The activation occurs through priming the immune system with an immunogen. This demonstrated intact perceptual priming abilities. The effect of implicit memory was tested employing priming procedures. The lexical decision task can be used to demonstrate conceptual priming. Boiler water is treated to prevent scaling, corrosion, foaming, and priming. The next step is priming, or the initiation of fatty acid synthesis. This can occur even if the subject is not conscious of the priming stimulus. Immune memory in insects was discovered through the phenomenon of priming. This is called "priming" the pump. This is similar to semantic priming in monolinguals. Rimfire priming was a popular solution before centerfire priming was perfected. The terms "positive" and "negative" priming refer to when priming affects the speed of processing. "Repetition priming", also called "direct priming", is a form of positive priming. The first experiment looked at power priming and the second experiment related to role play. A similar effect is known as "context priming".