from the visual world, along with luminance and chromaticity. In a memory task involving images of natural scenes we investigate whether binocular disparity enhances long-term visual memory. We found that forest images studied in the presence of disparity for relatively long times (7s) were remembered better as compared to 2D presentation. This enhancement was not evident for other categories of pictures, such as images containing cars and houses, which are mostly identified by the presence of distinctive artifacts rather than by their spatial layout. Evidence from a further experiment indicates that observers do not retain a trace of stereo presentation in long-term memory.

The Role of Binocular Disparity in Rapid Scene and Pattern Recognition

“…The results of Experiment 1 seem to indicate that binocular disparity does not contribute to the fast recognition of visual scenes, if anything, a nonsignificant trend for worse recognition of stereo pictures emerged, a result which is strikingly different from the observation of Liu and colleagues (2000), who found that stereo produced a small (2.5%) enhancement in the recognition rate of faces with a viewing time of 1.5 s and the observation of Valsecchi and Gegenfurtner (2012), who found a significant improvement in the long-term memorization rate when observers viewed the same forest pictures for 7 s.…”

“…The pictures were taken in the Schiffenberger Wald, in the vicinity of Giessen, using a Fujifilm Finepix W1 3D digital camera (Fujifilm Holdings Corporation, Tokyo, Japan). A subset of the images was used by Valsecchi and Gegenfurtner (2012). In the present and in the following experiments, the images were displayed in a mirror stereoscope.…”

“…McKee et al, 1990; also see Valsecchi & Gegenfurtner, 2012; Westheimer, 2011). The first question we asked in the present study is thus whether the visual system uses disparity in order to encode scenes for short-term recognition.…”

“…Furthermore, we constructed our mask images with a stereo structure that had depth relations consistent with the overlap (occlusions) in the 2D pattern. As targets we used forest images, a category of images for which Valsecchi and Gegenfurtner (2012) showed that binocular disparity enhances long-term memorization.…”

“…Valsecchi and Gegenfurtner (2012) demonstrated that binocular stereo can improve the long-term memory for natural scenes, although this is the case only under very specific conditions, i.e. only for scenes where a semantic encoding could not support recognition (forest scenes).…”