Scientists at Washington University in St Louis were able to decode brain activity while monkeys reached around an obstacle to touch a target.
Over the past 30 years, researchers have discovered that clear information can be obtained by decoding the activity of large populations of neurons.
The study published in the online edition of the journal Science demonstrated that multiple parameters can be embedded in the firing rate of a single neuron and that certain types of parameters are encoded only if they are needed to solve the task at hand.
They also discovered that the population vectors could reveal different planning strategies, allowing the scientists, in effect, to read the monkeys' minds.
It was a coincidence that the two monkeys chosen for the study had completely different cognitive styles.
One was a hyperactive type, who kept jumping the gun, and the other was a smooth operator, who waited for the entire setup to be revealed before planning his next move, according to scientists.
The difference was clearly visible in their decoded brain activity. "That's what makes this really interesting," Daniel Moran from the School of Medicine at Washington University in St Louis, said.