Many people have experienced intuitive knowing at some point in their life. Intuitive insights might occur by knowing that someone you are close to has just had an accident or that the phone rings and even though there is no called ID you still know who it is before answering.
Experiments
A series of scientific experiments has been conducted in 1997 by Dean Radin in which he had a random number generator select between calming and disturbing pictures which were then shown to a test subject. During this test several body functions of the test subject were measured including skin conductance, heart rate and blood volume. Approximately 5 seconds before the picture was displayed on the screen, the test subject showed a measurable difference in response depending if the picture was calming or disturbing. This experiment was repeated multiple times by other researchers.
The Institute of Heartmath decided to repeat it with additional measurement of body functions. An ECG was used to measure the heart rate variability and a EEG recorded the brain wave patterns during the experiment. There were 26 adult test subjects and the experiment was repeated after two weeks with the same people. The only particularity of these 26 people was that they were experienced meditators.
The test subjects were seated infront of a screen with a computer mouse in their hand. When they were comfortable to start a test run, they pressed the mouse button. After this the screen remained black for 6 seconds, at the end of the 6 second period the computer randomly selected a picture - either calming or disturbing - and displayed it for 3 seconds, then the screen remained black for another 10 seconds. This process was repeated 45 times for each person. After both runs of this experiment were finished a total of 2340 trials were collected.
Results
The skin conductance data did not show any significant indications for intuition. After checking back with Dean Radin on his experiments he confirmed that he had excluded experienced meditators because they had not shown any response in skin conductance. Since all test subjects were experienced meditators this only confirmed his unpublished test results.
An analysis of the heart rate variation data finally showed a significant indication that the heart knew in advance if a calming or a disturbing picture was about to be shown :
On this graph the "0" time point mark the time when the picture is displayed. The upper graph shows the heart rate variation for calming picture, the lower graph shows the data for a disturbing picture. Approxinately 4.5 seconds before the participant is shown the picture both graphs begin to diverge in a significant manner.
Conclusion
The conclusion drawn from these experiments is that the heart of the test subjects knew several seconds in advance which picture would be shown to them, even though at that time the picture was not even selected by the random number generator determining the picture selection process. It might be interesting to note that many human cultures, ancient and modern, regard the heart as a conduit to a source of information and wisdom beyond normal awareness. These experiments have shown first scientific evidence for this intuitive capacity of humanity.
Two scientific papers describing this experiment in detail are available at this link.