How is temporal pre masking possible? I was just learning about psychoacoustic audio data compression and came across some sources suggesting that a strong tonal component (masker) that occurs within a certain short timespan after a weaker component (maskee) has the effect on the brain that, it will be unable to perceive the maskee.

What I find really hard to digest is how can it affect the causality of time? Is it because the maskee signal gets picked up by the ear but gets dropped before it gets perceived in the brain due to the masker signal happening before the communication/processing delay between the ear and the brain?

Any thoughts on this?
Auditory processing has a latency of around 40ms from stimulation at the cochlea to awareness in the brain. Those 40ms appear in a number of auditory cognitive effects and mark the separation between the perceived "now" and the past. Within these 40 ms the brain can group information and produce masking effects. Pre-masking is much shorter than post-masking, because of causality, but it's not necessarily 0.