I missed the authors' preference for traditional reviews. I have also embedded wiki-style suggestions and questions in the draft of the article. The authors need to address these.
Blake is the undoubted world expert on binocular rivalry--a good choice for author of this article.
Tong is a good choice to take up Blake's mantle when Blake relinquishes it.
The article gives a good coverage of the topic, highlighting the important issues in a generally easy-to-read way.
Occasionally, the authors use words beyond the boundaries of ordinary readers' vocabularies. Blake and Tong might consider simplifying their language further.
My suggestions included making explicit links to concepts that readers might need more information about. These could be seen as part of a list of topics that need to be included in Scholarpedia.
There are some issues that could be included in the article:
- Is it the retinal image size of rival stimuli that governs rivalry or is it the perceived size?
- What is the relation of binocular rivalry to normal and pathological eye dominance (i.e., sighting dominance and strabismic amblyopia respectively)?
- What is the relation of binocular rivalry to binocular fusion? Can neural models of these two phenomena be reconciled?
- What's the connection between computational models of rivalry and the neural models (I'm thinking here of the model of Noest et al.:
- Klink, P. C., van Ee, R., Nijs, M. M., Brouwer, G. J., Noest, A. J., & van Wezel, R. J. A. (2008). Early interactions between neuronal adaptation and voluntary control determine perceptual choices in bistable vision. Journal of Vision, 8(5, 16), 1-18.
- Noest, A. J., van Ee, R., Nijs, M. M., & van Wezel, R. J. (2007). Percept-choice sequences driven by interrupted ambiguous stimuli: A low-level neural model. Journal of Vision, 7(8), 10.)
- Has the neural model of rivalry been applied to other phenomena of visual multistability and to rivalry-like phenomena in other modalities?
I'm not saying these issues are essential to cover, but I'd like the authors to consider including some of them.
I'm looking forward to seeing the authors' responses to my suggestions.
We thank the two reviewers for their helpful comments and suggestions. <review> I could not see any comments from Reviewer B. </review> Several minor changes have been made throughout the manuscript, to improve clarity and render the text easier to read, as recommended by both reviewers.
Response to Reviewer A
Reviewer A's comment. "Blake himself, and others, have conducted some very nice studies of this wave-like spread of dominance. These could be cited here." Authors' response: The format of scholarpedia is to resemble an encyclopedia entry rather than a scientific review article, we have therefore opted to use a minimum of citations throughout the text. Along similar lines, the reference section must also be very short for Scholarpedia. We have therefore focused mostly on previous review articles in the field, with minimal reference to original papers. It can be noted that the two authors have not cited a single empirical paper of their own work in this article.
Reviewer A suggested that several issues could be included in the article:
* Is it the retinal image size of rival stimuli that governs rivalry or is it the perceived size?
Authors' response: rivalry does scale with eccentricity in a manner that reflects the cortical magnification properties of V1. This point has been added to the article. there is evidence that it's image size not perceived size that governs rivalry's dependence on size, and that has been added.
* What is the relation of binocular rivalry to normal and pathological eye dominance (i.e., sighting dominance and strabismic amblyopia respectively)?
Authors' response: In this article, we want to restrict discussion of pathological dominance as its relationship to rivalry in normal subjects still remains poorly understood. There is some evidence to suggest that if visual sensitivity is matched in the two eyes for amblyopes, normal rivalry can occur (Leonards & Sireteanu, 1993).
* What is the relation of binocular rivalry to binocular fusion? Can neural models of these two phenomena be reconciled?
Authors' response: We have avoided much discussion of neural models of rivalry in this article, largely because this article is aimed at more general readers and any discussion of the specifics of these models would become quite technical. Several models of binocular rivalry have been proposed (e.g., Lehky, Liang & Chow, Wilson, Freeman, Dayan, van Ee, Grossberg), each with its own merits. However, in our view there is insufficient empirical evidence to strongly favor one model over others, so it would be difficult to pick out a particular model to discuss in brief.
* What's the connection between computational models of rivalry and the neural models (I'm thinking here of the model of Noest et al.: o Klink, P. C., van Ee, R., Nijs, M. M., Brouwer, G. J., Noest, A. J., & van Wezel, R. J. A. (2008). Early interactions between neuronal adaptation and voluntary control determine perceptual choices in bistable vision. Journal of Vision, 8(5, 16), 1-18. o Noest, A. J., van Ee, R., Nijs, M. M., & van Wezel, R. J. (2007). Percept-choice sequences driven by interrupted ambiguous stimuli: A low-level neural model. Journal of Vision, 7(8), 10.) * Has the neural model of rivalry been applied to other phenomena of visual multistability and to rivalry-like phenomena in other modalities?
Authors' response: see response above.
Original text: Not all left and right eye image differences trigger rivalry; the following do not rival but instead meld into either a superimposition of the two monocular views (binocular transparency) or a stable average of the two (binocular fusion): dichoptic differences in þicker rate, dichoptic differences in contrast level (to be distinguished from contrast polarity), large differences in left- and right-eye spatial frequency amplitude spectra, and large differences in speed of random-dot motion.
Reviewer A's comment. "This is all too compressed. It also ignores the class of dichoptic differences, the various stereoptic disparities, that yield stereopsis and allelotropia. "
Authors' response: This section has been revised considerably to explain the visual conditions in which rivalry fails to occur. Regarding allelotropia, we feel that this topic falls outside of the scope of this review and its discussion could prove confusing or distracting to the general reader.
Original text: "This increased predominance of a stronger rival stimulus comes about for two reasons: suppression durations of a strong stimulus are notably briefer than those of a weak stimulus and, in some circumstances, dominance durations of a strong stimulus can last longer than dominance durations of a weak stimulus."
Reviewer A's comment: These two descriptions seem to be corollaries so it is puzzling why the former is expressed more strongly than the latter. Can the authors clarify?</review>
Authors' response: This section has been revised to better explain Levelt's law of dominance durations.
Reviewer A's comment: There were some early studies showing that binocular rivalry had no effect on stereopsis, such as
- Ogle, K. N., & Wakefield, J. M. (1967). Stereoscopic depth and binocular rivalry. Vision Research, 7, 89-98.
- Treisman, A. (1962). Binocular rivalry and stereoscopic depth perception. Quarterly Journal of Experimental Psychology, 14, 23-37.
We have added a brief description and explanation of Treisman's findings. In our view, the Ogle and Wakefield studies are flawed because they do not ensure that one of the two stereo half-images was undergoing suppression throughout the viewing period. Commenting on this would be a distraction to the discussion of this topic.
Reviewer A's new response
The authors have, on the whole, done a good job responding to my comments. I am happy to accept the article as it is, although I hope they will be equally conscientious in responding to some lingering inconsistencies and rough spots in the article that I have pointed out. I also made a few copy editing changes the authors might like to include.
By the way, as best as I can tell, Reviewer B made no comments that are public. Unless Reviewer B communicated privately with the authors, I'm guessing that the authors will still need to respond to Reviewer B's review.
Reviewer B: Reviewer B
I have now read the article and think it is generally very good. I really have just two suggestions. (1) in the first sentence, "dissimilar" seems too vague. After all, disparities make fusible images dissimilar to some extent. I'd use a stronger word or phrase like "highly dissimilar", "very different", or perhaps best "incompatible".
(2) I believe that Wilson (PNAS, 100, 14499-14503, 2003) was the first to show that eye rivalry and the flicker & swap rivalry could be accommodated within a system with multiple levels of rivalry. Perhaps this should be cited at the end of the section "What Rivals during Binocular Rivalry?"
In general, a very interesting and clear article.