To understand an example, you need to understand the logic behind the experiment that serves as the example. Morphine tolerance in the example in Chapter 1 would be shown when October 4, 2022 by 8i9x6 paw-lick latencies decrease over time with repeated injections of morphine. paw-lick latencies increase over time with repeated injections of morphine. paw-lick latency do not vary as a function of time. short latencies indicate reduced pain sensitivity. See Answer paw-lick latencies decrease over time with repeated injections of morphine.