A、They will have higher blood pressure. B、They will gradually lose their appetite. C、Their immune functioning could be improved.

　　Joyful laughter and meditation look similar in the brain. A small study from Loma Linda University researchers shows that when people engage in humor-associated joyful laughter, their brain wave frequencies are similar to that which are seen when a person engages in meditation. (23) The study included 31 people who were hooked up to an EEG monitor—which measures density of brain wave frequencies—as they watched 10-minute video clips. The clips had humorous, distressing or spiritual tones. When the participants watched the humorous videos, their brains produced significant gamma wave levels, similar to what you’d see when a person meditates. (24) Meanwhile, when they watched the spiritual videos, their brains produced significant alpha brain wave bands, similar to what you’d see when a person is at rest. And when they watched the distressing videos, their brains produced flat brain wave bands, similar to what you’d see when a person is detached and doesn’t want to be in a situation, researchers noted. "We suggest humor-associated joyful laughter may be another lifestyle intervention to provide health, and wellness benefits," the researchers wrote in the study. The findings were presented at the Experimental Biology 2014 conference; because they have yet to be published in a peer-reviewed journal, they should be considered preliminary. The researchers’ previous research has also showed an association between joyful laughter and blood pressure, as well as levels of hormones linked to appetite. (25) Other research has linked joyful laughter with improved immune functioning and decreased stress.
　　23. What does the speaker say about the study?
　　24. What behavior looked similar to watching spiritual videos in the brain?
　　25. What will happen if people laugh a lot?