In the 50s and 60s, the CIA funded experimentation with LSD in a number of American universities, where students like Ken Kesey were paid to take LSD under observation. That much I've been able to verify with reliable sources.
I remember hearing a story that during an LSD experiment, the experimenters were fascinated by Kesey's ability to accurately estimate how much time had passed--most subjects experienced wild time distortion under LSD. They didn't realize that Kesey was counting his breaths in a deliberate attempt to screw with them.
Is there any truth to this story? It's very difficult to google.
That story comes from early in the book The Electric Kool-Aid Acid Test, written by Tom Wolfe and published in 1968. Wolfe was granted access to Kesey in 1966 to write a book about Kesey and his group of friends nicknamed "The Merry Pranksters". Wolfe attended many of their events throughout that year, but he also interviewed Kesey and the Pranksters about past events.
The book begins by recounting the major events in regards to LSD of the lives of Kesey and the Pranksters, including the story of how Kesey was introduced to psychedelic drugs while a student at Stanford University during the 1960-61 school year. A friend of Kesey's and fellow student Vic Lovell was taking part in a program where students would get paid a small fee for taking psychedelic drugs so doctors could study their effects. Lovell recommended Kesey join the experiment, so he did.
Wolfe recounts the story you describe. As Kesey told Wolfe, during one of these sessions on psychedelic drugs, they started a stopwatch and wanted Kesey to tell them how long he thought it was until a minute had passed. Kesey said he would have had no idea how to estimate that time, but they had taken his pulse earlier and he overheard one say how many beats per minute his pulse was. So he took his own pulse, and accurately measured a minute. The doctors were surprised, and Kesey didn't tell them how he'd pulled it off:
"Now when I say 'Go,' you tell me when you think a minute is up by saying, 'Now.' Have you got that?"
Yeah, he had that. Kesey was soaring on LSD and his sense of time was wasted, and thousands of thoughts per second were rapping around between synapses, fractions of a second, so what the hell is a minute—but then one thought stuck in there, held ... ma-li-cious, de-li-cious. He remembered that his pulse had been running 75 beats a minute every time they took it, so when Dr. Fog says 'Go,' Kesey slyly slides his slithering finger onto his pulse and counts up to 75 and says:
"Now!"
Dr. Smog looks at his stop watch. "Amazing!" he says, and walks out of the room.
You said it, bub, but like a lot of other people, you don't even know.
How much truth there is to the story depends on how believable you find Kesey's recollection to be, and Wolfe's stylized retelling of it. Perhaps there's some CIA/university documentation that would back up the results of the experiment. In any case, Kesey was generally a pretty good self-promoter, though he was rarely accused of being an outright bullshitter. It could have happened. It also could have been a bit of an embellishment by Kesey to make for a good story. But it's in the book The Electric Kool-Aid Acid Test, which is likely where every source has taken the story from.