Another possible source of evidence for the mind's surviving the brain is the occurrence of near- death experiences. People who have come close to death because of medical emergencies often report that they experience going off into a tunnel with a bright light at the end, only somehow to be pulled back. Even the famous atheistic philosopher A. J. Ayer reported a near-death experience that temporarily weakened his conviction that death would be the end of him. However, reports of near- death experiences are only very weak evidence for the existence of souls, because science provides plausible alternative explanations. Heart attacks and other medical conditions can cause shortage of oxygen in the brain with cognitive effects that are heightened by people's expectations: many people have heard about walking down a tunnel toward a light. Out-of-body experiences can be induced by laboratory experiments that produce confusion between the senses, and may be due to neural disruptions at the boundary between the temporal and parietal regions. Hence reports of near-death experiences are like reports of communications with the dead in that we can explain them without supposing that minds survive death.