Cleve Backster (born 1924) is a polygraph expert best known for his controversial experiments with biocommunication in plant and animal cells using a polygraph machine in the 1960s which led to his theory of "primary perception." He is currently director of the Backster School of Lie Detection in San Diego, California.
His course of study changed dramatically in the 1960s, when he reported observing that a polygraph instrument attached to a plant leaf registered a change in electrical resistance when the plant was harmed or even threatened with harm. He argued that plants perceived human intentions, and as Backster began to investigate further, he also reported a finding that other human thoughts and emotions caused reactions in plants that could be recorded by a polygraph instrument. He termed the plants' sensitivity to thoughts "primary perception," and published his findings from the experiments in the International Journal of Parapsychology. The article was met with wide criticism of his research methods. However, Backster gained the interest of other researchers, and he expanded his experimental range to test for primary perceptions in other life forms, such as yogurt, bacteria, and human cells. His work was in part inspired by the research of Sir Jagadish Chandra Bose, who claimed to have discovered that playing certain kinds of music in the area where plants grew caused them to grow faster.
Since those early days Backster has presented his work at numerous scientific meetings, including those of the Institute of Noetic Sciences (IONS), founded by astronaut Edgar Mitchell, and the Institute for Transpersonal Psychology in Palo Alto, CA. He was a guest on June 27, 2007 on the popular evening radio show, "Coast To Coast AM", during which he discussed with host George Noory and with callers to the program his experiments with primary perception and findings of an interconnection between all living cells. He had been a guest several times before on Art Bell's Coast to Coast, as well as on Jeff Rense's radio shows, and has presented papers at many international conferences and meetings as well as those in the U.S.A.
While Backster's work has notable support among many outside the scientific and academic community, and his acceptance and encouragement of this support has hindered his reputation with many established scientists, the scientific community is split in deciding how to deal with the implications of Backster's research. The very nature of his hypotheses that living subjects of experimentation are capable and inclined to respond directly, at a cellular level, to those conducting the experiments creates an inherent difficulty in getting many in academia to even look at his data. This attitude on the part of academia is clearly at variance with the scientific method, but nevertheless remains the largest hindrance to Backster's ability to gain more widespread credibility.
In November 1975 a little known report called “Organic Biofield Sensor” was published. The research was done by Dr. Harold E. Puthoff and Randall Fontes at Stanford Research Institute in Menlo Park, California. This Report supports the possibility that plants may respond to human consciousness as contended by Cleve Backster. 
His biocommunications work is most famously discussed in The Secret Life of Plants by Peter Tompkins and Christopher Bird. Backster's work is discussed in his book, published in 2003, titled Primary Perception. The book was translated into Chinese in 2006 and Japanese in 2007.
The Backster School of Lie Detection is located in San Diego, California, and is the longest running polygraph school in the world. The school was originally founded in New York City in 1960, shortly after Mr. Backster left his position with the Central Intelligence Agency. Backster founded the CIA's polygraph unit shortly after World War II. More to come.
Backster's "Primary Perception" theory was referenced in the Discovery Channel television show MythBusters. The team attempted to reproduce Backster's experiments using a polygraph and an EEG machine. It reproduced the plant experiment and initially got something peculiar as predicted by Backster's work. However, after more carefully controlling the conditions of the experiment to eliminate the possibility of external influence, the plant did not demonstrate any measurable reaction to external stimulus. The team was similarly unable to coax any measurable response out of yogurt cultures, white blood cells, or eggs. These experiments were then responded to by Backster on a 2008 radio broadcast of Coast to Coast AM, where he criticized the conditions of the Mythbusters experiment. Italian public television RAI produced, in 1975, a four parts serial based on Backster's work and titled "La traccia verde" (the green trace)