Final answer:
It is true that there is no guarantee helpful ideas will emerge during the incubation stage of creative performance; this stage allows for subconscious processing but success is not guaranteed for everyone.
Step-by-step explanation:
The statement that there is no guarantee that helpful ideas will come to mind during the incubation stage of creative performance is true. The incubation stage is one of the four proposed stages of creativity, which also include preparation, illumination, and verification. During the incubation stage, individuals take a break from actively trying to solve a problem or generate new ideas, which allows for subconscious processing. Although this stage is often associated with the spontaneous emergence of insights and ideas, there is no absolute certainty that these ideas will manifest for every individual or situation. Therefore, while incubation can be beneficial, success in this stage isn't guaranteed.