When you touch something you sense it’s hot or cold, but my experience tells me that first brain first senses an extreme in temperature and only then it decides if some thing is hot or cold.

It happened during cold weather I think, I turned the tap and touched water, I just removed my hand since the water was extreme or very away from my body temperature, and a split second from it I sensed I just touched cold water and not hot so I proceeded further to wash my hand.

I don’t know if some one has done research about it, but this pattern seems to be everywhere, the brain gets alert first when something triggers it, then it thinks about it and sees if something is positive or negative (or classifies it).

May be this is an energy saving act of brain, if everything is done in parallel and with same energy intensity, then our brain will consume too much energy (which is costly in nature), may be it puts various parts to low energy state and triggers some parts to high energy or processing state after some activation. It’s very similar to we having multiple cores (some very specialized) on our computer and most of them are at sleep most of the time.