Figure 2.

Graph of Latencies. Latencies from technician-defined starting points for attempting to sleep until defined time points are shown, ranked in order of increasing latencies to the t₀ reference point. Time points are coded: Z – Time Zero (beginning of first 60-second epochs scored as Stage 1); 4 – Sleep latency according to the stipulated definition for 4-second scoring; 2 – Sleep latency according to the stipulated definition for 20-second scoring; 6 – Sleep latency according to the stipulated definition for 60-second scoring. The insomnia subject # 1 was ranked 8^th in this graph, for which the 4-second sleep latency was imputed.