Why do you want to meditate ? - That's the most important question.
Not really. Zen meditation, the tradition I practice, isn't really about achieving anything practical. Meditation is a lot "dumber" than behavioral therapies like self-talk or psychedelics for that matter. There are a couple of breathing rules, a couple of posture rules, and you follow them. You sit. And you will, with practice, enter a state of focus; in old Buddhist teaching there are several
dhyanas, in our group (which I admittedly haven't attended in a while :/) we just say
samadhi. For many people, entering
samadhi is difficult and requires a lot of practice, but the process is always basically the same.
Neurologically,
samadhi is characterized by a transition of mental rhythm as viewed on EEG from alpha waves, which are the typical mental pattern of sitting quietly, to a variety of mental rhythms normally seen in deep sleep, most famously theta waves. Of course, in order to view this on an EEG, the subject must be confident enough not only to enter samadhi but to do so while on an EEG, which can make studying the phenomenon difficult.
http://www.consciousnessandbiofeedb...al-States-Psychological-and-Physiological.pdf
In any case, what we do know is that doing this little dance seems to be good for you. "Why" is of relatively small importance, over-all.
If you are interested in meditation, you really should just make sure you are sitting and breathing appropriately, and read a good guide that describes how to do so. Sam Harris wrote
an effective tutorial, and there are many others available; I enjoyed
Zen Training by Katsuki Sekida. The most important component of meditation is (highlight to read):
actually doing it
