Porpoises plan their dives and can set their heart rate to match
Heart rate controllersSolvin Zankl/Alamy Stock PhotoBy Andy CoghlanTwo captive harbour porpoises called Freja and Sif have helped to reveal that porpoises —and probably all cetaceans — consciously adjust their heart rate to suit the length of a planned dive. By doing this, the animals optimise the rate at which they consume oxygen beforehand to match...
I regard the brain as a computer which will stop working when its component fail. There is no heaven or afterlife for broken-down computers. That is a fairy story for people afraid of the dark