Christian contemplation is defined by writers like St. Augustine, St. Bonaventura, St. Teresa, and St. John of the Cross.
Things evidently started to go wrong around the time of Thomas Merton. I enjoyed his first books, including "Seeds of Contemplation," but he went off the rails. As you may know, he was killed by an electric shock in his hotel room while attending a Buddhist convention in Asia in the interests of ecumenism.
In fact I know one scholar who wrote an excellent book on the mystical poetry of Henry Vaughan, then got involved with LSD, and wrote a second book comparing Christian contemplation with acid trips. No, they are not the same.
That's because the practice itself is a bad practice. You might as well try to reach God with a ouija board or a crystal ball. It's basically divination, a practice forbidden in Scripture.
For the record, I am not questioning the motives of all of the contemplatives. Some have good motives, and otherwise excellent teachings. But the pracitice is basically Christian divination. It's a seance for God. Only that's not the Scriptural way to pray or to meditate. We do not conjure up God's presence for ourselves (defined as: : to summon a devil or spirit by invocation or incantation b : to practice magical arts").