Moving Stimuli Are Less Effectively Masked Using Traditional Continuous Flash Suppression (CFS) Compared to a Moving Mondrian Mask (MMM): A Test Case for Feature-Selective Suppression and Retinotopic Adaptation

Abstract

Continuous flash suppression (CFS) is a powerful interocular suppression technique, which is often described as an effective means to reliably suppress stimuli from visual awareness. Suppression through CFS has been assumed to depend upon a reduction in (retinotopically specific) neural adaptation caused by the continual updating of the contents of the visual input to one eye. In this study, we started from the observation that suppressing a moving stimulus through CFS appeared to be more effective when using a mask that was actually more prone to retinotopically specific neural adaptation, but in which the properties of the mask were more similar to those of the to-be-suppressed stimulus. In two experiments, we find that using a moving Mondrian mask (i.e., one that includes motion) is more effective in suppressing a moving stimulus than a regular CFS mask. The observed pattern of results cannot be explained by a simple simulation that computes the degree of retinotopically specific neural adaptation over time, suggesting that this kind of neural adaptation does not play a large role in predicting the differences between conditions in this context. We also find some evidence consistent with the idea that the most effective CFS mask is the one that matches the properties (speed) of the suppressed stimulus. These results question the general importance of retinotopically specific neural adaptation in CFS, and potentially help to explain an implicit trend in the literature to adapt one’s CFS mask to match one’s to-be-suppressed stimuli. Finally, the results should help to guide the methodological development of future research where continuous suppression of moving stimuli is desired.

No evidence for surface organization in Kanizsa configurations during continuous flash suppression

“…Given the importance in feature overlap between mask and stimuli in determining the effectiveness of CFS (Hong & Blake, 2009;Maehara, Huang, & Hess, 2009;Moors, Wagemans, & de-Wit, 2014;Yang & Blake, 2012) and the fact that the stimuli in the different conditions differed in various ways, we did not use a traditional Mondrian style CFS mask in the main experiment. Indeed, pilot results using a classical CFS mask indicated prolonged suppression for the cross condition, containing only vertical and horizontal orientations as in the traditional Mondrian CFS mask, indicating feature-selective depth of suppression (Yang & Blake, 2012).…”

Weighing the evidence for a dorsal processing bias under continuous flash suppression

“…Although moving targets are more difficult to suppress with CFS, it is possible when applying the appropriate methods (Kaunitz, Fracasso, Skujevskis, & Melcher, 2014;Moors, Wagemans, & de-Wit, 2014). Some studies looked at motion processing under CFS and found it to be partially preserved (Kaunitz, Fracasso, Lingnau, & Melcher, 2013;Kaunitz, Fracasso, & Melcher, 2011).…”

Strength of continuous flash suppression is optimal when target and masker modulation rates are matched

“…Several studies have shown that CFS is feature selective. For instance, similarities in target and masker spatial frequency (Maehara, Huang, & Hess, 2009;Yang & Blake, 2012) and speeds (Moors, Wagemans, & De-Wit, 2014) have been shown to enhance suppression. It is therefore likely that CFS would involve suppression processes that are selective in the temporal dimension.…”

“…It is therefore likely that CFS would involve suppression processes that are selective in the temporal dimension. However, because Mondrian maskers are temporally broadband and CFS studies typically use static targets (but see Ananyev, Penney, & Hsieh, 2017;Kaunitz et al, 2014;Moors et al, 2014), the proposition has not been specifically addressed. In this study, we measured the temporal selectivity of CFS by comparing 2-and 10-Hz narrowband noise maskers on targets modulating at a range of temporal frequencies.…”