A team of researchers has conducted a study regarding sleep talkers and has found that most sleep talking is not only negative in nature, but involves a large amount of swearing, according to Medical Xpress.

In their paper published in the journal Sleep, the group describes their study, which involved watching and recording hundreds of volunteers as they slept. Most people talk in their sleep at some point, but as the researchers with this new effort note, not much research has been done to find out what sleeping people have to say.

To find out, the group enlisted the assistance of 230 volunteers who agreed to spend two nights sleeping in the researcher’s lab while being recorded. Noting that most people do not speak in their sleep very often, the researchers restricted participants to those who had certain sleep disorders that are known to cause sleep talking to happen more often.