There is a huge amount research into this subject. It is vast and nebulous as such I cannot give you an overall picture of this. I can however illustrate some of the complexities to this.
Firstly I would say that what you mean by human perception is extremely complex, there are different modalities of perception. For example in terms of a visual stimulus, we may simply perceive its basic shape, outline, colour, whether or not it is moving. We then may also perceive higher levels of information such as the function of the object. Similarly there are different aspects to other stimuli.
These different components of perception are transmitted by different neurons leading to the brain and then processed by different areas of the brain suited to specific tasks and then are integrated together to give us a conscious idea of what the object is.
Therefore when measuring the latency of human perception you would first have to decide what exactly you mean by this?
The other aspect is that a lot of study has occurred in this area as we are aware that perception can be altered by states of illness (for example audio evoked responses in schizophrenia, or visual evoke responses in multiple sclerosis). The perception of pain is yet another huge area of study.
Again this is such a vast area of research that I wouldn't really know where to point you to. However for a entertaining read on how perception can change in neurology I would recommend reading the books of Oliver Sacks, in particularly "The Man Mistook His Wife for a Hat" and an "Anthropologist on Mars".
I am sorry I haven't provided you with more detail but good luck in reading around this subject. If you are more specific about what perceptions, (e.g. perception of faces, perception of danger etc..) then maybe you will receive more specific answers.