There has been some confusion regarding this passage. Who is the personage described as the "Spirit of the Lord?" This term can be used to mean either the Holy Ghost or Jehovah. The vast majority of scriptures which use the term are speaking of the Holy Ghost. Phrases like "the Spirit of the Lord came upon him," and "the Spirit of the Lord which was in him" make it clear that the term refers to the third member of the Godhead. In Nephi 11, verses 6-7 also make it clear that the "Spirit of the Lord," in this passage, is not the pre-mortal Christ.
Now that we have established that Nephi is conversing with the Holy Ghost, we must underscore the singularity of this event. No other prophet describes a vision in which he/she sees and converses directly with the Holy Ghost. This unusual conversation brings new meaning to the phrase "caught away in the Spirit."
James E. Talmage
"That the Spirit of the Lord is capable of manifesting Himself in the form and figure of man, is indicated by the wonderful interview between the Spirit and Nephi, in which He revealed Himself to the prophet, questioned him concerning his desires and belief, instructed him in the things of God, speaking face to face with the man [1 Nephi 11:11]. However, the Holy Ghost does not possess a body of flesh and bones, as do both the Father and the Son, but is a personage of spirit. Much of the confusion existing in human conceptions concerning the nature of the Holy Ghost arises from the common failure to segregate His person and powers. Plainly, such expressions as being filled with the Holy Ghost, and His falling upon persons, have reference to the powers and influences that emanate from God, and which are characteristic of Him; for the Holy Ghost may in this way operate simultaneously upon many persons even though they be widely separated, whereas the actual person of the Holy Ghost cannot be in more than one place at a time." (Articles of Faith, p. 42, as taken from Latter-day Commentary on the Book of Mormon compiled by K. Douglas Bassett, p. 36)