I'm not advocating the "truth" of the following articles, but they make interesting reading.
What Happens After You Die? The Brain Keeps Working Long Enough for Thoughts to Form -- "The current medical definition of death is when the heart stops beating...from that point, it takes up to 20 seconds before brain waves are no longer detectable."
Are 'Flatliners' Really Conscious After Death? -- "Parnia and his colleagues are currently investigating the pervasiveness of consciousness after death."
James 2:26 "...the body without the spirit is dead..."