

The section of the book they selected is the poet himself describing a near death experience within the poem, and is about 700 lines into the poem, which continues for another several hundred more lines after this section. Specifically it is from a poem within the novel, the novel itself being constructed of the foreword, the poem itself, and the afterword (a very extended and interpretive analysis of the poem), with the foreward and afterward supposedly written by a different author who is presenting and analyzing the poem of a Mr. On a literary level, K's baseline is from the book Pale Fire, by Nabokov. If he is calm and unemotional, he'll respond quickly (as he did after killing Sapper), if he is starting to develop emotional responses he'll respond more slowly, and with greater stress in his voice (as he did after returning from the memory doctor). Whenever K hears a word or words from his baseline he has to repeat them. On a functional level, the test works by interleaving portions of a pre-memorized "baseline" with questions designed to provoke an emotional response. The cells interlinked test is designed to test the opposite, to ensure that replicant Blade Runners aren't acquiring emotional responses to the job of killing replicants. If you recall from the original Blade Runner there was the Voit-Kompff test, which was an empathy test designed to elicit an emotional response, with the idea of catching a replicant who is not exhibiting the correct human emotions.

On a plot level, it is meant as an anti-empathy test. Not sure what level of explanation you are seeking but I'll try.
