This may be helpful:
Letter to the Bishops of the Catholic Church on Some Aspects of Christian Meditation
(prepared by Cardinal Joseph Ratzinger, now known as Pope Benedict XVI)
Here are two excerpts that relate to the Original Post:
16. The majority of the great religions which have sought union with God in prayer have also pointed out ways to achieve it. Just as “the Catholic Church rejects nothing of what is true and holy in these religions,” neither should these ways be rejected out of hand simply because they are not Christian. On the contrary, one can take from them what is useful so long as the Christian conception of prayer, its logic and requirements are never obscured…
19. Therefore, one has to interpret correctly the teaching of those masters who recommend “emptying” the spirit of all sensible representations and of every concept, while remaining lovingly attentive to God. In this way, the person praying creates an empty space which can then be filled by the richness of God. However, the emptiness which God requires is that of the renunciation of personal selfishness, not necessarily that of the renunciation of those created things which he has given us and among which he has placed us. There is no doubt that in prayer one should concentrate entirely on God and as far as possible exclude the things of this world which bind us to our selfishness. On this topic St. Augustine is an excellent teacher: if you want to find God, he says, abandon the exterior world and re-enter into yourself. However, he continues, do not remain in yourself, but go beyond yourself because you are not God: He is deeper and greater than you. “I look for his substance in my soul and I do not find it; I have however meditated on the search for God and, reaching out to him, through created things, I have sought to know ‘the invisible perfections of God’ (Rom 1:20).” “To remain in oneself”: this is the real danger. The great Doctor of the Church recommends concentrating on oneself, but also transcending the self which is not God, but only a creature. God is “deeper than my inmost being and higher than my greatest height.” In fact God is in us and with us, but he transcends us in his mystery.