EEG based evaluation of stereoscopic 3D displays for viewer discomfort

Background: Consumer preference is rapidly changing from 2D to 3D movies due to the sensational effects of 3D scenes, like
those in Avatar and The Hobbit. Two 3D viewing technologies are available: active shutter glasses and passive polarized
glasses. However, there are consistent reports of discomfort while viewing in 3D mode where the discomfort may refer to
dizziness, headaches, nausea or simply not being able to see in 3D continuously. Methods: In this paper, we propose a theory
that 3D technology which projects the two images (required for 3D perception) alternatively, cannot provide true 3D visual
experience while the 3D technology projecting the two images simultaneously is closest to the human visual system for depth
perception. Then we validate our theory by conducting experiments with 40 subjects and analyzing the EEG results of viewing 3D
movie clips with passive polarized glasses while the images are projected simultaneously compared to 2D viewing. In addition,
subjective feedback of the subjects was also collected and analyzed. Results: A higher theta and alpha band absolute power is
observed across various areas including the occipital lobe for 3D viewing. We also found that the complexity of the signal, e.g.
variations in EEG samples over time, increases in 3D as compared to 2D. Various results conclude that working memory, as well
as, attention is increased in 3D viewing because of the processing of more data in 3D as compared to 2D. From subjective
feedback analysis, 75% of subjects felt comfortable with 3D passive polarized while 25% preferred 3D active shutter technology.
Conclusions: We conclude that 3D passive polarized technology provides more comfortable visualization than 3D active shutter
technology. Overall, 3D viewing is more attractive than 2D due to stereopsis which may cause of high attention and involvement
of working memory manipulations. © 2015 Malik et al.; licensee BioMed Central.