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

Does one need to be aware of a visual stimulus for it to be perceptually organized into a coherent whole? The answer to this question regarding the interplay between Gestalts and visual awareness remains unclear. Using interocular suppression as the paradigm for rendering stimuli invisible, conflicting evidence has been obtained as to whether the traditional Kanizsa surface is constructed during interocular suppression. While Sobel and Blake (2003) and Harris, Schwarzkopf, Song, Bahrami, and Rees (2011) failed to find evidence for this, Wang, Weng, and He (2012) showed that standard configurations of Kanizsa pacmen would break interocular suppression faster than their rotated counterparts. In the current study, we replicated the findings by Wang et al. (2012) but show that neither an account based on the construction of a surface nor one based on the long-range collinearities in the standard Kanizsa configuration stimulus could fully explain the difference in breakthrough times. We discuss these findings in the context of differences in the amplitudes of the Fourier orientation spectra for all stimulus types. Thus, we find no evidence that the integration of separate elements takes place during interocular suppression of Kanizsa stimuli, suggesting that this Gestalt involving figure-ground assignment is not constructed when rendered nonconscious using interocular suppression.