Good question!
Apparently your question is on backward masking, which means that the masker follows the stimulus (the probe). Backward masking generally occurs at higher levels, typically the cortex. In case of visual stimuli this can be the primary visual cortex, or V1 (Mace et al. 2005). Processing of the probe is then thought to be interfered with by a ongoing processing of the masker, as long as the masker-probe interval is not too long. So no, there are no connections that fold back and forth onto itself. Cortical processes are often affected by consciousness/alertness so the presence of backward masking effects can be interpreted as a marker of cortical processing/higher-level processing.
Forward masking on the other hand works at the neural level through adaptation processes. Although forward masking effects can be seen at the cortical level as nicely explained by Brosch & Screiner 1997, forward masking typically occurs in the periphery (cochlea or auditory nerve in hearing) and are unaffected by mental state. Hence, the presence of forward masking indicates that the neural process under investigation reflects a peripheral processes that also happens subconsciously, whereas the presence of backward masking effects generally point towards higher-level neural process that is typically affected by mental state. Hope this helps.