From a new study:
'High caffeine users' - those who consumed more than the equivalent of seven cups of instant coffee a day - were three times more likely to have heard a person's voice when there was no one there compared with 'low caffeine users' who consumed less than the equivalent of one cup of instant coffee a day.
This article available online at:
http://www.theatlantic.com/daily-dish/archive/2009/01/tripping-with-coffee/206722/
