Abstract
Ever since Selig Hecht (1928) reported that the binocular fusion of red and green led to the percept of what is sometimes called "cortical yellow," the very existence of this phenomenon has been disputed. In his experiment, red light was presented to one eye, green light to the other. Wratten filters and available incandescent lights were employed. Subsequently, Edwin Land and William Hunt (1936) repeated the experiment utilizing polarizing filters. They also reported a positive result: that is, some observers said they saw yellow, rather than experiencing binocular rivalry. To be clear, these authors were not reporting the appearance or "reddish green" – whatever that is. Nonetheless, many authors have denied the existence of this "dichoptic red plus green equals yellow" effect, sometimes arguing that it is not consistent with ideas of color opponency. As part of "Project LITE: Light Inquiry Through Experiments," we have developed a simple binocular viewer that can be used to probe a wide variety of binocular phenomena. It is designed for use with many smart phones and similar devices (iPhone, iPod, android phone, etc.). We have also developed controllable software using HTML5 that runs on all of these devices (found at http://lite.bu.edu). Together, they help the viewer to experience diverse visual effects including: binocular rivalry; stereopis utilizing novel textured forms of random dot stereograms; binocular luster; as well as binocular addition of colors. The software includes an app to help individual observers make the red and green screen colors isoluminent. Here we report results of our red-green binocular color addition experiments utilizing our viewing device and software. Some observers indeed report binocular rivalry as might be expected classically. However, many observers (including the one presenting this report) see yellow or yellowish orange. The significances of these observations for theories of color vision will be discussed.
Meeting abstract presented at VSS 2013