I happen to be the first Guiana pig. A protocol was developed where by the meditator alternated between neutral states of mind and specific states of meditation. Among the various states that were initially tested, four were chosen as the objects of further research : the meditation on 'Altruistic love and compassion,' on " focussed attention", on "Open presence," and on the " Visualisation" of mental images.
There are methods in buddhist practice devoted to cultivating loving kindness and compassion. Here, the meditations try to generate all pervading sense of benevolence, a state in which love and compassion permeate the entire mind. They let pure love and compassion be the only object of their thoughts : intense, deep, and without any limit or exclusion. Although not immediately focussing on particular persons, Altruistic love and compassion includes a total readiness and unconditional availability to benefit others.
Focussed attention, or concentration, requires focussing all once attention upon one chosen object and calling one's mind back each time it wonder. Ideally this one pointed concentration should be clear, calm, and stable. It should avoid sinking into dullness or being carried away by mental agitation.
Open presence is a clear, open, vast, and alert state of mind, free from mental constructs. It is not actively focussed on anything, yet it is not distracted. the mind simply remains at ease, perfectly present in a state of pure awareness. When thoughts intrude, the meditator does not attempt to interfere with them, but allows the thoughts to vanish naturally.
Visualisation consists of reconstituting in the mind's eye a complexed mental image, such as the representation of a Buddhist deity. the meditator begins by visualising as clearly as possible every detail of the face, the clothes, the postures, and so on, inspecting them one by one. Lastly he visualises the entire deity and stabilises that visualisation.
These various meditations are among the many spiritual exercises that a practicing Buddhist cultivates over the course of many years, during which they become ever more stable and clear.